◄Previous: 1 What is endurance?

# 2 Who needs endurance?

Endurance events require the body to sustain effort for a prolonged period, and to do this it needs a considerable supply of energy. Endurance exercise relies on the aerobic energy system, which uses oxygen to convert the body’s extensive store of carbohydrates and fats into energy. When the aerobic system becomes the dominant energy system in exercise, it dictates that endurance becomes the major feature of the activity. Table 1 shows the aerobic and anaerobic energy systems’ contribution to maximal exercise.

## Table 1 Estimates of anaerobic and aerobic energy contribution during selected periods of maximal exercise

Duration of exhaustive exercise (sec) | % of energy supplied by the anaerobic system | % of energy1 supplied by the aerobic system
--- | --- | ---
0–10 | 94 | 6
0–15 | 88 | 12
0–20 | 82 | 18
0–30 | 73 | 27
0–45 | 63 | 37
0–60 | 55 | 45
0–75 | 49 | 51
0-90 | 44 | 56
0–120 | 37 | 63
0–180 | 27 | 73
0–240 | 21 | 79
a Approximately ± 10% at the 95% prediction level

Source: Gastin (2001)
1 Approximately ±10% at the 95% prediction level

As the duration of exercise increases, so does the contribution from the aerobic energy system. Additionally, as exercise intensity is reduced, or intermittent rest periods are included (as in team sports), the aerobic contribution to exercise will increase. So, does this mean that success in all events and sports relies on endurance? To answer this question, you will analyse the endurance needs of three athletes in the next activity.

## Activity 2

Allow 20 minutes for this activity

Imagine that you are working with three athletes; a water polo player, a 200 m sprinter and a marathon runner. You are performing a needs analysis of their sport/event to determine how much endurance focus is needed in their training programme. Consider the duration and intensity of each sport/event that each athlete participates in, then answer the question: for which of the athletes is endurance relatively more important, and why?

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### Discussion

A water polo player is required to repeatedly sprint swim, wrestle opponents, tread water and recover between efforts indicating that all energy sources will contribute to performance. Zinner et al. (2015) suggested that in a match, 50–60% of a water polo player’s energy is supplied by the aerobic energy system indicating that endurance will play a large role. For the sprinter, their 200 m personal best is 26.4 seconds. Therefore, according to Table 1, 27% of their energy will come from the aerobic energy system during the race. Additionally, on a race day the aerobic energy system will contribute to recovery between heats. Therefore, endurance should still play a role in training. For the marathon runner, as a beginner the marathon may take them 4–5 hours and the aerobic energy system will supply approximately 97.5% of their energy (Gastin, 2001). Therefore, endurance will be the focus of that individual’s training programme.

With endurance identified as a ‘need’ for the athlete, you need to understand how to train it effectively; here, you first need to determine which physiological attributes are relatively more important for endurance performance. You’ll tackle this in the next section.

◄Contents►Next: 3 Endurance exercise: physiological determinants

OpenLearn - Training for endurance in sport and fitness
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