Quick answer
- In two dose-response studies, 6 to 12 minutes of 1-minute hot and cold swaps helped athletes recover at least as well as 18.
- For cold alone, a meta-analysis found the best soreness results at about 52 to 59°F for 11 to 15 minutes. Colder water calls for shorter dips.
- Lab protocols use 1 to 4 minutes of heat per minute of cold. Sauna routines stretch the heat to 10 to 20 minutes.
- How often: Finnish studies found the strongest health links at four to seven sauna sessions a week.
In this article · 8 sections
How long should each part of contrast therapy last, how many rounds should you do, and how often? Researchers have tested contrast therapy duration more than most people realize. Here are the studies that matter most, what each one found, and how to turn them into a protocol for a sauna and cold plunge.
For whole-session planning, see how long contrast therapy should last. For per-round limits and warning signs, see how long to stay in the sauna and cold plunge.
The dose-response studies
The most direct research on duration comes from the Australian Institute of Sport. Athletes did a hard session, then 10 minutes later alternated 1 minute in hot water and 1 minute in cold for 6, 12 or 18 minutes, or simply rested. Two hours later, they were tested again.
- Cyclists: 11 trained men, hot water about 101°F and cold about 58°F. Six and 12 minutes improved performance in the second session compared with rest, and all three durations eased fatigue and soreness. There was no dose-response: 18 minutes wasn't better (European Journal of Applied Physiology, 2011).
- Runners: 10 trained men, about 100°F and 59°F. Six minutes improved the second 3,000-meter run compared with rest; 12 and 18 minutes didn't (International Journal of Sports Physiology and Performance, 2012).
The lesson: past a modest dose, more minutes didn't buy more recovery.
The big reviews
- Contrast water therapy, 18 trials: better than passive rest for muscle soreness and strength loss for up to four days after hard exercise. All the trials carried a high risk of bias, and contrast wasn't clearly better than other active options like cold water or compression (PLoS One, 2013).
- Team sports, 23 studies and 606 athletes: cold water immersion helped several recovery measures, and contrast water therapy helped athletes feel less fatigued, though neither changed how sore they felt (Journal of Strength and Conditioning Research, 2017).
- Cooling after exercise, 36 studies: cooling, especially cold water immersion, eased delayed-onset muscle soreness at 24, 48 and 96 hours compared with doing nothing, while blood markers of recovery didn't change (PLoS One, 2015).
One caveat runs through all of it: these studies used tubs of water, ice baths and traditional saunas, not an infrared sauna and cold plunge in a private suite. They're the best guide available, not a precise recipe.
How long to stay in the cold
A meta-analysis of nine trials found that cold water immersion eased muscle soreness slightly better than rest, with the best results at about 52 to 59°F for 11 to 15 minutes (Sports Medicine, 2016). Our plunges are kept at 45 to 49°F, far colder, so the same principle points to much shorter dips: 30 seconds to 3 minutes.
Heat-to-cold ratios
Lab protocols mostly fall between 1:1 and 4:1. The dose-response studies used 1 minute hot to 1 minute cold. A 2020 study used 4 minutes of heat to 1 of cold for four rounds, and found that infrared heat paired with cold therapy produced bigger changes in forearm blood flow than hot and cold water baths (Medical Science Monitor, 2020).
Sauna routines stretch the heat side much further: 10 to 20 minutes in the sauna and 30 seconds to 3 minutes in the plunge. Few studies compare ratios head to head, so choose the split that feels good.
How long to stay in the heat
- In the Finnish heart study of 2,315 men, sauna sessions longer than 19 minutes were linked to a lower risk of sudden cardiac death than sessions under 11 minutes (JAMA Internal Medicine, 2015).
- In a randomized trial, a 15-minute sauna after exercise for eight weeks improved fitness and blood pressure more than exercise alone (American Journal of Physiology, 2022).
How often to do contrast therapy
The same Finnish study found its strongest health links at four to seven sauna sessions a week, compared with once. The popular "11 minutes of cold and 57 minutes of heat a week" comes from a 2021 study of Danish winter swimmers, who did both two to three times a week (Cell Reports Medicine, 2021). It describes their habit rather than a tested dose, but it's a handy benchmark. Once or twice a week is a good place to start; our guide on how often to sauna and cold plunge helps you set a rhythm.
How to build your protocol from the studies
- Start with your session length. 25, 55 or 85 minutes, minus 5 to 10 for settling in and showering.
- Pick your rounds. One or two in 25 minutes, two or three in 55, three plus a rest in 85. The studies suggest more isn't automatically better.
- Split each round. Give most of it to heat and a short dip to cold. 12 minutes and 1 minute is a friendly first try.
- Pick your finish. Cold for a jolt, warm to wind down.
- Change one number at a time on your next visit.
A first protocol for 55 minutes: settle in for 3 minutes, then three rounds of 12 minutes in the sauna, 1 minute in the plunge and 1 minute to breathe, then a 10-minute shower. That's 55 minutes on the dot. Sharing the suite? Keep the same shape and leave an extra minute or two each round for taking turns. Try it at our San Diego or Temecula studio.
Safety, whatever your numbers
Shorter is smarter while you're learning. Leave the heat if you feel dizzy or sick, or your heart is pounding. Leave the cold if you can't slow your breathing, you're shivering hard or your fingers go numb. If you're pregnant, have a heart condition or high blood pressure, or have another medical concern, check with your doctor before you start.
Questions people ask.
What is the best contrast therapy ratio?
No ratio has been proven best. Lab studies used 1 minute hot to 1 minute cold, or 4 minutes hot to 1 minute cold. With a sauna and plunge, many people do 10 to 20 minutes of heat and a short cold dip.
How often should you do contrast therapy?
Once or twice a week is a common start. In Finnish studies, the strongest health links were with four to seven sauna sessions a week.
How many contrast therapy rounds should I do?
Two to four is common. In lab studies, 6 to 12 minutes of hot and cold swaps worked at least as well as 18. In a 55-minute session, two or three rounds fit comfortably.
Where does the 11 minutes of cold a week idea come from?
From a 2021 study of Danish winter swimmers, who averaged about 11 minutes of cold water and 57 minutes of sauna a week. It describes their habit, not a tested dose.
Should contrast therapy end on cold?
It's your call. End cold to leave wide awake, or warm to leave relaxed. Studies haven't settled which is better.
Sources
- Versey N, Halson S, Dawson B. Effect of contrast water therapy duration on recovery of cycling performance: a dose-response study. European Journal of Applied Physiology, 2011.
- Versey NG, Halson SL, Dawson BT. Effect of contrast water therapy duration on recovery of running performance. International Journal of Sports Physiology and Performance, 2012.
- Bieuzen F, Bleakley CM, Costello JT. Contrast water therapy and exercise induced muscle damage: a systematic review and meta-analysis. PLoS One, 2013.
- Higgins TR, Greene DA, Baker MK. 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, 2017.
- Hohenauer E, et al. The effect of post-exercise cryotherapy on recovery characteristics: a systematic review and meta-analysis. PLoS One, 2015.
- Machado AF, et al. Can water temperature and immersion time influence the effect of cold water immersion on muscle soreness? A systematic review and meta-analysis. Sports Medicine, 2016.
- Kim J, Jung H, Yim J. Effects of contrast therapy using infrared and cryotherapy as compared with contrast bath therapy on blood flow, muscle tone, and pain threshold in young healthy adults. Medical Science Monitor, 2020.
- Laukkanen T, et al. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine, 2015.
- Lee E, et al. Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm, randomized controlled trial. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 2022.
- Søberg S, et al. Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men. Cell Reports Medicine, 2021.
