Testing in sport games. Player performed badly in fitness test:  Then what?

The Holy Grail for Sport Science is the achievement of “objectivity” when evaluating athlete’s condition, monitoring his/her progress and for prescription of exercises. One of the main tools for this purpose is testing. During decades of development of modern sports, hundreds of tests, which aim to improve performance, were invented.

However training is a very complex process. The consequences of influences and interactions of many different factors are often difficult to predict,  control and test. Among different sports, those with variable and intermittent activity patterns are, possibly, most difficult for exact and precise training intervention. Despite all attempts there are no clear picture and exact guidances for now.

The following article was provoked by interesting discussion, initiated by Mendez-Villanueva and Buchheit paper: “Football-specific fitness testing: adding value or confirming the evidence?” (Mendez-Villanueva & Buchheit, 2013). Authors questioned traditional approach to testing in football. Mostly I agree with them and want to develop topic a little bit further. My article is mainly devoted to the ball games like football, basketball, handball and tennis, thus in many occasions I use the word “player”. However, maybe coaches in other intermittent sports (e.g. combat sports) will find this information useful as well. I assume that readers are familiar with most of the tests which I am going to discuss, thus I do not give detailed test’s descriptions. Otherwise reader may find more detailed information about particular test elsewhere. The main purpose of the article is to discuss genuine nature of tests, their appropriateness and usefulness for athletes.

Activity patterns in intermittent sports

Intermittent sports are characterised by various actions, with unpredictable intensity and duration. Generally, activity pattern consists of relatively short high-intensity bouts alternating with periods of low intensity or rest.

Intensity and length of the bouts, as well as rest periods are often variable and unpredictable.

Inside bouts athletes need to produce maximal power and/or speed. They have to maintain this power and speed if the bout will be longer than a few seconds. This demands special quality, which is speed/strength endurance. Even during as short exercise as 100 meters sprint, athletes are unable to maintain maximum speed to the end. Sometimes there is insufficient recovery between intense bouts thus players have to have ability to perform in under-recovery state.

Between bouts, sometimes, players can rest (e.g. tennis and boxing) however, often, they are denied complete rest and have to perform necessary basic level of activity. For example, in football, this is cover, support, regrouping, etc. During these periods athletes need to “refuel tanks” for the next intense bout.

Qualities player needs

To be able to meet requirements outlined above, athlete has to have following physical abilities:

Good aerobic conditioning for:

1. To produce high intensity in the long bouts.

Though high-intensity bout is considered as “anaerobic” this term is a bit of deceptive. Aerobic energy production often is significant, especially, in the later periods of the game and when the intense bout is long.

2. To recover between bouts.

Some high-energy compounds, such as creatine phosphate ( PCr), which are used anaerobically during high-intensity bursts, can be restored only with sufficient amount of oxygen thus depend on aerobic capacity. In addition, oxygen is needed to clear metabolic by-products.

3 To maintain basic level of activity.

Most of the sport games have the relatively high level of oxygen consumption. For example average oxygen uptake in football is about 70-75 % of VO2max.

Good anaerobic capacity for:

1. To produce high intensity work.

Anaerobic energy production mainly from PCr and anaerobic glycolysis plays significant role during high intensity exercise.

2. To tolerate high intensity.

I consider ability to buffer and clean by-products of energy turnover as “anaerobic ability” (see article) though term “anaerobic” is a bit of deceptive here because metabolites are produced during aerobic work as well. However anaerobic pathway resulted in relatively more metabolites production than aerobic one thus demands more intense buffering and clearing.

Strength and power for:

1. Speed and accelerations, tackles, shots, punches, etc.

2. Better adaptation to muscle’s damage.

3. Improving running economy

4. Agility

Why we need testing?

Before prescribing test for their athletes, coaches should understand why they need to do that. There may be 5 main reasons:

1. To confirm that coaches already know.

Perhaps coaches already see that their player lacks of endurance or strength but for some reasons they are not sure about this. Then they want to perform test. Will be this test more reliable than coach’s observation? Possibly it will, in some cases, but not in all. Test is never the same as game situation, thus caution is needed when extrapolating its result to real game.

2. Compare with industry standards. Are industry standards valid?

Another reason to perform test is a comparison of your player with other athletes in the same sport. However there is a trap here. Sometimes industry standards for a certain physical quality are set favourable for a particular type of players (Carling & Collins). For example, if country’s football philosophy for many years emphasises physicality over agility, then physical conditioning coaches prioritise strength tests which are better performed by bigger players. This strategy may put small but agile players in disadvantage and even restrict them from being picked up for a high-level. This is not good for football. Barcelona FC provided a good example how small players can be very effective on a pitch.

3. Motivation

Testing may provide motivational stimulus for improvement. Athletes can compare their results with the previous achievements or with the results of their peers and this may motivate them for training harder.

4. Diagnosing the cause of the problem.

Testing may help to find the reason for  bad performance. For example, if athlete has poor acceleration, tests of absolute strength and reactive strength may help to reveal lagging areas. Then these problems can be addressed with specific training.

5. Exercise prescriptions, monitoring a progress and current form.

And finally, testing may provide reference velocities and loads for exercise prescription and helps to monitor a progress. For instance, coach who is planning interval session at 95% of speed at Maximal Oxygen Uptake needs to know this speed. Or, when prescribing strength programme, it would be useful to know athlete’s Repetition Maximum. Improvement in reference values may confirm to coach that training programme is successful. Some tests (e.g. countermovement jump, heart rate tests) may be used to evaluate athlete’s form.

What is a good test?

There are, in my opinion four important requirements for every test which are worth to mention.

1. Test has to be valid. This means that it should measure what it is supposed to measure. For example, if we are going to measure VO2 max, we will not ask athlete to squat with the barbell to exhaustion. Instead, we will probably ask him/her to run maximal incremental test. Athletes will be fatigued in both situations but only in latter they will be able to achieve maximum oxygen consumption. In addition, test should be suitable for chosen sport. Perhaps, it makes no sense to test footballer on a rowing machine.

2. Test has to be reliable and sensitive. If we repeat it after sufficient recovery, result should be close. Natural variations should not hide changes in quality which is measured. Test should be easily replicated and should not be dependent too much on different conditions.

3. Test should be standardised. Its conditions and procedure has to be the same in every trial and for everyone. Unrelated factors which may influence a result should be controlled as much as possible.

4. It should not be too complicated and time consuming. Complexity increases a probability of confounding bias and decreases reliability, whereas time is important factor in busy training schedule of elite level athletes.

This will be good to know

In following chapter I am going to suggest tests which are, in my opinion, necessary in training process. These tests have universal value and, in opposite to sport-specific tests are rather human-specific.

1 VO2 max – general aerobic capacity.

VO2 max is athlete’s maximal ability to utilise oxygen during exercise.

Generally VO2 max depends on ability to deliver oxygen to the working muscles and on their ability to utilize it. Delivery depends on cardio-respiratory function, as well as on blood volume and haemoglobin content.

Utilisation depends on capillary’s bed density, oxidative enzymes and on mitochondria amount, size and effectiveness.

Some good level of VO2 max is needed for players (e.g . 55-60 ml/min*kg for footballers ) though they probably don’t need such big values as middle distance runners and cross-country skiers (70-85 ml/ min*kg). VO2 max test cannot distinguish between different components of aerobic capacity. If coach is not happy with his player’s endurance and VO2max is abnormally low then it is probably worth to investigate further and to refer player for medical examination.

2. Speed at VO2 max (vVO2max) – exercise prescription and monitoring a progress

Speed at VO2max is a minimal velocity which can elicit VO2max. So, during VO2 max test, researcher can find not only VO2max per se but how fast athlete ran when this value was achieved. This speed reflects both VO2max and running economy. Running economy refers how efficiently athlete uses oxygen for given work/distance/speed. It depends on many factors. Among those are running technique, player’s constitution, muscles strength, muscle-tendon stiffness, muscle’s fibres type and many others. So, if two athletes with the same VO2 max show different vVO2max it is possibly due to difference in running economy.

However coach doesn’t have to immediately try to improve running economy for player with lower vVO2max. First of all, economy for straight continuous running (like in VO2max test) is different from economy in intermittent runs with change of direction (real game)(Buchheit, Haydar, Hader, Ufland, & Ahmaidi, 2011). Secondly, player’s morphology may be not perfect for economical continuous run, where slim long legged athletes have advantage, but may be good for sprints, tackles and agility. So it depends. Coach needs to look at whole picture and to consider player’s specialisation.

On a field speed at VO2 max can be found in 5-6 min time-trial or 1.5 – 2km run ( longer for fitter players). This speed gives reference velocity for interval training. Usually these are long intervals (30 sec- 4 min). For example, series of 4 min intervals may be at 95 % of vVO2max whereas 30 sec intervals at 130%.

Improvement in vVO2 max tells us about progress in running economy and/or VO2 max. This is good for player.

3. Thresholds speeds – prescription and monitoring improvement.

We need to know two thresholds speeds: aerobic threshold and anaerobic threshold.

Aerobic threshold. This is the upper border of moderate intensity. Workload is relatively easy. On the Borg scale it is 3-4 marks from 10. Talking during running is not difficult, HR – at about 75 % of maximum. Below this speed we are doing recreational and recovery runs. Continuous running above aerobic threshold develops basic aerobic fitness.

Tests: Blood lactate (first rise of lactate above baseline), gas exchange test to define Gas Exchange Threshold ( another name for aerobic threshold). On a field: Borg scale and heart rate – as described above.

Anaerobic threshold. This is higher border of heavy intensity domain which is all intensities between aerobic and anaerobic thresholds. There is equilibrium between lactate production and clearance. Thus it may be defined as Maximal Lactate Steady State (MLSS). Another trait of this threshold is a rapid acceleration in lactate accumulation during incremental test so it can be defined as Lactate Turn Point. Another definition for this threshold is Critical Speed, though this speed (derived mathematically) is usually higher than “lactate” speed). And finally, anaerobic threshold may be correspondent to gas exchange indices, more precisely, with the rise of ventilation without correspondent rise of CO2 – Respiratory Compensation Point.

Tests for anaerobic threshold : MLSS test, blood lactate (Lactate Turn Point), Gas exchange test ( Respiratory Compensation Point), Critical Speed tests. On a field – 10 km speed, Daniel’s tables .

In my opinion, aerobic and anaerobic thresholds speeds are very important for exercise prescription.

Generally, between these thresholds are intensities for continuous running. Closer to anaerobic threshold this running becomes more demanding. This intensity may be used for shifting anaerobic threshold up and for improving ability to tolerate and clean metabolites. Above anaerobic threshold coach may start to consider interval training.

Improvement in speeds at aerobic and anaerobic thresholds tells us about progress in running economy, aerobic fitness and, especially at higher border of this range, ability to tolerate metabolites.

4. Absolute speed – prescription

Though it is not too often when player achieves max speed during the game it is worth to know this indicator.

Maximum speed may be a reference velocity for short intervals (less than 30 sec) and repeated sprints training. It may be helpful for calculating fatigue index during running analogy of Wingate test (see below). Finally this speed can be helpful in monitoring athlete’s physical form and overall fatigue.

5. Testing anaerobic capacity

Wingate test.

Wingate test is 30 seconds of maximal cycling where peak power, mean power and rate of power decline are the main variables. Possibly Wingate is the most popular anaerobic test in the world. From practical point of view, rate of power decline is, in my opinion, most important information because it reflects player’s ability to maintain high intensity inside single, relatively long bout.

Alternative for Wingate test for sports, where main activity is running, may be 30 sec ( 200-250m) sprint with flying start. This run is relatively short for significant aerobic contribution (though it is present) and for pacing. However it is long enough for noticeable speed decline. We need to measure overall sprint time, fastest 20 m ( this is usually between 20 and 40) and slowest/last 20 m. Rate of speed decline (Fatigue index) may be defined as: (slowest time for 20 m – fastest time for 20 m)/ slowest 20 m. Perhaps, it is too complicated to measure 2 splits in real life, so last 20 m speed and mean 20 m speed may be enough: (slowest 20 m – mean 20 m)/ slowest 20 m.

There are other methods for testing anaerobic capacity. There validity is questionable. I have devoted special article to this topic.

Some analytics

In sport games athlete needs capacity to perform repeatedly high-intensity work. It depends on ability to produce energy aerobically and anaerobically, on ability to efficiently transform this energy into mechanical work as well as on ability to maintain homeostasis. From this point of view described above tests can provide valuable information.

Maximal oxygen uptake test gives us information about player’s general aerobic capacity. It is integrated measure of oxygen delivery and utilisation capabilities.

If athlete improved his/her speed at VO2 max without improvement in VO2 max itself we can conclude that most likely this is due to improvements in running economy. Overall, we can consider this as positive adaptation though we have to remember that running economy with the directional changes may be different from continuous running.

Running economy depends mostly on biochemical and biomechanical factors. Former to some extent connected with buffering/ clearance capacity. More metabolites means higher ventilation and higher HR for the same work thus lower efficiency.  Biomechanical factors: running technique, strength, muscle-tendon properties, etc. greatly influence work efficiency as well. Simply from running economy data we cannot distinguished between relative contribution of these two groups of factors.

Maybe some helpful information about buffering/clearance may be derived from anaerobic threshold test. If it occurs at higher percent of VO2 max, this, probably, tells us that biochemical efficiency improved. Indeed, if athlete runs at higher percent of VO2 max, with higher speed and his/her metabolic state, indicated by blood lactate level, is still in equilibrium then we can conclude that clearance/buffering system is coping well at such intensity. Though this is speculative conclusion, I have found support for my opinion in Billat et.al (Billat, Bernard, Pinoteau, Petit, & Koralsztein, 1994). They found that, anaerobic threshold , when expressed as fraction of VO2 max, was strongly correlated with time to fatigue at vVO2 max in group of sub-elite runners. Thus, in my opinion, this index can be connected with ability to tolerate 5-10 min of intense effort which possibly to the great extent depends on ability to clean and tolerate metabolites.

The results of three tests give us relatively comprehensive picture about athlete endurance capacity during the game.

1. VO2 max test gives us information about athlete’s ability to maintain basic intensity throughout the whole game and to recover between intensity bouts. Speed at VO2 max, derived from the same test, tells us about players running economy though, as I mentioned before, that should be interpreted with a caution.

2. We can measure player’s ability to maintain intensity inside single bout (speed endurance) by 200 m sprint test. We are interested in improvement of fatigue index without compromising absolute speed.

3. Anaerobic threshold/MLSS test with oxygen consumption measurements gives us additional information about player’s aerobic capacity (speed at threshold) and, when expressed as a fraction of VO2max, ability to perform multiple intense bouts in under-recovery state (metabolite tolerance).

Testing strength and power.

I am not going to discuss in great details this group of tests because, in my opinion, it is up to coach which of them to choose and for what reason. However a few considerations should be taken into account.

Usually we are testing strength against external load (e.g. barbells) whereas for explosiveness coaches use different kind of jumps as well as short (5-10m) accelerations. Every test may require some technical skills which, actually, may be irrelevant to the athlete’s specialisation.

Hence, testing explosiveness and maximal strength, coach has to be sure that technical component, which is irrelevant to sport, is minimal. Otherwise player may fail in the test because of technical unpreparedness or has to spend too much precious training time for learning the test.

Another consideration is that player’s morphology can greatly influence result in particular strength and power tests giving “unfair” advantage to some athletes. However in many sport games like, for example, football and hockey players with different body constitution can be equally successful thus assessing them on the basis of physical tests may be non-informative.

And finally, caution is needed when using physical testing for talent identification in young athletes. First of all it is difficult to be sure which physical qualities are so decisive that they can eclipse other abilities like, for example, technical skills and decision making. Secondly, growth and maturation can dramatically change physical abilities. Buchheit et al. found that young academy players, who showed the same results in physical testing at the age of 12, were significantly different at the age of 16 despite similar training regime (Buchheit & Mendez-Villanueva, 2013).

Here are some power/strength tests which, in my opinion, may be useful for sport games though coaches may consider other tests, more suitable for their sports.

1. 5 and 10 m acceleration – industry standards and monitoring progress.

Acceleration is inseparable part of the most of sport games so it seems logical to measure it. However in this test movement pattern is not the same as in a real game. In addition, this test doesn’t give you an answer why acceleration is not fast enough.

2. Countermovement jump – progress, fatigue and industry standards.

This test is one of the most popular for assessment lower body power and is widely used in sport. However it provokes a lot of discussions. In most simple variant only jump height is measured and player uses his/her hands to assist the jump. Some researches argue that hands should be on hips for avoiding upper body influence. In my opinion, this makes jumping pattern unnatural. Usage of contemporary technical devices allows measuring other variables such as: ground reaction force, rate of force development, power, etc. This may make test more informative. Performance in countermovement jump may be a measure of fatigue (Claudino et al., 2017)

3. Two legs standing jump – progress and industry standards.

The advantage of this test is that it measures explosiveness in horizontal direction. Disadvantages are that body size may influence it and some level of technique is required.

4. Multiple jumps (e.g. 5 jumps) – progress.

This test may be good because it evaluates unilateral explosiveness and effectiveness of stretch-shortening cycle. However it requires some technical skills and players with specific body constitution (longer legs) have advantage in it. So, in my opinion, there are no industry standards here, just look at player’s improvement.

5. Squat repetition maximum RM – prescription.

Though, loaded squats, in my opinion, are beneficial for sprints, there should be no industry standards for RM. Not all sprinters and players are keen to do maximal squats. Squat with high loads requires some serious back strength and proper technique. It is not always safe. Loaded squat is more difficult for taller (longer legs) player. However estimation of athlete’s RM is a useful tool for exercise prescription. For the sake of safety RM can be estimated from sub-maximal test.

Questionable tests

There are tests which are very popular among professionals. However, in my opinion, their universal value is overestimated. They may be useful for confirming what coaches already know and for monitoring a progress in some exercises. However they cannot help to identify the problem. Sometimes their validity may be questioned as well.

1. Shuttles runs

These are Bip tests, Yo-Yo tests, 30-15 test and many others. They claim to be highly relevant to sport games because they include turns and accelerations. However, in real game, movement patterns, intensities and rest periods are not the same as in shuttles tests. Secondly, if player performed badly in this test, then where is the problem? Is that his/her aerobic capacity? Running economy? Clearance/buffering? Technique in turns? Strength for acceleration and deceleration? We won’t get the answer.

2. Repeated sprints

These are another popular group of tests which are widely used in sport games. Usually this test consist of certain amount of maximal sprints (20-40 meters) separated by specified rest periods. Coach may be particular interested in mean sprint time and in rate of speed decline. However main predictors for these variables are: aerobic capacity ( VO2max and vVO2max) and maximal speed (Bishop, Girard, & Mendez-Villanueva, 2011; Buchheit; Girard, Mendez-Villanueva, & Bishop, 2011). We can and, in my opinion, should find these predictors in other tests, thus repeated sprint test doesn’t give us any additional, specific and valuable information.

3. Heart Rate testing

There are two main ideas behind different HR tests. First of all, heart’s function is a one of the main predictors of VO2 max. Thus it reflects athlete’s aerobic capacity. Secondly, HR is influenced by autonomous nervous system therefore its fluctuations at rest and recovery may reflect player’s training status and fatigue. However, HR may be influenced by many different factors independent of player’s fitness and current form. In addition, athlete’s level, training period, psychological factors and test design play their roles too. Thus HR testing should be considering with caution and only together with results of other fitness and psychological tests. Interested reader can find more detailed information here.

Useless tests

1. Agility tests

Agility is ability to perform a rapid whole-body movement with change of velocity and/or direction in response to a stimulus (Sheppard & Young, 2006). I just want to add that such kinetic changes should be performed smoothly and efficiently in different, often unpredictable circumstances, and in complex environment. You cannot completely predict and rehearse that in advance. None of the agility tests can mimic real game situation and, at the same time, be standardised because agility is genuinely spontaneous quality. Thus, in my opinion, agility is best tested in the real game. Basically, coaches can see if their players are agile or not. No need to test that.

2. Game-specific tests

The best game-specific test is a game itself. The closer test mimics a real game the more different factors influence the result thus standardisation becomes difficult. There are many elements that influence physical/technical performance in the real game and the problem for such tests is to control these influences and to separate the problem. Game-specific test at best gives the same result as a game – something is wrong. However, what is wrong exactly?

Take for example, popular Hoff test for footballers (Hoff, Wisl?ff, Engen, Kemi, & Helgerud, 2002) which includes dribbling with the ball change of direction etc. The test claims examining aerobic abilities for footballers in sport-specific environment. However if player performs badly in this test: what is the reason? Is that because of his technical skills, agility, or aerobic/anaerobic endurance? We can speculate infinitely with the same success as after watching this player in the real game. Waste of time.

Conclusion.

We have to understand one important thing. Physical qualities, needed for sport games, are game-specific. However this doesn’t mean that we have to chase game-specificity in testing. First of all, game itself is a best game-specific test. Secondly, due to multifactorial influences, game-specific testing often does’t allow to distinguish between different contributors to performance.  Trying to duplicate game situation in testing, we risk providing coaches with information which at best has no additional value and at worst is confusing and misleading. Rather than being game-specific, testing  should be quality and/or aim-specific and to provide coaches with information about problematic areas, as well as to help them in prescribing exercise and monitoring player’s progress. Scientists should be able to answer the question : “then what?” after testing. What they can add to that is already known? What they can recommend? Testing should be for the sake of performance not for the sake of testing itself.

References

Billat, V., Bernard, O., Pinoteau, J., Petit, B., & Koralsztein, J. P. (1994). Time to exhaustion at VO2max and lactate steady state velocity in sub elite long-distance runners. Arch Int Physiol Biochim Biophys, 102(3), 215-219.

Bishop, D., Girard, O., & Mendez-Villanueva, A. (2011). Repeated-sprint ability—Part II. Sports Medicine, 41(9), 741-756.

Buchheit, M. Should we be recommending repeated sprints to improve repeated-sprint performance? : Sports Med. 2012 Feb 1;42(2):169-72; author reply 172-3. doi: 10.2165/11598230-000000000-00000.

Buchheit, M., Haydar, B., Hader, K., Ufland, P., & Ahmaidi, S. (2011). Assessing running economy during field running with changes of direction: application to 20 m shuttle runs. Int J Sports Physiol Perform, 6(3), 380-395.

Buchheit, M., & Mendez-Villanueva, A. (2013). Reliability and stability of anthropometric and performance measures in highly-trained young soccer players: effect of age and maturation. J Sports Sci, 31(12), 1332-1343.

Carling, C., & Collins, D. Comment on “football-specific fitness testing: adding value or confirming the evidence?”: J Sports Sci. 2014;32(13):1206-8. doi: 10.1080/02640414.2014.898858. Epub 2014 May 30.

Claudino, J. G., Cronin, J., Mez?ncio, B., McMaster, D. T., McGuigan, M., Tricoli, V., . . . Serr?o, J. C. (2017). The countermovement jump to monitor neuromuscular status: A meta-analysis. Journal of Science and Medicine in Sport, 20(4), 397-402.

Girard, O., Mendez-Villanueva, A., & Bishop, D. (2011). Repeated-sprint ability—Part I. Sports Medicine, 41(8), 673-694.

Hoff, J., Wisl?ff, U., Engen, L., Kemi, O., & Helgerud, J. (2002). Soccer specific aerobic endurance training. Br J Sports Med, 36, 218-221.

Mendez-Villanueva, A., & Buchheit, M. (2013). Football-specific fitness testing: adding value or confirming the evidence? Journal of Sports Sciences, 31(13), 1503-1508.

Sheppard, J. M., & Young, W. B. (2006). Agility literature review: Classifications, training and testing. Journal of Sports Sciences, 24(9), 919-932. doi: 10.1080/02640410500457109