Optimal Rest Between Sets is NOT Determined by Goal or Load
by Dr. Brent Brookbush DPT, PT, MS, CPT, HMS, IMT
Introduction:
How long should you rest between sets (for the same or similar muscle groups)? Most companies providing personal training and strength training certifications have published recommendations; however, these sports medicine education providers continue to make the same mistake. They suggest that rest between sets, or inter-set rest periods, should be based on training goals. For example, individuals with the goal of muscle endurance or fat loss would benefit from shorter rest periods, and individuals looking to increase hypertrophy or maximal strength would benefit from longer rest periods. These recommendations miss the fact that weight loss is not correlated with rest between sets, neither is building muscle mass, and even the relationship between strength (lifting heavier weight) and rest between sets falls apart if a long rest period is standardized.
Some publications have suggested that rest between sets may be based on the repetitions per set, which is likely closer to optimal but still misses a key variable that has a significant influence on ideal recommendations. An interesting topic related to shorter rest or longer rest is what to do during that rest times (e.g. active recovery, active rest, compound sets, super-sets, circuit training, etc.). Does filling rest periods with additional activity increase metabolic stress, decrease the performance of compound movements, increase muscle soreness, or have a significant effect on strength gains and other chronic adaptations (we answer this question below)?
When we develop a course we start by performing a systematic review of all the peer-reviewed published original research that we can find on the topic (You can call this our "anti-cherry-picking initiative"). While developing our course "Acute Variables: Rest Between Sets " we noticed a strange trend in the research. Like many of our movement professional colleagues, we had been taught that our rest between sets recommendations should be based on goal or load (e.g. short rest for endurance, long rest for max strength and power). However, fairly early in our review, we noticed the research did not support these recommendations. The first hint that something was wrong, was that generally, longer rest between sets resulted in better outcomes for every goal; not just max strength and power, but strength endurance and hypertrophy as well. The epiphany came when we found a few studies that compared various rest between set durations and reported the number of reps performed in each subsequent set. The problem with earlier recommendations was not that the duration was too long or too short, the recommendations were being determined based on the wrong variable! If recommendations based on specific training goals were replaced with a more general goal of optimizing the highest quality repetitions per set and volume per routine, recommendations would have achieved far more accuracy.
Note, acute variables, like rest between sets have an impact on almost every fitness, strength, sports performance, and physical rehabilitation routine. Every sports medicine professional (personal trainers, fitness instructors, physical therapists, athletic trainers, massage therapists, chiropractors, occupational therapists, etc.) should familiarize themselves with the research and annotations described below.
Brookbush Institute's Position Statement
- Rest between set durations should be based on sets/exercise (volume), and not load or training goal. General recommendations include moderate (2 min) rest between sets if performing 2 sets/exercise, long rest (3 min) if performing 3 sets/exercise, and very long rest (> 4 min) if performing 4 sets or more/exercise. Further, longer rest between set durations may have a larger influence on strength endurance training (high rep; 12 - 20 reps) than maximum strength and power training (low reps; 1- 6 reps). It may be reasonable to conclude that very long (> 3 min) rest between set durations is only necessary when performing 3 or more high rep sets (> 15 reps), and that no additional benefit will be attained for rest between set durations longer than 2 minutes during very high-intensity training (< 6 reps/set). It is likely more accurate to think of rest between sets in terms of work/rest ratios; however, for practical purposes, the rest between set durations recommended below will result in the same outcomes.
Rest Between Sets Recommendations:
General
- Long (3 min) rest between set durations
Specific
- 2 sets/exercise: Moderate (2 min)
- 3 sets/exercise: Long (3 min)
- 4 or more sets/exercise: Long (3 min) or very long (> 3 min)
- Alternative: Circuit training with short (1 min) rest between exercises
- Additional Strategy for Power: Inter-set rest of 10 - 20 seconds (sec)
Additional Courses and Articles:
Acute Variable Courses
- Acute Variables: Rest Between Sets
- Acute Variables: Repetition Tempo
- Acute Variables: Repetition Range
- Acute Variables: Circuit Training
- Acute Variables: Sets Per Muscle Group
Additional Strength Training Articles
- Unique Hip Anatomy, Foot Placement, and Squat Form
- Squat Depth Recommendations
- Are Olympic Lifts the Best Choice for Power Development?
How Load and Rep Range affect Rest Between Set Durations
The first two studies annotated below highlight that load is likely not an influential factor when considering rest between sets. The first study (Scudese et. al.) investigated max strength training with heavy loads; 3 repetition maximum (3-RM)/set. The findings demonstrated that the total number of reps/set was not significantly different when comparing 2, 3, or 5-minute (min) rest between sets, and 2 min rests only resulted in a trend toward decreased reps/set on the 4th set (a reduction that was not statistically significant). The second study actually demonstrates that there was no statistically significant difference in reps/set when comparing 3 and 5 min rests with 80% of 1-RM loads, but with the 50% of 1-RM loads, more reps were performed with 5 min. This implies that lighter loads with higher rep ranges may require more rest between sets than heavier loads with fewer reps! It may be reasonable to conclude that very long (> 3 min) rest between set durations is only necessary when performing multiple high-rep sets (equal to or more than 15 reps/set and/or 4 sets/exercise).
Annotations
Scudese et al. compared 16 trained men (age: 23.75 ± 4.21 years) performing short (1 min), moderate (2 min), and long (3 min and 5 min) rest between set durations, during bench press, for 4 sets/session, 3-RM loads, with reps until failure/set, with no attempt made to control rep tempo. The findings demonstrated that the short (1 min) rest between set durations resulted in significantly fewer reps in subsequent sets, starting with set 2, and resulted in less total volume of exercise. However, there was no significant difference between moderate (2 min), and long (3 min and 5 min) rest between set durations for sets 1-3, and only a trend toward fewer reps on set 4 when comparing moderate (2 min) and long (3 min) rest between sets.
- Scudese, E., Willardson, J. M., Simão, R., Senna, G., de Salles, B. F. and Miranda, H. (2015) The effect of rest interval length on repetition consistency and perceived exertion during near maximal loaded bench press sets. The Journal of Strength & Conditioning Research, 29(11), 3079-3083.
Senna et al. (2017) compared 16 resistance-trained men (age: 20.75 ± 2.54 years) performing short (1 min), moderate (3 min), and long (5 min) rest between set durations, with either 50% or 80% of 1-RM loads, during triceps pull-downs, for 4 sets/exercise, reps until failure/set, with no attempt to control rep tempo. The findings demonstrated that when performing reps until failure/set with 80% of 1-RM loads, short (1 min) rest between sets resulted in a significant reduction in reps during subsequent sets and total volume of exercise when compared to longer rest between sets; however, 3 min and 5 min rest between sets resulted in similar reps/set and volume of exercise. When performing reps until failure/set with 50% of 1-RM loads, the number of reps/set and volume of the exercise was increased with longer duration reps between sets, including a significant difference between 3 min and 5 min rest between sets.
- Senna, G. W., Rodrigues, B. M., Sandy, D., Scudese, E., Bianco, A. and Dantas, E. H. M. (2017) Heavy vs light load single-joint exercise performance with different rest intervals. Journal of Human Kinetics, 58, 197-206, doi: 10.1515/hukin-2017-0077
More Sets per Exercise Requires More Rest Between Sets
The following studies compare various rest between set lengths with mostly moderate loads. The easiest trend to identify is that longer rest between sets results in more reps during subsequent sets. However, it may also be noted that rest durations longer than 2 min, do not seem to have a significant effect on the total number of reps for set 2. Last, if considering the studies above (Scudese et al. and Senna et al., 2017), and the study described below by Senna et. al. (2011), it can be reasonably concluded that rest durations longer than 3 min are unlikely to have a significant effect on the total number of reps until more than 3 sets/exercise is performed. These findings resulted in the "specific recommendations" mentioned above - moderate rest between set durations (2 min) is likely sufficient if performing 2 sets/exercise, long rest (3 min) is sufficient for 3 sets/exercise, and longer rest (> 4 min) is only recommended when performing 4 sets or more/exercise. Note, more the 5 sets/exercise/session is not recommended; for more on this topic refer to Acute Variables: Sets Per Muscle Group .
Annotations
Richmond et al. compared 28 resistance-trained men (age: 21.5 ± 3.2 years) performing short (1 min) or long (3 min and 5 min) rest between set durations, during bench press, for 2 sets/session, 75% of 1-RM load, and reps until failure/set. The findings demonstrated that reps decreased significantly during the 2nd set with short (1 min) rest between sets; however, reps/set was maintained during a 2nd set with long (3 min and 5 min) rest between set durations (115).
- Richmond, S. R. and Godard, M. P. (2004) The effects of varied rest periods between sets to failure using the bench press in recreationally trained men. The Journal of Strength & Conditioning Research, 18(4), 846-849.
Monteiro et al. compared 25 recreationally active men (age: 26.84 ± 4.59 years) performing short (1 min), moderate (2 min), and long (3 min and 5 min) rest between sets, during bench press for 7 sets, 10 RM load, reps until failure/set, with no attempt to control rep tempo. The findings demonstrated that shorter rest periods resulted in fewer reps performed during additional sets, fewer total reps/session, and an increased rate of perceived exertion. Interestingly, there was no difference in 2nd set performance between short (1 min), moderate (2 min), or long (3 min and 5 min) rest between set durations.
- Monteiro, E. R., Neto, V. G. C. and da Silva Novaes, J. (2019) Acute effects of different rest period between sets on neuromuscular bench press performance. ConScientiae Saúde, 18(2), 183-189.
Miranda et al. (2007) compared 14 resistance-trained men performing short (1 min) or long (3 min) rest between sets during a routine of 6 upper body exercises (wide grip lat pull-down, close grip pull-down, machine seated row, barbell row lying on a bench, dumbbell seated arm curls, and machine seated arm curls), for 3 sets/exercise, 8-RM loads, reps until failure/set, and no attempt made to control rep tempo. The findings demonstrated that the long (3 min) rest between sets resulted in more reps/set and total exercise volume; and further, that the difference in the number of reps/set was significantly larger for the 3rd set.
- Miranda H., Fleck, S.J., Simao, R., Barreto, A.C. Dantas, E.H. and Novaes, J. (2007) Effect of two different rest period lengths on the number of repetitions performed during resistance training. Journal of Strength and Conditioning Research, 21 (4), 1032-1036.
An RCT by García-López et al. compared 21 untrained individuals (age: 25 ± 5 years) performing no exercise (controls), short (1 min) or long (4 min) rest between sets of machine biceps curls for 5 weeks, 2x/week, 3 sets/exercise, 60% of 1-RM loads (increased 5% in weeks 3, 4 and 5), reps until failure/set, and a tempo including a maximum velocity concentric contraction (maxV). The findings of the study demonstrated that the long rest between sets group was able to complete similar reps/set for sets 1 and 2, with a small decrease in reps during set 3, and the short rest between sets group exhibited a significant decrease in reps/set during sets 2 and 3.
- García-López, D., De Paz, J. A., Moneo, E., Jiménez-Jiménez, R., Bresciani, G. and Izquierdo, M. (2007) Effects of short vs. long rest period between sets on elbow-flexor muscular endurance during resistance training to failure. The Journal of Strength & Conditioning Research, 21(4), 1320-1324.
Senna et al. (2011) compared 15 resistance-trained men (age: 23.6 ± 2.64 years) performing short (1 min) or long (3 min and 5 min) rest between set durations, during bench press, chest flyes, leg press and knee extensions, 5 sets/exercise, 10 RM loads, reps to failure/set, with a self-paced slow controlled tempo. Findings demonstrated that the long (3 min and 5 min) rest between set durations resulted in a similar reduction in reps during subsequent sets of the bench press exercise. However, for all other exercises, significant differences were noted when comparing short (1 min) and long (3 min and 5 min) rest between set durations, with short (1 min) rest resulting in a decrease in reps by the 2nd set, long (3 min and 5 min) rest resulting in a decrease by the 3rd set, and the most total reps performed with the long (5 min) rest between set duration.
- Senna, G., Willardson, J. M., de Salles, B. F., Scudese, E., Carneiro, F., Palma, A., & Simão, R. (2011). The effect of rest interval length on multi and single-joint exercise performance and perceived exertion. The Journal of Strength & Conditioning Research, 25(11), 3157-3162.
Final Thoughts: Author's Note on Validity
Although it may not have been obvious at first that the rest between sets should have been determined by sets/exercise, the recommendation appears to have some validity when considering it from a physiological perspective. In fact, we had one of those facepalm moments like, "how did I not see this sooner"? That is to say if we think of rest between sets as our attempt to recover from fatigue, and we consider that fatigue is likely to increase with each subsequent set, then we may deduce that longer rest may be needed with each additional set. One point we make in the course Acute Variables: Rest Between Sets is that increasing the rest between sets with each subsequent set should be researched further (e.g. 2 min rest before the 2nd set, 2.5 min rest before the 3rd set, 3 min rest before the 4th set, etc.)
Perhaps, the reason these recommendations were missed by previous educators, texts, and courses, is it does rely on two additional assumptions. First, our recommendations are dependent on the assumption that reps are performed to failure during each set. Second, the goal of our resistance training programming must include the intent to improve the total number of reps for each set. Admittedly, these assumptions are not ground-breaking, but they are significant. If a person is not pushing themselves to failure, and they are not trying to achieve a new personal best number of reps, then the recommendations for rest between sets are not as significant for optimizing a routine. However, these two assumptions are congruent with the available research that suggests sets to failure and exercise volume are significantly correlated with optimizing improvements made from resistance training. It will be interesting to see if physiological research highlights the mechanism that results in a gradual build-up of fatigue throughout the course of a session (e.g. contractile protein disruption, altered pH values, pooling of various enzymes and substrates, depletion of "energy molecules", etc.), and further validates the recommendations of this course.
© 2023 Brent Brookbush
Questions, comments, and criticisms are welcomed and encouraged