As a coach choosing the right strength training exercises for athletes can be a daunting task with so many options out there: free weights, exercise machines, isometrics, uphill ambulation with an additional load, drop jumps, self-resistance exercises, and so on. In this post, adapted from Science and Practice of Strength Training, we explore the various classes of exercises used for strength enhancement for both beginning and qualified athletes. Classification First, let’s start by exploring the different classes of strength training exercises. Exercises used for strength training are typically classified according to the change in muscle length. They may be static, or isometric, which literally means “constant length,” or dynamic, a category further divided into exercises with concentric, eccentric, or reversible muscle action. Dynamic exercises are also sometimes labeled isotonic (from iso, meaning “constant,” and tonic, meaning “tension”). The underlying assumption is that the muscle produces an unvarying amount of tension while shortening as it overcomes a constant resistance. This is not the case for intact muscles. If external resistance (weight lifted) is constant, the tension exerted by a muscle varies during shortening because of …