As part of our Biohacking Masterclass Series, we will explore a number of different techniques and practices to improve your daily performance. This series will range from obvious subjects like exercise and nutrition to fringe subjects like breathing techniques and sleep hygiene. Consult your physician before implementing any of these topics. We are not your physician.
I got stronger after eliminating one of the most popular ‘recovery’ tools from my post-training routine. If you’re training for strength, size, speed, and/or endurance, you should consider eliminating it too.
Training is about creating bodily adaptations that enable improvements in performance. These adaptations require proper recovery. For example, to gain muscle mass (i.e. hypertrophy), your muscle cells need to tear and then repair. Over thousands of years of evolution, our bodies have fine-tuned the physiological processes to respond to intense stress and adapt for the next exposure. Many of us have unknowingly disrupted these processes, resulting in suboptimal training gains.
I spent years seeing athletes hopping in ice-brimmed cold tubs after hard training sessions. If I had to guess, you have probably heard of the same thing. Obviously, there’s reasoning behind it, right? If the top athletes in the world are doing it, why wouldn’t I?
I bought into the thinking. As a collegiate athlete, it was often prescribed to me regardless of the training stimulus. The sermon was, “If you trained hard, get in the cold tub. It’s part of getting stronger (and tougher?). Without much room for negotiation and an appreciation for folks like Wim Hof, I bought into the practice.
That was, until the research publications made their way onto my computer screen.
The first study made me curious. The second, suspicious. As I opened my tenth, I rewrote my ideal recovery protocol.
What does the science say?
If you’re strength training, cold tubbing demolishes nearly all measures of muscular adaptation compared to other forms of recovery like active cool-downs.
One of the most complete investigations evaluated the effects of cold tubs on muscle mass, strength, and hypertrophy-stimulating pathways after a 12-week strength program. Participants in the cold water immersion (CWI) group were evaluated against an active recovery group (10 minutes of stationary biking at slow pace).
At the end of the 12 week program, participants in the CWI group saw significantly smaller gains in muscle mass. Conversely, athletes in the active recovery group experienced statistically significant increases in overall muscle mass, type I & II (slow- and fast-twitch) muscle fiber size (cross-sectional area), and total number of myonuclei (cellular components of muscle fibers). Importantly, fast-twitch muscle fibers did not increase in size when strength training was followed by CWI. These fibers are responsible for the majority of ‘athletically-relevant’ events (i.e. more force can be produced in less time). If you want to be more explosive, you want to train this fiber type.
Strength changes were similarly remarkable at the end of the study. Strength was significantly greater in the active recovery group versus CWI across measurements of maximal strength, and maximal isometric torque. After 12 weeks, participants who eliminated cold tubs saw 56% greater improvement in maximal strength across a series of one-rep max (1RM) measurements over those who participated in CWI. When single-digit percentage improvements are meaningful, one as high as 56% can lead to dramatic changes in performance.
Again, chemical and cellular signs of hypertrophy and muscular adaptation were nearly all stunted in the CWI group. Satellite cells, which are responsible for many of the processes that regulate increased muscle mass, were all significantly greater in the active recovery program compared to the CWI program. Researchers saw a the same picture at the protein signaling level as well, though the exact mechanisms behind many of these pathways are still being investigated. 
Similar results were repeated in other studies evaluating bodily adaptations to strength and endurance training. [2-4]
But is there a place for getting cold in my training?
If you require peak physical performance for a competition (i.e. game, race, etc) and you had an intense training session, then possibly. Findings are mixed and rely on self-reported measures of pain or soreness.
A select number of studies have found benefits with both cold water immersion and contrast water therapy (CWT), where the latter is the practice of alternating between cold and hot water every few minutes for 20 to 30 minutes total [5-9]. General findings of these studies show support for decreased muscle soreness 24 hours after exercise with CWT  or decreased feelings of fatigue at 24 hours post CWT or 72 hours post CWI . Following delayed-onset muscle soreness (DOMS) inducing exercise, contrast water therapy led to slightly less perceived pain. Finally, an investigation of contrast therapy on rugby players determined a decrease in blood lactate levels (partially responsible for soreness), but the change had little effect on performance . Overall, the results suggest there could be a mildly beneficial effect on perceived soreness. The tradeoff: diminished physiological adaptations that enable strength, endurance, or muscle mass gains.
What can you do instead?
Perhaps the most critical recovery tool is sleep. Top athletes around the world are notorious for their extended sleep time. In terms of injury prevention, sleeping over 8 hours keeps you on the field. That’s been shown in studies too: when athletes sleep 6 hours instead of 8, the percentage chance of injury goes up over 200% . If you want to have the benefits of performance enhancing drugs, read this quick breakdown on sleep.
Countless studies support the use of dry saunas for both strength and endurance recovery. Endurance athletes were able to use saunas to run further on their next run. Critical recovery hormones skyrocket: in some cases, growth hormone shot up 1600%. If you have access to a dry sauna, read our full research breakdown so you’re prepared. If you don’t, taking a 1-hr hot bath (~100℉) was shown to produce similar benefits as a dry sauna, including a significant increase in growth hormone release.
Finally, we see diet as another under-utilized recovery tool. The typical western diet is loaded with inflammatory compounds, so your post-exercise fueling will contribute to your perceived levels of soreness. Again, we’ve equipped you with a quick toolkit with our immunity research here so you can better understand what labels to avoid and what whole foods to consume.
- Roberts et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. J Physiol. 2015. 18: 285-4301.
- Yamane et al. Post-exercise leg and forearm flexor muscle cooling in humans attenuates endurance and resistance training effects on muscle performance and on circulatory adaptation. Eur J Appl Physiol. 2006. 96, 572-580.
- Crowe, M.J.; D. O’Connor, D. Rudd. Cold Water Recovery Reduces Anaerobic Performance. Int. J Sports Med. 2007. 28: 994-998.
- Sellwood et al. Ice-water immersion and delayed-onset muscle soreness: a randomised controlled trial. Br J Sports Med. 2007. 41, 392-397.
- Ingram et al. Effect of water immersion methods on post-exercise recovery from simulated team sport exercise. Journal of Science and Medicine in Sport. 2009. 12: 417-42.
- Higgins et al. Effects of Cold Water Immersion and Contrast Water Therapy For Recovery From Team Sport: A Systematic Review and Meta-Analysis. Journal of Strength and Conditioning Research. 2016. 31(5): 1443-1460.
- Hamlin, Michael J. The effect of contrast temperature water therapy on repeated sprint performance. Journal of Science and Medicine in Sport. 2007. 10, 398-402.
- Vaile et al. Effect of hydrotherapy on the signs and symptoms of delayed onset muscle soreness. Eur J Appl Physiol. 2008. 102, 447-455.
- Vaile, Joanna M.; Nicholas D. Gill, Anthony J. Blazevich. The Effect of Contrast Water Therapy on Symptoms of Delayed Onset Muscle Soreness. Journal of Strength and Conditioning Research, 2007, 21(3), 697-702.
- M.D. Milewski et al., Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. Journal of Paediatric Orthopaedics 34, no. 2 (2014): 129-33.