There are about as many resistance exercise protocols as there are strength training participants. Personal preferences largely determine one's training equipment, exercise selection, sets, resistance, repetitions, speed, range, and progression. In addition to these training variables, people who perform multiple sets must determine how much recovery time to take between repeat exercise bouts. Individuals who do resistance exercise primarily to improve their muscular fitness typically rest approximately 2 minutes between successive sets of exercise.11 This is an appropriate recovery period for most practical purposes, as it allows sufficient time to largely replenish the exercised muscles' internal energy source of creatine phosphate. A high-effort set of resistance exercise significantly reduces creatine phosphate levels. However, creatine phosphate restoration is a relatively rapid process, with about 50% renewal after 30 seconds' rest, about 75% renewal after 60 seconds' rest, about 88% renewal after 90 seconds' rest, and almost 95% renewal after 2 minutes' rest. Under normal circumstances, the exercised muscles' internal energy source should be fully restored after a 3-minute recovery period.11
With respect to age, there is evidence that youth strength trainers (ages 11 to 14 years) require less inter-set recovery time than adult strength trainers (mean age 21 years).3 With respect to gender, research is less clear regarding inter-set recovery requirements for younger women and older women. In one study, younger females (ages 20 to 30 years) and older females (ages 60 to 80 years) required similar recovery time between sets of knee extension exercise, but the older woman required less recovery time between sets of knee flexion exercise.10 However, for most strength trainers the general recommendation of approximately 2 minutes' rest between repeat bouts of resistance exercise is an excellent guideline with respect to both training effectiveness and time efficiency.
Competitive Strength Trainers
Body builders, whose primary training objective is to increase muscle mass (hypertrophy), typically take relatively short rest periods between exercise sets.11 This type of training is associated with blood congestion within the exercised muscle tissue (reactive hyperemia), which results in temporary muscle enlargement referred to as "pumping up." On the other hand, power lifters, whose primary training objective is to increase muscle strength, typically take relatively long rest periods between exercise sets.11 This type of training is associated with higher-level neuromuscular performance with near-maximum weight loads.
With respect to specific recovery times, body builders generally rest 30 to 90 seconds between successive sets of exercise, with longer breaks for multiple-joint exercises and shorter breaks for single-joint exercises.4 Power lifters are more likely to rest 2 to 5 minutes between successive sets of exercise, with longer breaks for their performance lifts (squats, bench presses, and dead lifts), and shorter breaks for their auxiliary exercises.4
Several studies have examined the effects of various inter-set recovery periods on muscle strength, muscle size, and muscle endurance. Most of the research comparing 5-minute and 3-minute recovery periods has revealed similar training responses (bench press and leg exercises) that are significantly greater than training responses to 1-minute rest intervals.
A study with recreationally trained men found that maximum effort bench press performance decreased during the second exercise set regardless of the rest period length.6 There was no significant performance difference between the 5-minute and 3-minute recovery periods, but both of these longer inter-set rests were more effective than the 1-minute recovery period.
Senna and associates attained similar bench press responses with trained men.8 In this study, recovery periods of 5 minutes and 3 minutes produced similar performance results that were significantly better than those attained with 1-minute rests. A follow-up study that also included a 2-minute recovery period found similar bench press results with 5-minute and 3-minute inter-set rests that were significantly better than those achieved with 1-minute rests.9 Additionally, the 5-minute recovery period produced significantly better results than the 2-minute recovery period.9 Conversely, other research comparing 5-minute and 2-minute recovery periods has revealed similar increases in quadriceps muscle size and strength.1 A similar study examined strength gains in trained men who took 4-minute or 2-minute rests between successive sets of barbell squats.13 Both recovery protocols resulted in large strength gains, with no significant differences between inter-set rests of 4 minutes or 2 minutes.
Other studies have examined moderate and short inter-set recovery periods. Most of these have compared 2- to 3-minute rests with 30- to 60-second rests.
Schoenfeld and associates investigated changes in muscle mass and strength with resistance-trained men using 3-minute or 1-minute rests between exercise sets.7 After 8 weeks of training, bench press and squat strength increased significantly more with the 3-minute inter-set recovery periods than with the 1-minute rests, as did thigh muscle thickness.
Another study compared the effects of 3-minute and 1-minute rest intervals on workout performance as assessed by the total number of exercise repetitions completed.5 All six resistance exercises were performed for significantly more total repetitions with the 3-minute inter-set recovery periods than with the 1-minute rests.
Willardson and Burkett examined the sustainability of squat and bench press repetitions using 30-second, 1-minute, or 2-minute inter-set rests.12 Squat performance was sustained significantly better with 2-minute recovery periods than with 30-second recovery periods. Bench press performance was sustained significantly better with 2-minute rest intervals than with 1-minute or 30-second rest intervals.
One research study reported different rest period results with respect to muscle strength and muscle hypertrophy.2 Strength gains were similar with inter-set recovery intervals of 2.5 minutes and 1 minute, whereas muscle cross-sectional area increased significantly more with 2.5-minute rest periods.
Summary
Based on the studies presented, it would appear that muscular response to inter-set recovery intervals may vary with respect to individuals, as well as for muscle strength and muscle hypertrophy. Research generally indicates similar responses to 5-minute and 3-minute rests, both of which seem to be more effective than 1-minute rests. Studies also suggest that recovery periods of 2 to 3 minutes may be more effective than recovery periods of 30 to 60 seconds. The fact that internal muscle energy stores are 95% to 99% replenished within 2 to 3 minutes after a high-effort exercise set supports 2- to 3-minute recovery intervals as a general recommendation for inter-set rest periods.
Wayne L. Westcott, Ph.D., is Professor of Exercise Science at Quincy College in Quincy, MA. He has authored/co-authored 28 books on strength training and is an active member of the New England Chapter of ACSM.
References
1. Ahtiainen J, Pakarinen A, Alen M, et al. Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men. J Strength Cond Res. 2005; 19(3):572-582.
2. Buresh R, Berg K, French J. The effect of resistive exercise rest interval on hormonal response, strength, and hypertrophy with training. J Strength Cond Res. 2009; 23(1):62-71.
3. Faigenbaum A, Ratamess N, McFarland J, et al. Effect of rest interval length on bench press performance in boys, teens, and men. Pediatr Exerc Sci. 2008; 20:457-469.
4. Haff G, Haff E. Resistance training program design. In: Coburn J, Malek M, editors. NSCA's Essentials of Personal Training. 2nd ed. Champaign (IL): Human Kinetics; 2012. 369 p.
5. Miranda H, Fleck S, Simao R, et al. Effect of two different rest period lengths on the number of repetitions performed during resistance training. J Strength Cond Res. 2007; 21(4): 1032-1036.
6. Richmond S, Godard M. The effects of varied rest periods between sets to failure using the bench press in recreationally trained men. J Strength Cond Res. 2004; 18(4): 846-849.
7. Schoenfeld B, Pope Z, Benik F, et al. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res. 2016; 30(7): 1805-1812.
8. Senna G, Willardson J, De Salles B, et al. The effect of rest interval length on multi and single-joint experience performance and perceived exertion. J Strength Cond Res. 2011; 25(11): 3157-3162.
9. Senna G, Willardson J, Scudese E, et al. Effect of different interset rest intervals on performance of single and multijoint exercises with near-maximal loads. J Strength Cond Res. 2016; 30(3):710-716.
10. Theou O, Gareth J, Brown L. Effect of rest interval on strength recovery in young and old women. J Strength Cond Res. 2008; 22(6): 1876-1881.
11. Westcott W. Resistance training: Programs and progressions. In: Bryant c, Merrill S, Green D, editors. American Council on Exercise Personal Trainer Manual. 5th ed. San Diego (CA): ACE; 2014. 340 p.
12. Willardson J, Burkett L. The effect of rest interval length on the sustainability of squat and bench press repetitions. J Strength Cond Res. 2006; 20(2):400-403.
13. Willardson J, Burkett L. The effect of different rest intervals between sets on volume components and strength gains. J Strength Cond Res. 2008; 22(1):146-152.