In the pursuit of greater progress in the gym, many lifters look to increasing intensity, training volume, or exercising more frequently. However, one critical aspect of training that is often overlooked are rest periods.
Rest periods are the intervals between sets or bouts of activity, allowing the body to recover before engaging in the next bout. These intervals are a crucial component of strength and conditioning programmes, influencing the effectiveness of different training modalities such as maximal strength, hypertrophy, muscular endurance, and power training.
The Role of Rest Periods
The duration of rest periods can influence the effectiveness of a workout by affecting muscle recovery, energy system replenishment, and hormonal responses.
Muscle recovery during rest periods involves the clearance of metabolic byproducts such as lactate and hydrogen ions, which can cause fatigue. Additionally, rest periods allow for the resynthesis of adenosine triphosphate (ATP) and phosphocreatine, essential energy substrates for high-intensity exercise. The length of the rest period can dictate how effectively these processes occur, impacting subsequent performance.
Hormonal responses, particularly the release of anabolic hormones like testosterone and growth hormone, play a crucial role in muscle growth and repair. Research has shown that the duration of rest periods can influence hormonal levels, thereby affecting muscle hypertrophy and strength gains.
Recent Research on Rest Periods
Strength and Power
For those focusing on maximal strength and power, rest periods tend to be longer. Strength and power training typically involves lifting heavy weights, or lifting weights as fast as possible, for low repetitions (1-5 reps). This type of training heavily taxes the neuromuscular system and requires more time for recovery between sets.
Current evidence suggests that significant gains can be achieved from short rest periods (1-2 mins) especially for beginners. However, for trained individuals, rest periods of 2-5 mins seem to be optimal for strength and power training (Grgic et al., 2018). Longer rest periods ensure that the energy stores, primarily ATP and creatine phosphate, are sufficiently replenished. This recovery time also allows the nervous system to recuperate, enabling you to maintain high performance and lift maximal weights in subsequent sets.
Hypertrophy
Hypertrophy, or muscle growth, usually involves moderate to heavy weights with moderate repetitions (5-12 reps). The goal is to maximise mechanical tension by training to/close to failure.
The evidence surrounding rest periods for hypertrophy training is less clear. Schoenfeld et al. (2016) reported that longer rest periods of 2-3 mins may maximise muscle growth in trained individuals. However, a new preprint study from Singer et al. (2024) found slightly conflicting results. They included a mix of trained and untrained participants and found that rest periods of ~90 secs were sufficient to maximise muscle growth, although the lower body seemed to respond better to longer rest periods of ~2 mins. Additionally, it is important to note that even short rest periods of ~60 secs still resulted in substantial gains in muscle size.
Based on the current evidence, it seems that hypertrophy can be optimised with rest periods ranging from ~1.5-3 mins. Those with more training experience should aim for the higher end of this range (2-3 mins), whereas beginners seem to be able to optimise their gains with shorter rest periods (90 secs). Additionally, more time should be spent resting between lower body sets compared to upper body sets.
Muscular Endurance
Training for muscular endurance involves higher repetitions (15+ reps) with lighter weights. The aim is to enhance the muscle’s ability to sustain prolonged activity. Rest periods of 0-90 secs are optimal here. Minimal rest periods help improve the muscle’s endurance capacity by increasing its ability to clear lactate and other metabolic byproducts. This type of training conditions muscles to perform under continuous stress, enhancing their stamina.
Conditioning
Conditioning workouts, often incorporating elements of cardiovascular training and functional movements, aim to improve overall fitness, stamina, and athletic performance. The rest period in conditioning workouts can vary widely (15 secs-2 mins) depending on the intensity and structure of the workout. High-intensity interval training (HIIT) might involve very short rest periods to keep the heart rate elevated, whereas circuit training with heavy weights might require longer rest to ensure proper form and prevent injury.
Individual Factors and Adjustments
While the above guidelines provide a general framework, individual factors such as sex, fitness level, and training experience can influence optimal rest periods.
Male/Female Differences
The research on rest periods for male and female lifters is evolving, and there isn’t a clear consensus on needing drastically different rest times. However, there is potential for shorter rest for women due to faster recovery, as some studies suggest women might recover slightly faster than men, particularly in the first minute after a set (Fulco et al., 1999). This could allow women to benefit from shorter rest periods, thus allowing for more volume to be performed during training sessions. Additionally, metabolic differences, such as a higher percentage of slow-twitch muscle fibres and the role of oestrogen, contribute to faster recovery in women. However, regardless of gender, rest periods should be tailored to individual training goals.
Fitness Level and Training Experience
Untrained lifters typically can manage with shorter rest periods (60-120 secs) compared to experienced lifters, especially during strength training. This is because they are not yet adapted to training, thus meaning that they aren’t able to exert enough force to require much recovery. A minute or two after applying their current maximum effort, they can apply another maximum effort. On the other hand, trained lifters typically lift much heavier weights, and this increased load places a significant demand on both the muscles and the nervous system, thus requiring greater recovery time.
However, when it comes to conditioning, experienced lifters typically have better cardiovascular and muscular endurance, enabling them to recover faster and reduce rest times without compromising performance.
Conclusion
Rest periods are a vital aspect of designing effective strength and conditioning programmes. They vary significantly depending on the training goal—whether it is maximal strength, hypertrophy, muscular endurance, or power. Additionally, individual differences such as training status and gender can influence optimal rest durations. Ultimately, tailoring rest periods to the individual ensures a more personalised and effective approach to strength and conditioning. By optimising rest periods, lifters can enhance their performance, prevent injury, and achieve their training objectives more efficiently.
References
Fulco, Rock, Muza, Lammi, Cymerman, Butterfield and Braun, 1999. Slower fatigue and faster recovery of the adductor pollicis muscle in women matched for strength with men. Acta Physiologica Scandinavica, 167(3), pp.233-239.
Grgic, J., Schoenfeld, B.J., Skrepnik, M., Davies, T.B. and Mikulic, P., 2018. Effects of rest interval duration in resistance training on measures of muscular strength: a systematic review. Sports Medicine, 48, pp.137-151.
Schoenfeld, B.J., Pope, Z.K., Benik, F.M., Hester, G.M., Sellers, J., Nooner, J.L., Schnaiter, J.A., Bond-Williams, K.E., Carter, A.S., Ross, C.L. and Just, B.L., 2016. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. The journal of strength & conditioning research, 30(7), pp.1805-1812.
Singer, A., Wolf, M., Generoso, L., Arias, E., Delcastillo, K., Echevarria, E., Martinez, A., Korakakis, P.A., Refalo, M.C., Swinton, P.A., Schoenfeld, B.J.(2024). Give it a rest: A systematic review with meta-analysis on the effect of inter-set rest interval duration on muscle hypertrophy.SportRχiv.
