Imagine you’re a detective trying to identify criminals in a crowded room. Some are guilty, and some are innocent. Your job is to catch the bad guys without wrongly accusing the good ones. This scenario is surprisingly similar to how physiotherapists use diagnostic tests to identify injuries or diseases. But instead of handcuffs and magnifying glasses, we rely on concepts like sensitivity, specificity, and likelihood ratios. These terms might sound intimidating, but once you understand the basics of Bayesian statistics, they become powerful tools for making better clinical decisions.

Let’s break it down with a detective analogy and some practical examples.

The Detective Analogy

Sensitivity: This is your ability to correctly identify the bad guys (patients with the injury or disease). A highly sensitive test means you’re catching most of the criminals. Can be expressed as probability (e.g. 0.95) or as percent (95%)

False Negatives (1−Sensitivity): These are the bad guys who slip through your net.

Specificity: This is your ability to avoid falsely accusing the good guys (healthy patients or those with a different injury). A highly specific test means you’re not pointing finger at innocent people.

False Positives (1−Specificity): These are the good guys mistakenly labeled as criminals.

While sensitivity and specificity are important, they don’t tell the whole story. To truly refine your detective work, you need two more tools: Likelihood Ratios and Prior Probability.

Making Test Results Practical

Likelihood Ratios help you understand how much a test result changes the probability of a diagnosis. Think of them as magnifying glasses that sharpen your focus.

Positive Likelihood Ratio (PLR): How much a positive test increases the likelihood of a disease. This is ratio of true positive to false positive.
Formula: Sensitivity ÷ (1−Specificity)
A high PLR means the test is great at confirming a diagnosis.
Negative Likelihood Ratio (NLR): How much a negative test decreases the likelihood of a disease. It is based on ratio of false negative to true negative.
Formula: (1−Sensitivity) ÷ Specificity
A low NLR means the test is excellent at ruling out a diagnosis.

These ratios adjust your Prior Probability—your initial belief about the likelihood of an injury or disease before testing. Prior probability can come from:

Prevalence data: How common the injury is in similar patients.
Clinical judgment: Your experience and the patient’s symptoms.
Uninformed estimates: When you have no strong prior belief (e.g., evenly splitting probabilities between possible diagnoses).

Practical Example: Diagnosing a Shoulder Injury

Let’s say an athlete comes to you with shoulder pain, and you suspect a SLAP lesion (a type of shoulder injury). According to research by Behnam Liaghat and colleagues, the prevalence (prior probability) of SLAP lesions in similar cases is 30.7%, or odds of 0.44 (30.7 ÷ 69.3).

You decide to use the Biceps Load II Test, which has:

Positive Likelihood Ratio (PLR): 26.38 (very strong)
Negative Likelihood Ratio (NLR): 0.11 (quite good)

If the test is positive:

Multiply the prior odds by the PLR: 0.44 × 26.38 = 11.6
Convert the new odds to a percentage: 11.6 ÷ (1 + 11.6) = 92%
Conclusion: There’s a 92% chance the athlete has a SLAP lesion.

If the test is negative:

Multiply the prior odds by the NLR: 0.44 × 0.11 = 0.05
Convert the new odds to a percentage: 0.05 ÷ (1 + 0.05) = 5%
Conclusion: Most likely you can rule out a SLAP lesion.

What if you use multiple tests? You can multiply the prior probability by the likelihood ratio for each test, refining your diagnosis after each test.

Another Example: Groin Injury and Rectus Femoris Involvement

Let’s say a football player comes in with an acute groin injury. Initially, you don’t strongly suspect the Rectus Femoris (RF) muscle is involved. But then the player mentions the injury happened while kicking a ball, which increases the likelihood of RF involvement. You perform the Thomas Test RF stretch, and it reproduces the player’s symptoms.

Here’s how Bayesian reasoning helps you quantify this (all numbers are based on studies of Andreas Serner et al.):

Initial belief: 13% of acute groin injuries involve the RF.
After learning the injury occurred during kicking: The probability rises to 28% (odds 28:72) .
After a positive Thomas Test RF stretch (PLR 5.47):
Multiply the odds (28 ÷ 72) by the PLR of  (5.47): (28 ÷ 72) × 5.47 = 2.13
Convert to a percentage: 2.13 ÷ (1 + 2.13) = 68%
Conclusion: There’s now a 68% chance the RF is involved.

This step-by-step updating of probabilities is Bayesian reasoning in action—a logical, structured way to refine your diagnosis based on new information.

Why Bayesian Statistics Matters

Many physiotherapists find Bayesian statistics intimidating, but the truth is, you might already be using it without realising it. Every time you update your diagnosis based on new test results or patient history, you’re applying Bayesian principles. It’s not about complex math—it’s about thinking logically and systematically.

By understanding sensitivity, specificity, likelihood ratios, and prior probability, you can make more informed decisions and provide better care for your patients.

Summary

Bayesian statistics isn’t just for mathematicians—it’s a practical tool for clinicians. It helps you quantify uncertainty, update your beliefs, and make smarter diagnostic decisions. So the next time you’re faced with a tricky case, channel your inner detective and let Bayesian reasoning guide you.

For a deeper dive into Bayesian statistics for medical tests, check out this excellent explanation:

The post Application of Bayesian Statistics in Physiotherapy Testing. appeared first on Sport Science Support.

I decided to write this short blog when I read Edg E, Johann et al. (2006) paper on buffering and repeated sprint performance: “Comparison of muscle buffer capacity and repeated-sprint ability of untrained, endurance-trained and team-sport athletes.” It is always interesting  how manipulation with statistics can change the conclusions of a study.

When I almost finished my writing, I came across the blog, which was devoted to the correlation mistake in COVID-19 study. Strikingly, the mistake was quite obvious, the study came from quite a famous university (Yale), and it changed the conclusion dramatically: from an almost perfect correlation to R2= 0.15-0.40.

Therefore, I realised that such mistakes, often made in pursuit of the desired result, are quite common in science. Unfortunately, it is often difficult for the general public to see such nuances, therefore false conclusions, and even sensations, may arise.

That is why we should not trust scientists automatically just because they are scientists.

Verification, peer review and criticism are fundamental to the scientific process.

Math and back-squat.

There is a strong positive correlation between back-squat and mathematical abilities in a group of male teenagers!

Most of the sports practitioners who read this announcement probably think, “ This is rubbish!”. Maybe, however, I can do an experiment to prove that.

So teens age is 13-19 years old, right?

I will take two boys for each year (a total of 14), and combine them into one group. Then I will give them a math test and a loaded back-squat. The math test should become progressively easier for older boys. Thus, the older the boys are, the better their math results, because they will have more knowledge. At the same time, seniors will also do better in back-squat because they are bigger and stronger.
I am sure that I will find a pretty strong correlation.

However, common sense tells us, quite rightly, that the relationship between these two qualities is unlikely. So why have I found correlation?

It is because most of us don’t realise that correlation does not necessarily mean a causal relationship.

Math and squat performance are both depend on age, and through that, they are connected with each other. But, unfortunately, being smart in numbering does not help you in weight-lifting.

Repeated sprints and buffering.

In this example, I will show you how looking at correlation from a different angle can completely change the conclusions of the study.

There were three female groups: non-athletes, endurance athletes, and team-sport athletes.
The authors investigated their performance in repeated sprints (RS) and their buffering abilities.

Researchers combined all participants together (as I did with teenagers) and found a positive correlation between the ability to buffer acidosis and performance in 5x 6 sec sprints on cycle-ergometer.

The conclusion is looming that RS depends on the capacity to buffer acidosis.

According to Google Scholar, this paper was cited 118 times, and I am sure that some of the citations stated: “Repeated sprints ability depends on buffering.”

Though authors acknowledged that we should be careful with such a conclusion and there may be other factors involved.

Still, I cannot avoid feeling that they a bit push me to admit the casual relationship between buffering and RS.

Let’s have a look at the graph.

Credit: Edg E, Johann et al. (2006)

The figure which contains inside it all 19 participants indeed stretches towards up-right. That means a positive correlation (r=0.67 in the study). It is how the authors look at correlation.

Non-athletes are generally more on the lower-left part in the graph. This means that they were worse in sprints and buffering, perhaps because they were simply less trained.

Endurance athletes are generally lower than players, which means that they performed weaker in repeated sprints ( overall work).
Players are more on the right as well, due to having a better buffering capacity.

So does this mean that athletes with better buffering are better in sprints?

Not necessary. For example, players may be better in RS because they were bigger, which is important in the cycle-ergometer test. The authors acknowledged that.

Moreover, in my opinion, this study showed exactly the opposite: being better in buffering does not make you better in sprinting.

Let’s have a look at the graph differently.

Credit: Edg E, Johann et al. (2006)

For that, I pooled participants not in one group but in three homogeneous groups accordingly to sports specialisation.

Now we even don’t need calculations. We can see that two figures which outlined players (red line) and non-athletes (green line) stretch pretty horizontally in parallel to axis X. That means that participants inside these groups, despite having different buffering capacity showed similar performance. The endurance group (blue line) stretches vertically in parallel to Y. Thus endurance athletes, despite showing different performance, had similar buffering.

In fact, none of the three groups showed a relationship between buffering and RS performance.

So what is the problem?

Well, it is basically the same as in my math-squat example: you should be careful while combining heterogeneous participants.

If you want to find a true relationship between two variables, you should control other influences as much as possible.

In the math-squat example, I should take boys of the same age, whereas in Edg E, Johann et al. (2006) study, it would be better to compare athletes of the same sport.

There is another important thing.
When there is a small sample size in the study, which is mostly the case in our field, it is necessary to present individual data for every athlete.

Firstly, because a couple of outliners can dramatically change group statistics. Additionally, coaches are interested in the results of every athlete rather than in abstract group numbers. However, researchers often prefer to confuse practitioners with complicated math, even if there are less than ten people in the study. This may be deceptive.

In the present study, there were 6; 7; and 8 people in each group.

The authors did not present individual results in the table, and they did not compare participants within groups. Though, in my opinion, it would be a sensible thing to do. Fortunately, we can derive individual data from the graph.

So thoughtful and attentive practitioners can follow a common sense, and make their own conclusions.

This conclusion maybe quite the opposite to what was stated in the paper: “the findings of the present study are unique, in that while previous investigations have identified a relationship between buffering… and short (60 s) or long (40min) high-intensity exercise efforts, a relationship between buffering and short (6-s), repeated-sprints (total work, r = 0.67) has also been identified.”

My conclusion is that:

Based on the results of the present study, there are no relationships between 6s x 5 repeated sprint performance on cycle-ergometer and buffering capacity in groups of female team-sport athletes, endurance athletes, and non-athletes.

COVID-19 and poo.

A Yale University study found an almost perfect correlation (R2 = 0.99!) between the amount of viral RNA in sewage and admission to hospital with COVID-19 three days later. You can imagine that this, if true, provides a unique opportunity to pre-prepare beds for the influx of patients.

I have found good explanation of this “sensational discovery” in Alexander Danvers blog.

Authors made the following mistake: they firstly plot both variables against time, smoothened data, and only then compared them between each other. Smoothened plots showed an almost perfect correlation.   Instead, they should plot raw data against each other from the start. That gives a much more real correlation: R2= around 0.15-0.4. This range was obtained by automatically extracting data from the graph in the article.

Hospital admission and amount of virus RNA in sewage.

You cannot compare smoothened data (lines) for correlation. You should compare raw data (dots).

Credit: Yale University

Well, I can understand everything. Err… Almost everything.

In the RS study, the researchers used correlation in their own way and entitled to it. Maybe they should analyse the data differently, but this is just my opinion.

Yale scientists can make a simple mistake in statistics, although we may expect a higher standard from this university. What is really surprising is that after getting R2 = 0.99, they did not scratch their heads and said: “Something isn’t right, we should check our results again.” No, instead, they went public.

That is wrong.

Math is a great tool if you use it correctly. However, improper use leads to incorrect conclusions and misleads people who rely on scientists. Sometimes this is the result of errors, but sometimes it is intentional manipulation. Many times I met this phenomenon in the Sports Science. Now I see that perhaps this is a common problem for Science as a whole.

It is a worrying sign.

References.

Edg E J, Bishop D, Hill-Haas S, Dawson B, Goodman C. Comparison of muscle buffer capacity and repeated-sprint ability of untrained, endurance-trained and team-sport athletes. Eur J Appl Physiol. 2006;96(3):225‐234. doi:10.1007/s00421-005-0056-x

Jordan Peccia, Alessandro Zulli, Doug E. Brackney, Nathan D. Grubaugh, Edward H. Kaplan, Arnau Casanovas-Massana, Albert I. Ko, Amyn A. Malik, Dennis Wang, Mike Wang, Daniel M. Weinberger, Saad B. Omer. SARS-CoV-2 RNA concentrations in primary municipal sewage sludge as a leading indicator of COVID-19 outbreak dynamics. BMJ Yale.doi: https://doi.org/10.1101/2020.05.19.20105999

The post On the perils of correlation: From Sports Science to COVID-19 studies. appeared first on Sport Science Support.

When I enter the UK, often border officer asks me a question:

-What is your profession, sir?

-I am a sports scientist.

-Wow! So what are you doing?

Er…It is a good question.

Indeed, what sports scientists do?

Practical side.

There is  a practical aspect of the training process, which is carried out by a variety of specialists. Obviously, these are sports coaches, as a rule, former athletes from this sport, but they are not the only ones. Today, many professionals, who may not have experience in the sport they currently work in, are helping athletes achieve their best. These are strength and conditioning  coaches, physiotherapists, nutritionists, etc.

May we call them sports scientists?

Well, though their degree is often attributed to sports science, that, in my opinion, does not guarantee the ability to implement a comprehensive scientific approach to training.
They may be great specialists in their field but not scientists.

Practitioners sometimes lack scientific criticism and expertise. This may make them vulnerable to pseudoscience and weird ideas.

For example, once my student, 11 years old tennis player, started to go toilet every 10 min during our conditioning session. When I asked him what happened, he told me that his sports coach advised him to drink 4 litres of water a day. Coach read that in some “scientific” paper.

Another problem is that sometimes practitioner has very narrow expertise in a particular field and may miss a comprehensive picture.

When I worked in a professional football team during the pre-season, physio forced players to sit in cold water after training. He was a good guy, but really had no idea about all the disputes over recovery strategies (see article). Cold water immersion may give some limited benefits when you need to recover quickly between games during a competitive season. However, in my opinion, during pre-season training, this method probably impairs adaptation. Again, I am not insisting that I am absolutely right, although my opinion is based on quite extensive research. Still, at least, you have to learn something about treatment before advising it. This physio just heard that “everyone uses a cold bath”.

In conclusion:
Practitioners, even in “scientific” areas, are not always scientists. Doctors are not scientists despite working in medicine, and programmers are not the same as computer scientists. Being a practical scientist means not only the ability to use the method effectively, but also an understanding of “why” and “when”. They should have at least a general idea of ​​how the whole system works.

Theoretical side.

Another side of training art is theoretical.
This is covered by academia.
We expect that they dig deep into the science of training and give innovative but, at the same time, carefully weighed  advice.

Well, I can say that you need to be very careful before taking academic advice on board. Whereas practitioners are often susceptible to pseudoscientific ideas, academia sometimes can be blamed for creating them.

“Black cat phenomenon.”

Often scientists devote themselves to some idea, which is basically incorrect. However, they are so passionately (and often sincerely) looking for “a non-existent black cat in a dark room”, that ultimately they can convince themselves and others that the black cat was found. This usually is achieved with the biased interpretations of facts, non-robust experiments, inappropriate statistics, etc. Or it is just a result of simple mistakes. Then the non-existent cat is getting wrap in nice scientific papers and is presented to the public as a discovery. Usually, the practical implementation of such discoveries is just a waste of time and money, but sometimes this may be harmful.

Just at a time when I am writing this blog post, a good example came from “The Economist.” It is not from the sports science but illustrates my point well.

There was a psychological study which had found that children from religious families are more greedy than secular kids.
This sensational result was published in many scientific and popular journals, including such respected as “The Economist”.

However, the study was wrong. It was a simple coding mistake. As I understand, while analysing data, authors mistakingly included country code ( e.g. US-1; Canada-2, etc.) as a value into calculations instead of treating them as non-value labels.

Even though the mistake was spotted relatively fast by another scientist, it took almost four years for the journal, which published the initial study to publish a retraction.
During these years, “discovery” was published more than 80 times!

Incompetence.

Unfortunately, sometimes, the main goal of theoretical scientists is to publish a paper, and they really do not care about the quality of their work. They may be extremely incompetent and really far from reality.

Four years ago, I read the article of a group of Russian scientists, all of them PhD, who suggested a novel method— the definition of fatigue threshold based on a visual-discrimination task. In their experiment, the participant pedalled on a bicycle ergometer at 114% of VO2max for one hour. Well, anyone who is familiar with sports physiology should know that at VO2 max an athlete can withstand 5-10 minutes. So their definition of VO2 max was nonsense. Yes, authors were not physiologists, but they were writing the paper on physiological threshold. Should I trust these scientists? Well, probably not.

Sports science problem.

The specificity of sports science is that it is exploring the pretty uncertain, changeable, and multifactorial environment.

Predictions and theories of sports science are not easy to test in fully controlled experiments. The effects of the training studies are not always possible to attribute to particular causes. Laboratory findings are often not applicable in real-life situations.

All these and many other factors make sports science vulnerable to various biases.

Advice coming from academia is often impractical in the real sports environment. Results from studies are spoiled by “confirmation bias”, inappropriate statistics, and wrong assumptions.

In my previous blog posts, I gave examples of such theories — “Critical power” in physiology and “the Quiet Eye” in psychology.

Applied sports scientist: Bringing science into practice.

We are living at the time of informational flooding. The sports field is full of pseudoscientific ideas and “magic” training methods. In my opinion, there is a need for people who can navigate in these “stormy seas.”

These experts are practical or how they began to call themselves “applied” sports scientists.
Applied sports scientists should have scientific intuition based on wide knowledge, practical experience, and continuous education, which may help to filter nonsense from innovations.

They should be open to new ideas and methods coming from academia and practitioners; however, at the same time, to defend athletes from useless or even harmful rubbish.

Although not required, it is beneficial for a sports scientist to have coaching experience or sports background. That helps to get in touch with reality and test ideas.

Compared to academia, applied sports scientists perhaps should have a broader area of expertise.
They have to know “nothing but about everything.” I mean that applied sports scientists may not know everything in detail; however, he/she understands what specialists in different science fields are talking about and may evaluate suggested approaches and ideas. Moreover, because they know about everything, they can understand interactions between different factors and how this may influence the outcome of training and performance.

If needed, applied sports scientist can go deep and learn “everything about nothing”. This means the ability to make detailed research on a particular problem and to suggest a solution.

To drink or not to drink.

A good example of everyday life of applied sports scientists is the “beetroot juice problem”.

There is advice coming from academia about the benefits of drinking beetroot juice. This should enhance endurance. Sometimes studies report remarkable and, honestly, hard to believe improvements. However, beetroot juice is not a pretty pleasant drink, and some athletes don’t like it or even have gastric inconvenience after drinking it.

Martin Buchheit, the sports scientist from “Paris Sent German” football club, critically analysed evidence of benefits of drinking beetroot juice. In his opinion, although there may be some minor benefits, overall the usefulness of juice is overestimated. So he decided to leave it on the table, but not force the players to drink it if they do not like it.

This is a good example of an optimal solution for everyday life in high-level sport. Nothing extraordinary. That looks like an insignificant episode. However, imagine if a nutritionist insists that Neymar  drinks beetroot juice, which the Brazilian possibly does not like. That can really annoy him and even distract his game! And this drink may actually be quite useless. I do not think the manager will be happy. One should take into account not only the possible advantages of a scientific idea but also the personal likes and dislikes of the athletes.

Conclusion.

Applied sports scientist is a necessity in contemporary high-level sport.

Their tasks are:

1. Critically evaluate ideas coming from academia and practical coaching.

2. If the idea is worth to use, help “to shape” it: to make academical idea more practical and practical method more scientific.

3. Based on the understanding the whole picture, build training programmes and give recommendations that integrate as many influencing factors as possible.

4. Be innovative and try to find unordinary solutions. That should be based on science and common sense.

So what is my usual answer to the border officer?

“I advise people how to train better.”

The post Applied Sports Science: The link between science and reality. appeared first on Sport Science Support.

So what is the problem?

The problem here is typical for conditioning training and testing in sports games — a trade-off between game-specificity and quality-specificity.

The most game-specific exercise or test is …a game. However due to the game is a mix of qualities, it is pretty hard to separate one of them to emphasise its development or for testing it.

For the purpose of this discussion, we can split factors affecting every endurance activity in two groups (for more detailed discussion about models of endurance see article).

We can call the first group, “universal-physiological” factors. It includes oxygen uptake, fuel reserves, metabolite clearance, and tolerance capacities. Whatever sport you are doing, if it demands some level of endurance, it would be good to have a reasonable level of these abilities. For example, on average, high-level footballers have around 60-65 ml/kg/min VO2 max, which is pretty good among the general athletic population.

The second group may be called “running economy,” though it does not necessarily refer to running.
This means how efficiently an athlete is performing an endurance exercise.
It is obvious that it is sport-specific.

Some athletes may be very well built for a particular activity and not for another.
Perhaps Mo Farrah beats Messi on various endurance distances not only due to superior physiological qualities but additionally because he is better built for distance running ( e.g., has relatively long and slim legs) and has better running technique.

However Messi may be happy to play 1 vs 1 game against Mo. And not only because he is better with the ball but because he probably will be superior in accelerations, decelerations and change of directions (COD) as well ( to some extent due to relatively low centre-of-mass).

Thus the main argument for apologists for sport-specific conditioning training is that you should give exercises for which player is built for and develop sport-specific running economy together with physiological qualities. For footballers, they argue, it is SSG, repeated sprints and shuttles.

Well, there are two buts, however.

First, it may be exactly the specificity that coaches would like to avoid. This is because accelerations decelerations, sprints, and CODs induce mechanical strain on joints and ligaments and cause exercise-induced muscle damage. Although this may be necessary for training adaptation, the player may already receive more than enough of this kind of load during his/her technical-tactical training. Indeed, almost all football exercises, include these components and we sometimes need to save players from additional  strain while developing their physiological qualities.

Secondly, coaches may wish to avoid sport-specificity because they want to achieve quality-specificity.

For example, the aim of the workout is cardio adaptation and I give interval training 4x 4 min at 95% vVO2 max with 2 min passive rest. I need more or less stable and steady increase in HR with optimal stroke volume and relatively constant running economy. Of course, I cannot completely avoid other influences like, for example, metabolites accumulation, however the aim is to find a “better deal”  for emphasising cardiovascular load. Thus I want to keep all irrelevant influences at a minimum. Intermittent activities, including turnings, accelerations, and decelerations, may bring confounding and difficult to account effect.

Should Messi run laps?

Well, it depends on whether he and his conditioning coach are satisfied with some of his physiological qualities  (e.g.VO2max).
It is very important to understand that running laps in football is the exercise for developing needed physiological qualities, not the aim itself.
There is no need for a player to fit some standards in the distance running. This training should be individual. A coach may need differently structured running exercises for players with different abilities.

A significant advantage of straight runnings is that it is easy to control the volume and intensity. It has less technical components, and it is less the mix of qualities than SSG and shuttles. Thus it is perhaps easier to associate changes in result with the change in particular quality.

A disadvantage is that they are probably boring and psychologically demanding. Many players don’t like it. A good result in running laps to a great extent depends on athlete constitution. Thus not all good players build for efficient distance running, and it is not fair to compare players against each other in running tests. Game is not just running. Instead, compare player against him/herself. Explain to them what do you want to improve and make them your allies.

Can we develop everything you need in SSG?

Without doubts, small-side games are the most game-specific method for conditioning. Coach can target conditioning together with improving agility, technical, and tactical skills.
Games create great emotional environment, and players are not bored.

The problem is to control the workload and to target specific physiological parameters.

Game is game and intensity in it fluctuates significantly. The same game may be very demanding for one and easy for another. It demands the mix of qualities, and it is difficult to separate and emphasise something particular needed. However, game allow unlimited modifications; thus, coach’s creativity can improve its benefits and overcome some limitations for conditioning.

Are shuttles football-specific form of exercise?

Many sports practitioners argue that shuttles are more specific for sports games than laps.
This is because shuttles include accelerations, decelerations, and CODs.

In my opinion, shuttle-running is not game-specific. Pre-determent, 180 degrees change of direction in shuttles has little common with unpredictable CODs during the game. Accelerations and decelerations in shuttles are not maximal but rather optimal exclusively for shuttles. In games, they are different (see the picture below).

Three-frames pictures of predetermined 180 degree COD in shuttle-ran (lower picture)  and unpredictable same-degree turn during real game ( Nani is chasing Messi). 

In my opinion, shuttle-running is a form of circuit training; it is a mix of distance running, and strength needed for decelerations and accelerations. You may add jumps, push-ups, etc. if you want. As every circuit training, it may be beneficial overall, but it is not quality-specific training.
If you want to develop specific physiological qualities, shuttles bring confusion without providing additional benefits.

Conclusion.

For developing universal physiological qualities, straight/laps running is the best method.

SSG is the most game-specific method for conditioning.

Shuttle-running is a form of circuit training, and it is not exceptionally game-specific.

Photo: Mica Asato

The post Conditioning training in football: Shuttles, laps, or small-side games? appeared first on Sport Science Support.

I met with Sven Herzog who has been team’s Strength and Conditioning coach for four years. He was a former sub-elite runner and got his Degree In Germany and Canada.

Ice-hockey

In German championship games are played two times per week—on Friday and Sunday. This pattern demands short tactical training and recovery procedures on Saturday whereas Monday is a day off.

Hockey match consists of three 20 min periods. Usually player has approximately ten 45-sec shifts on the ice during one period.  Work to rest ratio  approximates 1:2. During single 45-sec shift players are involved in tackles, collisions, short sprints, accelerations, and decelerations. However a significant part of the 45-sec bout they spend in “tactical” skating.

It is necessary to note that every player is wearing special sensor during the game which allows Sven to collect information about a physical load. This includes overall time and distance on ice, sprints, accelerations and decelerations, impacts and power output.

Training

Sven builds his conditioning training mostly on bikes. These sessions typically mimic game load with respect to time intervals and power output.

He does not like machines and uses mostly free weights for strength training. Sven prefers small repetitions numbers: not more than 5 and around 80% of RM. He considers this pattern of strength training as more useful for ice-hockey.
Sven pays considerable attention to the speed of lifting. For that, he measures bar velocity and uses velocity based training methods in weightlifting (for velocity-based training information look here).

Basic exercises

Different variations of squats, lunges, pulls and deadlifts are used. Though Sven doesn’t chase high absolute values for lifting, he considers achieving personal best of 1.5 bodyweight in the back squat and 2 bodyweight in deadlift as a norm.

A specific training programme is designed to tackle typical for hockey players misbalances. For example, players have a disproportional development of muscles on a side where they hold a hockey stick and excessive anterior pelvic tilt due to a specificity of skating.
Sven actively uses elastic bands for these exercises.

Significant attention is paid to posture, deep muscles activation, and pelvic floor muscles.

Breathing technic is used as a method of relaxation after the game and a method for deep muscles activation (e.g.diaphragm).

Sven tries to include a plyometric session at least once a week.

He considers training principles for designing Strength and Conditioning programme simple:

Identify sport-specific demands.
Identify potential problems.
Try to compensate disbalances.

Recovery

As is customary in an elite team, players receive meal immediately after training and games. Athletes commonly use cold bath after games (15 degrees 5 min ).
Sven differentiates recovery procedure for players depending on the game’s load:
Players who did not play or played small part of the game perform match-imitation exercise on a bike.
Players who played a full game have a cold bath followed by rolling foam massage and stretching. Additionally, Sven gives breathing exercises for relaxation. “Hockey game is a real battle, breathing helps to recover player’s body and mind.”

Monitoring

Monitoring can be divided on three categories: External, physiological and psychological.

External
Sven collected information about rolling average workload for few weeks from wearable sensors, and he tries that acute training load do not to exceed  significantly this average values. Especially it is essential for players who are coming back from the injuries. He uses special software which warns him about excessive training load for a particular player.

Physiological measures include HR variability and morning HR. Players report these to Sven every morning before the session. Though he is a bit skeptical about HR variability robustness, he uses its abnormality as a warning signal and may refer player for further medical examination.

Psychological monitoring consists of Borg scale assessment 15 min after the session and short readiness assessment in the morning.

Countermovement jump.

In sports science literature countermovement jump is considered as a valuable assessment of neuromuscular fatigue. Sven uses this assessment bimonthly, and if player’s result drops by 10-15 %, he may release athlete from training and give him a rest.

Training philosophy

Sven considers his role as a provider of advice and reasonable guidance rather than indisputable orders. He is trying to build trustful and honest relations with the athletes. “At the end of the day, they are professionals and have to take care of their regime, health, and training. I am here to help them, but I am not their boss.”

During training sessions, Sven draws session training plan on the school board and players follow this plan by themselves. “ I am not blowing a whistle during a training, players follow the plan without commands. This allows me to pay attention to the individual athlete, correct his mistakes and work on his weaknesses. Basically, it allows me coaching”.

Sven thinks that in German sports education system exists a gap between sports science and practical coaching. Many young university graduates although have good theoretical knowledge in sports science cannot put this into practice due to lack of coaching skills. They do not understand the psychology of elite athletes and many practical aspects of sports training.

Sven has great respect to the former Soviet Union school of sports science. He thinks that ideas of Yuri Verkhoshansky and Robert Roman are still in use in elite sport. “ Many so-called “new” methods in western training methodology are basically the same ideas that were developed in the Soviet Union many years ago.”

Conclusion

Strength and conditioning training In Augsburger Panther is an excellent example of contemporary ideas and tendencies in sports training. It combines a scientific approach with practical nuances of high-level competition. Importantly, Sven tries to make his training individual as much as it is possible in a team sport. He identifies athlete’s problems and monitors his training status and readiness. It is not an easy task when you have 25 players in the gym! With the relatively limited budget, Sven achieves a really good result. I think his work during four years in Augsburg made a crucial contribution to the team’s performance and relatively low level of “non-collision” injuries.
I really appreciate Sven openness and readiness to share his time and ideas. Unfortunately, some coaches try to keep in secret their training. In my opinion, those sports practitioners who try to hide their training methods, actually, have nothing valuable to hide.

Photo: From Augsburger Panther with permission. 

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In my article written three years ago I gave an example of a successful weight loss programme which I implemented with one of my clients. He lost 3 kg ( from 75 to 72), significantly improved endurance and strength and got rid of beer-belly. It took one year, and I was really proud of my work. After that, we did not see each other for two years. He called me a few days ago and asked for the training again. He is 80 kg now, his belly is much bigger then it was, and he cannot run at all. I have to admit that we lost our fight against obesity and physical decline. Why? Because although I had managed to change his weight, I failed to change him. Unfortunately, our chances in new attempt are small as well.

Energy balance.

Even though the human body is a very complicated mechanism, losing or gaining weight depends on a simple balance between energy utilised and spent. I just want to emphasise “utilised” which is different from “consumed”. Not all calories which are stored in food can be transferred into energy or body energy stores. So when you are looking at energy content labels, it does not give you exact information on how many calories you actually get. The efficiency of utilisation depends on many factors which are beyond the scope of this article. We need to understand that the same food eaten by different people or in different circumstances may give different calories.

In its turn “spent” does not mean only physical and mental activity. A body needs a significant amount of energy ( basal metabolic rate) for maintaining its functions even when there is no physical activity at all. This basal metabolic rate (BMR) is different for different people  and conditions.

Energy spent on the same physical activity is different for different subjects and conditions as well. It again depends on many factors which I cannot discuss here. Amount of calories spent on your workout which is given to you by your sports watches is based on general population data and is just approximation.

To summarise: People get energy from the food and spend it on metabolic maintenance, activities ( mental and physical) and growth. The rate and effectiveness of energy extraction and expenditure are individual and depends on many factors. Thus all labels and indirect calculations are just approximations. However, it is easy to understand your energy balance just looking at scales. If your weight is stable energy balance is neutral, if crawling up — positive, if sliding down — negative.

Going to war.

So, if we utilise energy more than we spend it should go somewhere. It can go for natural physiological growth, if you are still young, for building muscle’s mass (you need to exercise for that) and, unfortunately (well, from the evolution point of view maybe not, unfortunately), it may be stored as fat. We need some amount of fat for normal body function, but when it is excessive, it is believed to be the cause of a lot of problems. So people go to war against obesity.

You are looking at the mirror, and you are not happy with your appearance? You put on your favourite trousers and suddenly realise that they are tight? Yes mate, you gained a few extra kilos and probably became overweight.
So you decided to take the situation under control and to get rid of these annoying kilos. You go on one of highly-advertised diet ( protein, low carbohydrate, low fat, crash, etc.) and/or you come to a personal trainer with the great endeavour to burn fat in vigorous physical exercises.
You are really determent to win the fight against looming obesity especially since the amount of overweighting is just a few kilos and the task does not look so hard…
Well, I can “encourage” you by saying that though you will be able to win a few battles, it will be hard to win the war.

Your allies and enemies

You have some allies in this fight. Actually, we have a self-regulated mechanism for defending current weight-status.

Set-point theory.

This theory postulates that our body has some genetically predetermined body weight which it tries to “defend” during life. In my opinion, it is only partially correct and environmental factors play a significant role. I am not going to discuss set point theory in details here but some explanation why we relatively slow gain weight is on a surface.
If you get some additional kilos, you need extra energy to support this extra mass. First of all this mass takes energy just for its metabolical maintaining ( increased BMR) and secondly, you make extra work for carrying additional mass. Also, fat cells produce the hormone— leptin which can decrease appetite. So, if energy consumption will not increase, weight gain may plateau for a relatively long time.

Time.

However, your enemy is very cunning, invisible and patient. It does not rush. And it has a mighty ally – time.
First of all, time means ageing. Yes, we become older. We become less physically active, our hormone’s level and BMR decrease. Thus we spend less energy. Unfortunately, we very often do not cut our food consumption accordingly and energy balance becomes positive. Excessive energy is stored as fat.
Secondly, time means that small changes gradually accumulate and become huge. Just 30 grams per day gain by increasing food consumption or decreasing activity, which are unnoticeable on scales, eventually give you ten kilos over one year.
Finally, time means established habits and routines, and they are often not healthy.

No hope?

More than half of the people who came to me for training and advice want to lose weight. I have to say honestly that in most cases we are unsuccessful.
Actually, such failure is a global trend, but not all weight-loss service providers are honest.

Why losing weight is so difficult? Well, many clients want to lose weight rapidly and a lot. Especially women who are worried about their appearance for particular events ( wedding holidays etc.). It isn’t rare that female clients ask me to lose 10-15 percent of their body mass just in few weeks.

Ok, we can design a programme for rapid weight loss, but people don’t realise the price they will have to pay.
They don’t understand how much they need to exercise and they don’t know how difficult to implement food restriction in a long-term.

Physical activity.

Clients who come to me with the aim to lose weight most often want to book just two sessions per week. I can say that although it is good for maintaining health and wellbeing, it will unlikely significantly affect body mass. We are very economical creatures regarding physical activity. 5 km running is approximately one 100 grams “Snickers”. So even if you did the equivalent of 20 km run during two sessions per week you just need to consume the equivalent of 4 “Sinkers” additional food to compensate this energy. And trust me, unnoticeable for you your body will do this.
To increase energy expenditure significantly, you need to exercise much more: 4-6 times per week. Who is ready for this physically, mentally and organisationally?

Dieting.

Restrictive diets.

Restrict food consumption and you will lose weight rapidly. However, this may happen not so quick as you expect.
Firstly it is pure arithmetic. You restrict calories, your body weight goes down, and now you need less energy to maintain and carry your mass. If energy consumption remains the same your weight plateaus. If you want to lose more, you need to cut food again.
Secondly, a body considers insufficient energy income as stress. It switches to safe mode and starts to spend less. Spend on what? On heat production, on physical activity and even mitochondria (cell’s power stations) become more economical.
And finally, food may become an obsession. You think about it all the time and gradually or abruptly you give up. Consequences may be dare. Your weight will bounce to the previous level and even more.

Skewed diets.

Another way of dieting is to manipulate with the food content. Whereas I strongly support substitution of junk food with the healthy one, I am really sceptical about “ magic diets”. Examples may be “protein diet,” “low carbohydrates diet” and so on.

We need certain amount of different nutrients, vitamins, and minerals. These come from the diets which are determent by cultural traditions, climate and available resources. I think all regional diets ( e.g. Mediterranean or Japanese) are healthy and provide all necessary for life.
When one goes on an unusual diet that may kick body out of comfort zone and consumed calories may be not utilised efficiently. Though you may achieve some short-term weight-loss effect due to the stress of unusual food composition and non-efficient energy utilisation, long-term consequences may be not so promising. You may gradually adapt to new diet and start to extract calories more efficiently, or your health and well being may deteriorate.

Digging deeper. Style of life.

It was always, the case that we gain weight because our energy balance is positive but only recently a lot of people start to eat more than spend and obesity becomes a global problem.
That is because life for people in developed countries changed dramatically.
There are some of these changes:

Food was limited throughout all human history thus we evolve to eat when we have an opportunity because it may be a shortage later. Excessive food can be stored in the body (fat) and used in hungry times. However, there is no food shortage for many people anymore thus fat reserves are not being used.

Quality of food changed as well. Now food producers make high-calories, tasty food which is very attractive for people and commercially profitable.

Quality of work. We don’t need to work physically for our food. More and more people spend their working hours behind the desk.

Social. We are eating when we meet each other (business lunches, parties etc). This food is often not necessary. Also social life  is associated with drinking, overeating and junk food.

We are eating when we are stressed. In the previous time, people did this as well, but they reacted on stress physically thus spent energy. Now we don’t need to run or fight when we are stressed, so additional energy ends up in fat deposits.
Evolutionary food connected with pleasure thus may provide some “cure” for stress. Stress makes us eat more junk food which usually offers more pleasure and more calories.

So actually we can see that we gain weight because of a changed style of life, so why it is a problem?

What is the real harm?

Today from every corner we hear about the harmfulness of obesity. But where this notion comes from?
It comes from data that excessive weight connected with high blood pressure, high cholesterol level, cardiovascular diseases, etc. However “connected” does not mean “the reason for.” In their very interesting paper “Biomedical Rationale for a Wellness Approach to Obesity: An Alternative to a focus on Weight Loss“ Paul Ernsberger and Richard Koletsky
argued that inactivity, bad diet, and stress are the causes of health problems regardless of weight gain. Of course, often excessive weight follows these bad habits, but overweighting is more an indicator of the unhealthy lifestyle rather than the cause of poor health itself.

So shedding excessive kilos does not guarantee health improvement and in a long-term may be even harmful. When you see fire-alarm lamp switches on indicating a fire, you are not going to hit the lamp, aren’t you? You need to find and extinguish the source of fire.

The same is true about the fight against obesity. Aggressive weight loss programme can give short-term result without changes in the quality of food and lifestyle. However, after some period, you most likely will bounce back and even higher. This yo-yo pattern is more dangerous for health than just to be obese.

Am I a defeatist?

No, I am not. It is different to be defeatist and to understand clearly the difficulties ahead.
Where there is a problem, there are people who make money from it. Weight loss becomes a profitable industry. Dieticians suggest magic diets, doctors magic medicine, and sports professionals magic training programmes. I don’t believe in magic. Not only because their long-term weight loss effect is questionable. More importantly, weight loss itself is not a solution. Long-term health and psychological problems will not disappear together with excessive kilos. The real magic hides in simple changes in lifestyle. However, as it often happens in life, simple changes are the most difficult.

We have to realise that our environment changed and there is no natural regulation of energy balance anymore. We don’t need to climb more trees to get more bananas.
The only way is to change yourself with the power of our will.

What to do.

A some advice which, of course, is not something new.

1. You have to exercise to become stronger and healthier. Stronger you are the easier is an exercise for you. The weaker you are, the more difficult exercise for you — this is a vicious circle.

2. Try to eat healthier. Healthy food can be enjoyable and tasty. It is just a matter of habit.

3. At the same time, don’t be obsessed with healthy lifestyle otherwise it drives you crazy and you will bounce back to the bad habits. You can allow yourself cakes and drinks sometimes. However, there is a simple rule: You have to exercise additionally if you spoiled yourself with extra food.

4. Make time your ally. Make exercising and healthy eating a routine. Organise your schedule. When you are tired after your work that doesn’t mean that you are not able to exercise. Do it instead of watching TV and you will feel better.

5. Socialise without eating or eat and drink less. Yes, it is difficult but possible.

6. You have to eat less with the ageing.

7. Remember: Obese and inactive parents — obese and inactive children. Change yourself in the sake of your children.

8. Learn to cope with stress. Of course, it is easier to say than do and coping with stress is a big problem nowadays. About overeating and stress, my experience is: I react on stress with running rather than with eating.

Conclusion

“Undeniably, weight loss programs can benefit health. This is especially true when these programs emphasise permanent lifestyle changes and encourage exercise and healthier food choices. On the other hand, positive lifestyle changes can be encouraged without a primary focus on weight loss” Paul Ernsberger and Richard Koletsky.

Photo from fishki.net

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However, in real life people want result faster. Very often I have clients who need to shed a few kilos for a corporative event or prepare for their first long-distance race just in few weeks. Whereas I do not like to rush, sometimes I can train them to tolerate high volumes relatively fast.
I am doing this by splitting session into two running parts with strength exercises and stretching between.

Dividing running workout into two parts allows creating higher volume with lesser mental and physical strain. Additionally, two parts allow more variability in session. For example, you can make the first part relatively intense and make your student tired. Then, in the second segment, you teach him/her to keep steady pace and to tolerate tiredness. Or vice-versa, first portion may be relatively easy with increasing intensity during the second one.

There are two reasons for doing lower body strength exercises between running. First is straightforward — to increase leg strength which is really important for ruining. The second is a little bit more arguable. In my opinion, some strength exercises after potentially damaging workouts, including long runs, help to realign disturbing muscle fibers (see article). These exercises should not be explosive and should not include significant eccentric component.

Practical example.

A friend of mine, a healthy young woman, is an occasional  runner. The longest distance she did was 10 km. It was two times in her life with an approximate speed of 10.5 km/hour. Her usual distances were 3 — 7 km ( rarer than once a week) with speed 10.5—11.5 km/hour.
She asked me to help her in preparation for 10 miles (16 km) event. We had just 6 weeks, and I could train her only twice a week. We decided that our goal is finishing in 1.5 hour ( an approximate speed of 11 km/hour).

My plan was to make her accustom to long continuous run while maintaining a relatively good pace.
To make physical and mental sides of training easier and at the same time to achieve significant training volume I split workout into two parts. In the first part we did the main work, and in the second we learned to tolerate tiredness. Between these parts, we did lower body strength exercise and some stretching.

Runnings gradually progressed in volume and intensity. We started from 5—2 (first part —second part) km continuous run and did 8 —5 km intervals and threshold runs at the end of the main preparation period (4-th week). At that time we made mock 10 miles race ( speed 10.3 km/hour) just to prove to her that she can run such long distances.
Remaining two weeks were tapering. She ran a few times  5—6 km with a good pace ( 11.5 km/hour).

Her race went smoothly and delightfully. We did 10 miles in 1.23.50 ( 11.5 km/hour) which is a really good time considering it was her first long-run event. Cool weather and exciting atmosphere of the race helped us.
I think in this case, when there was limited time for preparation, splitting workout method was a good choice.

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Plot

MMA fighter had to lose 7 kg in two days for the international fight in the O2 arena in London. He needed to weigh-in 61 kg; thus 7 kg was more than 10% of his pre-cutting weight (68 kg). Yes, it is a difficult task. So BBC closely followed him these days; to saunas, bathrooms, and toilets. Fighter ate glasses of ice, sweated and showed us his urine. Around him were devoted coaches and sports scientist from Liverpool John Moor university who bravely seated with the athlete in the sauna and informed us how life-threatening all this stuff is. Everybody worked. Fighter suffered enormously and shared his feelings with TV audience. The show was accompanied by sad music. Struggle, struggle, struggle. And he didn’t win. I am not scorning but, at the same time, I don’t feel sorry for him.

Something seems strange.

Actually, I am writing this post because I had a similar experience with my fighter ( kickboxer) some time ago. The weight-cut was even relatively bigger – from 77 to 67. What was different that everything was done without drama, suffering and sports scientists. And we won.
The question that I asked myself from the first minutes of watching the film was: Where the fighter was before? Why he and his team left weight-cutting for the last 48 hours? At the beginning, I thought that he received an offer to fight just two days before the event. Sometimes it happens in combat sports, especially with low-level fights. Though in such case organisers usually may relax strict weight category limits. However just after 5 min of watching I realised that my guess was wrong.

BBC actually started to film him three weeks before the fight. So he knew about the fight at least three weeks before. And I suppose even earlier; do you think that BBC jumped filming right from the moment fighter received the offer?

It can be done without suffering.

We had five weeks for preparation. The offer was to defend Russia Champion title, and it was entirely unexpected. We were not ready. My fighter did not train systematically at that moment and had excessive passion to the body-building exercises, so he was heavy, bulky and slow. Not the best conditions for a 67 kg category.

But he was eager to fight. Just a year before he unexpectedly won the title defeating the World Champion and many people considered that victory as an accident. So he really wanted to prove the opposite. We decided to accept the challenge.
Watching the documentary people may get an impression that weight-cutting is the main thing to do before the fight. Actually, it is not. The main thing is to be at the peak of your physical and mental form just at the right moment when the bell rings. So I worked out my weight-cutting strategy following my training plan not vice-versa, otherwise, your fighter may end up on the ring floor with the perfect body-weight.

There are different strategies for losing weight. Most of them, however, recommend flat and gradual loss throughout the whole preparation period. If we followed this strategy, we needed to cut 2 kilos in each of five weeks of training. That, in my opinion, doesn’t work because goals, workload and mental state should be different in every part of the preparation period. Yes, 2 kilos per week sounds not too much compared to 10 kg, nevertheless, it is still a serious number. So how your fighter supposed to be in perfect conditions if he always has a significant negative energy balance and impaired mental state?

First two weeks of our preparation was devoted to general physical conditioning. We ran a lot. The volume of work was high with relatively low intensity. We had two trainings a day. On the morning session, we run 7-8 km doing some exercise. On the second session, we ran the same distance and additionally did some boxing training in the gym. So basically, we run 15-16 km a day together with light boxing training. This workload created a significant energy deficit.

We revised fighter diet but did not make big changes. Just make it a little bit healthier and cut some cakes. I strongly advise against severe calories restriction. If you go below basal metabolic rate, your body may switch to the “safety mode.” It begins to spend less in rest and unwilling to exercise. So you may better allow cakes sometimes. That is not so many calories compared to workload expenditure, but it helps to “deceive” the body. Honestly, I think every athlete has his/her eating habits, and you have to think twice before insisting on changes. Our knowledge about nutrition remains limited, and we hear million advice and recommendations are continually changing. Listen to your athlete and follow common sense. In that instance, my fighter ate just slightly less than usual, and his calorie consumption covered his basic metabolic needs. So it was not tremendously cruel, and actually he was not so hungry. Of course, it wasn’t easy and his mood and emotional tonus slightly deteriorated. However, I expected this and preferred that it better happened on early stage. Additionally, the most challenging part of training was still ahead thus at the first stage significant energy disbalance didn’t combine with the severity of training. He lost 7 kg for two weeks.

At the second two weeks intensity increased. It was most difficult part of preparation. Interval runs and a lot of sparring workouts. However overall energy expenditure dropped. Mostly due to decrease in the volume of training (less running) and partly because his basal metabolic level dropped as well. When you have higher body weight, you are spending more calories to support this mass. Because he lost 7 kg, the need for supporting energy became less. So suddenly for him, it became enough food and feeling of hunger disappear! His mood went up and felt himself  faster and stronger. Special training methods helped to build his confidence and needed mental state. He lost 2 kilos.

Last week was tapering. Sports games, tactical preparation, light sparring workouts. When we sat on the train leaving for the fight, he told me “Peter, I am feeling like a killer-machine”. I think this is a good mental and physical state for a fighter. A day before the fight we played football with local boys near our Moscow hotel. And he lost the last kilo.

He had won that fight after the 5-th round when his opponent refused to continue. He couldn’t cope with the high tempo and was utterly exhausted. The fight had been won mainly due to the excellent physical conditioning, in spite of the fact that losing significant weight in boxing often followed by decreasing in strength and endurance. In this case, however,  it had been done mainly at the first stage and did not spread out to the whole preparation period. Sportsman had enough time to build up his “new” physical and mental conditions while remaining in a good mood and health. No drama.

No applause.

Why don’t I feel sorry for the fighter? Well, you have to be professional. First of all, try to keep yourself in shape all the time. At the end of the day, it is your job. If you are overweight but still remain inside your natural weight limits, then prepare yourself in advance. However if you want to cut weight immensely and to get into a category that is unnatural for you, you are seeking dishonest advantage and the risk is your problem. In just 24 hours between weighing and fighting, the athlete in the film ate and drank back 8 kilograms and in the ring was 69. Do not you think that this is a form of allowed cheating?

Ok, ok I understand that BBC and fighter from documentary created this film with the good intentions; to show how dangerous weight-cutting may be, and to condemn this practice. Possibly they achieved the opposite:  brave hero struggled and fell honourably. People take off their hats and salute to the madness of the braves. Not me.

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Sport Science advice must be unbiased.

Imagine you are tossing a coin. Suppose you got tails five times in a row. Now you are preparing for the next throw. What do you expect more: heads or tails?

It is forgivable if you answered “heads” because we may intuitively think that if just one outcome from different possible events repeats it cannot last forever and a probability that such outcome will end increases with every subsequent throw. However, the right answer is that probability remains 50/50 independently of what happened in previous throws. The coin has no memory to remember how it fell before. Of course, the coin must be fair https://en.wikipedia.org/wiki/Fair_coin. Yes, it is forgivable mistake to think otherwise if you are working in a non-scientific field, but is it acceptable for a scientist?

Now have a look at following citation: “I am aware that the All Blacks have not been beaten there since 1996. (In statistical terms, this only means that the probability that the All Blacks will lose there becomes increasingly more likely with each successive game that they win. Clearly it is impossible that the All Blacks will never ever lose another game at Eden Park. So the only reality is that the probability that they will lose their next game at Eden Park increases with each new game. Not the opposite, as some would want you to believe.)”

The author of the citation is Tim Noakes, renown sports scientist from South Africa. This paragraph is from a letter which he wrote to the South Africa rugby team during their preparation for the challenging game against invincible All Blacks from New Zealand. I found it in his book “Challenging Beliefs: Memoirs of a Career.” Tim wanted to inspire his countrymen, and since he is a very respected scientist, he brought this “scientific” argument to support South Africans winning hope. However, scientifically it is a nonsense. Probability in this case, similar to the coin toss, is independent of past games.

I deliberately pick up this Tim Noakes citation because I greatly respect him. I respect Tim as an athlete who ran numerous super marathons, and I appreciate him as a sports practitioner who worked with the great coaches and athletes. I can say that his scientific philosophy and views are often very close to mine and he is more scientist than I am. So should I carp at this silly mistake? Should we demand, for example, from a professor of History or Literature knowledge of basics in Probability Theory?

Well, perhaps not. Maybe sports scientists should know statistics better than historians because they very often use it in their papers but, at the end of the day, if they manage without such knowledge — it’s ok. Actually, Tim Noakes honestly admitted in his book that he is weak in math and stats and that he is always trying to have a team of people around him who can help with this.

Fair enough, I have no problem with that. However, I don’t like the tone of this citation. I don’t like the words: in statistical terms, clearly, the only reality. I don’t like this unreserved overconfidence, especially from the man whose scientific credo is “ Challenging beliefs”. Did he demonstrate how overconfidence coupled with ignorance easily create another erroneous belief?

Tim Noakes is an apologist for some scientific concepts which sometimes go against generally accepted theories. Often I support him. I almost completely agree with his views on water replacement strategy ( see article). I think his Central Governor theory makes a lot of correct conclusions. Maybe I am, like many nutritionists, sceptical about his support of “Low- carbs” diet but I have to honestly admit that I am not a prominent specialist in nutrition https://en.wikipedia.org/wiki/Low-carbohydrate_diet.

However, what if his level of overconfidence and bias in these theories is the same as it was in “flipping coin problem”? Reading his book, I have a feeling that if something goes against his assumptions ( like, for example, that game which South Africans lost), he tends to explain this by conspiracy theories rather than trying to review his conceptions. Perhaps he, like many other revolutionaries, started as a fighter against old beliefs but, eventually, becomes a passionate defender of the new dogmas.

Nevertheless, in this post, the question is not about Tim Noakes theories. Moreover, it is not only about him. It is about Sport Science in general. In my opinion, the most dangerous trap for a scientist is a bias in favour of the theory that he/she created and ignoring objective reality. Unfortunately, it very often happens in Sport Science. And if even Tim is not immune from that what we can say about thousands less scrupulous scientists?

Many sports practitioners, athletes, and coaches believe scientists and follow their advice. These “field workers” probably have no time for detailed analysis and critical approach. So, they trust scientific theories, especially if such theories packed in a beautiful wrapper and promise a great result. Unfortunately, a nice wrapper does not mean good stuff. Sport scientists should improve a genuinely scientific quality and ethical standards of their recommendations. Biased coin produces unfair flipping..
.

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