Isometric exercises involve the tightening of certain muscles. They are not effective at building strength but good for maintaining. They can be performed anywhere since the exercises are done in one position without movement. Unfortunately, you have to do many different isometric exercises to work a whole muscle group as opposed to other types of exercises.
Someone who has an injury or arthritis may benefit from isometric exercises.
Studies have shown that isometric exercises may also help lower and control your blood pressure. As with any exercise routine, you should always check with your doctor.
Minus the Gym
"20 Isometric Exercises"
"10 Minute Isometric Upper Body Workout"
"Lower Body Isometrics"
"20-Minute Full Body Workout"
"Upper Body Isometrics"
"Bruce Lee Workout and Isometrics"