Written by Peter Joffe
The Holy Grail for Sport Science is the achievement of “objectivity” when evaluating an athlete’s condition, monitoring his/her progress, and prescription of exercises. One of the main tools for this purpose is fitness testing. During decades of development of modern sports, hundreds of tests aiming to improve performance were invented.
However, training is a very complex process. The consequences of many variables’ influence and interaction are often difficult to predict, control, and verify. Among the different sports, intermittent sports are arguably the most difficult to achieve accurate and precise training interventions. Despite all attempts, there is still no clear picture and precise instructions.
The following article was provoked by an interesting discussion, initiated by Mendez-Villanueva and Buchheit paper: “Football-specific fitness testing: adding value or confirming the evidence?” (Mendez-Villanueva & Buchheit, 2013).
The authors questioned the traditional approach to testing in sports games. Mostly I agree with them and want to develop the topic a little bit further. My article is mainly devoted to ball games like football, basketball, handball, and tennis; thus, I use the word “player” on many occasions. However, coaches in other intermittent sports (e.g., combat sports) may find this information useful as well.
I assume that readers are familiar with most of the tests I will discuss; thus, I do not give detailed test descriptions. Otherwise, the reader may find more detailed information about a particular test elsewhere. The article’s main purpose is to discuss the genuine nature of tests, their appropriateness, and their usefulness for athletes.
Activity patterns in intermittent sports.
Intermittent sports are characterised by various actions, with unpredictable intensity and duration. Generally, the activity pattern consists of relatively short, high-intensity bouts alternating with low-intensity periods or complete rest.
The intensity and length of the bouts and rest periods are often variable and unpredictable.
Inside bouts, athletes need to produce maximal power and/or speed. Often they have to maintain this power and speed for longer than a few seconds. That demands a special quality, which is speed/strength endurance. Sometimes there is insufficient recovery between intense bouts; thus, players have to perform in an under-recovery state.
Sometimes, between bouts, subjects can rest (e.g., tennis and boxing); however, they are often denied complete rest and have to perform the necessary basic activity level. 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 the requirements outlined above, an athlete has to have the 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 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 oxygen, thus depending on aerobic capacity. Also, oxygen is needed to clear metabolic by-products.
3 To maintain a basic level of activity.
Most sports games have a 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 efforts.
Anaerobic energy production, mainly from PCr and anaerobic glycolysis, plays a significant role during high-intensity exercise.
2. To tolerate high intensity.
I consider the ability to buffer and purge energy metabolism byproducts to be “anaerobic capacity” (see
article). However, the term “anaerobic” is a little misleading here, as metabolites are also produced during aerobic exercise. However, the anaerobic pathway led to the formation of relatively more metabolites than the aerobic pathway, requiring more intensive buffering and clearance.
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 fitness testing in sport games?
Before prescribing tests for their athletes, coaches should understand why they need to do that. There may be five main reasons:
1. To confirm what coaches already know.
Perhaps coaches already see that their player lacks stamina or strength, but for some reason, they are not sure about this. Then they want to test. Will this test be more reliable than the coach’s observation? Perhaps in some cases, but not all. Test settings never entirely match game situations, so care must be taken when extrapolating the test result to a real game.
2. Compare with industry standards. Are industry standards valid?
Another reason to do the test is to compare your player to other athletes in the same sport. However, there is a catch here. Sometimes industry standards of a certain physical quality are set to be favourable for a certain type of player(Carling & Collins). For example, if the country’s football philosophy emphasises physicality over agility, then physical conditioning coaches prioritise strength tests that are better performed by bigger players. This strategy may put small but agile players at a disadvantage and even restrict them from being picked up for a high level. That is not good for football. Barcelona FC provided a good example of how small players can be very effective on a pitch.
3. Motivation.
Testing may provide a motivational stimulus for improvement. Athletes can compare their results with previous achievements or with their peers’ results, which may motivate them to train better.
4. Diagnosing the cause of the problem.
Testing can help find the cause of poor performance. For example, if an athlete has poor acceleration, testing absolute strength and reactive strength can reveal lag areas. Then these problems can be solved with the help of special 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 progress. For instance, a coach who plans an interval session at 95% of speed at Maximal Oxygen Uptake needs to know this speed. When prescribing a strength programme, it would be useful to know the athlete’s Repetition Maximum. Improvement in reference values may confirm to the coach that the training programme is successful. Some tests (e.g., countermovement jump, heart rate tests) may be used to evaluate an athlete’s form.
What is a good test?
There are, in my opinion, four essential requirements for every test.
1. Test has to be valid. That means it should measure what it is supposed to measure. For example, if we measure VO2 max, we will not ask the athlete to squat with the barbell to exhaustion. Instead, we will probably ask him/her to run the maximal incremental test. Athletes will be fatigued in both situations, but only in the latter will they achieve maximum oxygen consumption. Also, the test should be suitable for the 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, results should be close. Natural variations in the test (Error of measurement) should not spoil changes in parameter, which is measured. The test should be easily replicated and should not be dependent too much on different conditions.
3. Test should be standardised. Its conditions and procedure have to be the same in every trial and for everyone. Unrelated factors that may influence a result should be controlled as much as possible.
4. It should not be too complicated and time-consuming. Complexity increases the probability of confounding bias and decreases reliability, whereas time is an essential factor in elite-level athletes’ busy training schedules.
This will be good to know.
In the following chapter, I am going to suggest tests which are, in my opinion, necessary in the 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 an athlete’s maximal ability to consume oxygen during exercise.
Generally, VO2 max depends on the ability to deliver oxygen to the working muscles and their ability to utilise 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 VO2 max levels are 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 or cross-country skiers (70-85 ml/ min*kg).
VO2 max test cannot distinguish between different components of aerobic capacity. If the coach is not happy with his player’s endurance, and VO2max is abnormally low, it is probably worth investigating further and sending the player for medical examination.
2. Speed at VO2 max (vVO2max) – exercise prescription and monitoring a progress.
The speed at VO2max is a minimal velocity, which can elicit VO2max. So, during the VO2 max test, the researcher can find VO2max per se and how fast the athlete ran when this value was achieved. This speed reflects both VO2max and running economy. Running economy refers to how efficiently an athlete uses oxygen for given work/distance/speed. It depends on many factors. Among those are running technique, player’s constitution, muscle strength, muscle-tendon stiffness, muscle fibres type, and many others. If two athletes with the same VO2 max show different vVO2max, it is possibly due to a running economy difference.
However, the coach doesn’t have to improve the running economy for players with lower vVO2max immediately. First of all, the economy for straight continuous running (like in standard VO2max test) is different from the economy in intermittent runs with a change of direction (real game)(Buchheit, Haydar, Hader, Ufland, & Ahmaidi, 2011). Secondly, players’ morphology maybe not perfect for an economical, continuous run, where slim, long-legged athletes have advantages but maybe good for sprints, tackles, and agility. So it depends. The coach needs to look at the whole picture and to consider the player’s specialisation.
In a field speed at VO2 max can be found in 5-6 min time-trial or 1.5 – 2km run. This speed gives reference velocity for interval training. Usually these are long intervals (30 sec- 4 min). For example, a 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. That is good for the player.
3. Thresholds speeds – prescription and monitoring improvement.
We need to know two thresholds speeds: aerobic threshold and anaerobic threshold.
Aerobic threshold. That is the upper border of moderate intensity. The 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 the 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. That is a higher border of heavy intensity domain, which is intensities between aerobic and anaerobic thresholds. There is an 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 the incremental test, which 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, the anaerobic threshold may correspond to gas exchange indices, more precisely, with the rise of ventilation without a 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 the anaerobic threshold, this running becomes more demanding. This intensity may be used for shifting the anaerobic threshold up and improve the ability to tolerate and clean metabolites. Above the anaerobic threshold, the 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 the higher border of this range, the ability to tolerate metabolites.
4. Absolute speed – prescription.
Though it is not too often when a player achieves max speed during the game, it is worth knowing this indicator.
Maximum speed may be a reference velocity for short intervals (less than 30 sec) and repeated sprints training. It may help calculate the fatigue index during the Wingate test’s running analogy (see below). Finally, this speed can help monitor an 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 the practical point of view, the rate of power decline is, in my opinion, the most important information because it reflects the player’s ability to maintain high intensity inside a single, relatively long bout.
An alternative for Wingate test for sports, where the 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 a noticeable speed decline. We need to measure overall sprint time, fastest 20 m ( this is usually between 20 and 40) and slowest or last 20 m. Rate of speed decline (Fatigue index) may be defined as:
( the slowest time for 20 m minus fastest time for 20 m)/ slowest time 20 m.
Perhaps, it is too complicated to measure two splits in real life, so the last 20 m speed and mean 20 m speed may be enough:
(the slowest 20 m minus mean 20 m)/ slowest time 20 m.
There are other methods for testing anaerobic capacity. Their validity is questionable. I have devoted special article to this topic.
Some analytics.
Sports games athletes need the capacity to perform high-intensity work repeatedly. It depends on the ability to produce energy aerobically and anaerobically, to transform this energy into mechanical work and maintain homeostasis efficiently. From this point of view described above, tests can provide valuable information.
The maximal oxygen uptake test gives us information about player’s general aerobic capacity. It is an integrated measure of oxygen delivery and utilisation capabilities.
If an athlete improves his/her speed at VO2 max without improvement in VO2 max itself, we may conclude that this is most likely due to advances in the running economy. Overall, we can consider this a positive adaptation though we have to remember that the running economy with directional changes may differ from continuous running.
Running economy depends mostly on biochemical and biomechanical factors. Former to some extent connected with buffering/ clearance capacity. More metabolites mean 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 improving vVO2 max data, we cannot make conclusions about these two groups of factors’ relative contributions.
Maybe some helpful information about buffering/clearance may be derived from the lactate threshold test. If lactate turn point occurs at a higher percent of VO2 max, this probably, tells us that biochemical efficiency improved. Indeed, if an athlete runs at a higher percent of VO2 max, with higher speed and his/her metabolic state, as indicated by blood lactate level, is still stable, then we can conclude that the clearance/buffering system is coping well at such intensity.
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 a fraction of VO2 max, was strongly correlated with time to fatigue at vVO2 max in a group of sub-elite runners. This index, in my opinion, to a great extent, depends on the ability to clean and tolerate metabolites.
The three tests’ results give us a relatively comprehensive picture of athlete endurance capacity during the game.
1. VO2 max test gives us information about the athlete’s ability to maintain basic intensity throughout the game and recover between intensity bouts. The speed at VO2 max, derived from the same test, tells us about players running economy.
2. We can measure player’s ability to maintain intensity inside a single bout (speed endurance) by 200 m sprint test. We are interested in improving fatigue index without pacing (thus total time should improve also).
3. Lactate threshold/MLSS test with oxygen consumption measurements gives us additional information about the player’s aerobic capacity (the speed at threshold).
Expressed as a fraction of VO2max, this test is associated with the ability to perform multiple intense bouts in a state of insufficient recovery (metabolite tolerance).
Testing strength and power.
I will not discuss this group of tests in great detail because it is up to the 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 an external load (e.g., barbells), whereas for explosiveness, coaches use a different kind of jumps and short (5-10m) accelerations. Every test may require some technical skills, which, actually, maybe irrelevant to the athlete’s specialisation.
Hence, testing explosiveness and maximal strength, the coach has to ensure that the technical component, which is irrelevant to the sport, is minimal. Otherwise, the player may fail in the test because of technical unpreparedness or spend too much precious training time learning the test.
Another consideration is that players’ morphology can greatly influence particular strength and power tests giving some athletes an “unfair” advantage. However, in many sports games like, for example, football and hockey, players with different body constitutions can be equally successful; thus, assessing them based on 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 isn’t easy 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 their 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 that may be useful for sports 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 an inseparable part of most sports games, so it seems logical to measure it. However, in this test movement pattern is not the same as in a real game. Also, this test doesn’t give you an answer to why acceleration is not fast enough.
2. Countermovement jump – progress, fatigue and industry standards.
This test is one of the most popular for assessing lower body power and is widely used in sports. However, it provokes a lot of discussions. Only jump height is measured in most simple variants, and the player uses his/her hands to assist the jump. Some researchers argue that hands should be on the hips for avoiding upper body influence. In my opinion, this makes the jumping pattern unnatural. Usage of new technical devices allows measuring other variables such as ground reaction force, rate of force development, power, etc. That may make the 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 a horizontal direction. The 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 the unilateral explosiveness and effectiveness of the stretch-shortening cycle. However, it requires some technical skills, and players with specific body constitutions (longer legs) have an advantage. So, in my opinion, there are no industry standards here; just look at a 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. The loaded squat is more difficult for taller (longer legs) players. However, the estimation of an athlete’s RM is a useful tool for exercise prescription. For the sake of safety, RM can be estimated from the 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 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 tests, and many others. They claim to be highly relevant to sports games because they include turns and accelerations. However, in the real game, movement patterns, intensities, and rest periods are not the same as in shuttles tests. Secondly, if the player performed poorly in this test, then where is the problem? Is that his/her aerobic capacity? Running economy? Clearance/buffering? The technique in turns? Strength for acceleration and deceleration? We won’t get the answer.
2. Repeated sprints
These are another popular group of tests that are widely used in sports games. Usually, this test consists of a certain amount of maximal sprints (20-40 meters) separated by specified rest periods. The coach may be particularly interested in mean sprint time and rate of speed decline. However, the 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). In my opinion, we can 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 one of the main predictors of VO2 max. Thus it reflects athlete’s aerobic capacity. Secondly, HR is influenced by the autonomous nervous system; therefore, its fluctuations at rest and recovery may reflect players’ training status and fatigue. However, HR may be affected by many different factors independent of player’s fitness and current form. Also, the athlete’s level, training period, psychological factors, and test design play their roles. Thus HR testing should be considered with caution and only together with other fitness and psychological tests. The interested reader can find more detailed information here.
Useless tests.
1. Agility tests
Agility is the 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, and complex environments. You cannot completely predict and rehearse that in advance. None of the agility tests can mimic real game situations 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. Many elements influence physical/technical performance in the real game, and the problem for such tests is to control these influences and 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, the 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 a sport-specific environment. However, if the 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—a waste of time.
Conclusion.
We have to understand one important thing. Physical qualities needed for sports games are game-specific. However, this doesn’t mean that we have to chase game-specificity in testing.
First of all, the game itself is the best game-specific test.
Secondly, due to multifactorial influences, game-specific testing often does’t allow us to distinguish between different contributors to performance. Trying to duplicate game situations 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 “aim-specific” and provide coaches with information about problem areas and help them prescribe exercise and monitor player’s progress. Scientists should be able to answer the question: “then what?” after testing. What can they add to what is already known? What can they 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