Researchers conducted a meta-analysis of 8 randomized controlled studies.

The studies were 4–12 weeks in duration, and resistance exercise was performed 2–3 times per week: 2 studies used handgrip training, 1 study focused on wrist flexor training, 3 studies used lower-body training, and 2 studies used full-body training programs.

All of the studies used postexercise cold water immersion. Three studies exposed only the upper limbs, two studies exposed only the lower limbs, and three studies employed whole-body cold water immersion. Cold water immersion was applied for 10–20 minutes at a water temperature of 10–15℃ (50–59℉). The participants began cold water immersion between 3 and 15 minutes after finishing the exercise session.

Muscle size was assessed using a variety of techniques, including DEXA, ultrasound/magnetic resonance imaging of various different muscle groups, muscle biopsy, and the circumference of the arms and legs.

Analyses were conducted to determine the influence of intervention duration (i.e., less than 8 weeks or 8 weeks or more), training status (i.e., trained or untrained), and training frequency (i.e., two or three days per week) on the outcome.

Cold water immersion reduces muscle growth during resistance training Original paper