TRAINING TO IMPROVE PHYSICAL PERFORMANCE: SPECIFIC CONSIDERATIONS

In addition to the general considerations of overload and variation, a coach should also be aware of specific issues, or the principle of specificity, when physically preparing athletes for competition. The principle of specificity dictates that training should be relevant to the demands of the sport and the athlete in question. Once this has been ascertained, in order to maximise fitness, each element of physical performance should be considered and trained in isolation. Specificity also dictates that the physiological demands of an event must be replicated in training. For example, if a sport requires short bursts of high intensity, training should be planned to include such activity. Specificity is further enhanced when the movement characteristics of a sport are matched in training. For example, many sports (e.g. tennis, rugby, squash) involve repeated changes in direction; hence the strength and speed training for these sports should include activities that promote the required braking forces and leg muscle explosiveness that allow for quick directional changes. The rest of this section will examine strength and speed development in more detail before going on to discuss the value of tailoring training towards anaerobic and aerobic competitive demands.

Speed of movement (e.g. how quickly someone can run) is related to the type of muscle fibres that one has. Muscle can be categorised into two types: fast-contracting and slow-contracting fibres. The proportion of fast and slow fibres within a muscle is partly genetically determined. However, the existence of other influencing factors means that speed is still highly trainable. At the level of the whole body, speed can usually be enhanced by increases in muscle power and movement technique, as well as by a reduction in body mass. As discussed earlier, maximal speed can only ever be achieved over extremely short durations (see Figure 11.1). Hence, if the principle of specificity to speed training is to be applied, such training should incorporate very short periods of repeated maximal effort activity interspersed with long recoveries. Consequently, sprinters in athletics should have at least 5 minutes rest to allow for complete recovery after each exercise bout.

Similarly, for most sports players, maximal speed training should involve sprints of approximately five seconds followed by around one minute of recovery before the next sprint is performed. The fact that speed is essential in many sports means that this type of training is an important component in developing the fitness of many athletes.

If an athlete is attempting to train for improvements in maximal speed, and he or she is experiencing a decline in performance, then modifications are perhaps needed to the rest (lengthened) or exercise duration (reduced) to suit that athlete. Similarly, if an athlete is experiencing high heart rates and heavy breathing during a speed session, it is likely that the session is causing too much activation of the cardio-respiratory system. The engagement of the cardio-respiratory system in this regard reflects use of aerobic as opposed to the desired anaerobic energy reactions. In either case, the athlete needs to be given more recovery or shorter sprint duration to allow the session to meet the aim of maximal-speed development. The example given earlier of an explosiveness training session (see Figure 11.2) shows a successful attempt to minimise the use of the cardio-respiratory system within it.

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Maximal strength is rather like speed, in that very heavy demands are placed on the working muscles for very short periods of time. Also, like speed training, strength training requires very short bouts of activity followed by longer periods of rest that allows the muscle’s energy stores to be replenished. Only when the muscle can produce relatively high forces in training will it adapt to become stronger in the long term. The development of strength is likely to be beneficial to athletes in all sports, due to the fact that muscle strength provides protection from injury and improvements in muscle control that can transfer to all activities. The main adaptations that can be achieved from training in this way are an increase in muscle size (known as hypertrophy) and maximal strength. Although they often go together, it is usually desirable to separate these two in terms of training goals.

For example, in athletics, competitors in jumping events need to be extremely strong but may also want to minimise their body (and thus their muscle) mass. Their training, therefore, should focus on developing maximal strength while minimising the hypertrophy of the muscle. In contrast, forwards in rugby may want to develop both maximal strength and muscle mass. To concentrate on the development of maximal strength, an athlete should train with heavy weights followed by a long rest period to allow for recovery within the working muscles. On the other hand, muscle hypertrophy is best achieved by training with lighter weights and slightly shorter recovery periods (Kraemer et al. 1990).

Exercise that is classed as anaerobic is inherently related to strength and speed. The training of the anaerobic energy system, therefore, adopts similar principles to those used for developing strength and speed. Consequently, a training session to enhance anaerobic fitness will comprise repeated bouts of short exercise (e.g. five to around thirty seconds), with the interval between these being between around five to ten times the length of each bout (see Table 11.4).

When performing exercises to enhance anaerobic fitness, the use of the aerobic energy system should be low. By interspersing periods of work with long rest periods, there is less contribution from the aerobic system, which, in turn, allows anaerobic processes to be the main providers of energy. It is essential that anaerobic training is performed at a very high intensity; therefore the athlete must work as hard as possible during the exercise periods.

Table 11.4 Interval (running) training sessions to enhance anaerobic fitness

Intended aim of session Sprint Rest between Number of

duration sprints repetitions

Short-sprint i) Repetition of very 5 seconds 50 seconds 10–15 duration high-quality sprinting

ii) Fatigue-resistance and 5 seconds 30 seconds 15 speed-endurance

Long-sprint i) Repetition of high-quality, 30 seconds 150 seconds 6 duration sustained performance

ii) Fatigue-resistance in 30 seconds 90 seconds 10 sustained performance

The use of rest intervals between exercise bouts has been termed interval training. A selection of interval training sessions designed to improve anaerobic fitness is given in Table 11.4. If athletes find these sessions too easy or too hard, the coach should alter the rest periods to ensure the session provides the appropriate stimulus for training adaptations.

The main aim of anaerobic training is to improve the ability of the athlete to perform sustained high-intensity activity for events such as 200m running, 50m swimming or even sports like rugby and football where short, high-intensity bursts are interspersed with longer periods of low-intensity activity. Anaerobic fitness is also essential as a component of longer-duration events such as Olympic rowing, middle- to long-distance running, and cycling, where a sprint finish may be required towards the end of a race.

Additionally, aerobic fitness is a requirement of most sports. For example, long-duration events, where activity is maintained at a relatively constant, low-intensity (such as triathlons, a 10,000m run or a 1500m swim) are almost exclusively aerobic. However, in repeated-sprint sports, aerobic requirements are also high. This is because aerobic fitness promotes recovery between high-intensity exercise bouts. Hence, most exercise will improve aerobic fitness, even strength and sprint training (Dawson et al. 1998; Kraemer et al. 1995).

Consequently, although the traditional way of enhancing aerobic fitness has been to perform low-intensity exercise over prolonged periods of time, a whole range of activities can be used to develop it. A common factor in doing so, however, is the necessity to provide an overload of both exercise duration and intensity. Therefore, rather than just exercising at a low intensity for a longer time, optimal development of aerobic fitness also requires interval sessions where higher-intensity work is interspersed with rest periods.

This allows for more use of fast-contracting muscle fibres (Dudley et al. 1982) and greater stress on the cardiovascular system (Billat et al. 2001). In turn, the fast-fibres and the cardio-respiratory systems adapt to the training and, with time, aerobic fitness improves. The differences between interval training sessions for aerobic and anaerobic fitness are that aerobic interval sessions are not usually performed at a maximal intensity, while the rest period between exercise bouts is usually a little shorter. Table 11.5 shows a selection of training sessions that would be suited to the development of aerobic fitness.

Table 11.5 A selection of (running) training sessions to enhance aerobic fitness Intended aim of session Details of session

Short-duration interval To improve aerobic fitness at 5 sets of (10 repetitions of [10 very high movement speed seconds hard run, 20 seconds

walk recovery]) 2 minutes between sets Medium-duration interval To improve aerobic fitness at 6 repetitions of (3 minutes hard

sustained high running speeds run, interspersed with 2 minutes walking recovery) Continuous exercise To improve general aerobic 45 minutes of low-intensity,

fitness and endurance continuous exercise

CONCLUSION

The aim of this chapter has been to highlight how an understanding of sports physiology can help to inform coaching practice. Hence, a series of principles have been presented and discussed that should enable a coach to make decisions regarding the best strategies for enhancing the fitness of athletes in order to optimise their competitive performance.

Although it is beyond the scope of this chapter to provide definitive answers in relation to precise fitness questions and demands of individual athletes and the sports they perform, through applying the principles discussed it is hoped that all coaches can approach the development of their athletes’ fitness with a greater level of knowledge and confidence.

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1. Using the general points highlighted in this chapter, devise exercise training sessions to enhance the following components of fitness relevant to your sport of choice:

a) Movement speed b) Endurance fitness

2. Why is strength training important for the preparation of competitors in most sports? How would you draw up general training guidelines that would enhance the following aspects of strength?

a) Maximal strength

b) Muscle hypertrophy (muscle size)

3. How would you apply the principles of progression and variation to the training sessions that you have devised in answering questions 2 and 3 above?

REVIEW QUESTIONS