Describe the difference between physical activity and physic

Describe the difference between physical activity and physical fitness. What are the types of muscles fibers found in humans? What are the average percentage for each fiber? Draw a diagram of the length-tension relationship for muscles.

Solution

Answer:

34. Physical activity is a different concept to physical fitness, although the two are often related. Physical activity has been defined as ‘any bodily movement produced by skeletal muscles that result in caloric expenditure’.

Therefore, physical activity is commonly described by the following four dimensions:

(i) Frequency:

The number of events of physical activity during a specific time period.

(ii) Duration:

Time of participation in a single bout of physical activity.

(iii) Intensity:

Physiological effort associated with participating in a special type of physical activity

(iv) Type of activity:

Any assessment of physical activity should ideally measure all of these dimensions and account for day-to-day variation. Three of these dimensions (i.e. intensity, frequency and duration) of physical activity are fundamental because their assessments provide the ability to calculate energy expenditure (EE) associated with physical activity.

In contrast, physical fitness comprises cardiorespiratory endurance (assessed by either measured or estimated VO₂ max), muscle endurance and muscle strength, both of which are specific to a muscle group and must therefore be measured individually. Flexibility, balance, agility and coordination are additional components of physical fitness.