Effects of periodic and continued resistance training on muscle CSA and strength in previously untrained men.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 21771261 · doi:10.1111/j.1475-097X.2011.01031.x
What was done
Fifteen previously untrained young men were allocated to continuous training (CTr) or retraining (RTr) groups performing high-intensity bench press training over a 15-week period. The CTr group trained continuously for 15 weeks. The RTr group trained for 6 weeks, completed a 3-week detraining period with no training, and resumed training from week 10 to 15. The primary outcomes were one-repetition maximum (1-RM) strength and MRI-measured muscle cross-sectional area (CSA) of the triceps brachii and pectoralis major.
What was found
Both groups achieved similar significant increases in 1-RM and muscle CSA during the first 6 weeks (P < 0.01). In the CTr group, CSA and 1-RM continued to increase (P < 0.05), though gains during the final 6 weeks were smaller than during the initial 6 weeks (P < 0.05). In the RTr group, 3 weeks of detraining did not cause significant decreases in muscle CSA or 1-RM, and retraining elicited gains comparable to the initial training phase. At 15 weeks, cumulative improvements in 1-RM and muscle CSA were similar between groups. Exact numeric means and standard deviations were not reported in the abstract.
Why it matters
These findings indicate that short detraining periods (up to 3 weeks) do not compromise overall muscle hypertrophy or strength development in early-stage resistance training, as rapid re-adaptation occurs upon resuming exercise.
Limits
The sample size is very small (n = 15 total across both groups). The study was limited to untrained young men and evaluated only a single upper-body movement (bench press). The abstract omits exact point estimates, confidence intervals, and variance metrics.
Cited by
- supports Studies on periodic resistance training show that taking periodic weeks off results in rapid regaining of lost muscle size and strength, yielding similar long-term results to continuous training.