“Muscles recover more quickly if I sit in a tub of hot water, right? WRONG!”
There are 4 different methods for using water immersion in recovery:
- Cryotherapy (cold water immersion)
Thermotherapy (hot water immersion, such as a hot tub)
Contrast therapy (alternate between hot and cold water)
Temperate water immersion (temperature is not as important as the effects of hydrostatic pressure and buoyancy)
Does Hot Tubbing help recovery after exercising or cycling?
There are NO known benefits to muscle recovery, muscle soreness, or increased sports performance following Hot Water Immersion or “hot tubbing.
According to the research, soaking in hot water can worsen muscle recovery, causing a detriment to subsequent training or sports performances.
Heat Acclimation & Hot Tubbing
The ONLY known benefit to Hot Water Immersion (hot-tubbing) for athletes is heat acclimation adaptations for athletes not acclimated to hot environments.
Most professional/elite cyclists recover using cold water immersion or contrast therapy.
Theory vs reality of hot tubs & muscle recovery
“Although a hot spa may make athletes feel good after a ride, it is likely to have no effect on recovery from performance and may even impede recovery by causing fluid loss through promoting sweat production and delaying post-exercise decreases in core temperature”
Thermotherapy refers to being immersed in water that raises your core body temperature, which would be water that is hotter than 97°F (36°C) and generally between 100 to 115ºF (38 - 46°C).
Of the 4 types of water immersion techniques, thermotherapy (hot-tubbing) is the least effective, even though nearly every training center, health resort, gym, and sports complex has a hot tub or spa.
The theory behind this form of “therapy” is that the hot water increases the flow of nutrients to muscles after exercising by widening the blood vessels, which improves circulation and blood flow.
However, the research shows only an increase in the surface skin temperature and circulation, as the heat doesn’t penetrate deep enough to affect muscles (heat pads do though, as they are hotter and you wear them longer).
muscle damage & avoiding the spa
After you have been active, your muscles are already heated. There is a reason you do a cool-down after a ride and not a “heat-up.”
Intense physical exertion causes trauma to your muscles, including micro-tears. Cold acts as a natural compression and will help aid recovery by reducing swelling and slowing the flow of blood to traumatized areas. Heat, by contrast, makes the swelling and inflammatory response worse. This is why even hot tub manufacturers do not recommend soaking if you have inflamed muscles.
Muscle recovery is defined as the return of the muscle to its pre-exercise state following exercise.
Cycling performance: Science of different water immersion techniques
“Very little scientific evidence exists to support the use of Hot Water Immersion as a post-exercise recovery intervention.”
A 2008 study, published in the International Journal of Sports Medicine compared cold water immersion, hot water immersion, and contrast water therapy as a post-exercise/cycling recovery technique to next day cycling performance.
The results after 14 minutes of hydrotherapy:
Both Cold Water Immersion (CWI) and Contrast Water Therapy (CWT) enhanced next day cycling performance over 5 days of testing
Cycle-sprinting was enhanced by both CWI and CWT
Hot Water Immersion in a spa set at 100°F (38°C) led to nearly a 4% reduction in both sprinting and cycling performance (~4% slower/worse)
While the previous study only looked at next-day performance. How does taking a dip effect sports performance right after a 30-minute soak?
A 2013 study that was published in the European Journal of Applied Physiology, compared cold water immersion, contrast water therapy, and hot water immersion on cycling performance, 40-minutes after soaking.
The researchers’ conclusion:
“Cold water immersion at 15°C (59°F) was the most effective as it was the only treatment that maintained cycling endurance in the subsequent bout”
Why doesn’t Hot Water Immersion aid athletic recovery?
There are several reasons why, such as:- The hot water adds an additional strain to your cardiovascular system
- More sweating = promotion of dehydration
- Increased body temperature at a time when you want your body to cool down
- Exacerbates swelling and inflammation
Hot tub manufactures & there “Science”
If you look at any hot tub/spa website or brochure, you will find all the supposed health benefits of hot tubbing, including benefits to muscle recovery from exercise.
A large hot tub/spa company, says on their website, “studies have shown that both heat and cold therapy can promote healing and prevent muscle damage following exercise.”
If you actually read the study that was cited, you will discover that hot tubs and cold tubs were not even tested. Instead, heat packs and cold packs were applied to the skin. In the case of the heat pack, it was applied for 8 hours. The study also happened to be sponsored by Pfizer pharmaceuticals.
Sitting in a hot tub for 20 minutes is hardly comparable to wearing a hot-pack for 1/3 of the day, but I don’t need to point out the obvious.
I prefer hot springs with a view (Near Pucón, Chile)
Another large hot tub website says,
“one study found that hot tubs and hydrotherapy helps sore muscles because the soaking reduces lactic acid.”
At least this study actually looked at hydrotherapy, however, hot tubbing was not part of the investigation. This research only looked at Contrast Water Therapy that alternated between 53°F (12°C) water and 97°F (36°C) water baths.
The researchers' conclusion was
“contrast water immersion is a valid and effective means of accelerating recovery from high-intensity exercise in both males and females”
This is good to know. But this is clearly not the same as soaking in a spa or hot tub after a day of riding
Hot Tubs & Marketing
The reasons these hot tub companies resort to “trickery” is because there are no real benefits to hot tubbing for muscular recovery or sports performance (unless acclimatizing to hot environments).
Saunas vs hot tub & recovery
“Sauna bathing, an activity that has been a tradition in Finland for thousands of years and mainly used for the purposes of pleasure and relaxation”
Hot tubs and saunas are both equally ineffective at promoting muscle recovery and subsequent sports performance. Saunas, like hot tubs, increase core body temperature, which places considerable strain on the thermoregulatory and circulatory systems, especially right after exercising.
Why is a sauna bad for sports/exercise recovery?
Many bodily systems are activated to maintain a healthy temperature. As a result, your heart rate doubles, you sweat profusely, blood flow becomes altered, and your body releases cortisol and catecholamines.
All of which impose additional stress after you just stressed the body sufficiently by exercising or engaging in intense physical activity.
Sauna bathing for endurance training
If you are looking to add sauna bathing to your training regimen (as opposed to recovery strategy) there are some benefits. Most notably, an expansion of plasma volume, which will improve endurance performance as the physiological responses are similar to those produced during vigorous walking (for sedentary and out of shape people).
“75% of the participants recorded slower performance times after the sauna intervention”
Final thought
Hot tubs certainly feel wonderful, but that is the extent of their benefit for muscle recovery and won’t do anything for your riding performance.
If you are looking for some easy to implement post-exercise recovery strategies, you can always try compression socks, massage, naps, or contrast water therapy (~15-minutes).
If you just want to relax while soaking in a tub of hot water under the stars, then cheers.
For some easy to implement recovery tips, check out my blog on “Recovery Techniques”
Jesse is Director of Pedal Chile and lives in Valdivia, Chile. Jesse has a Master of Science in Health & Human Performance and a Bachelor of Science in Kinesiology. Hobbies: MTBing, snowboarding, reading, taster of craft beers, & researcher.
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