Bodybuilders have been training with 60-second rest periods to boost metabolic stress and elicit greater anabolic hormones for the past decade. Using short rest periods results in a greater physiological and perceptual response than taking longer rest periods. New research suggests that shorter rest periods may not be the best approach for building muscle.
RESTING LESS BETWEEN SETS MAY BE HINDERING YOUR GAINS Key Points:
- Longer rest periods have been found to result in greater muscle growth than resting less between sets!
- Short rest periods severely limit the weight you can lift the next set and reduce training volume.
- Short rest periods can be beneficial for isolation exercises such as preacher curls, triceps extension, etc.
- Multi-joint exercises require longer rest periods.
Introduction
Bodybuilders have been training with 60-second rest periods to boost metabolic stress and elicit greater anabolic hormones for the past decade. Using short rest periods results in a greater physiological and perceptual response than taking longer rest periods. New research suggests that shorter rest periods may not be the best approach for building muscle. One of the other biggest myths is that increased metabolic stress by taking short rest periods results in more muscle growth.
This is why people incorporate techniques like supersets and drop-sets and use short rest periods to increase lactate and metabolic stress. In the coolest study of the year, researchers infused lactate in the bloodstream of resistance-trained men. Post-exercise, the subjects that had the infusion had higher blood lactate levels. Still, they did not have any additional increases in protein synthesis compared to the regular resistance exercise group. This dispels the myth that metabolic stress (increased lactate) has some magical muscle-promoting effect.[1]
The Damaging Effects of Resting Less Between Sets
Other studies have reported that short rest periods (1 minute), despite higher lactate, resulted in less protein synthesis (68%) post-exercise, compared to 5 minutes (139%).[2] Another study found that comparing 30-second rest periods to 150-second rest periods using the same total workload resulted in similar muscle growth. Still, greater muscle growth trended towards the group that took longer rest periods.[3] Note that smaller muscle groups like the abs, calves, and arms can be trained with shorter rest periods, while other muscle groups such as the quads, back, and chest will require longer rest periods.
Fatigue and Resting Less Between Sets
The major drawback of taking short rest periods is that you begin sets fatigued, which results in less total volume. Volume is a potent stimulator of muscle growth to a certain point. By using short rest periods, each additional set will reduce repetitions, resulting in a reduced total workload volume. A classic example is a study that measured total volume lifted (sets x reps x weight) with three different rest periods: 30 seconds, 60 seconds, and 2-minutes between sets).
Total volume lifted:
- 30 second rest periods: 58,168 pounds
- 60 second rest period: 63,635 pounds
- 2-minute rest periods: 66,280 pounds
The researchers concluded that longer rest periods favored a higher total volume and induced a similar blood lactate response. A shortened rest period may be detrimental to long-term neuromuscular adaptations and hypertrophy responses in resistance-trained men.[4]
IS METABOLIC STRESS THE KEY TO BIGGER MUSCLES?
If metabolic stress were the primary driver of muscle growth, then eccentric exercise or lowering the weight would cause very little muscle growth because metabolically eccentric contractions produce very little metabolic stress. Studies have found that eccentric exercise produces less metabolic stress (i.e., lactate) than concentric exercise (i.e., lifting the weight).
The metabolic cost required for eccentric exercise is approximately fourfold lower than for the same exercise performed concentrically. Increased cardiorespiratory and hemodynamic responses have been reported following eccentric exercise than concentric exercise at the same absolute workload (i.e., the same weight lifted up and down).[5] However, eccentric exercise still contributes to muscle growth, despite less metabolic stress.[6] When concentric and eccentric exercises are performed at the same absolute workload, similar increases in muscle growth occur, despite lower metabolic stress occurring with eccentric exercises. Also, there are blood flow restriction programs in which pressure is applied with a tourniquet around the legs. This generates high metabolic stress because of hypoxia (absence of oxygen).
When comparing studies that use tourniquet training or blood flow restriction training with weights compared to blood flow restriction training without weight (i.e., researchers applied blood flow restriction but no exercise), both produce metabolic stress. However, only the group that performed tourniquet training with weights experienced increased muscle protein synthesis and muscle growth.[7]
Metabolic stress must be combined with tension for muscle growth to occur. It’s more likely that muscle tension, not metabolic stress, is driving muscle growth. There is intense debate about whether metabolic stress is a driving factor for muscle growth, but more research needs to be conducted.
IS GREATER GH RESPONSES WITH 1 MINUTE REST PERIODS GOING TO INCREASE MUSCLE GROWTH?
In the early 90s, several studies showed that men who performed bodybuilding-style routines (10–12 reps) with 1-minute rest periods produced greater growth hormone (GH) testosterone than powerlifters lifting with 3-minute rest periods.[8] This led to a rise in all bodybuilders taking short rest periods to get the greatest anabolic hormone levels during their workout. As you have read previously, acute anabolic hormone responses have little impact on muscle growth.
Short rest periods reduce the quality of effective reps because they must use less weight/reps and, therefore, less tension on the muscle. Shorter rest periods mean you will perform fewer repetitions than the previous set, resulting in lower training volume. Longer rest periods have been found to result in greater muscle growth! I know I am killing a decade of bodybuilding magazines that promote the Short Rest Periods for Size, but the truth hurts. Short rest periods will cause a greater muscle pump due to greater metabolic stress, which will not lead to greater muscle growth.
In 2016, muscle guru Ph.D. Brad Schoenfeld found that lifters who used a 3-minute rest period had greater muscle growth than groups using 1-minute rest periods.[9] A similar study found that training with 1-minute rest periods resulted in roughly half the muscle growth compared to a 3-minute rest period.[10] Another big problem with short rest periods is that it severely limits the weight you can lift the next set. By resting longer, you will use the same weight and do more repetitions the next set, resulting in a greater training volume.
THERE IS NO MAGIC REST PERIOD NUMBER: START YOUR SETS WHEN YOU FEEL RECUPERATED
Heavy weight resistance exercise seems to provide a superior muscle growth response to light weight training when not taken to complete failure. You may want to ditch the stopwatch and use your perception of whether you are ready to do a set. Researchers found that when subjects were told to “Choose a rest period you feel will allow you to complete a maximal effort during your next set” while doing a heavy squat protocol of 5 sets for 5 reps; nearly 100% of the subjects completed all the prescribed sets and reps successfully.[11]
The rest times averaged between 4 and 5 minutes, but again this was using a powerlifting type protocol, but for bodybuilders, the research recommends greater than 3 minutes rest periods for muscle growth. Rest periods are subjective. Perform your next set when you feel that you have fully recovered from the previous set for optimal muscle growth.
The biggest issue with short rest periods is that you begin your next set in a fatigued state, which leads to a diminished training volume. The other issue with short rest periods with large muscle groups like the legs will cause a massive cardiovascular demand! You will breathe like a freight train after 1-minute rest periods with squats. Before starting your next set, ask yourself, has my breathing returned to normal?
You are training to build muscle, not get a cardiovascular workout! Also, is a synergistic muscle used in the exercise still fatigued? For example, are your triceps still burning from your last set of bench presses? If you start your next set with pre-fatigued triceps, your training volume for the chest will go down.
SHORT REST PERIODS: A BAD RETURN ON VOLUME INVESTMENT
The problem with comparing short versus longer rest periods studies is that the longer rest period groups can do more volume (sets x reps). What if you had the short rest period do more sets to equate the volume from longer rest periods? Would it build more muscle? Researchers had subjects train for 10 weeks, but they equated the volume of longer rest periods by having the 1-minute group do more sets until the total volume was similar.
When the volume was equated, both the short rest period and longer rest period group had similar increases in muscle growth; however, the short rest period group had to do 50% more sets to compensate for the reduced volume than the longer rest period group completed![12] The big question is, “Why would anyone want to perform double the sets when you can achieve the same results with longer rest periods?”
Researchers in a 2018 meta-analysis analyzed 23 studies on rest period durations, which included 491 participants (413 males and 78 females).
The literature review revealed that individuals can achieve significant strength gains with rest periods shorter than 60 seconds. Resistance-trained individuals require rest intervals longer than 2 minutes to achieve maximum strength gains. Short to moderate rest intervals (60–120 s) suffice for untrained individuals to maximize their muscular strength gains.[13]
This suggests that taking longer rest periods will maximize muscle strength gains and muscle growth. One should rest until they are ready to perform their next set, and a clock should not determine it. In some muscle groups like the arms and calves, you can use 1 minute rest periods and perform the next set. Exercises that incorporate a large number of muscle groups like deadlifts and squats will require longer rest periods to maximize volume and muscle hypertrophy.
Resting Less Between Sets Key Points:
- Longer rest periods have been found to result in greater muscle growth than resting less between sets!
- Resting less between sets can severely limit the weight you can lift the next set and reduce training volume.
- Resting less between sets can be beneficial for isolation exercises such as preacher curls, triceps extension, etc.
- Multi-joint exercises require longer rest periods.
REFERENCES:
1. Rasmus Liegnell et al., “Elevated Plasma Lactate Levels via Exogenous Lactate Infusion Do Not Alter Resistance Exercise-Induced Signaling or Protein Synthesis in Human Skeletal Muscle,” American Journal of Physiology. Endocrinology and Metabolism 319, no. 4 (October 1, 2020): E792–804.
2. James McKendry et al., “Short Inter-Set Rest Blunts Resistance Exercise-Induced Increases in Myofibrillar Protein Synthesis and Intracellular Signalling in Young Males,” Experimental Physiology 101, no. 7 (July 1, 2016): 866–82.
3. Julius Etienne Fink et al., “Acute and Long-Term Responses to Different Rest Intervals in Low-Load Resistance Training,” International Journal of Sports Medicine 38, no. 2 (February 2017): 118–24.
4. Lopes, Charles & Crisp, Alex & Schoenfeld, Brad & Ramos, Mayara & Germano, Moisés & Verlengia, Rozangela & Mota, Gustavo & Marchetti, Paulo & Aoki, Marcelo. (2018). Effect of Rest Interval Length Between Sets on Total Load Lifted and Blood Lactate Response During Total-Body Resistance Exercise Session. Asian Journal of Sports Medicine.
5. T. J. Overend et al., “Cardiovascular Stress Associated with Concentric and Eccentric Isokinetic Exercise in Young and Older Adults,” The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences 55, no. 4 (April 2000): B177-182.
6. Martino V. Franchi, Neil D. Reeves, and Marco V. Narici, “Skeletal Muscle Remodeling in Response to Eccentric vs. Concentric Loading: Morphological, Molecular, and Metabolic Adaptations,” Frontiers in Physiology 8 (July 4, 2017): 447.
7. JEAN NYAKAYIRU et al., “Blood Flow Restriction Only Increases Myofibrillar Protein Synthesis with Exercise,” Medicine and Science in Sports and Exercise 51, no. 6 (June 2019): 1137–45.
REFERENCES
8. William J. Kraemer and Nicholas A. Ratamess, “Hormonal Responses and Adaptations to Resistance Exercise and Training,” Sports Medicine (Auckland, N.Z.) 35, no. 4 (2005): 339–61.
9. Brad J. Schoenfeld et al., “Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men,” Journal of Strength and Conditioning Research 30, no. 7 (July 2016): 1805–12.
10. Ariel Roberth Longo et al., “Volume Load Rather Than Resting Interval Influences Muscle Hypertrophy During High-Intensity Resistance Training,” The Journal of Strength & Conditioning Research, 9000.
11. P. Ibbott et al., “Variability and Impact of Self-Selected Interset Rest Periods During Experienced Strength Training,” Perceptual and Motor Skills 126, no. 3 (June 2019): 546–58.
12. Ariel Roberth Longo et al., “Volume Load Rather Than Resting Interval Influences Muscle Hypertrophy During High-Intensity Resistance Training,” The Journal of Strength & Conditioning Research, October 7, 2021.
13. Jozo Grgic et al., “Effects of Rest Interval Duration in Resistance Training on Measures of Muscular Strength: A Systematic Review,” Sports Medicine (Auckland, N.Z.) 48, no. 1 (January 2018): 137–51.
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