Specificity

The Principle of Specificity maintains that if you want to see specific results, you should perform exercises that are specific to those results.

For example, if you want to increase your bicep strength, you should perform bicep exercises. If you want to run a 5K race, you should train by running. If you want to improve in a specific sport, you should perform exercises that are specific to that sport..

This principle, though simple, is important to keep in mind if there are specific results you want to see from your workouts.

Individuality

The Principle of Individuality maintains that no two individuals will benefit from exercise exactly the same way physically or psychologically. Differences in genetics, age, experience, body size, and health status can all affect the outcomes of a workout.

Keeping this in mind can be important when training with a buddy or a group. Don't fret if you don't see the same results at the same time as others.

Flexibility

Flexibility is an often neglected component of physical fitness; yet, it is important to maintain proper posture, prevent injury, and reduce muscle soreness and tension.

Stretching is an ideal way to improve flexibility. The best time to stretch is at the end of a workout, when one's muscles are warm and more pliable.

The American Council on Exercise recommends stretching for 30 minutes 3 times per week to improve and maintain flexibility, or stretching a minimum of 5-10 minutes at the end of every exercise session.

Strength Training

Strength or Resistance Training is any type of exercise in which your muscles are working against a force. Examples include using free weights, weight machines, a resistance band, or even gravity.

Strength training should ideally be done 2-4 days per week--allowing for a 48 hour rest period before working the same muscle groups again.

A typical strength training program involves performing 10-15 repetitions in 2-3 sets, with a few minutes rest in between sets. However, any amount of resistance training can be beneficial.