Are Longer Breaks Between Sets Truly Better for Muscle Growth? (New 2024 Study)

Best Rest Time Between Sets for Muscle Growth Summary

• The best rest time between sets for muscle growth appears to be longer than 60 seconds, offering a small but consistent hypertrophic benefit, particularly in the arms and thighs.
• The study found that excessively long rest intervals (over 180 seconds) do not provide additional advantages compared to moderate rest periods (60-120 seconds).
• The study suggests that training to failure does not significantly interact with rest interval duration, meaning the benefits of longer rest periods are consistent regardless of training intensity.

What is the Best Rest Time Between Sets for Muscle Growth?

There has been much debate about whether taking longer rest periods during resistance training significantly enhances muscle growth. However, a recent study titled “Give it a Rest: A Systematic Review with Bayesian Meta-Analysis on the Effect of Inter-Set Rest Interval Duration on Muscle Hypertrophy,” led by Brad J. Schoenfeld and his team, challenges the prevailing belief.¹ The study suggests that while some muscle groups might benefit from longer rest periods, the advantages may not be as substantial as previously thought. This raises important questions about the best rest time between sets for muscle growth.

Review of the Literature: The Role of Rest Periods in Muscle Hypertrophy

Over the years, rest intervals between sets have been a topic of extensive research in the fitness community. Traditional wisdom has long suggested that longer rest periods—typically between two to three minutes—are essential for maximizing muscle hypertrophy. This belief is rooted in the idea that extended recovery time allows for greater volume (sets and reps) in subsequent sets, leading to more significant muscle growth. Understanding the best rest time between sets for muscle growth is crucial for anyone serious about resistance training.

Recent meta-analyses have explored the effects of manipulating various resistance training (RT) variables on muscle hypertrophy, such as load, volume, frequency, and proximity to failure.^2-4 These studies have enhanced our understanding of how different training variables influence muscle growth. Among these variables, the rest interval—the time between sets during RT—is considered crucial for promoting skeletal muscle hypertrophy.

The National Strength and Conditioning Association recommends relatively short rest periods (30 to 90 seconds) to optimize muscle hypertrophy. This recommendation is based on acute research indicating that shorter rest periods can enhance the post-exercise hormonal response, which has been largely debunked for promoting muscle growth.⁵ However, McKendry et al. found that short rest intervals (1 minute) elevated acute testosterone levels; they also blunted the myofibrillar protein synthetic response, which is critical for muscle hypertrophy.⁶

Longitudinal research on the influence of rest intervals on muscle hypertrophy has produced mixed results. A systematic review by Grgic et al. concluded that short and long inter-set rest periods are viable for untrained individuals aiming to optimize hypertrophy. However, longer rest periods may benefit those with previous RT experience more.⁷ This 2017 review laid the groundwork for further exploration, but recent research, including the current meta-analysis, has provided new insights into the best rest time between sets for muscle growth.

Overview of the Study Protocol

The recent study by Schoenfeld and his colleagues aimed to provide a clearer understanding of the impact of rest interval duration on muscle hypertrophy by conducting a systematic review and Bayesian meta-analysis. The research team meticulously screened 359 studies and selected 9 that met their rigorous inclusion criteria. These studies involved trained and untrained individuals of varying ages and fitness levels who participated in resistance training programs. This study was pivotal in determining the best rest time between sets for muscle growth.

The subjects performed various exercises targeting different muscle groups, with rest intervals between sets ranging from 60 seconds to over 180 seconds. The participants performed RT 2–6 times a week for 5–10 weeks. The analysis included 19 measurements that assessed muscle growth in different body regions (arms, thighs, whole body). Researchers used techniques such as ultrasound, muscle biopsy, circumference measurements, magnetic resonance imaging (MRI), bioelectrical impedance analysis, and dual-energy X-ray absorptiometry (DXA) to measure muscle growth. By analyzing the data from these studies, the researchers sought to determine whether longer rest periods truly provided a significant advantage in promoting muscle growth and identifying the best rest time between sets for muscle growth.

Results of the Study

The study revealed that rest intervals longer than 60 seconds offer a small hypertrophic benefit. However, the advantage of extending rest periods beyond 90 seconds diminishes. Specifically, the difference in muscle hypertrophy was negligible when comparing rest intervals of 120 seconds versus 180 seconds. This suggests that while a certain amount of rest is necessary for optimal performance, excessively long breaks may not yield additional benefits. Understanding this balance is key to finding the best rest time between sets for muscle growth.

When analyzing the effects of rest interval length on specific muscle groups, the results suggested a small benefit for rest intervals longer than 60 seconds. For example, arm muscle growth slightly favored longer rest durations. Furthermore, for the quadriceps femoris, the effect was modestly in favor of longer rest intervals.

Discussion: Decoding the Best Rest Time Between Sets for Muscle Growth

The study’s results offer a fresh perspective on the role of rest intervals in resistance training. While traditional beliefs advocate for longer rest periods, this research suggests a more nuanced approach. The small hypertrophic benefit observed with rest intervals greater than 60 seconds challenges the idea that more extended recovery periods are always better. Instead, a balance must be struck between sufficient recovery and maintaining workout intensity.

Research indicates that very short rest periods (≤ 60 seconds) can significantly reduce the number of repetitions performed across multiple sets compared to longer rest durations, potentially harming long-term muscular adaptations. However, Longo et al. reported greater increases in quadriceps femoris muscle growth occurred when training with 180-second versus 60-second rest periods over a 10-week intervention. Although volume load was reduced more in the shorter rest condition, similar hypertrophy was observed when additional sets were performed to equate volume load.⁸

Practical Applications: Optimizing Your Training for Maximum Gains

So, how can you apply these findings to your training routine? Here are some practical takeaways that can help you determine the best rest time between sets for muscle growth:

Moderate Rest Intervals (60-90 seconds): For most lifters, rest intervals of 60 to 90 seconds seem to strike the right balance between recovery and maintaining workout intensity. This range allows you to perform sufficient volume without significantly reducing your ability to lift heavy weights, which is crucial for muscle growth.

Tailor Rest Periods to Muscle Groups: Consider adjusting your rest intervals based on your target muscle group. For larger muscle groups like the quadriceps, slightly longer rest periods (up to 120 seconds) might be beneficial, while smaller muscle groups may respond well to shorter intervals.

Avoid Excessively Long Rest Periods: While it might be tempting to rest for extended periods to fully recover, this study suggests that the benefits of rest periods longer than 180 seconds are minimal. Instead, focus on keeping your rest intervals within the recommended range to maximize hypertrophy and ensure you use the best rest time between sets for muscle growth.

Conclusion: Rethinking Rest Periods for Optimal Muscle Growth

The debate over the ideal rest period for muscle growth has been ongoing, but this recent study by Schoenfeld and his team provides valuable insights. While longer rest intervals can offer some benefits, the advantage may not be as significant as previously believed. By carefully tailoring your rest periods to your specific training goals and the muscle groups you’re targeting, you can optimize your workouts for maximum hypertrophy. Remember, more is not always better—sometimes, a moderate approach yields the best results, especially when it comes to finding the best rest time between sets for muscle growth.

Incorporating these findings into your training routine can help you break through plateaus and achieve your muscle-building goals more efficiently. As always, the key to success lies in understanding your body’s unique needs and making informed adjustments to your training strategy. With these insights, you’ll be better equipped to determine the best rest time between sets for muscle growth.

References

1               Singer, A. et al. Give it a Rest: A systematic review with Bayesian meta-analysis on the effect of inter-set rest interval duration on muscle hypertrophy. (2024).

2               Lopez, P. et al. Resistance Training Load Effects on Muscle Hypertrophy and Strength Gain: Systematic Review and Network Meta-analysis. Med Sci Sports Exerc 53, 1206-1216 (2021). https://doi.org:10.1249/mss.0000000000002585

3               Schoenfeld, B. J., Ogborn, D. & Krieger, J. W. Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. J Sports Sci 35, 1073-1082 (2017). https://doi.org:10.1080/02640414.2016.1210197

4               Schoenfeld, B. J., Grgic, J. & Krieger, J. How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. J Sports Sci 37, 1286-1295 (2019). https://doi.org:10.1080/02640414.2018.1555906

5               Kraemer, W. J. & Ratamess, N. A. Hormonal responses and adaptations to resistance exercise and training. Sports Med 35, 339-361 (2005). https://doi.org:10.2165/00007256-200535040-00004

6               McKendry, J. et al. Short inter-set rest blunts resistance exercise-induced increases in myofibrillar protein synthesis and intracellular signalling in young males. Exp Physiol 101, 866-882 (2016). https://doi.org:10.1113/ep085647

7               Grgic, J., Lazinica, B., Mikulic, P., Krieger, J. W. & Schoenfeld, B. J. The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review. Eur J Sport Sci 17, 983-993 (2017). https://doi.org:10.1080/17461391.2017.1340524

8               Longo, A. R. et al. Volume Load Rather Than Resting Interval Influences Muscle Hypertrophy During High-Intensity Resistance Training. J Strength Cond Res 36, 1554-1559 (2022). https://doi.org:10.1519/jsc.0000000000003668