Rest periods between sets are often the most overlooked part of a workout program. While everyone is hyper-aware of sets, reps, %RM, total volume, etc., inter-set rest periods are often forgotten, vague or estimated, but equally important. While your sets and reps need to match your performance goals (metabolic/endurance, hypertrophy, and strength/power), so too do your rest periods.
Rest Periods for Metabolic/Muscular Endurance:
Metabolic/muscular endurance training typically involves lighter loads combined with higher repetitions. Since metabolic/muscular endurance training is aerobic training (with the use of oxygen), rest period recommendations are <30 seconds, as recovery will be quicker. Further recommendation is to explore different rest periods (ex.15 seconds, 20 seconds, etc.) to maximize training effectiveness.
Rest Periods for Muscular Hypertrophy:
Muscular hypertrophy training goal is to increase muscle size, specifically thickness of the muscle fibers. Most bodybuilding workouts fall into this category of training. While recovery between sets is important, the goal is not to be fully recovered between sets to elicit the “pump” or blood flow. Additionally, maximizing the use of glycogen stores (the fuel used for short, intense bouts of exercise) is the major focus within each set and is typically achieved with 30-90 seconds of rest. Further recommendation for muscular hypertrophy rest periods is to explore how your training benefits from different ranges within the 30-90 second period.
Rest Periods for Muscular Strength/Power
When training is for muscular strength or power, a maximal or near-maximal effort, where the exercise typically is <10-15 seconds is required for adaptation. Thus, a full recovery or near-full recovery is the inter-set recovery goal. Guidelines for strength and power rest periods are at least 2 minutes, or a range of 2-5 minutes. This full/near-full recovery period allows the phosphagen system (also called the ATP (adenosine triphosphate)-PC (creatine phosphate) system, to recover properly allowing full effort within sets.
Each of the inter-set rest period recommendations are designed to allow you enough recovery time to achieve a high level of performance, but to also optimize the training adaptation (metabolic/endurance, hypertrophy, and strength/power) to help you reach your goals. I encourage you to explore within the recommended rest period ranges to identify what exact rest period helps you maximize your training.