Sweat it out: The benefits of saunas post-workout

Saunas have long been utilised for their soothing and rejuvenating properties, but their benefits extend far beyond mere relaxation, especially when used post-workout.

Stepping into a sauna after a strenuous exercise session can amplify the rewards of your workout routine in numerous ways. From aiding in muscle recovery to promoting detoxification, saunas offer a host of advantages that can enhance your overall well-being and fitness journey.

Let's delve deeper into the benefits of incorporating sauna sessions into your regimen.

The benefits

Saunas raise our core temp and trigger a cascade of thermoregulatory processes that provide a broad range of benefits from athletic performance, cardiovascular health, mental health, and sleep [1][2][3][4][5].

There’s also a reasonable association with lower all-cause mortality rates and dementia [6][7]. It's 'heat shock proteins' that have been all the rage lately so let's dig in.

Endocrine effects

• Noradrenaline: Promotes long-term reduction in sympathetic tone which favours improvements in blood pressure and heart rate variability
• Beta-endorphin: Naturally produced opioids that facilitate the feeling of well-being and decreased stress
• Leptin hormone: Mediates “hunger satiety” and may promote weight loss
• Prolactin: Supports neurogenesis but prolactin isn't always a hero of men's health
• Cortisol: Levels vary significantly among many studies, the mechanism behind this is unclear
• Sex hormones: FSH, LH, testosterone, and oestrogen remain unchanged [8]

Cardiovascular effects

• Cardiac function: Left ventricular ejection fraction and exercise tolerance have been shown to improve with repetitive sauna treatment in those with congestive cardiac failure
• Blood vessel function: Decreased arterial “stiffness” and decreased blood pressure places less stress on arteries [9]

Cognitive effects

• Sleep quality: Yet to be studied robustly but most self-report benefits; this may be due to temp regulation post-sauna [10]
• Cognitive performance: Brain-derived neurotrophic (BDNF) factor improves neuronal plasticity and neuron survival/growth [11]
• Neurodegenerative disease: Release of heat shock proteins (HSPs) that improve resilience to stress along with BDNF that supports improved neurogenesis [9]

Types of saunas

Most of the studies on benefits have been on dry saunas and there’s only been a couple of studies that have made a direct comparison so I generally lean towards the dry heat [11].

For optimal temp, dry saunas should be 80-100°C, whereas steam rooms can be lower at 38-49°C because the humidity saturation makes it more difficult for our body to cool via sweating.

Infrared saunas are also effective at a lower temp because it’s the IR spectrum that penetrates our dermis and generates heat to stimulate sweating. However, most IR saunas also have a heating element as many simply expect a hot room.

The jury is still out on whether they're superior but it's important to note IR is different to red light therapy (mostly wavelength differences) but they can be combined — we’ll dig into photo-biomodulation another time.

Timing and frequency

Post-exercise sauna bathing has been shown to improve explosive strength and muscle soreness, likely due to increases in growth hormone and heat shock proteins [12].

I love to sauna after a workout, particularly now that I'm approaching my 40s and acutely aware of the decline in my androgen hormones.

Most studies have been on saunas longer than 15 mins so I try to aim for 20 mins but this isn't always realistic after a big training session.

Cardiovascular and all-cause mortality benefits are “dose-dependent” which means: more = better. 1-2 sessions per week is a great place to start but increasing benefits have been displayed up to 4-7 sessions per week [13].

Hot tips

A few things to keep in mind when it comes to saunas.

Low and slow

For those getting into it, I suggest short 5-10 minute bursts on the lower bench (it’s cooler) before building tolerance and endurance to sit on the top bench (and even stand!). Listen to your body; there's no need to cook yourself until you’re ready. 

Rehydrate with electrolytes

We really have to be disciplined as we can lose around 1L in a 15-20 minute sauna depending on temp [14].

Warm water and Celtic sea salt are a great combo to replenish electrolytes but I suggest Hyro for something more palatable. 

Sauna hat

A tall, wool hat keeps our head cooler to avoid overheating too fast and allows us to sustain longer periods that increase our core body temp (the goal). 

Booze

We’ve all probably been to a sweaty party at some point in our lives but saunas and booze simply don’t mix! A vast majority of sauna deaths are related to alcohol intoxication [15].

Hangovers

Saunas were the silver bullet of my 20s when I was prone to overdoing it but there's little evidence to suggest that saunas have a measurable benefit.

+90% of ethanol is broken down in the liver with a tiny fraction excreted via sweat and there is the risk of further exacerbating dehydration but there is a lived n=1 effect so I personally recommend doing one post-excess [16].

Sperm

Hot, sweaty balls probably aren’t a turn-on for our partners and they may adversely affect our fertility. Our testicles are mighty sensitive and not just to touch.

Even just a couple of degrees hotter will reduce spermatogenesis and sperm quality but 1-2x a week isn’t going to make us infertile and sperm production returns to normal within a few weeks of cessation [17].

Some enthusiasts suggest an ice pack in the sauna but I personally draw the line on anything involving cock and ball torture (the new-age CBT, apparently).

Finding the balance

For so many of us who are time-poor, it’s great to jump into the sauna to unwind after a long week but it isn't a substitute for strength & conditioning training; I suggest stacking it on top of training. 

If you're a hardcore sauna enthusiast then I suggest checking out the niacin detox protocol.

Ready to try something a little colder? Explore more about ice baths and the benefits of cold water immersion.

This post contains general information about health and wellness practices. It is not intended as medical advice and should not be treated as such. Please consult with a healthcare professional before starting any new health regimen. This information is provided without any representations or warranties, express or implied.