HOT in here!!
In the name of all things balanced - we go from cold exposure from last newsletter to benefits of extreme temperature, heat exposure aka sauna, hot shower, bath. While the physical experience is on the other end of the spectrum these passive forms of recovery, share similar benefits as cold exposure, with one fancy mechanism in particular - release of heat shock proteins (HSP).
HSP are a family of molecular “chaperones” that are known for their role in protein maturation and recycling. They are produced by cells in response to exposure to stressful conditions. In our case cold and heat exposure, and our friend exercise. But as you might guess, these little health marvels are expressed based on the duration and intensity of the exercise. These benefits are generally seen in aerobic training and strength training ie: when we get hotter.
So while cold and heat exposure, aka "exercise mimicking events" outcomes are very similar, the research leans more closely towards cold for mental health - heat for cardiac health benefit.
Benefits from the current research of :
Brain - increased expression of our brain's clean up proteins aka "BDNF;
- improved blood flow to brain, shown to clear amyloid-beta, a protein associated with Alzheimer's disease; - prevention or reduction of depression symptoms
Heart - reduced blood pressure; - improved elastic function of the inner lining of blood vessels;
- reduce markers of unhelpful inflammation; - improved heart function (please check with your GP for any diagnosed heart conditions or low BP before getting involved)
Endurance - stimulates red blood cell production and increases blood volume;
- heat shock protein (HSP) production which leads to improved mitochondrial function (the battery of our muscles and cells), and found to have higher base expression (even when not exercising)
- improved insulin sensitivity (easier for carbohydrates to be used as fuel and keep inflammation down)
- 10 days of heat exposure in immobilised humans prevented loss of mitochondrial function and increases HSP, and reduced muscle loss by 37%
Sleep - heat exposure in the evening (hot bath or shower is enough) promotes sleep onset. The fun part of stepping out of the heat is that the body then does a thermal-dumb, dropping your temperature which is required for sleep onset.
Gender differences:
- Males have a larger HSP response than females (exercise in heat). But the theory is estrogen may help to stabilise cell membranes, thus reducing the need to up regulate HSP after an acute stress. = estrogen protects us!
- Rat study - suggests HSP in the gut response in a positive way for females with estrogen's action being protective. - Reproductive years - the impact of progestrone is thermogenic it makes us hot, so we are cooler in our core temp in the first half of our cycle = to get the cardiac benefits that male counterparts get with sauna we have to approach sauna differently in 1st to 2nd phase of our cycle.
- Perimenopause - Estrogen-Sensitive Neurons and Hot Flashes - currently suggest that during periods of high estrogen surges (= larger peri-symptoms) heat exposure & exercise that produces ++ heat (ie HITT) might not be well tolerated and might exacerbate hot flashes.
Hot tips:
1) reproductive years: In the first half of the cycle (day 1 to ovulation) we need to have a cooling period - so 5 mins in the heat, 2-5 mins out to cool off, then return into the heat for 15-20 mins. In the second half just go for the 20 mins flat.
2) Males need half the time: research shows that females need to do about twice as many heat adaptation sessions (10, as opposed to 5) to get the same magnitude of adaptations as their male peers.
3) Exercising prior to the sauna means you enter a touch dehydrated, this effect during the sauna encourages the spleen to promote new red blood cell release. After exiting the sauna, resist the urge to gulp water. Instead, sip fluids gradually over the next 3 to 4 hours.
Protocols
• Frequency: 4 to 7 sessions per week
• Duration: Approximately 20 minutes per session
• 10 days consecutively is beneficial for endurance sports
Contraindications to sauna bathing include unstable angina pectoris, recent myocardial infarction, and severe aortic stenosis. Sauna bathing is safe, however, for most people with coronary heart disease with stable angina pectoris or old myocardial infarction. Please consult with your medical physician in regards to your health position before commencing sauna use.