By: Brian Sutton, MS, MA, NASM-CPT, CES, PES
Assigning appropriate rest periods are essential for your clients to perform optimally during their exercise program and minimize injury risk. Unfortunately, rest periods between sets are not a simple black and white issue.
As a fitness professional you'll have to consider several factors such as the client's aerobic capacity, health and injury history, goals, and overall design of the exercise program.
Rest Time for Muscular Endurance and Stabilization
Muscular endurance and stabilization adaptations are best developed with relatively short rest periods; generally 0–90 seconds. However, the current work capacity of the client may dictate longer rest periods if needed.
Hypertrophy Rest Time
Hypertrophy is best achieved with relatively short rests periods often ranging from 0 to 60 seconds. However, the load, volume, and the current fitness level of the client may require longer rest periods.
Maximal Strength Rest Time
Maximal strength adaptations are best achieved with relatively long rest periods, generally 3–5 minutes, depending on the client’s level of fitness and intensity of the exercises.
Power Training Rest Time
Power adaptations also require relatively long rest periods, generally 3–5 minutes, depending on the client’s level of fitness.
All of these recommendations can be modified based on the needs and abilities of your client. Generally speaking, fit individuals recover energy stores more rapidly than deconditioned individuals necessitating shorter rest periods. Conversely, beginning clients or individuals with chronic disease or orthopedic limitations require longer rest periods.
Client’s seeking fat loss should opt for relatively short rest periods to keep their heart rate elevated, thus maximizing caloric expenditure.
Client's seeking hypertrophy should also opt for relatively short rest periods. High volume resistance exercise targeting large muscle groups with shorter rest periods has been associated with a large increase in serum growth hormone and testosterone levels, particularly in men.
Client’s seeking maximal strength or power should opt for longer rest periods to ensure each lift is performed as explosively as possible. Longer rest periods are necessary to restore ATP energy supplies back to baseline.
The bottom line is to select rest periods that are specific for your client’s goals and abilities. Using a stopwatch and/or performing the talk test can help gauge whether or not your client’s rest periods are sufficient.