Physical Activity – Terms and Definitions

Support.Dictionary1Terms and Definitions Relating to Physical Activity

Aerobic Activities

Aerobic activities such as brisk walking, basketball, swimming, soccer, or dancing typically use large muscle groups in rhythmic repetitive movements and are conducted at a pace that can be continued for more than a few minutes. These activities improve the efficiency and capacity of the cardiorespiratory system. Aerobic activities are also called endurance activities or cardio activities.

Anaerobic Activities

Anaerobic activities such as sprinting or powerlifting require energy production systems that do not use oxygen because the activities exceed the capacity of the cardiorespiratory system to distribute oxygen and other metabolites. They can be maintained for a few minutes.

Cardiorespiratory Fitness

Cardiorespiratory fitness is the ability of the circulatory and respiratory systems to provide oxygen during sustained aerobic physical activity.


Exercise is a form of physical activity that is planned, structured, repetitive, and performed with the goal of improving health or fitness.


Reaching failure means that a certain set should be done until another rep is not possible, i.e. to max out.

Functional Ability

Functional ability is the capacity of a person to perform tasks or behaviors that enable the person to carry out everyday activities, such as climbing stairs or walking on a sidewalk. Functional ability is key to a person’s ability to fulfill basic activities in life, such as personal care, grocery shopping or playing with the grandchildren.


Overload is the physical stress placed on the body when physical activity is greater in amount or intensity than usual. The body’s structures and functions respond and adapt to these stresses. For example, aerobic physical activity places a stress on the muscles and the cardio respiratory system, requiring the lungs to move more air and the heart to pump more blood and deliver it to the working muscles. This increase in demand increases the efficiency and capacity of the lungs, heart, circulatory system, and exercising muscles. In the same way, muscle strengthening and bone-strengthening activities overload muscles and bones, making them stronger.

Physical Fitness

Physical fitness refers to attributes that people have or achieve that relate to their ability to perform physical activity. Several components of physical fitness, such as cardiorespiratory endurance, muscle strength and endurance, body composition and balance are associated with health and functional capacity.

Repetition, Rep

A repetition is one complete movement of a particular exercise. Doing eight squats translates to eight repetitions, or reps.


A set is one complete series of reps from beginning to end. The completion of eight squats is one set of eight reps.

Strength Training

Strength training, also called resistance training, a refers to activities designed to improve the strength, power, endurance, and size of skeletal muscles. Strength training causes the body’s muscles to work or hold against an applied force or weight. These activities often involve relatively heavy objects, such as weights, which are lifted multiple times to train various muscle groups. Muscle-strengthening activity can also be done by using elastic bands or body weight.


A structured session of physical exercise.

References, Sources

Physical Activity, Exercise, and Physical Fitness: Definitions and Distinctions for Health-Related Research, C.J. Caspersen, K.E. Powell, G.M. Christenson. Public Health Reports, Mar-Apr 1985.