Interesting questions: Sports science advice.







On this page I am going to select some questions that may be of interest not only to the person asking it, but also to other people. I reserve the right to rephrase the question a little.

Do you prefer partial squats or full squats for developing strength in sports games?

A.K. Fitness instructor.

I must honestly admit that I have not researched this issue deeply. However, I am an advocate of the traditional full squat (FS). This is because people I trust (e.g. Jonathon M Sullivan )are critical of the arguments for using partial squats (PS).

PS proponents make three main arguments.

1. In sports games, you never start movement from the deep squat.

2. In PS you can lift heavier.

3. FS kills your knees.

As for the first argument, I can say that strength training doesn’t have to mimic real-life play. In the game, you never do push-ups, pull-ups, crunches, etc. However you may use these exercises in training because their gains transfer to the game actions . In fact, some studies have shown that FS is transferable exercise whereas PS is not. This means that by doing FS you improve in other exercises (including PS), but by training PS you only improve in PS.

On the second argument, I can argue that, despite the lower load in the FS, you work out the muscles in a greater range, tension and momentums.

Finally, it seems that there are no conclusive evidence that FS is more dangerous for skeletal system than PS. Quite the opposite: the latter can be more dangerous due to the greater load.

In conclusion: FS looks more useful and natural, and there is no evidence that it is more dangerous.

To read:

Stress for Vertebral Bodies and Intervertebral Discs with Respect to Squatting Depth (Hagen Hartmann , Klaus Wirth , Christoph Mickel , Michael Keiner , Andre Sander and Dennis Yaghobi ).

Influence of squatting depth on jumping performance (Hartmann, H, Wirth, K, Klusemann, M, Dalic, J, Matuschek, C, and Schmidtbleicher, D.).

Correlations between maximal strength tests at different squat depths and sprint performance in adolescent soccer players (Michael Keiner , Andre Sander , Klaus Wirth , Hagen Hartmann , Dennis Yaghobi).


Should I use HRR (heart rate recovery) as determinator for rest periods during interval training?
S.B. Fitness enthusiast.

It depends on what you want to achieve and what kind of interval training you do.
If you need maximum effort during each interval (for example, long sprints of 30 seconds), simply monitoring the intensity is enough. HRR does not determine the ability to complete the next interval.

Likewise, if you need to maintain a given intensity for relatively long intervals (eg 6×4 min. 90% vVO2 max).
You can stick to a pre-planned rest period (for example, 2 minutes) or even let experienced athletes to decide their rest periods themselves, independently of heart rate.

Slow HRR rate may reflect acidosis and accumulation of metabolites.
But these are not the only factors in fatigue. And HRR can be influenced by other factors.

Thus specific HR, does not mean full recovery for the next interval. Conversely, you can perform the next work interval without waiting for your heart rate to recover.
So, if the goal is better performance at work intervals —don’t look at HRR.

Maybe the only time when you can start next interval at some predetermined HR is actually when you don’t want to be below this HR in rest not when you don’t want to be above.
For example, when the goal of interval training is to work “through fatigue”.

So, you deliberately deny athlete from complete recovery, and if during pre-planed rest periods HR recovers too quickly, athlete will start next interval earlier.

Thus, in case you use HRR in interval training:

It is not that you can start late because you waiting for HR to recover. Rather you can start earlier because HR has already recovered.

More about Heart Rate in the article.


Is HRV (heart rate variability) useful for training and recovery?
O.H. Semi-professional footballer.

HRV is time fluctuations between two successive beats. The idea is that because it is influenced by the sympathetic (increases the heart rate) and parasympathetic (slows down the heart rate) nervous systems, HRV reflects the balance of the two systems. So when they both work in balance, HRV is higher. There is more variation in the length of time between two consecutive beats.

In my opinion, HRV is an unreliable indicator during exercise because sympathetic influence is stronger and variability may be naturally low.

You can use resting HRV because it is believed that overtraining and fatigue decreases HRV by increasing sympathetic influences.

However, your sympathetic influence can increase for different reasons, for example, because you are excited about the competition. I described HRV in more detail in the article. And you can find a good analysis in this blog.

In my opinion, if you are going to use HRV, use it consistently, at the same time of the day (it is better to measure HRV in the morning). Compare single measure to the usual average. And use it together with other indicators (like RPE).


Do I have to run on a certain pulse?
M.A. Beginner runner.

I believe that this is not necessary. It can be helpful to get heart rate data after exercise. Typically, a lower heart rate with sub-maximal effort indicates an improvement in fitness or current form.
However, sticking to a certain heart rate while running?
Nature gives us a good built-in sensor – “How are you feeling?” Why should we trust HR more? Because it is something objective, and “How are you feeling?” is subjective?
I don’t think so.

HR is just one of the indicators of strain. Important, but just one.


I have a fight soon, and I need to lose some extra pounds. Should I do this gradually throughout my preparation, or in a specific preparation period?

D.A. Boxer

I highly recommend that you maintain your normal weight near combat weight. It is not good to distract your preparation for a fight with the problem of significant weight loss.

It happened once in my practice (see article). At that time, I decided to aggressively lose most of the excess weight during the first two weeks of training. It was a period of general fitness – more running and less sparring. This is because I didn’t want my fighter to be nervous and starving during the special training period with a lot of intense work and sparring.


My kid ( 9 y.o.) is really good in tennis. But he likes football and hockey as well.
His tennis coach insists on more tennis lessons – “ To develop the right technique”.
Should we give up other sports?
T.W. Tennis mom.

I strongly recommend comprehensively developed tennis player. Various game sports (preferably football or basketball, but hockey is ok as well.) up to the age of 14 would be beneficial. Sometimes tennis coaches, especially with old mentality, do not understand that. Tennis is changing. It becomes more athletic. Tennis players should be and will be all-round athletes.

You can find more in this article.


Looking into a lot of the examples of MAS (maximal aerobic speed) training, they are straight line runs. How do you adapt this for change of direction drills? If I was doing drills involving many accel/decels, how can I work out what MAS % they are working at?

A.S. Sport scientist at professional football club.

Speed which elicit VO2 max will be lower if you include CODs (Change of Direction). At least it is obvious in 180 CODs. Player has to decelerate turn and to accelerate. Thus metabolic rate will be higher than in straight runs.
How much?

It depends on player morphology (for shorter players it may be easier), how trained is he/she for this kind of work, shuttles length (shorter-more turns thus higher load).

Martin Buchhiet found (for quite small sample of game-sports athletes) that vVO2 max was around 20% lower in 20 m shuttle-run compare to straight running (article).

Another interesting question is: Why do you need this?

To prescribe speed for shuttle-runs?

What is the reason to give shuttles in training for footballers? 🙂


Why are Sherpas and Andeans not the best runners? After all, they are best adapted to hypoxia.
B.J. Interested reader.

Mainly because they don’t run much.
Imagine that you are working in the tourism industry.
Option one: you are dealing with a huge flow of tourists.
Therefore, a developed infrastructure is needed: transport, hotels, etc.

Option two: you work with a small number of tourists. You don’t need a lot of transport, hotels and other things. You need an efficient, exclusive service to squeeze as much money as possible from the individual traveler.

Now imagine that from option 2, you suddenly need to switch to option 1. You cannot handle the dramatically increased customer flow because you simply do not have the infrastructure to do so.

Now replace the tourists with oxygen, and the infrastructure with mitochondria, muscle mass, etc.
Highlanders do not have the necessary adaptations for intensive running, as their high altitude lifestyle (5000m) makes such running impossible.

So, to be a good runner, you need to find balance.
It is possible that Kenyans and Ethiopian runners who live and train at an altitude of 2500 m, have this balance. This altitude allows both: intense training and the benefits of hypoxia.

A little bit more about hypoxia in the article.