Cold/Hot exposure Challenge

[Fanta]

Hi,

I haven't found any program or challenge involving either cold (dressing lighter in winter and doing exercise outside sub-zero C, cold shower, cold plunge) and/or hot exposure (dry/wet sauna, infrared, etc.).

It may be out of this site's scope in terms of fitness, but I am curious if anyone in the team has ever considered creating such a challenge.

 

[neilarey]

@Fanta it's a nice suggestion. It's tricky one but ... maybe?

Just thinking out loud... I have a personal bias toward heat exposure. I sauna 3 times a week for 30 minutes at 95-100°C, because that “hot stress” acts like a gentle training signal for the cardiovascular system and cellular repair pathways. In the short term, your heart rate rises and your blood vessels dilate, which increases blood flow and shear stress on the vessel walls. That shear stress is one reason passive heat can improve vascular function over time (think: more responsive arteries, better endothelial signaling, and often lower blood pressure in intervention studies). Heat also nudges up heat-shock proteins and other protective stress-response systems that help cells manage damage and recover. The strongest human evidence is still observational (sauna users tend to be healthier in multiple ways), but large cohort work has linked frequent sauna bathing with lower cardiovascular and all-cause mortality risk, and follow-up studies have reported similar associations in both men and women.

Most people don’t have regular sauna access, so the plan can be simple and still useful: any safe, repeatable “passive heating” exposure can approximate parts of the stimulus. Options include a hot bath (or deep hot shower) where you aim to feel distinctly warm and lightly sweaty for 15-30 minutes, 2-4 times per week. The mechanism isn’t identical to a Finnish sauna, but hot water immersion and other passive heating methods have RCT evidence for improving cardiometabolic and vascular markers, including blood pressure and peripheral vascular function. The practical rules are boring but important: hydrate, avoid alcohol, get out if you feel dizzy or nauseated, and be cautious with very high heat if you have low blood pressure, cardiovascular disease, are pregnant, or take meds that affect hydration or heart rate.

On cold exposure... I am not a fan Cold is a sharp tool: it can spike stress responses, feel miserable, and if someone’s goal is strength or hypertrophy, frequent cold-water immersion right after resistance training may interfere with some training adaptations (timing matters). So my stance is: heat is my primary lever, and cold is optional, highly individual, and not required for great health outcomes.

 

[Fanta]

@neilarey

I'm a beginner to cold plunges. I just did my second session this morning! I did it right after getting out of bed, before anything else.

I've been reading and listening to a lot of people on this topic - mostly to prepare mentally for the experience... I've no doubt it has benefits, especially psychological and hormonal, for both genders. YES it is a stress, the hormetic kind, but so is physical training and work and many other things.

I spent months... MONTHS... working up my mental block on trying it out.

The main points I've read about cold exposure benefits are:

• the person does it willfully under their own terms, so it's a controlled stress - and it has been proven to get people out of PTSD, and builds up mental resilience (I see the same mental resilience building up with the 5 min plank challenge!! Mind over Body)
• it spikes the heart rate initially - this is actually what one wants to occur, the shock and the gasp - but the body quickly kicks in the calming response
• it improves RHR and HRV (I'm tracking this one out with my Garmin! will report if I see any improvements)
• it builds brown fat - brown fat ramps up metabolism, and endurance towards cold
• it helps boosts testosterone naturally (both genders benefit from this)
  

I totally get the reluctance... it's not a popular thing. As I said, I took months working up the courage to dunk into a not-so-cold bath yesterday

As to sauna and red/IR light therapy - I'm also ALL for it. I'm waiting on a SaunaSpace kit I ordered on Black Friday - sadly for me they got so many orders they are back logged manufacturing them, good for their business though!!! I need to build patience waiting to receive it, can't wait to set it up here!!!!

I am about to read a book on cold plunges... Maybe what we could think about, using a few references, is a challenge that involves cold and hot exposures?
Or two challenges, one about cold, one about hot, that could be mixed together into a proper schedule?

I can report back on my findings if that could be of interest it doesn't have to be crazy and show-offy - the consensus average to cold exposure seems to be 10-11 minutes per week to get benefits, so 3 minutes every other day, in a sense. I'm curious about optimal timings of hot/cold exposures with respect to physical training as well!

 

[Fanta]

Reporting in on day 24:

Getting used to cold water went much faster than I anticipated. Brown fat development and resilience are definitely improvements that get qualitatively felt pretty quickly.
Appetite ALSO boosted up - definite change in metabolism.

I'm now doing 50F/10C cold plunges for 3m15s or about (last 4 days).
I no longer get stressed mentally before going in, this lasted less than a week to be honest. Doing it daily makes that go away pretty quickly.

Slowly bringing down the temperature as I get used to it. Definite skin prickling sensation appeared at 52F/11C.

Other news: received a red light therapy sauna space, assembling it today! Will be able to incorporate hot sessions in my day too!

 

[Fanta]

Here's a thought:

How about just a radio button on the user profile, like the 5 min plank, the streaks, etc. but for hot and cold sessions?

For example:

- 3 minute cold plunge at 50F/10C
- 2 minute cold plunge at 40F/4.4C
- 1 minute cold plunge at 34F/1.1C

And similar for hot sauna?

Could make a fun icon of a bath tub or a barrel with the temperature overlaid on top of the icon, and maybe an ice cube or two?