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. 2019 Jun;37(11):1286-1295. doi: 10.1080/02640414.2018.1555906. Epub 2018 Dec 17.

Abstract

Training frequency is considered an important variable in the hypertrophic response to regimented resistance exercise. The purpose of this paper was to conduct a systematic review and meta-analysis of experimental studies designed to investigate the effects of weekly training frequency on hypertrophic adaptations. Following a systematic search of PubMed/MEDLINE, Scoups, and SPORTDiscus databases, a total of 25 studies were deemed to meet inclusion criteria. Results showed no significant difference between higher and lower frequency on a volume-equated basis. Moreover, no significant differences were seen between frequencies of training across all categories when taking into account direct measures of growth, in those considered resistance-trained, and when segmenting into training for the upper body and lower body. Meta-regression analysis of non-volume-equated studies showed a significant effect favoring higher frequencies, although the overall difference in magnitude of effect between frequencies of 1 and 3+ days per week was modest. In conclusion, there is strong evidence that resistance training frequency does not significantly or meaningfully impact muscle hypertrophy when volume is equated. Thus, for a given training volume, individuals can choose a weekly frequency per muscle groups based on personal preference.

Keywords: Exercise frequency; dose-response; hypertrophy; resistance training.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adaptation, Physiological
  • Humans
  • Lower Extremity / physiology
  • Muscle Strength*
  • Muscle, Skeletal / anatomy & histology*
  • Muscle, Skeletal / physiology*
  • Resistance Training / methods*
  • Time Factors
  • Upper Extremity / physiology