Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training.
Level 2 - randomized trial
Small parallel-group randomized trial in humans.
PubMed 31513450 · doi:10.1152/japplphysiol.00127.2019
What was done
Sixteen young men (mean age 22.9 ± 4.6 years, body weight 85.1 ± 17.9 kg) completed 7 weeks of whole-body resistance training (3 sessions per week). After each session, participants underwent either cold water immersion (CWI: 15 min at 10°C, n = 8) or passive recovery (15 min at 23°C, n = 8). Before and after the training period, investigators assessed maximal strength (1-RM leg press, bench press), jump and push-up performance, body composition via dual-energy X-ray absorptiometry, and skeletal muscle biopsies to evaluate type II muscle fiber cross-sectional area and post-exercise molecular markers (at +1 h and +48 h).
What was found
Improvements in 1-RM leg press were similar between groups (pooled increase 130 ± 69 kg, effect size [ES]: 1.53 ± 90% CI 0.49). However, increases in type II muscle fiber cross-sectional area were attenuated in the CWI group compared to control (-1,959 ± 1,675 µm²; ES: -1.37 ± 0.99). CWI blunted post-exercise mTORC1 signaling (rps6 phosphorylation) at +1 h (-0.4-fold, ES: -0.69 ± 0.86) and +48 h (-0.2-fold, ES: -1.33 ± 0.82), while increasing basal FOX-O1 protein content (1.3-fold, ES: 2.17 ± 2.22). CWI also attenuated training-induced increases in HSP27 (-0.8-fold, ES: -0.94 ± 0.82) and reduced HSP72 protein content (-0.7-fold, ES: -0.79 ± 0.57).
Why it matters
These findings show that regular post-exercise cold water immersion suppresses anabolic signaling and muscle fiber hypertrophy during resistance training, indicating it should be avoided when maximizing muscle growth is the primary goal.
Limits
The study had a very small sample size (n = 8 per group) and included only young, healthy men over a relatively short 7-week training period. Only a single CWI protocol (15 minutes at 10°C) was evaluated, so findings may not generalize to different water temperatures, durations, or female and older populations.
Cited by
- supports Cold water immersion immediately following resistance training reduces muscle hypertrophy and strength adaptations due to vasoconstriction decreasing muscle blood flow.