PERFORMANCE DIAGNOSIS FOR CONDITIONING

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优秀足球运动员的参考数据：

Endurance IAT (km/h) (m/s)	VO2max(ml/kg/min)	Basic Speed 30m (s)	Starting speed 5m (s)	Heart Size HV (ml/kg)	Body Fat %(%)
> 14.4 [4.00]	> 60	< 4.00	< 0.98	> 13.0	< 11.0

Table 1: Recommended conditioning, physiological and anthropometric

values for high-performance footballers.

  PERFORMANCE  DIAGNOSIS  FOR  CONDITIONING   

              BY PROF . WILFRIED KINDERMANN

Speed and endurance determine the physical conditioning requirements for football. Match analyses show that, on average, a player covers a distance of 10 km (ranging individually from 7 to 13 km) in a 90-minute football match. About 60-70% of the total distance is covered at a walk or a trot, 20-25% at mid-range intensity, and 10% at a high-intensity run or sprint.

The most frequent sprint distances during a match range from 5 to 20m. Only a few studies consider the difference stemming from the various playing positions. Midfielders run more than others, whereas strikers and outside defenders appear to sprint more often and greater distances. We prefer a system of performance

diagnosis that evaluates the indi- vidual components of conditioning in isolation, i.e. independently of ball-specific situations. This enables us to pinpoint deficiencies in the basic elements of physical condi- tioning and to minimise them through suitable training methods, which often include non-sport- specific training. Running training without a ball is certainly not inappropriate to football if you consider that only 150 to 200m are run with the ball during a match. In football, performance diagnosis is conducted only in the form of a field test in an athletics hall or on a sports field. This makes it possible to limit the time requirements, since several players can be testedsimultaneously. It also ensures standardised testing conditions. The test consists of a step test and a sprint test. It takes about 3 or 4 hours, at most, to test a team of 20 players. The step test (Figure 1) uses the lactate performance curve to determine the individual anaero- bic threshold (IAT) as an indica- tor of endurance performance capability. The heart rate is also measured using a wireless system. The lactate concentration is at the IAT between 2 and 3 mmol/l, on average,  with a corresponding heart rate of 165 to 170 beats per minute. The anaerobic thresh- old, which is often calculated as 4 mmol/l, overestimates most players’ endurance. The maximum  oxygen intake (VO2max) can be calculated from the maximum run ning speed (Figure 1). Additional spirometry contributes no addi- tional information relevant to performance diagnosis and would serve only to increase outlay. Before the step test, a 5 x 30m sprint test is conducted (Figure 2). The rest period between the sprin and step tests lasts around 30 minutes. In addition to the time measured at 30m, which indicates basic speed, the intermediate time at 5 and 10m are also measured electrically as indicators of starting speed and acceleration capability. The lactate concentration value is dependent on various factors and can indicate, inter alia, delayed recovery capability. The sports medicine performance diagnosis for football players also includes the determination of body fat percentage and, if possible given the time constraints heart size (or heart volume when measured with an echocardio- graph).

The body fat percentageis calculated by measuring skin fold thickness at specific sites (calliper method). Table 1 contains recommended val- ues for the parameters defined in the above tests. It is acceptable to diverge from these recommended values when taking into considera- tion an individual player’s position and tactical duties. In terms of speed and endurance, footballers cannot be compared with sprinters or long distance runners. Players with high endurance are often weak sprinters, and good sprinters often have low endurance. A

football player in good condition should have a suitable mixture of speed and endurance. Strong players are usually faster than weaker ones. Teams in the lower divisions attempt to use endurance to compensate for deficiencies in speed and skill. As a rule, it is easier to train endurance in fast and agile players than it is to increase speed in high-endurance players. This aspect should also be considered when selecting foot- ball talent. Rather than focusing primarily on endurance, we should promote youth players who demonstrate speed and good

technique. Systematic training can significantly improve endurance, even in adult players. The internationally published liter- ature lacks systematic, long-term studies that would make it possible to assess the developments in con- ditioning requirements and capa- bilities in top football. In German top football throughout the 1990s,the conditional performance         

capability, which was evaluated in a retrospective long-term study, remained unchanged (Figure 3). Given that the busy football   calendar puts pressure on training and recovery times, it seems hardly possible to increase the current level of physical condi- tioning. On the other hand, how- ever, important minimum levels of conditioning must be maintained. In order to do so, we have to make optimal use of the prepa- ration period, refresh player conditioning in one-match weeks, and give players with busy match schedules a timely break to recover and rebuild their conditioning. From a medical point of view, we should lend full support to the decision to eliminate the UEFA Champions League second round, which until now has been played out in the group system. This means that four two-match weeks will be cancelled and can be used for recovery and training. This reduction in the number of matches can do nothing but  good for the quality of football and player health.

Prof. Wilfried Kindermann  Director of the Institute for Sport and Preventive Medicine at the Universi of Saarland, Saarbrücken

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