Prescribing a number of repetitions to perform is not always ideal in strength training. Sometimes it’s better to regulate the time under tension (TUT) rather than count reps. The wrist roller exercise is one example that we looked at a few weeks ago.

Prone lateral ball rolls and lower Russian twists (also known as “windshield wipers”) are two more exercises where TUT prescription is useful. With these movements, before you even finish saying “one more,” the trainee has knocked off two or three, so it’s best to assign a time (e.g., thirty seconds).

You can extend this concept further by using a method known as autoregulation. Basically, you monitor the duration of a set and terminate the exercise once performance drops below a predetermined level. The drop off rate will vary depending on whether you’re training for maximum strength, power or hypertrophy. I go into more detail on pages 52-53 of The Elite Trainer.