Sauna for Muscle Recovery After Sport: Research and a Practical Routine

Using a sauna for muscle recovery means working with a physiological repair process, not a feeling. According to the available studies, the sauna influences this process mainly through blood volume, the response to heat stress and the perception of muscle pain. The strongest evidence exists for endurance athletes: after three weeks of regular sauna sessions after training, runners’ plasma volume rose by 7.1% (Scoon et al., 2007). For strength training, a sauna is more suitable than a regular ice bath straight after training, which can blunt gains in muscle mass (Roberts et al., 2015). Heat does not eliminate muscle soreness, but it can ease its perception (Wang et al., 2021). In practice, a simple routine applies: fluids first, then within an hour of training two to three rounds at 80–90 °C with a brief cool-down, and then a meal. The sauna does not replace sleep, nutrition or training planning.

What happens in the body during a sauna session

A Finnish sauna works with an air temperature of around 80–100 °C and low humidity. The body responds as it would to moderate physical exertion. Blood vessels in the skin dilate, the heart speeds up and the body begins to shed heat intensively through sweating.

A Finnish study with eight healthy men compared three sauna regimes. At 80 °C in dry air, body temperature rose by 1.1 °C and heart rate by approximately 60%. At 100 °C, the figures were 1.9 °C and approximately 90%. Noradrenaline levels rose by roughly 100 to 160%. Cortisol fell at both 80 and 100 °C, and growth hormone rose only in some regimes (Kukkonen-Harjula et al., 1989).

For an athlete, two things follow. The sauna is an additional load on the circulatory system, not passive rest, so do not enter it after training until your breathing and heart rate have settled. And the body’s response depends on both temperature and humidity, so it makes sense to work with a stable temperature that you can repeat.

Blood volume and endurance: the runners study

The most frequently cited work on the sauna and sports performance comes from New Zealand. Six endurance runners completed two three-week periods. In one, they used the sauna immediately after training; in the other, they did not. The sauna was at approximately 90 °C and sessions lasted 31 minutes on average, around 13 times in total (Scoon et al., 2007).

Results after the sauna period:

• running time to exhaustion increased by 32%, which the authors converted to an improvement of approximately 1.9% in a time trial,
• blood plasma volume rose by 7.1% and red blood cell volume by 3.5%,
• the improvement in performance correlated strongly with the increase in plasma volume.

The mechanism is physiologically logical. Repeated heating leads the body to retain a larger volume of fluid in the bloodstream, which improves both cooling and oxygen delivery. The limitation is equally clear: six men and three weeks. This is a signal, not a universal rule.

Heat shock proteins (HSP)

Heat shock proteins are cellular “repair” molecules. They help proteins keep their correct shape when the cell is stressed by heat, oxidative stress or intense exertion. Their production is triggered, among other things, by warming of the body, which is where their name comes from.

Claims that a sauna multiplies HSP levels and thereby directly speeds up the repair of muscle fibres are not supported by the available studies in athletes. HSP are therefore an interesting mechanism, not a finished argument.

Muscle soreness after exercise and muscle recovery: what meta-analyses show

Muscle soreness is delayed pain in the muscles after unaccustomed or eccentric exercise, referred to in the scientific literature as DOMS (delayed onset muscle soreness). It appears with a delay, not immediately after training, and gradually subsides over several days.

A meta-analysis of 32 randomised studies with 1,098 participants found that heat applied within one hour of exercise reduces pain in the first 24 hours and later (Wang et al., 2021). Warm compresses had the strongest effect. The sauna, as whole-body heat, was barely represented in these studies, so the result can be applied to the sauna only with caution.

A second meta-analysis (18 studies) looked at contrast therapy, that is, alternating warm and cold water. Compared with passive rest, it reduced muscle soreness and loss of strength at all measured time points. Compared with other recovery methods, however, the difference was not marked (Bieuzen et al., 2013). A typical protocol in the studies: approximately 1 minute in cold water (8–15 °C) and 1–3 minutes in warm water (35–45 °C), 6–24 minutes in total.

So what helps with muscle soreness? Mainly time, sleep, sufficient protein and light movement. Heat contributes chiefly to the perception of pain and the recovery of strength. Research knows of no shortcut that would eliminate muscle soreness.

Heat or cold after strength training

Cold water after training dampens the inflammatory response. In strength training, however, inflammation and the signalling associated with it are part of the process by which muscle grows.

In an Australian study, 21 men did strength training for 12 weeks. One group used cold water immersion after training; the other did an active cool-down. The active recovery group gained more strength and more muscle mass. Cold water also dampened the activity of muscle growth signalling pathways and satellite cells (Roberts et al., 2015).

This does not mean that cold is bad. Nor does it mean that a sauna “adds” muscle mass. It simply suggests a sensible order:

• if the goal is strength and muscle size, do not schedule an ice bath routinely straight after every strength session,
• for endurance, tournaments and several matches in a row, rapid cooling can make sense, because the aim is fast recovery rather than maximum adaptation.

If you want to work with both heat and cold in your garden, see the hot tubs and cold plunge tubs category or the comparison heated or cold plunge tub.

The heart and blood vessels in the long term

The largest dataset on sauna use comes from eastern Finland. The study followed 2,315 men aged 42–60 for almost 21 years on average. Men who used the sauna 4–7 times a week, compared with those who used it once a week, had a 63% lower risk of sudden cardiac death, a 50% lower risk of death from cardiovascular disease and a 40% lower risk of death from any cause (Laukkanen et al., 2015).

This is an observational study. It shows an association, not a cause. People who use the sauna frequently may also differ in lifestyle. For an athlete, something else is essential: regular sauna use is a load that a healthy body tolerates well over the long term.

Where the evidence ends

An expert text should also state what we do not know:

• Small samples. Studies on the sauna and performance often have 6–20 participants.
• Mostly men. Data on women and older athletes are rare.
• Different protocols. Temperature, humidity, duration and timing vary. Research has not established a precise time “window” after training.
• Hormones. Short-term changes in growth hormone or cortisol after the sauna exist, but there is no evidence that they lead to greater muscle gain.
• Infrared cabins operate at a lower air temperature and have their own, even smaller body of studies. The differences are discussed in the article sauna with a heater or infrared cabin.

Sauna for muscle recovery after training, step by step

The routine is based on the conditions of the cited studies. Where research does not give an exact figure, it is a practical recommendation. You will need a sauna with a stable temperature and a thermometer by the bench, water, scales after a long session, and a way to cool down: a shower, cold air or a cold plunge tub. Including breaks, allow 30–45 minutes.

Step 1: Settle down and rehydrate

Cool down with an easy jog, shower and drink. If you train for a long time or in the heat, weigh yourself before and after training and replace the weight lost with fluids. Dehydration impairs endurance performance (Sawka et al., 2007), and the sauna increases fluid loss further. The weight lost in the sauna is water, not fat. Do not enter the sauna thirsty or dizzy.

Step 2: Timing within an hour of training

The runners in the study by Scoon et al. used the sauna immediately after training, and the meta-analysis on muscle soreness assessed heat applied within one hour of exercise. In practice, this usually means 15–30 minutes after the end of training, once your breathing has settled and you have replaced fluids.

Step 3: A temperature of 80–90 °C and 2–3 rounds

A temperature of 80–90 °C in dry air corresponds to the conditions of most studies with a Finnish sauna. A well-established pattern is 2–3 rounds of 8–15 minutes. More minutes do not mean better recovery. If you use the sauna rarely or have just finished a demanding session, start at 70–80 °C on a lower bench; a higher bench means a higher temperature. When water is poured on the stones, humidity rises and the perceived temperature increases quickly. If you feel palpitations, nausea or dizziness, leave the sauna immediately.

Step 4: A brief cool-down between rounds

30 seconds to 2 minutes of cold water or cold air is enough, followed by a few minutes of sitting quietly. A brief cool-down between rounds is a normal part of the sauna cycle and is not the same as a long ice bath after strength training.

Step 5: After the sauna, fluids, food and sleep

Replace fluids, eat a meal with protein and carbohydrates, and let the body cool down calmly. Sufficient sleep matters more for muscle recovery than the sauna itself. Avoid alcohol before, during and after the sauna, as it worsens dehydration and increases the risk of a drop in blood pressure.

The sauna by type of training

When to skip the sauna after training

• Acute injury with swelling or bruising: heat dilates blood vessels, and in the first days the injured area calls for cold and rest instead.
• Fever, infection, nausea or dizziness.
• Pain that lasts unusually long, is sharp or is accompanied by swelling. This is not ordinary muscle soreness; see a doctor.
• Heart and vascular disease. With heart and vascular disease, high blood pressure, during pregnancy and when taking medication that affects circulation, consult a doctor before using the sauna after training.

Stable conditions as a prerequisite for regularity

All the positive results in the studies share repetition under controlled conditions: the same temperature, the same duration, regularly several times a week. The effects on blood volume appeared after a series of sessions, not after one. In public wellness facilities, this runs up against time and capacity. With your own sauna there is no journey, so you can fit a post-training session into an ordinary working day, provided the sauna holds a stable temperature.

That is determined by the structural base. Roof and floor insulation with 10 cm of PAROC mineral wool limits heat loss, a correctly sized Harvia sauna heater holds the temperature without fluctuation, and benches made of lime wood, with its low thermal conductivity, do not burn on contact with the skin. One example is the Nordic Cube, with 10 cm PAROC insulation in the walls, roof and floor. The more compact Nordic Pod for 2 people has a 44 mm solid wall, and a 6 kW Harvia heater is selected for it in the configuration. The heater is not included in the sauna price; it is added according to type. Saunas are used in private homes as well as in sports and accommodation facilities, where regularity matters even more.

Next step: Technical parameters of individual models are listed in the Finnish saunas and outdoor and garden saunas categories. We prepare the configuration, including the heater, on request via the contact page.

You may also be interested in

• Hot tub health benefits: who they help and when to take care
• Sauna construction quality and service life
• The sauna in winter: operation and electricity consumption

Sources

1. Scoon GSM, Hopkins WG, Mayhew S, Cotter JD. Effect of post-exercise sauna bathing on the endurance performance of competitive male runners. J Sci Med Sport. 2007;10(4):259–262. doi:10.1016/j.jsams.2006.06.009. PubMed 16877041
2. Kukkonen-Harjula K, Oja P, Laustiola K, et al. Haemodynamic and hormonal responses to heat exposure in a Finnish sauna bath. Eur J Appl Physiol Occup Physiol. 1989;58:543–550. doi:10.1007/BF02330710
3. Wang Y, Li S, Zhang Y, et al. Heat and cold therapy reduce pain in patients with delayed onset muscle soreness: a systematic review and meta-analysis of 32 randomized controlled trials. Phys Ther Sport. 2021;48:177–187. doi:10.1016/j.ptsp.2021.01.004
4. Bieuzen F, Bleakley CM, Costello JT. Contrast water therapy and exercise induced muscle damage: a systematic review and meta-analysis. PLoS One. 2013;8(4):e62356. doi:10.1371/journal.pone.0062356
5. Roberts LA, Raastad T, Markworth JF, et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. J Physiol. 2015;593(18):4285–4301. doi:10.1113/JP270570
6. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542–548. doi:10.1001/jamainternmed.2014.8187
7. Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377–390. PubMed 17277604

Note: This article is for information only and does not replace consultation with a doctor. If you have heart or vascular disease or high blood pressure, are pregnant or take medication, consult a doctor before using the sauna regularly after training.