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You’re scrolling through Instagram and see a prominent climbing coach climb out of a sauna tent and throw himself into a bath full of frozen water bottles, telling the viewer in voiceover that he adopted the contrast bath technique after listening to a popular podcast. Gah! An Instagram influencer following a podcast influencer! But wait, you think… Should I get a sauna tent?
Hold that Amazon purchase! Because deciding whether to use heat or cold (or both) depends on what your goal is.
Cold therapy
Nothing numbs the pain like a nice ice pack! I couldn’t have gotten through foot surgery without days upon days of icing, and just about every climber I know has iced a sore or injured finger at one point or another. This common practice is backed by research: Cold does have an analgesic effect. It causes vasoconstriction (a constriction of blood vessels), which in turn can clear swelling, creatine kinase (a marker of muscle damage), and other inflammatory substances out of an injured joint, muscle, or extremity.
A long practice of research suggests that submitting tissues to cold therapies—ice packs, ice baths, cryotherapy, etc.—can reduce muscle soreness and swelling, as well as enhance recovery, power, and performance after a hard workout. This is likely due to the analgesic effect of cold therapy. Cold therapies are also useful in lowering core body temperature in very hot weather, which can also lead to improved performance.
So when to use it?
Ice your joints or muscles when you need pain relief or need to perform well on back-to-back hard days, such as multi-day comps or important climbing trips. In short, icing is helpful if you are fatigued or injured and need to make the next session really count.
But icing is not without its drawbacks. While ice baths may help with short term recovery or pain relief, they may not be great for long-term gains. Inflammation is often thought of as a bad thing, but acute inflammation following a hard training day is what signals the body’s tissues to rebuild, repair, and adapt to a new training load. Tamping down inflammation via cold therapy actually blunts a key signaling protein that helps with recovery. This was demonstrated by a well-designed study in which athletes performed an exercise protocol, then drank a protein shake with tracers that showed researchers exactly where the protein molecules ended up in the body. The athletes then placed one leg in an ice bath and the other in a neutral temperature bath. The study found that the leg in the cold bath took up significantly less amino acids from the protein shake—a finding that has matched findings of other, longer-term studies.
For this reason, climbers should probably avoid using cold therapy on a regular basis. Reserve it for when you need acute recovery—such as after an injury—or if you’re going for intense, back-to-back climbing days.
Katie Pajerowski, physical therapist, agrees.“Knowing that ice can potentially blunt protein synthesis signaling,” she told me, “my advice to climbers as far as when and how to use cold therapy depends on the context and their specific problem or injury. For instance, if a climber is in the process of recovering from a finger pulley injury, an important part of this process is progressive strengthening so that the body will lay down new connective tissue and gradually re-build the load tolerance of the injured pulley. In this case, I would not want a climber to use ice after a training or rehab session, because it’s not worth the possible risk of reducing those gains in connective tissue strength. On the flip side, if a climber is managing some finger irritation in a performance context, like a competition, or a redpoint attempt while on a climbing trip, this may be an appropriate situation to use cold therapy to decrease irritation in the short-term.”
Heat therapy
Most research around heat relates to hot baths/saunas for promoting acclimation to hot weather, which these therapies are quite good at doing. If you live in Canada but are headed bouldering in the Virgin Islands for a winter vacation, heat therapy can train your body to tolerate the weather and may help you have a far more productive climbing trip. There’s also research suggesting that these whole-body therapies (saunas/ hot baths) can increase blood flow, increase connective tissue elasticity, improve long-term cardiovascular health and longevity, reduce arterial stiffness, and reduce blood pressure.
Heat packs applied to the surface of the skin don’t penetrate much below the skin, so they will not have any profound whole-body effects; that said, they can have analgesic effects, and they can also increase local range of motion and perceived muscle stiffness, which can be useful if you’re trying to work on your flexibility.
Contrast baths
Contrast baths, in which you submit the body to alternating cold and heat stimuli, is not new, but there is frustratingly little research about its utility for athletes; and the research that does exist is riddled with non-standardized protocols and conflicting outcomes. It seems to be a way to reduce the user’s perception of pain and fatigue—but it’s hard to draw clear conclusions beyond that.
One purported use of contrast therapy is to clear edema, which is localized swelling and fluid. The theory is that alternating cold and heat could make blood vessels alternate between dilation and constriction, thereby “pushing” the fluid out of the swollen area. However, the bathing itself doesn’t perform this action as well as muscle contraction does, which is why climbers should prioritize physical therapy, which is known to play a useful role in acute injury recovery when that recovery involves swelling and edema.
Because of the lack of solid literature about the effects of contrast baths, it’s hard to draw any real science-backed conclusions about whether or not it’s worth your time. Some people swear by it, though. If this is you, great! Contrast bathing may be helpful on some level, and it can also (for the masochists out there) be kind of fun.
Christine Neal, physical therapist at The Climb Clinic, describes it this way: “Contrast bathing has been shown to increase superficial blood flow and skin temperature… using cold, heat, or both are considered ‘passive modalities’ and should be used as only a part of a program to control swelling, as different modalities may have a different effect on each climber.”
So should you use hot therapy, cold therapy, or contrast baths? If you’re looking for quick recovery or pain relief, these are viable options. But using each therapy in a targeted, thoughtful manner that aligns with your goals will give you better outcomes than ordering that sauna tent and dipping in an ice bath daily.
Marisa Michael, MSc, RDN, CSSD is a board-certified specialist in sports dietetics and author of Nutrition for Climbers: Fuel for the Send. She serves on the USA Climbing medical committee and has a private practice in Portland, Oregon. Find her online at nutritionforclimbers.com or on Instagram @realnutritiondietitian for nutrition coaching, workshops, and writing services.