Who, what and why?
Coldwater immersion baths are often used to speed up recovery in both endurance and team sports. It is thought to be effective by moving fluid back from muscle tissue into the circulation, preventing reduction in contractility and associated muscle power.
In spite of its widespread use and popularity, the way this technique is applied is not very sophisticated, typically comprising between 5 and 15 mins full body immersion in water at 10-15 C.
Heart Rate Variability (HRV) has successfully been used to gauge the degree of recovery following cold baths. The objective of the new study at the Vrie University of Amsterdam was to compare standard 5-15min cold bath with a customised protocol as well as the other commonly used active recovery technique.
What did they do?
They recruited 10 active young males to perform exercise tests followed by different recovery protocols: custom cold water bath, standard bath and active recovery over a 3 week period.
After baseline measures of Muscle Power and HRV the participants performed 60 squat jumps at maximal effort, followed by a bike warmup and a 2:30 maximal effort time trial to exhaustion. HRV was measured using Bioforce which contains the same core algorithm as ithlete.
After 10 mins they were then subjected to either a 10 min bath at 15 C, 10 mins of active recovery on the exercise bike or a customer length cold bath between 10-17 mins at 12. The length of the custom bath was set by software which took into account their age, height and weight, so that older and heavier subjects spent longer in the cold tub (lucky them!).
HRV was measured both immediately after the exercise and after the cold water bath. The difference between the two numbers gave an HRV recovery number, with a higher number indicating better recovery. Muscle power was also measured after the bath as the maximum number of squat jumps during 30secs.
What did they find?
- HRV recovery was significantly better with the custom time bath protocol than with the standard 10 mins at 15 C.
- Both kinds of bath protocol were significantly higher than the active recovery bike exercise.
- Muscle power was also significantly better after the custom bath than with the standard bath or with active recovery.
What does it mean?
Since the results showed both significantly better HRV recovery and post recovery muscle power with the new custom protocol than with standard techniques, this new method can be considered an advancement in the fast recovery of both cardiovascular and neuro-muscular performance when this is needed. Interestingly, the likely reduction in inflammation with the custom bath did not seem to reduce the muscle power response, so sometimes it seems you can have your cake and eat it!
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