Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training.

Plain-language summary

This study looked at whether plunging into cold water after weight training costs a man muscle growth or strength. Sixteen men trained three times a week for seven weeks, half sitting in cold water for 15 minutes at 10 degrees Celsius (50 degrees Fahrenheit) after each session and half resting at room temperature. The cold water group put on less muscle fiber size and showed weaker muscle-building signals, but gained the same strength on the leg press as the other group. Another study in this library asks the same question of cold water immersion after strength training, so the two are related and should be read together.

Key findings

• Cold water immersion after resistance training reduced muscle fiber growth compared to passive recovery.
• Strength gains (1-RM leg press) were similar between groups despite differences in muscle growth.
• Cold water immersion blunted markers of muscle-building signals (mTORC1 signaling) and increased markers of muscle breakdown.
• Heat shock protein responses, which help protect and repair muscle, were also lower with cold water immersion.