Terms Related to Muscle Actions

At any given time during a weight training exercise, the muscles worked may perform one of the following three types of activity.

Concentric muscle action

An action that shortens, or contracts, the muscle, such as when a muscle lifts a weight

Eccentric muscle action

An action that lengthens the muscle, such as when a muscle lowers a weight

Isometric muscle action

An action during which the length of the muscle does not change, such as when a muscle supports the body in maintaining a position during a weight lifting exercise

Terms related to weight training

As you evaluate weight training programs, or when you go to the gym, you’ll probably encounter the following terms related to weight training.

Repetition

Also referred to as simply a “rep,” a repetition is the complete movement cycle, including the concentric and eccentric motion, of a strength training movement.

Set

A set is several repetitions of strength training movement performed in a row. Your weight training program goals determine the number of reps in a set, as well as the number of sets performed, during any given workout.

Exercise

An exercise is a particular combination of sets and repetitions of a movement that you perform. Changing the number of sets or the number of repetitions produces a different exercise.

Workout

A workout is the collection of exercises you perform in one session.

Program

Your program is the series of workouts you perform in order to achieve your personal fitness goals.

Intensity

Intensity is a relative term to describe the tension or stress put on a muscle during a weight training exercise. The intensity of an exercise is determined by the weight or resistance used during the exercise, the number of sets performed, and the number of reps in a set.

Volume

Volume describes the total amount of work performed during a workout. Volume is typically calculated by multiplying the number of reps by the number of sets performed for each exercise to determine the total number of reps performed. The total number of reps may also be multiplied by the weight used to determine the total amount of weight lifted during the workout.

Rest

Rest is the amount of time you take between sets of an exercise and between exercises in the workout. If you perform one set of an exercise, then wait three minutes, then perform another set, your rest period is three minutes.

Recovery

Recovery is the amount of time you take between training sessions that work the same muscle group. If you performed leg exercises as part of your Monday workout, then performed the same leg exercises again the following Wednesday, you have had a 48 hour recovery period.

Terms Related to Weight Training Exercise Motions

Sagittal Plane

The sagittal plane separates the left half of your body from the right half of your body.

Frontal Plane

The frontal plane separates the front (or anterior) half of your body from the back (or posterior) half.

Transverse Plane

The transverse plane separates the upper half of your body from the lower half.

Flexion

Flexion describes a movement in which the angle of a joint decreases. For example, flexion of the elbow occurs during a bicep curl when the weight is lifted, because the angle between the forearm and upper arm decreases.

Extension

Extension is the opposite of flexion and describes a movement in which the angle of a joint increases. For example, extension of the elbow occurs during a bicep curl when the weight is lowered, because the angle between the forearm and upper arm increases as the arm straightens.

Abduction

Abduction describes a movement in which a limb is moved away from the midline of the body.

Adduction

Adduction is the opposite of abduction and describes a movement in which a limb moves toward the midline of the body.