Key Points

Rest periods of 2-3 minutes appear to be optimal for hypertrophy, as they allow for better muscle recovery, higher intensity, and heavier lifting.
Longer rest intervals appear to promote greater muscle strength and hypertrophy in trained individuals by supporting higher training volumes and mechanical tension.
Shorter rest periods (30-60 seconds) can increase metabolic stress and lead to an acute rise in growth hormone, but are generally less effective for long-term muscle growth.
Auto-regulated rest intervals, where you rest as long as needed, offer flexibility and can reduce workout time without compromising performance.

Introduction:

Along with weight, reps, and sets, rest periods are an important training variable when training for a specific goal. This is especially true in the case of hypertrophy. In my opinion, most people either pay too little, or too much attention to their rest periods. They are either dogmatic about resting an EXACT amount of time to control every aspect of their workout, or they simply go on Instagram for a few minutes between sets. But what does the science behind how long you should rest say? Turns out that finding the optimal rest period involves balancing several factors, including metabolic stress, muscle recovery, and the ability to lift heavier loads over the course of a workout. The purpose of this post is to dive into the different types of rest intervals, the science behind them, and how to choose the right approach for your hypertrophy goals.

Understanding Hypertrophy

Hypertrophy is the process of increasing muscle size, primarily through resistance training. This occurs when muscles experience micro-damage during exercise, which triggers the repair process that results in muscle growth. Key drivers of hypertrophy include:

Mechanical tension – the load placed on muscles during resistance training.
Metabolic stress – the build-up of byproducts like lactate during exercise.
Muscle damage – the small tears in muscle fibers caused by lifting weights.

All of these factors contribute to muscle growth, and your rest periods can either support or hinder them.

Rest Intervals and Their Role in Hypertrophy

1. Longer Rest Intervals (2-5 Minutes): Promoting Muscle Strength and Hypertrophy

One of the primary benefits of longer rest periods (2-5 minutes) is that they allow for greater recovery between sets, enabling you to lift heavier weights or perform more repetitions with good form. When you lift heavier weights or increase volume, you subject your muscles to greater mechanical tension, which is the major driver of hypertrophy.

Research shows that rest intervals of 2-5 minutes between sets can promote both muscle strength and hypertrophy, particularly in resistance-trained individuals. A study by Schoenfeld et al. (2016) found that subjects who took 3-minute rest intervals between sets experienced greater muscle growth compared to those who took shorter rest periods. In hindsight, it is pretty obvious why: more recovery time allowed for a higher intensity of training and workload in subsequent sets. This directly contributed to increased hypertrophy (1).

Additionally, longer rest intervals prevent excessive fatigue from building up too quickly. When fatigue sets in, performance drops, and you may not be able to lift as much weight or complete as many reps. By giving your muscles adequate recovery time, you can maximize the quality of each set, ensuring that you’re putting forth the kind of effort that promotes muscle growth.

2. Shorter Rest Intervals (30-60 Seconds): Leveraging Metabolic Stress

On the other hand, shorter rest periods of 30-60 seconds create a different kind of stimulus. These brief rest intervals can increase metabolic stress, a condition that occurs when byproducts like lactate accumulate in the muscles during exercise. Metabolic stress is believed to contribute to hypertrophy through several mechanisms, such as cellular swelling, increased growth factor release, and greater recruitment of muscle fibers (2).

Some studies suggest that shorter rest intervals can lead to an acute increase in growth hormone, a hormone that plays a role in muscle recovery and growth. This has led some to theorize that shorter rest intervals may promote hypertrophy due to their impact on metabolic stress and hormonal responses (2).

However, the long-term benefits of short rest intervals for hypertrophy are still very much up for debate. According to Grgic et al. (2017), who conducted a review of studies, while short rest intervals might increase metabolic stress and growth hormone levels in the short term, they do not necessarily lead to greater hypertrophy compared to longer rest intervals when looked at over a longer time frame (3). This suggests that while short rest periods may have some benefits, they might not be as effective as longer rest intervals for maximizing hypertrophy in trained individuals.

3. Auto-Regulated Rest Intervals: The Best of Both Worlds?

Auto-regulated rest intervals offer a flexible approach to rest, allowing you to rest as long as you feel necessary before your next set. Instead of sticking to strict rest times, you listen to your body’s signals and start your next set when you feel ready. This method can reduce the overall time spent in the gym without compromising performance or muscle growth.

In trained individuals, this approach has been shown to produce results comparable to fixed rest intervals in terms of hypertrophy and strength gains. De Salles et al. (2016) noted that auto-regulated rest intervals may help prevent unnecessary fatigue while still promoting adequate recovery for lifting heavier loads (4). The flexibility of this method can also make training more enjoyable and help with long-term adherence, as it allows for adjustments based on how you feel on any given day.

4. Why Not Stick to Shorter Rest Intervals for Metabolic Stress?

While short rest periods may seem tempting due to the perceived benefits of metabolic stress, there are some downsides. Short rest intervals can lead to more cumulative fatigue, which may impair your ability to maintain intensity throughout your workout. This means you might end up lifting lighter weights or doing fewer reps, which can limit the mechanical tension on your muscles, which is the primary driver of hypertrophy (2)(3).

Additionally, Grgic et al. (2017) found that despite the short-term hormonal responses triggered by short rest periods, they don’t necessarily lead to better hypertrophy results in the long run compared to longer rest intervals (3). This is because short rest periods can compromise performance in subsequent sets, reducing the overall training volume and intensity, which are crucial for long-term hypertrophy.

ANALYSIS

The optimal rest period for hypertrophy will vary depending on your training goals, experience level, and the specific exercises you are doing. If you are looking for a good rule of thumb for hypertrophy, based on the available research, it seems that rest intervals of 2-3 minutes provide the best balance for most people looking to maximize muscle growth for three main reasons.

Heavier Loads: Longer rest periods allow you to lift heavier weights and complete more reps with good form, both of which are essential for progressive overload—the key to continuous muscle growth.
Recovery: Longer rest gives your muscles and nervous system time to recover between sets, preventing excessive fatigue that could impair performance in later sets.
Training Volume: Longer rest intervals support higher training volume, which has been consistently linked to better hypertrophy outcomes. By ensuring adequate recovery, you can maintain intensity across your entire workout, maximizing the overall stimulus for muscle growth.

While shorter rest intervals may still be useful in certain contexts—such as improving endurance or creating a quick metabolic burn—they are generally less effective for maximizing hypertrophy in the long term. For best results, most people should aim to rest between 2-3 minutes between sets, especially when lifting heavy weights or performing compound exercises like squats, deadlifts, and bench presses.

Practical TAKEAWAYS

If your goal is hypertrophy, here’s how you can apply the science of rest periods to your training routine:

Use Longer Rest for Heavier Lifts: For compound movements like squats, deadlifts, and bench presses—where you’re lifting heavy weights—take 2-3 minutes between sets. This allows your muscles to recover so you can maintain high intensity across all sets.
Consider Shorter Rest for Isolation Movements: For accessory exercises or isolation movements (e.g., bicep curls or tricep extensions), you can experiment with shorter rest periods (30-60 seconds) to increase metabolic stress without compromising overall performance.
Auto-Regulate When Necessary: If you feel fatigued or are having an off day, auto-regulate your rest periods. Take as much time as you need to feel ready for the next set, but avoid resting too long and letting your heart rate drop too much.
Monitor Your Progress: Keep track of your workouts and how rest periods impact your performance. If you notice that shorter rest intervals are limiting your ability to lift heavier or complete all your sets, increase your rest time and see how it affects your results.

Conclusion

Rest intervals are an often overlooked yet crucial variable in designing an effective hypertrophy program. While shorter rest periods may offer some benefits related to metabolic stress, longer rest intervals of 2-3 minutes have been shown to promote superior muscle growth by allowing for greater recovery, higher intensity, and more training volume. Research consistently suggests that longer rest periods provide the optimal balance of recovery and performance, enabling you to lift heavier and achieve the mechanical tension needed for muscle growth.

Incorporate rest periods strategically into your training routine to maximize your hypertrophic gains. Balance is key: rest enough to maintain intensity but avoid excessively long breaks that could reduce workout efficiency. By finding the sweet spot in your rest intervals, you’ll be well on your way to building stronger, larger muscles over time.

Sources:

Schoenfeld, B., Pope, Z., Benik, F., Hester, G., et al. (2016). Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men. Journal of Strength and Conditioning Research, 30, 1805–1812. https://doi.org/10.1519/JSC.0000000000001272.
Salles, B., Simão, R., Miranda, F., Novaes, J., Lemos, A., & Willardson, J. (2009). Rest Interval between Sets in Strength Training. Sports Medicine, 39, 765-777. https://doi.org/10.2165/11315230-000000000-00000.
Grgic, J., Lazinica, B., Mikulic, P., Krieger, J., Schoenfeld, B. (2017). The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review. European Journal of Sport Science, 17, 983-993. https://doi.org/10.1080/17461391.2017.1340524.
De Salles, B.F., Simão, R., Miranda, F., et al. (2016). Rest interval between sets in strength training. Sports Medicine, 39(9), 765–777. https://doi.org/10.2165/11315230-000000000-00000.

DISCLAIMER

The information in this article is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider or medical professional before beginning any new exercise, rehabilitation, or health program, especially if you have existing injuries or medical conditions. The assessments and training strategies discussed are general in nature and may not be appropriate for every individual. At Verro, we strive to provide personalized guidance based on each client’s unique needs and circumstances.