Fitness Glossary

Illness
Symptoms that upset your health.

Incomplete proteins
Proteins which are low in one or more of the essential amino acids.

Iso kinetic Exercise
Isotonic exercise in which there is ACCOMMODATING RESISTANCE. Also refers to constant speed. Nautilus and Cybex are two types of iso kinetic machines, where machine varies amount of resistance being lifted to match force curve developed by the muscle.

Isometric Exercise
Muscular contraction where muscle maintains a constant length and joints do not move. These exercises are usually performed against a wall or other immovable object.

Isotonic Exercise
Muscular action in which there is a change in length of muscle and weight, keeping tension constant. Lifting free weights is a classic isotonic exercise.