2F2Q - What is Fitness?

What is Fitness?

In this context, when we speak of fitness we are referring to “physical fitness”. There are multiple components that are considered when focusing on optimal physical fitness. The level of intensity for each component changes as we age but should still be factored into our physical fitness plan. These physical fitness components include:

  • 1
    Cardiorespiratory endurance – is measured by the level at which your heart, lungs, and muscles work together when exercising or performing a physical activity for an extended period of time and at a given speed. This component shows how efficiently the cardiorespiratory system is functioning such as heart rate and oxygen consumption.
  • 2
    Muscular endurance – is measured by the number of repetitions (reps) of a given exercise that work a particular muscle or muscle group. Endurance involves repetitive contractions against a force for an extended period of time. This force can be applied through weights or machinery or through body weight and gravity. The greater one’s muscle endurance the more reps that muscle group can perform.
  • 3
    Muscular strength – is measured by the amount of force a muscle can exert to move an object whether it be weights (free or machinery), one’s body weight, or any object.
  • 4
    Muscular power – is measured by the amount of force exerted over a short period of time. Muscular strength measures the ability to exert force while muscular power measures the ability to exert force rapidly. Muscular power is often associated with the term “explosiveness”.
  • 5
    Flexibility – is measured by the range of motion of each joint and each group of muscles. Each group of joints or muscles may have a different range of motion or level of flexibility.
  • 6
    Balance – is measured by how long a particular position can be held whether stationary or moving. An example of a stationary position could be standing on one leg or maintaining a yoga position whereas a moving position might include a physical activity that requires balance like skiing.
  • 7
    Speed – is measured by the ability to move your body or body limb in a given direction as quickly as possible.
  • 8
    Agility – is measured by the ability to accelerate, decelerate, and rapidly change direction while maintaining balance and posture.
  • 9
    Quickness – is measured by the ability to react and change body position with a maximum rate of force production.


Many of these components are interdependent. In some cases improving one component may decrease the ability of another component. A classic example is building muscle strength tends to reduce one's flexibility. To obtain optimal physical fitness one’s exercise plan should include exercises to address each of these fitness components.

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