Endurance

Endurance is the ability to sustain an activity — to keep producing energy over a long period and resist fatigue. Like strength, it is a conditional ability, and it matters hugely in health, training and competition. It is usually measured by how many repetitions, or how long, an action can be performed.

Definitions

• Harre: endurance is the ability to resist fatigue.
• Barrow and McGee: the result of a physiological capacity of an individual to sustain movement over a period of time.
• H. Singh: the ability to sustain an activity.

Types of Endurance

Endurance is classified in two ways — by the nature of the activity and by its duration.

I. According to the nature of the activity. This grouping is based on the kind of activity involved.

• Basic Endurance — resisting fatigue under a medium-intensity load using aerobic muscular metabolism: slow-paced movement of large muscle groups over a long period, such as jogging, cycling or swimming for more than 30 minutes. It forms the base for all other types of endurance.
• General Endurance — the ability to perform general (non-sport-specific) movements for a prolonged time. It can involve higher-intensity work than basic endurance, but for a shorter duration, and can be built through general exercise.
• Specific Endurance — the ability to resist fatigue in the movements of a particular sport. It varies from sport to sport because the nature of fatigue differs; a hockey player's specific endurance is not the same as a marathon runner's or a cyclist's.

II. According to the duration of the activity. This grouping considers only cyclic activities and is based on physiological factors; following Harre (1986) it divides into:

• Speed Endurance — resisting fatigue in cyclic activities lasting up to 45 seconds; the classic example is the 400 m sprint. It depends mainly on the power and capacity to produce energy.
• Short Term Endurance — needed for activities lasting 45 seconds to about 2 minutes, such as an 800 m run; depends largely on speed endurance and strength endurance.
• Medium Time Endurance — needed for activities lasting 2 to about 11 minutes, such as the 1500 m and 3000 m runs or rowing; depends on speed and strength endurance, but to a limited extent.
• Long Time Endurance — needed for activities lasting more than 11 minutes, such as the marathon and cross country.

Methods to Develop Endurance

1. Continuous Method. Exercise is done for a long time without rest; because the duration is long, the intensity is kept low. Its sub-methods are:

• (a) Slow Continuous Method — a steady speed with no break for a long time, paced by heart rate. A trained athlete's heart rate should be 140-160 beats per minute, for at least 30 minutes; used for walking, running and cycling. Effect: mainly on the muscles, with some psychic and metabolic benefits — more muscle and liver glycogen, greater capillarisation, more and larger mitochondria, better thermal regulation, improved oxidative enzymes, more fat metabolism, a positive effect on heart and lungs, and improved willpower and self-discipline.
• (b) Fast Continuous Method — performed faster but at a uniform speed, with heart rate at 160-180 beats per minute; being more strenuous, the duration is at least 20 minutes. Effect: improves VO2 max and the muscles' capacity to use oxygen, markedly increases mitochondria, and improves anaerobic capacity.
• (c) Variable Pace Method — the pace changes, but the changes are pre-planned; heart rate ranges 140-180 beats per minute for 15 minutes to 1 hour. Very strenuous, so it suits trained athletes. Effect: raises muscle glycogen, increases mitochondria, improves heart-lung efficiency and VO2 max, and builds willpower and confidence.
• (d) Fartlek Method — a Swedish word meaning 'speed play'. It is like the variable pace method, except the speed change is not planned: the athlete varies pace at will in response to terrain, surroundings and feeling. Heart rate and duration are similar to the variable pace method. The diagram shows a typical fartlek course.

Fartlek training promotes weight loss, tests strength and endurance, improves speed and race tactics, builds the 'mind over matter' element, mimics the surges of a real race, raises physical and mental energy, improves flexibility, and develops both fast- and slow-twitch muscle response.

2. Interval Method. The most versatile method for improving endurance. The activity is done at a comparatively high intensity with intervals of incomplete recovery, on the principle that work should be done with enough speed and duration to raise the heart rate to about 180 beats per minute; after a short interval, when it drops to 120-130 beats per minute, work begins again. The diagram shows work bouts separated by rest intervals.

Effect: improved circulatory system, better aerobic capacity, greater lactic-acid tolerance and improved VO2 max. …