A post-workout ice bath doesn't improve performance, just makes you cold

Cold Water Immersion (CWI) is one of the most curious fitness trends of recent years. 

Whilst completing stretching exercises or using one of the best foam rollers have long been common ways of recovering post-workout, CWI enthusiasts claim that a dip in ice-cold water can speed up recovery after a tough session. 

There's even a suggestion that this technique could improve circulation, boost your immune system, and aid weight loss - all key benefits of CWI promoted by legendary 'Ice Man' Wim Hof. 

However, critics argue that there's little evidence to support any of these claims - and they might have a point. 

In a recently published study, researchers wanted to investigate the effects of CWI on a range of measures. The participants were split into two groups; one with CWI and one without. Both groups were familiar with resistance training and completed two 4-week blocks of lower body workouts. 

After the sessions, the CWI group dipped into 10-degree water for 10 minutes, while the exercise-only group underwent no cold water post-workout recovery interventions. All participants completed 16 training sessions overall across the study period. The researchers measured perception, muscle function, and muscle architecture at the start, mid-point, and post-exercise. 

The least surprising finding here was that study showed that after the training program, all recruits had improvements in muscle fiber pennation angle, isometric peak force, and performance in 1/4 squats. Disappointingly for CWI supporters however, the researchers found no difference between the two groups, with no apparent benefit to a cold water soak immediately after exercise. 

That said, there were no negative impacts of CWI either. So, if you enjoy taking a cold dunk after a workout, it's probably still safe to do so. Furthermore, other studies have highlighted various health benefits of cold showers, whether taken after exercise or otherwise.

There are caveats to the CWI study, too. The trial only recruited 13 men into the program, so the results may not be generally applicable. Likewise, they were all familiar with resistance training and were in their mid-20s to early-30s.