Among weight lifters, using rest periods is a common practice; however, there is significant variation in the length of rest periods between lifting bouts in a single session. The National Strength and Conditioning Association’s (NSCA) guidelines for rest periods are as follows:

  • Endurance: 1 minute or less
  • Strength: 2 minutes
  • Power: 3-5 minutes1

Other research indicates shorter rest periods (less than 2 minutes) enables muscle hypertrophy, or increased strength, due to an overall increase in metabolic stress.2,3 This information was further validated recently when 1 minute of rest was found insufficient, while 2 minutes was found sufficient in most cases.4

Other long-term weight training studies, however, have not demonstrated a clear connection between rest period length and hypertrophy.5,6,7,8 More recently, in fact, a longer rest period (over 6 minutes) has been associated with muscle hypertrophy among individuals doing resistance training due to an increase in training volume.4,9

Still more recently, another study was published which had been conducted using either rest periods of 2 minutes or a self-selected rest (typically less than 2 minutes) between sets.10 This study found that for both upper and lower body exercises performed at 3 sets of 75% of 1RM for 8-12 repetitions by individuals using self-selected rest periods, the study participants actually took shorter rests than the 2 minute controls. Further, those chronically trained (having more than 6 months of resistance training) may experience reduced training session durations when using self-selected rest periods.

Topic and information are referenced from S&C Research.11

References:
  1. Baechle TR, Earle RW. NSCA Essentials of strength training and conditioning, 3rd Ed. Human Kinetics Publishers. 2008.
  2. De Salles, B. F., Simao, R., Miranda, F., da Silva Novaes, J., Lemos, A., & Willardson, J. M. Rest interval between sets in strength training. Sports Medicine. 2009;39(9), 765-777.
  3. Schoenfeld, B. J. The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res. 2010;24(10), 2857-2872.
  4. Schoenfeld, B. J., Pope, Z. K., Benik, F. M., Hester, G. M., Sellers, J., Nooner, J. L., & Just, B. L. Longer inter-set rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res. 2015.
  5. Ahtiainen, J. P., Pakarinen, A., Alen, M., Kraemer, W. J., & Häkkinen, K. Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men. J Strength Cond Res. 2005;19(3), 572.
  6. De Souza Jr, T. P., Fleck, S. J., Simão, R., Dubas, J. P., Pereira, B., de Brito Pacheco, E. M., & de Oliveira, P. R. Comparison between constant and decreasing rest intervals: influence on maximal strength and hypertrophy. J Strength Cond Res. 2010;24(7), 1843-1850.
  7. Buresh, R., Berg, K., & French, J. The effect of resistive exercise rest interval on hormonal response, strength, and hypertrophy with training. J Strength Cond Res. 2009;23(1), 62-71.
  8. Villanueva, M. G., Lane, C. J., & Schroeder, E. T. Short rest interval lengths between sets optimally enhance body composition and performance with 8 weeks of strength resistance training in older men. European Journal of Applied Physiology. 2014;1-14.
  9. Henselmans, M., & Schoenfeld, B. J. The effect of inter-set rest intervals on resistance exercise-induced muscle hypertrophy. Sports Medicine. 2014;44(12), 1635-1643.
  10. De Salles, B. F., Polito, M. D., Goessler, K. F., Mannarino, P., Matta, T. T., & Simão, R. Effects of fixed vs. self-suggested rest between sets in upper and lower body exercises performance. European Journal of Sport Science. 2016;1-5.
  11. Beardsley C and Contreras B. Do you really need to time your rest periods? S&C Research. Accessed: 4/26/2016. http://www.strengthandconditioningresearch.com/promotions/time-rest-periods/