Glossary

Aerobic fitness: The ability of the body's circulatory and respiratory systems to supply fuel and oxygen during sustained physical activity.

Calorie: A measure of energy from food. 3,500 kilocalories of food energy = 1 pound of body weight.

Exercise: Any planned or structured physical activity. Exercise involves repetitive bodily movement to improve or maintain one or more of the components of physical fitness -- aerobic fitness, muscular strength and endurance, flexibility, and body composition.

Inactivity: Not engaging in any regular pattern of physical activity beyond daily functioning.

Leisure-time physical activity: Exercise, sports, recreation or hobbies not associated with regular job duties, household, or transportation.

Moderate-intensity physical activity: A level of effort in which a person experiences some increase in breathing or heart rate.

Physical activity: Any bodily movement produced by skeletal muscles that results in an expenditure of energy.

Physical fitness: A set of characteristics demonstrating a person's ability to perform physical activities that require aerobic fitness, endurance, strength or flexibility.

Regular physical activity: A pattern of physical activity is regular if activities are performed:

• Most days of the week, preferably daily.
• Five or more days of the week if moderate-intensity activities (in bouts of at least 10 minutes for a total of at least 30 minutes per day).
• Three or more days of the week if vigorous-intensity activities (for at least 20 to 60 minutes per session).

Vigorous-intensity physical activity: Any activity that presents a substantial challenge to an individual and refers to a level of effort in which a person should experience a large increase in breathing or heart rate (conversation is difficult or "broken").

Weight-bearing physical activity: Any activity that imparts a load or impact (such as jumping or skipping) on the skeleton.