Components of fitness
Strength - The ability of a muscle or group of muscles to exert a maximal force or overcome
a maximal resistance in a single contraction. The amount of strength generated is in direct
proportion to the size of the muscle or muscle group. Some sports require specific muscle
training to improve muscle size and strength.
Aerobic endurance - This component of fitness relies on proper functioning of your heart,
lungs, and blood vessels to transport oxygen to your tissues and carry away metabolic waste
products. Physical activity that trains for cardiorespiratory endurance focuses on repetitive,
dynamic, and prolonged movements using major muscle groups. You are improving this
component when you are jogging, cycling, swimming, hiking, and walking.
Muscular endurance - It is the ability of a muscle to resist fatigue while exerting a
submaximal amount of force. It is a measure of how long a muscle can withstand a
prolonged contraction or many repeated contractions. Training for muscular endurance
requires you to perform many repetitions at a lower weight than you would use for muscular
strength. Some common exercises that assess muscular endurance include pushups, sit-
ups, and pull-ups – all performed to a point of fatigue.
Flexibility - Flexibility is the ability of your joints to move through a range of motion. This
component of fitness helps to prevent muscular imbalances and allows you to move about
with ease. Two common ways to improve flexibility are static stretching and dynamic
stretching
Body composition - The last component of physical fitness, body composition, refers to the
ratio of fat mass to fat-free mass in your body. Overall health generally improves when you
have a lower amount of fat mass and higher amount of lean muscle mass.
Adaptations to training
Short term - There is an immediate change, such as an increase in heart and breathing
rate.
Long term - There is an improved aerobic endurance or an increase in muscle size.
Hypertrophy - An increase in the size of individual muscle fibres. Skeletal muscle is
composed of many individual fibres which are responsible for muscle contractions. For
hypertrophy to occur, the muscles has to be actively stimulated. THe easiest method of
doing this is as part of a weight training programme, resistance training.
Muscle tone - This can be seen when muscles are slightly tensed ready to work. Regular
training better tones muscles and improves posture. In addition muscular hypertrophy will
take place.
Decreased resting heart rate - It is a long term adaptation to aerobic exercise which aims
to decrease a person’s resting heart rate. The heart pumps blood around the body to deliver
oxygen to working muscles and remove waste products such as water and carbon dioxide.
The demand for oxygen increases during exercise, so the heart must work harder. After
training aerobically over a period of time the body will make physiological changes in order
to improve its ability to transport and use oxygen. The heart muscles become larger and
stronger through hypertrophy.