Strength and Fitness - The Impartial Guide to strength, fitness, endurance and nutrition

What Is Physical Fitness?

Physical Fitness Definition

Physical fitness can be defined as: a set of attributes that relate to one's ability to perform physical activity (McArdle et al., 1996).  An individuals physical fitness is made up of five measurable components: 1) Cardiovascular Fitness; 2) Muscular Strength; 3) Muscular Endurance; 4) Flexibility; and, 5) Motor Skills.  Improvements in each of these components will enable an individual to improve their daily tasks, quality of life and a wide range of sporting activities.

Physical Fitness: Cardiovascular Fitness

Cardiovascular Fitness refers to the ability of the heart, lungs and circulation (arteries, veins, capillaries, blood) to take in, transport and use oxygen.  All of these must be working efficiently for the working muscles to receive an adequate supply of oxygen during a physical activity.  An individual with a good level of cardiovascular fitness will be able to inhale large amounts of oxygen into the lungs, uptake large quantities of oxygen into the blood stream from the lungs, and be able to uptake and utilise large amounts of oxygen in their working muscles.  The level of cardiovascular fitness declines gradually with age.  The rate of decline can, however, be reduced by performing regular cardiovascular exercise. Individuals can improve their level of cardiovascular fitness by regularly taking part in activities such as walking, jogging, cycling, swimming etc.  An individuals level of cardiovascular fitness is assessed by measuring an individuals maximal oxygen uptake (VO2max).  This represents the maximum amount of oxygen that can be absorbed and utilised by an individual during physical activity and is measured in ml of oxygen per kg of bodyweight per minute.

Physical Fitness: Muscular Strength

Muscular Strength - refers to the ability of a muscle or group of muscles to exert a maximum force against a high resistance.  An individuals strength will reach a peak between the ages of 20-30 years of age.  Thereafter, an individuals strength will slowly decline reaching a more rapid decline after middle age.  It therefore becomes increasingly important to work on improving muscular strength as we age.  Muscular strength training involves performing a number of repetitions using some form of resistance. Typically this would involve a low number of repetitions (8-15) and fairly high resistance.  To train for muscular strength individuals can use: bodyweight, resistance bands, free weights such as dumbbells, and resistance machines.

Physical Fitness: Muscular Endurance

Muscular Endurance - refers to the ability of a muscle or group of muscles to overcome a low to moderate resistance repeatedly - using a higher number of repetitions than with muscular strength training.  Muscular endurance training involves the use of a high number of repetitions (20-250) with a lower resistance.  To train for muscular endurance individuals can use: bodyweight, resistance bands, free weights such as dumbbells, and resistance machines.

Physical Fitness: Flexibility

Flexibility - refers to the range of movement (ROM) that can be accomplished by the muscles and joints.  The greater the level of flexibility the greater the ROM will be.  An individuals level of flexibility is dependant on the structure of the joint, the shape of the bones, the tightness of the muscles, tendons and ligaments.  The level of flexibility varies from joint to joint (e.g. an individual may be flexible in the knee joint but not the shoulder joint).  Generally as we get older are level of flexibility decreases. We can improve are level of flexibility by performing stretching exercises.  This involves gently stretching the joint until you can fill a stretch in the muscle, and holding the stretch for 10-20secs, then relaxing the muscle.

Physical Fitness: Motor Skills

Motor Skills - refers to movement patterns controlled by the nerve to muscle relationship, referred to as neuromuscular responses.  Examples include: balance, co-ordination, re-action time, speed, power, and agility.  These skills are specific to the activity and train the nerve muscle connection.  Training for these skills involves repeated exercises called drills which work on improving the nerve muscle connection.

Therefore, training to improve physical fitness involves the use of specific training aimed at improving all of five components that make up physical fitness.  This best achieved through the use of a specific programme that is well structured to meet the individuals needs and goals.  A program should be progressive in order to continue to stimulate further improvements in the individual.

Physical Fitness References:

McArdle, W. D., Katch, F. I., and Katch, V. L. (1996) Exercise Physiology: Energy, nutrition, and human performance, 4th Edition. Williams and Wilkins, Baltimore, USA.