Throwing cold water on muscle growth: A systematic review with meta-analysis of the effects of post-exercise cold water immersion on resistance training- induced hypertrophy

This paper systematically examined the impact of post-exercise cold water immersion (CWI) in conjunction with resistance training (RT) on muscle growth. Through a comprehensive meta-analysis of available data, the study aimed to shed light on whether CWI, when used as a recovery strategy after RT sessions, influences the hypertrophic response of skeletal muscles. The analysis encompassed eight relevant studies, all focusing on CWI as the chosen method of cold application. Initial findings suggest that while RT alone fosters muscle hypertrophy, the addition of CWI might mitigate these gains to some extent. This attenuation is believed to occur through various physiological mechanisms, including alterations in inflammatory responses and reductions in post-exercise blood flow to muscles. The paper provides practical insights, suggesting careful consideration of the timing and frequency of CWI application to optimize muscle growth. However, the study acknowledges limitations in the existing research landscape, emphasizing the need for further investigation to fully grasp the effects of CWI on muscle hypertrophy, especially across diverse populations and training scenarios.

Some specific key points of note are:

  • Cold Water Immersion (CWI) and Resistance Training (RT): The combination of CWI right after RT might reduce muscle growth compared to RT alone, according to the meta-analysis results.
  • Mechanisms: The paper suggests that CWI may affect muscle growth by changing how the body responds to inflammation, reducing blood flow to muscles, and affecting nutrient delivery.
  • Practical Advice: To optimize muscle growth, it’s recommended to avoid using CWI immediately after RT and carefully consider when and how often to use it.
  • Study Quality: There are limitations in the studies reviewed, including differences in how they were conducted and reported, which may affect the reliability of the conclusions.
  • Future Research: More studies are needed to better understand how different ways of using CWI might impact muscle growth, especially in different groups of people and training situations.

Some general takeaways for athletes and practitioners are:

  • Impact of CWI: Cooling down with cold water after working out could slightly reduce muscle growth compared to just exercising.
  • How CWI Works: Cooling down might affect muscle growth by changing how the body responds to inflammation and how nutrients get to the muscles.
  • Advice for Practitioners: People planning to use CWI should be cautious about when and how often they do it to get the best results for muscle growth.
  • Study Challenges: The quality of the studies reviewed varies, which makes it harder to draw definite conclusions about the effects of CWI on muscle growth.
  • Future Studies: More research is necessary to understand better how using CWI in different ways might affect muscle growth, especially in different groups of people and exercise situations.