The Sauna Protocol: What I Have Discovered

by coach Rachael Warner Sanchez

Hello Higher Running Family! Coach Rachael here and we have an article for you that may be of some interest for those of us who are now being thrusted into summertime training! The long, beautiful days do come with one notable challenge……heat! Training in the heat can lead to some wonderful fall/winter performances but we must be careful to stay healthy while our bodies take on the additional load of both cooling us while staying dedicated to our day-in and day-out training. That leads us to today’s topic of using a sauna to help the body better adapt to heat.

What are Saunas (hint there are multiple)!

Dry Sauna: this is a traditional sauna people will most readily find at their local gyms, YMCAs, etc. The temperature typically ranges between 150-185F (65.5 – 85 C) and the relative humidity is low 10-30%.

Infrared Sauna: a type of “radiation” that is also dry but at a lower temperature ~120-150F (49 – 65.5 C) and reportedly produces a more direct body heat. They are gaining popularity.

Wet Sauna or “Steam Room”: these are also typically not as hot as a regular sauna BUT they are very humid as the name indicates.

What Does the Research Say:

Something that should be noted about studies is their potential limitations. Sometimes data can be “self-reported” and, even with the best of intentions, this can lead to data error. Secondly, it is very costly to do long studies with numerous participants. Another consideration is individuals who have been training for a long time and do not opt to participate in studies that require deviation from their normal routine/training methods. The data in less experienced runners will show significant improvements because they are not close to their “genetic ceilings” while individuals who have been training a long time may show more subtle changes. With that said, these studies are still worth our time!

One study (cited below) showed very promising results by breaking up participants (both men and women) into two groups. One group received a dry sauna protocol while the others did not. They were given the same testing protocol at the beginning and then again after the seven-week study. What is particularly interesting is that they tested the participants at a particular blood lactate level: 4 mmol of lactate (30-minutes effort on a treadmill). Peak core temperatures and heart rate were lower in the group that received the sauna protocol and who also ran at a faster pace in their second test. The group that did not receive the sauna protocol did not show the same improvements.

It is believed that some of these adaptations occur from a positive change/increase hematocrit and hemoglobin levels (these are beneficial blood profile markers). Bonus! There are other noted health benefits to sauna, but for the purposes of this article, the athletic side is being discussed.

What Have I Personally Noticed:

I have been getting into a sauna 2-3 times a week for the past month, typically, after workout sessions. The sauna is rather dry and is about 170F (76.6 C). The first time I stepped into the sauna, I had to remind myself to take a few deep breaths (I have only ever stepped foot in a sauna once or twice in my whole life) and then I calmly sat for 20 minutes. I admit this was probably too long for the first session. Interestingly, it took me almost half the time I was there to get a noticeable sweat rate. During the second sauna session, I sweated much sooner (within a few minutes). My sauna sessions since then have been about 25 minutes.

NOW for the good part! Just a few days ago, I had a 5 x 1-mile repeat workout. The temperature was about 75F (24 C) and humidity was around 85%. Just a nasty day! Now that I have years of running under my proverbial belt, I know that I struggle in the heat and really pull back paces in the summertime. So, an average of ~6:20 minutes per mile pace for the 5 reps would have usually met expectations in a heat adjusted sense. However, I split 6:03 down to 5:52 which made that one of the best ever performances in the heat ever. Those paces were assigned without adjustment. Needless to say, I could not believe it when the paces were hit. I won’t lie, halfway through the final mile repeat, I was feeling the heat and effort, but this was a huge victory. The recovery time was about 2:15 – 2:20 minutes between each one. I started sweating early on during my warmup and sweated a bit more while working hard and this was desired. It is ideal to sweat a bit earlier to keep the body’s core temperature lower, but the heat adaptation occurs when the body may not need to sweat “as much”. I did go to the sauna right after this workout.

Now here is the thing: the gains will not be exponential from the sauna. There is an upper limit to how much the body will assimilate the benefits of the sauna and translate that into faster splits, lower heart rate at lactate threshold, etc.

Going forward, I plan to continue using the sauna about 2 times a week to maintain the newly acquired heat adaptation. The sauna is another training stimulus of sorts, and I will be watching for fatigue levels and adjust accordingly. Just like speed workouts and long runs, this is an additional stress to the body, and I will always put recovery first. If a sauna session needs to be missed, then that is ok!

Now onto an explanation for the below image! I usually do not bring electronics into the sauna, but this time, I used my running watch and chest heart rate monitor strap to record the heart rate during a 25-minutes session. As you can see, my heart rate crept up the whole time, and it correlated with sweating and the sensation of getting hot. Around the 10-minute mark, I was sweating noticeably and at the end of the session, I had sweat “pouring” off me. I felt a bit uncomfortable around the 20-minute mark but perfectly safe to go the last 5 minutes. For context, this sauna session was after an 11-mile run which was a workout (8 x 800 meters and 2 x 200 meters intervals).

How to Implement, Cautions, and Who Benefits:

Please consult with your doctor if you have any concerns utilizing a sauna. While the sauna is well tolerated, there are certain medical conditions in which using a sauna is not advisable. For those who elect to use a sauna, hydration is very important! Not only do endurance athletes have to re-hydrate from their runs, but they also need to account for the sauna. Those prone to anemia/low iron stores, are well served paying special attention to their blood work. Lastly, please consider your total training volume. If the sauna proves to be too much of a stressor, it is arguable that more damage may happen than the modest gains from sauna exposure. Furthermore, if you are in the biggest block of training and only a few short weeks away from a major goal race, I personally would not recommend sauna exposure. A notable exception to this could be for athletes who are going to race in much hotter conditions than their current climate. Heat adaptations from the sauna can happen within just a few sessions and it would be a benefit provided the athlete monitors their recovery. The runner may need to scale back on intensity just a bit to make space for sauna sessions. Key take away: stay in tune with your body! There does not seem to be any need to go more than 4 times a week to the sauna. 2 times a week will also give benefits. If the sauna is completely new to you, 5, 10 or 15 minutes for the first session works just fine. Most protocols do not go past 30 minutes. After 30 minutes, I think the principle of diminishing returns comes into play as more hydration and recovery is required. Work the time up carefully and consider adding another day instead of long sauna sessions. The sauna is most effective if done very soon after completing a run.

The climate we live in could also indicate who gets the biggest gains from a sauna protocol. If someone is living in a cool climate and has opted for an early spring marathon in a warmer climate, this would be a great example of someone benefiting much more than a person already training in less-than-ideal conditions. Blood plasma volume (a marker of someone’s body prepared for heat) for someone who lives in Texas is, arguably, built up a bit more in early spring than someone from the far north. Therefore, the person living in the north could “play catch up” and build their blood plasma volume. Again, using a sauna should be done with caution and build up the time in the sauna gradually.

To summarize, I believe sauna training has a place in one’s training! Please let us know if you have used a sauna and what you noticed with your own running!

Sources:

1 – https://pubmed.ncbi.nlm.nih.gov/33211153/

2 – https://pubmed.ncbi.nlm.nih.gov/29269746/

3 – https://www.endureiq.com/blog/post-exercise-sauna-bathing-for-endurance-athletes-when-and-why