https://pmc.ncbi.nlm.nih.gov/articles/PMC6303131/ The present study shows that marked increases in strength can be attained by resistance-trained individuals with just three 13-min sessions per week, and that gains are similar to that achieved with a substantially greater time commitment when training in a moderate loading range (8–12 repetitions per set). This finding has important implications for those who are time-pressed, allowing the ability to get stronger in an efficient manner, and may help to promote greater exercise adherence in the general public. Alternatively, we show that increases in muscle hypertrophy follow a dose–response relationship, with increasingly greater gains achieved with higher training volumes.
Thus, those seeking to maximize muscular growth need to allot a greater amount of weekly time to achieve this goal. Further research is warranted to determine how these findings apply to resistance individuals in other populations, such as women and the elderly. Volume does not appear to have any differential effects on measures of upper-body muscular endurance.
