By reading this article, you will learn:

• Repetition tempo, which is sometimes referred to as repetition duration, describes movement velocity during eccentric, isometric, and concentric phases of one repetition. Thus, repetition tempo plays a major role in set duration, which is commonly referred to as time under tension (TUT).

• When a general population client is training for hypertrophy, the effective duration range for one repetition is 0.5 to 8 seconds. The key is making sure your client is training close to momentary muscular failure. When strength is the primary goal, there is evidence that repetition durations of less than 1 to 20 seconds are effective. Although power can be improved with a variety of tempos, a 2-second eccentric duration followed by a maximal speed concentric duration (i.e., “X”) is the most effective.

• For those working with elderly patients, strength, power, and physical function can be improved with 3/3- and 3/X-second tempos, but the latter is most effective.

• For those working with patients in cardiac rehabilitation or patients with cardiovascular disease, it is important to keep TUT short, which is accomplished by using faster repetition tempos (e.g., 1/1 vs. 2/2 seconds).