Sauna Training for Runners: How to Cut 2% Off Your 5K

Jeff Gaudette, MS |

Apr 5, 2026

The Quick Summary

Post-exercise sauna training triggers EPO release and blood volume expansion by recreating the dehydration signal that altitude training produces.

The Scoon study found that three weeks of post-exercise sauna sessions improved 5k performance by 1.9% and increased time to exhaustion at 5k pace by 32%.

The effective protocol: 85-90°C for 20-30 minutes, within 30 minutes of finishing your workout, 3-4 times per week for three consecutive weeks.

Use sauna after moderate workouts only, not after long runs, depletion sessions, or workouts already done in the heat.

Start 3-4 weeks before your goal race and stop completely 7-10 days out.

Heat training for runners costs $10-20 per session at most gyms and produces adaptations comparable to expensive altitude camps.

You’ve probably seen the Instagram posts: runners at altitude camps in Boulder or Flagstaff, talking about EPO gains and blood volume increases.

And you’ve probably thought: “That sounds great, but I can’t take three weeks off work to live at 7,000 feet.”

You might not need to.

Research by Scoon and colleagues found that runners who added 30 minutes of post-exercise sauna bathing to their normal training improved their time to exhaustion by 32%, equivalent to cutting nearly 2% off their 5k time.

That’s the difference between a 20:00 5k and a 19:36.

The mechanism: heat stress triggers the same EPO production and blood volume expansion as altitude training, but you can do it at your local gym for $15 instead of spending $3,000 at an altitude camp.

Strategic heat exposure drives adaptations nearly identical to altitude training: increased red blood cell production, expanded plasma volume, and improved oxygen delivery to working muscles.

For time-constrained adult runners, this protocol can deliver altitude-level gains without altitude-level disruption.

In this article, you’ll learn:

How heat exposure triggers the same physiological response as altitude
The exact protocol that produces measurable results in three weeks
Which workouts to pair with sauna sessions and which to avoid
What to expect week by week, and when to stop before your race

Why Does Altitude Training Work — and Why Can’t Most Runners Use It?

At elevation, reduced oxygen availability triggers your kidneys to release erythropoietin (EPO).

EPO signals your bone marrow to produce more red blood cells, increasing your blood’s oxygen-carrying capacity.

The access requirement is what makes altitude training impractical for most runners.

Getting meaningful hemoglobin increases from altitude training takes 500+ hours of exposure above 2,100 meters.

That’s not a weekend trip to the mountains.

That’s weeks of living at elevation, and most adult runners can’t take that time away from work and family.

Even “live high, train low” protocols require access to altitude houses or hypoxic tents that cost thousands of dollars monthly.

altitude training EPO mechanism — how altitude triggers red blood cell production — How altitude exposure triggers the EPO chain reaction

How Does Heat Exposure Trigger the Same Adaptations?

When you sit in a sauna after training, you sweat heavily, and that sweat draws primarily from your blood plasma.

As plasma volume drops and strategic dehydration sets in, blood flow to your kidneys decreases.

That reduction in renal blood flow triggers the same EPO release that altitude exposure produces.

The landmark study from Scoon and colleagues tested competitive male runners over three consecutive weeks of post-exercise sauna bathing.

Research has shown that three weeks of post-exercise sauna sessions increased plasma volume by 7.1% and red blood cell volume by 3.5% in competitive runners.

how sauna training mimics altitude — parallel EPO mechanism diagram — Two paths to the same adaptation: altitude and post-exercise sauna trigger EPO via different entry points

Plasma is the liquid component of blood, separate from red blood cells.

When both expand, your blood carries more oxygen per heartbeat.

That’s the same outcome altitude training works to produce, at a fraction of the cost and logistics.

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What Does Blood Volume Expansion Actually Do for Your Running?

Think about your cardiovascular system like a water pump.

When there’s more fluid in the system, each pump stroke moves more volume with less effort.

More blood volume means every heartbeat delivers more oxygen to working muscles without your heart working harder.

That shows up as lower heart rates at the same effort levels.

Research on competitive middle-distance runners found an 8% improvement in VO2max and a 4% improvement in running speed at lactate threshold after three weeks of post-exercise sauna bathing.

sauna training vs altitude training performance gains chart — VO2max improvement and time investment comparison — Left: heat training requires far less time investment. Right: 3-week sauna protocol performance gains (Kirby et al., 2021).

For context, traditional altitude training requires 500+ hours at elevation to produce similar hemoglobin increases, while heat training delivers comparable results in 10-20 sessions over 2-4 weeks.

Those VO2max and lactate threshold gains translate directly into race performance across every distance.

What’s the Sauna Protocol That Produces Results?

The research is consistent on the parameters that drive adaptation.

Temperature: Traditional saunas at 85-90°C (185-194°F) appear optimal. Infrared saunas at lower temperatures can work, though sessions may need to run slightly longer.
Duration: 20-30 minutes per session.
Timing: Enter the sauna within 30 minutes of finishing your workout. This capitalizes on your already-elevated core temperature and maximizes the physiological stimulus.
Frequency: 3-4 sessions per week for three consecutive weeks.
Fluid intake: Drink minimally during the session, no more than 100ml total.

sauna training protocol for runners — temperature, duration, timing, frequency infographic — The 5 protocol parameters that drive adaptation

That last point is the one most runners get wrong.

The Scoon study participants allowed themselves to become strategically dehydrated during heat exposure, and that controlled stress is part of what triggers the EPO response.

The dehydration during your sauna session is the physiological stimulus, so drink minimally and let it develop.

Your heat tolerance builds quickly.

Most runners notice significant improvement within 3-5 sessions.

When Should You Use Sauna Training — and When Does It Hurt Your Recovery?

Timing has two layers: where sauna training fits in your racing calendar, and which workouts you pair it with.

Start your sauna protocol 3-4 weeks before a goal race, which gives you time for approximately 12 sessions across three weeks before stopping.

Discontinue all sauna training 7-10 days before competition to let your blood volume adaptations stabilize and arrive at the start line fresh.

For workout pairing, use sauna after moderate to moderately-hard sessions where you finish feeling strong: tempo runs, threshold work, and steady-state efforts.

Skip it after depletion workouts, long runs exceeding 90 minutes, or sessions already completed in hot conditions.

After very hard training, heat exposure creates competing demands on your circulation.

Your body needs blood flow directed to muscles for repair, but heat drives circulation to the skin for cooling instead.

When you’re already depleted, that trade-off slows recovery rather than accelerating adaptation.

when to do sauna training in your race preparation — training calendar timeline — Optimal placement of a sauna training block in your race preparation cycle

Is Post-Exercise Sauna Training Safe?

Post-exercise heat training isn’t appropriate for everyone.

Avoid it if you have cardiovascular conditions, uncontrolled high blood pressure, or a history of heat illness.

Pregnant women should not use post-exercise heat training, and anyone on medications that affect sweating or thermoregulation should consult their physician first.

For everyone else, hydration before and after is non-negotiable.

Drink 500-750ml of fluid in the hour before your session.

Post-sauna, rehydrate aggressively with electrolyte-rich fluids and carbohydrates.

Research on post-exercise carbohydrate restoration recommends 1.2g per kilogram of bodyweight per hour for the first 4 hours after sessions combining hard training with heat exposure.

Exit immediately if you experience extreme dizziness, nausea, rapid heartbeat, or confusion: these are heat exhaustion signals requiring immediate cooling and rehydration.

How Quickly Will You See Results?

Plasma volume expansion begins within 4-7 days of starting the protocol.

You’ll notice lower heart rates at paces that previously felt harder within 10-14 days.

Peak adaptations arrive around week 3.

After three weeks of post-exercise sauna training, runners in the Scoon study improved their 5k performance by 1.9% and increased time to exhaustion at 5k pace by 32%.

Individual responses vary.

Runners with higher baseline fitness often see smaller percentage gains, since they’ve already developed more aerobic capacity to work with.

sauna training results timeline — week by week adaptations plasma volume heart rate VO2max — What to expect week by week during a 3-week sauna training block

How Do You Fit Sauna Training Into a Real Training Schedule?

Post-exercise sauna adds 20-30 minutes to workouts you’re already doing.

Start by securing consistent sauna access: most gyms have one, community centers often do, and home infrared units have become more affordable.

Schedule your first 3-week block during a base-building phase, not during race-specific training when every session targets a specific adaptation.

Run the block so it ends 3-4 weeks before your goal race, giving you time to complete 12 sessions and still take the 7-10 day pre-race break.

Monitor recovery carefully during week 1.

The added heat stress is a real training load, and some runners need to reduce overall volume by 10-15% initially.

Watch your resting morning heart rate: if it stays elevated 2 or more days in a row, reduce session frequency that week.

RunnersConnect Bonus

Don’t guess on the protocol. Get the exact sauna training parameters from the peer-reviewed research on one printable sheet.

Includes session safety checklist, workout pairing guide, and the 7-10 day pre-race stop schedule.

GET THE FREE GUIDE

Do infrared saunas work for post-exercise performance training?

Infrared saunas operate at lower temperatures than traditional saunas (typically 50-60°C vs. 85-90°C), but the available evidence suggests they can still trigger the dehydration and heat stress needed for adaptation.

You may need to extend session duration to 30-40 minutes rather than 20-30 to achieve a comparable stimulus.

The research on post-exercise sauna training has primarily used traditional Finnish saunas, so the dose-response for infrared is less precisely established.

If traditional sauna access isn’t available, infrared is a reasonable substitute. Just extend the session length.

How many times per year can I run a 3-week sauna block?

2-3 blocks per year is a practical upper limit for most runners.

Each block should align with a race preparation cycle, timed so it ends 3-4 weeks before your goal event.

Running consecutive blocks without a meaningful break produces diminishing returns, since the body adapts to repeated heat exposure over time.

A minimum 4-6 weeks between blocks gives your system time to reset and allows your training to progress normally without the added recovery demand.

What if I miss sessions during the 3-week block?

Missing 1-2 sessions is manageable if you stay consistent overall.

The adaptation builds cumulatively across the block, so occasional gaps don’t erase progress.

Avoid missing 3 or more sessions in a row, particularly in the first two weeks when the initial plasma volume expansion is establishing.

If illness, travel, or an unusually hard training week forces a longer break, consider restarting the 3-week clock rather than attempting to pick up mid-block.

How will I know the sauna protocol is working?

The first clear signal appears 10-14 days in: your heart rate will be noticeably lower at paces that previously required more effort.

Some runners also notice a lower resting heart rate in the morning.

By week 3, runs that previously felt hard should feel more controlled at the same speed.

You can also use race performance as a post-block benchmark, though accounting for other training variables makes this harder to isolate cleanly.

Does sauna training help specifically with racing in hot weather?

Yes, with a distinction worth understanding.

The protocol described here is optimized for blood volume expansion and performance gains in any conditions.

Heat acclimatization protocols (designed specifically to improve performance in hot race conditions) have some overlap but differ in their parameters and goals.

If your goal race is in hot conditions, a targeted heat acclimatization block may be more effective than the performance-oriented sauna protocol described here, though there is meaningful carry-over between the two.

Is post-exercise sauna training safe for masters runners?

The physiological mechanisms are the same regardless of age, and the available evidence doesn’t suggest older runners respond less well to the protocol.

Masters runners should be more conservative with session length initially (15-20 minutes rather than 20-30) and monitor recovery more closely, since recovery capacity generally decreases with age.

The contraindications (cardiovascular conditions, hypertension) are also more common in older runners, making medical screening a worthwhile step before starting.

Should I use a cold plunge after my sauna session?

Not immediately after.

Cold water immersion after heat exposure works against the adaptation mechanism: the dehydration stress you built during the sauna session is partially reversed when blood vessels constrict in response to cold.

If you use cold immersion as a recovery tool, separate it from your sauna sessions by several hours, or use it on non-sauna training days.

The two modalities serve different physiological purposes and shouldn’t be stacked back-to-back during a performance sauna block.

Jeff Gaudette, M.S. Johns Hopkins University

Jeff is the co-founder of RunnersConnect and a former Olympic Trials qualifier.

He began coaching in 2005 and has had success at all levels of coaching; high school, college, local elite, and everyday runners.

Under his tutelage, hundreds of runners have finished their first marathon and he’s helped countless runners qualify for Boston.

He's spent the last 15 years breaking down complicated training concepts into actionable advice for everyday runners. His writings and research can be found in journals, magazines and across the web.

Scoon, G. S., Hopkins, W. G., Mayhew, S., & Cotter, J. D. (2007). Effect of post-exercise sauna bathing on the endurance performance of competitive male runners. Journal of Science and Medicine in Sport, 10(4), 259-262.

Kirby, N. V., Lucas, S. J., Armstrong, O. J., Weaver, S. R., & Lucas, R. A. (2021). Intermittent post-exercise sauna bathing improves markers of exercise capacity in hot and temperate conditions in trained middle-distance runners. European Journal of Applied Physiology, 121(2), 621-635.

Lorenzo, S., Halliwill, J. R., Sawka, M. N., & Minson, C. T. (2010). Heat acclimation improves exercise performance. Journal of Applied Physiology, 109(4), 1140-1147.

Tyler, C. J., Reeve, T., Hodges, G. J., & Cheung, S. S. (2016). The effects of heat adaptation on physiology, perception and exercise performance in the heat: A meta-analysis. Sports Medicine, 46(11), 1699-1724.

Jentjens, R. L., & Jeukendrup, A. E. (2003). Determinants of post-exercise glycogen synthesis during short-term recovery. Sports Medicine, 33(2), 117-144.