Question:  After a long ride, my friend likes to jump in a Jacuzzi, but I’ve heard that’s not good for recovery. Is there a difference between cold / hot water post ride showers?

These types of questions are best answered with a bit of science and wisdom. Manipulation of temperature is believed to improve post-exercise recovery, with Jacuzzi’s, hot tubs, saunas, and ice baths being especially popular among athletes. However, it is unclear whether such temperature manipulations actually have positive effects. A recent study in the Journal of Physiology tried to answer this exact question.

The authors of this study investigated whether intramuscular temperature affects the acute recovery of exercise performance following fatigue induced by endurance exercise. They found that recovery from exercise was better maintained after warming the muscles to normal body temperature versus cooling the muscles. It is thought that muscles do better in the heat due to better glycogen re-synthesis versus cold muscles. Keep in mind, this is the result of one study and there is much more research ongoing in this area.

Studies aside, hot tubs can be very relaxing, as they promote sweating they can be healthful as well.  Jumping into a jacuzzi post ride is probably a good thing, but as with anything in life, the dose makes the poison, the basic underlying principle of toxicology. Staying in a jacuzzi for long periods of time may out do their benefits. High levels of chlorine or bromine used in hot tubs can irritate the skin, nose and respiratory system. Another concern with hot tubs has to do with sanitation and the chemicals used for cleaning them. Unless properly disinfected, hot tubs can harbor bacteria that can cause skin and other infections. Stay clear of tubs if the water is murky or green or doesn’t smell right. If you have heart problems, be sure to check with your doctor; overheating in a hot tub can stress the heart. As a rule of thumb, twenty minutes is an adequate time to spend in a jacuzzi. And as is all too common, we break out the alcoholic beverages in hot tubs and we stay in much longer than intended. Hot tubs are not designed for prolonged usage as it quite easy for your body to become overheated and/or dehydrated.

The benefit of cold exposure post ride is separate from the benefits of jacuzzi. Most of the research is mixed whether or not it helps recovery. Numerous articles have reported that cold water immersion (CWI), can enhance recovery of performance in a variety of sports, with immersion in 10-15 °C water for 5-15 minutes duration appearing to be most effective at accelerating performance recovery. However, studies are also beginning to show that intense cold exposure immediately post exercise may blunt the normal inflammation associated with exercise. This may not be a good because it “undoes” in a sense what you are trying to accomplish through exercise in the first place. However, the optimal CWI duration may depend on the water temperature, and the time between CWI and the subsequent exercise. The basic benefits of CWI seem to be its primary ability to decrease tissue temperature and blood flow, ameliorating hyperthermia, and improving autonomic nervous system function. The real power in cold may adapting to the cold in the first place completely separate from exercise.

In summary, skip the ice bath and jump into the Jacuzzi or sauna and it may even help your recovery after that big ride. Maybe even have a beer while you’re in there but watch the clock. Finally consider taking a cold shower in the morning!