Physical Education · Ch 7 — Physiology and Injuries in Sports
Physical Fitness Components Determined by the Physiological Factors
Physical Fitness Components Determined by the Physiological Factors
Having looked at the three physiological factors, we can now see how they combine to determine the components of physical fitness. Four components are considered here — strength, endurance, speed and flexibility — and each depends on a particular blend of fibre type, energy system and cardiorespiratory support.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your NCERT textbook's own diagram.
A single row of four coloured rounded-rectangle label tiles naming the four components of physical fitness that the physiological factors determine: a red tile reading 'Strength', a green tile reading 'Endurance', a yellow tile reading 'Sp …
Strength is the ability of the body to work against resistance. It has several sub-types, such as maximum strength, explosive strength and strength endurance, each requiring a different kind of exercise, intensity and duration, so the physiological demands vary. Different sports call for different amounts of strength and therefore different mixtures of slow- and fast-twitch fibres. Generally, in strength events where a sudden burst of energy is needed — weightlifting, jumps, sprinting and other power-, agility- and strength-dominated sports — force production is high and fatigue comes quickly, so a high percentage of fast-twitch fibre is essential.
Endurance is the ability of the body to keep working for a long time without becoming fatigued. It ranges from a brisk walk to a run to a full marathon; the intensity and duration differ, but every endurance activity shares the same features of long duration and low fatigue. Cycling, swimming and other sustained activities all fall under endurance. Good endurance requires a higher percentage of slow-twitch fibre than fast-twitch, and it is powered mainly by the aerobic system, with VO₂ max and ventilation capacity playing the dominant roles.
Speed is the ability to cover the maximum distance in the shortest possible time. Speed activities — the 100 m race, roller skating and any movement that must be completed in minimum time — depend on a very high percentage of fast-twitch fibre. A vital physiological factor is motor-neuron stimulation: the brain must signal the muscles to act extremely fast. To meet the energy demand of such brief, intense efforts, the ATP–CP system supplies the fuel.
Flexibility is the ability of muscles and tendons to lengthen without being damaged. Stretching and yoga call for a good deal of it. The main physiological determinants are the elasticity and extensibility of the muscles, the type of joint involved and body temperature; muscles, tendons and ligaments are all key contributors. Training also requires an understanding of how muscle groups cooperate:
- Agonists are the muscles that contract to produce a particular movement (the prime movers). …