Cold-water immersion after hard training is routine in sport, and studies of it have reported mixed results for performance, for how people feel, and for the muscle-damage marker . Mixed results are what a meta-analysis is for. Fifty-two studies went in.
Small benefits, mostly at 24 hours. Cold-water immersion improved the recovery of muscular power 24 hours after and after high-intensity exercise. It reduced serum creatine kinase 24 hours after high-intensity exercise, and it improved both muscle soreness and perceived feelings of recovery. The are small throughout.
Studies investigating cold-water immersion for recovery in physically active populations have reported mixed results across athletic performance, perceptual measures and creatine kinase. The purpose here was to pool them properly.
The September 2021 search covered Medline, SPORTDiscus, Scopus, Web of Science, the Cochrane Library, EmCare and Embase. Inclusion was limited to peer-reviewed English-language studies of active participants comparing immersion against passive recovery after an acute bout of strenuous exercise.
Fifty-two studies made it into the meta-analyses, divided into eccentric and high-intensity exercise subgroups, with random effects models and using water temperature and exposure duration as continuous moderators.
The results are modest and consistent. Immersion improved recovery of muscular power 24 hours after eccentric exercise and after high-intensity exercise, reduced serum creatine kinase 24 hours after high-intensity exercise, and improved muscle soreness and perceived feelings of recovery.
wat. Twenty-four hours later, the immersed athletes had slightly more power and felt better.
wat wat
The effects are real and modest, which is a different message from either the enthusiasm or the backlash around ice baths.
How do we know?
Moore and colleagues searched six databases in September 2021, split the studies into eccentric and high-intensity exercise subgroups, and ran random effects meta-analyses with water temperature and exposure duration as moderators.
What is still unknown
Effect sizes are small, with confidence intervals reaching close to zero for the power outcomes, and this covers a single bout of strenuous exercise rather than a training block.
Learn something?
Where to next
Do compression garments help muscles recover?recovery
Does an ice bath after training actually speed up recovery?recovery
What changed when basketball players tried to sleep ten hours?recovery