By Mike Perko, PhD

What does it mean to be physically “fit?”
Being fit is defined only by what kind of activity you do, how long you do it, or at what level of intensity.  In other words, it is more than being able to run a long distance or lift a lot of weight. Overall fitness is made up of five components:

• Cardiorespiratory Endurance
• Muscular Strength
• Muscular Endurance
• Body Composition
• Flexibility

To assess your total fitness, look at all five components together:

Cardiorespiratory Endurance is the ability of the blood, heart, and lungs to supply fuel during sustained physical activity. To improve your cardiorespiratory endurance, try activities that keep your heart rate elevated at a safe level for a sustained length of time like walking, swimming, or bicycling. Start slowly and gradually work up to a more intense pace.

Muscular Strength is the ability of the muscle to exert force. Make your muscles stronger by working them against resistance, such as weights or gravity. Exercises such as lifting weights or taking stairs are great.

Muscular Endurance is the ability of the muscle to continue to perform without fatigue. Try activities such as walking, jogging, bicycling, or dancing.

Body Composition refers to the relative amount of muscle, fat, bone, and other parts of the body. Body composition is important to consider for health and managing your weight.

Flexibility is range of motion around a joint. Flexibility in the joints helps
prevent injuries through all stages of life. Want to improve your flexibility? Try activities that lengthen muscles like swimming.

SOURCE: U.S. Department of Health and Human Services. Physical
activity and health: a report of the Surgeon General. 1996.