Isometric exercises are strength training exercises that don't let the joint angle and muscle length contract during the movement. This means that the exercise is done in a static position with the muscular intensity coming from the weights and your own body.
This type of exercise utilizes the body's own structure and weight to create resistence (which means you don't necessarily need to spend loads of cash on equipment to get fit!). To learn how to incorporate these exercises into your workout, check out this video.
Baltimore Personal Trainer Coach Nick Tumminello shows you a new way to use Isometric training exercises in your workout.