| A | B |
|---|
| exercise | physical activity that consists of a regular series of activities to train and strengthen the body |
| body composition | the division of total body weight into fat weight and fat-free weight which includes bone and muscle |
| endorphin | a substance produced inside the brain that has pain-killing effects |
| physical fitness | the ability to perform daily tasks vigorously and to perform physical activities while avoiding diseases related to a lack of activity |
| aerobic fitness | the ability to endure at least 10 minutes of moderate activity |
| flexibility | the ability to move muscles and joints through their full range of motion |
| aerobic exercise | physical activity that increases the supply of oxygen to the muscles, and that can be continued for a period of time without stopping |
| anaerobic exercise | physical activity that increases speed and muscular strength, and that cannot be continued for a few minutes without stopping |
| anabolic steroid | an artificially-made, complex substance that can temporarily increase muscle size |
| brain waves | electrical patterns produced by the brain that can fluctuate greatly during the sleep cycle |
| REM | (rapid eye movement) the dreaming part of the sleep cycle, in which the eyes move back and forth rapidly under the eyelids |
| insomnia | temporary or continuing loss of sleep |
