To be explored…

Topics listed below are ideas that are yet to be summarized. 

Infrared research

Sun exposure

Genetic difference

Heat shock protein deep dive

The Immunity Fix notes

Studies in Finland show bathing in a sauna 4 times a week reduces all-cause mortality and cardiovascular disease risk by 40%. It’s not only great for metabolic health and overall vitality but it also strengthens the immune system by activating heat shock proteins in the body. These heat shock proteins repair damaged molecules as well as impair viral replication. There are studies showing that frequent sauna bathing may help to prevent the common cold and flu.

Swimming in cold water also upregulates the body’s antioxidant defense systems like glutathione and cold shock proteins. It’s one of the most powerful ways of reducing inflammation and inflammatory pain.

Sustenance and survival were intricately linked to the changing seasons and climate. It directed migrations, availability of food sources and many bodily adaptations such as skin color or genetics. These changes can also facilitate great improvements to our health, immunity, and overall stress resilience. Unfortunately, in the modern society we rarely experience these effects and can stay in a constantly stable environment indefinitely. We can turn on the central heating or air conditioner at any moment and wear warm clothing.

Temperature appears to have a strong effect on respiratory diseases.

• Stewart (2015) has proposed several possible reasons why this seems to be the case: (1) people being in closer quarters to each other increases viral transmission, (2) lower temperatures help virions survive for longer on external surfaces, (3) the cold promotes susceptibility of catching an infection and (4) colder climate or reduced body temperature activates dormant viruses.
• Dormant viruses can become active during the winter when the host’s immunity is slightly compromised, thus increasing the risk of catching something else during spring or even reducing the likelihood of being infected with less impactful strains. It is well known that vitamin D levels, which is an important hormone for supporting the immune system, follows seasonal patterns, with peaks in late summer and troughs in winter. Seasonal nutrient deficiencies in other important vitamins and minerals like vitamin C, zinc or selenium also play a crucial role in the susceptibility and/or severity to these infections.

Effects of Fever and Heat on Infections

In humans, suppressing a fever with antipyretic medications increases the risk of influenza mortality and may lead to a higher risk of death in intensive care unit patients. However, a high fever isn’t always beneficial, especially if it gets out of control or during septic shock.

Raising body temperature strengthens the immune system by increasing white blood cells, lymphocytes, neutrophils, interferons and increasing the cytotoxicity of natural killer cells. Elevated core body temperature or fever also induces heat shock proteins that inhibit viral replication and reduce pro-inflammatory cytokines.

Benefits of Hyperthermic Conditioning and Sauna Therapy

Benefits:

• Taking a sauna has been associated with lower cardiovascular disease risk and improved heart health.
  • A Finnish study found that people who used the sauna 2-3 times a week had a 22% lower risk of dying from sudden cardiac events compared to those who did so only once a week. Subjects who went in the sauna 4-7 times a week had a 63% less likelihood to experience cardiac death and were 50% less likely to die from cardiovascular ailments compared to those who used it once a week. Their all-cause mortality was also 40% lower. The greatest benefits were found in those whose sauna sessions lasted 19 minutes or longer.
• Heat exposure improves insulin sensitivity by increasing the expression of a glucose transporter called GLUT4. This enables a faster clearance of glucose from the blood stream and directs it into muscle cells. In obese humans, two weeks of far infrared sauna sessions significantly improves systolic and diastolic blood pressure, flow-mediated dilation, fasting glucose, body weight and body fat.
• Sauna bathing is inversely associated with dementia and Alzheimer’s disease. Sauna sessions can increase endorphins and beneficial brain neurotrophic factors that facilitate the maintenance of already existing synaptic connections while simultaneously promoting the creation of new ones.
• Exposure to high temperatures upregulates heat-shock proteins (HSPs). HSPs help the body adapt to the heat and stress. HSPs also have additional benefits:
  • HSPs clear out accumulated free radicals and cellular debris similar to autophagy
  • HSPs repair damaged and misfolded proteins that disrupt homeostasis
  • HSPs increase glutathione and overall antioxidant activity
  • HSPs activate monocytes, dendritic cells and macrophages to improve antigen presentation and immune signaling
  • HSP20 promotes muscle relaxation and regulates cardiac muscle cell function
  • HSP elevation from exposure to heat has been shown to increase the lifespan of flies and worms up to 15%
• Sauna sessions strengthen the immune system by increasing white blood cell count. Because of its stimulating effect on the lymphatic system, saunas may help improve toxicant-induced health problems. This may result in less sickness and clearer skin.

A review article concluded: “Regular visits to the sauna significantly reduce the frequency and severity of influenza infections in children and adults.” Some researchers claim that taking the sauna regularly could be as protective as vaccination, at least against certain infections.

Since HSP70 inhibits the export of viral ribonucleoprotein complexes, hyperthermia via sauna sessions may reduce RNA viral replication.

Hyperthermia and sauna may prevent or dampen the cytokine storm response. The anti-viral (and anti-tumor) qualities of interferon are potentiated by elevations in temperature.

Viral warts have even been successfully treated with local hyperthermia, likely due to increased type-1 interferon. Many viruses have mechanisms to inhibit the production of interferons, making hyperthermia a potential strategy to circumvent this viral defense mechanism.

The minimal effective dose for facilitating thermal hormesis and stimulating the immune system seems to be at a core body temperature of around 100.4°F (38°C), basically, a temperature indicative of a fever. Based on Finnish studies, the optimal frequency for taking a sauna is between 15-30-minute sessions at 70°C to 100°C (156-212°F) 2-4 times per week. Doing more isn’t necessarily going to be better and you can even start to see diminishing returns in the health benefits at higher frequencies or longer durations. It’s important to consume some salt, perhaps ¼ to ½ tsp of salt and 10 oz. of water after a sauna session but this will depend on the individual.

Drinking alcohol prior to or during the sauna may be dangerous as it can promote stroke and death. High heat combined with alcohol intoxication raises blood pressure and is not a good combination.

Some additional antiviral effects with sauna use are mediated by the increase in nitric oxide (NO). NO is a transient gas and a signaling molecule involved with cardiovascular function and other physiological processes. NO been shown to inhibit replication of SARS coronavirus by suppressing the replication cycle. NO, or its derivatives, reduces the palmitoylation of nascently expressed spike (S) protein, which prevents the fusion between the S protein and its receptor, angiotensin converting enzyme. NO also decreases viral RNA production during the initial stages of viral replication. Put simply, NO seems to block the entry of SARS-CoV into the cell and may reduce its replication and lower the viral load.

• Because sauna therapy promotes the expression of endothelial NOS, endogenous antioxidant activity and lowers oxidative stress, this would theoretically help boost type-1 interferon production (which is inhibited by oxidative stress) and reduce loss of eNOS activity. Uncoupling of eNOS can lead to endothelial barrier dysfunction and acute lung injury during RNA infections. Thus, the use of sauna or other hyperthermic stressors may induce additional antiviral mechanisms by increasing NO production, which would seemingly help strengthen endothelial cells against oxidative stress during viral cytokine storms.
• Sauna-induced NO production also has benefits on cardiovascular function, blood flow, circulation, mitochondrial health, and hypertension.
• In type-2 diabetics, infrared sauna improves stress, fatigue, general health and social functioning indicators.
• Heart failure is associated with reduced nitric oxide and increased inflammation. A 15-minute infrared sauna session has been shown to significantly reduce diastolic blood pressure in patients with heart failure.
• One single sauna session for 30 minutes at 163.4°F in patients with cardiovascular risk factors reduced arterial stiffness and blood pressure. Sauna therapy also improves heart rate variability and arterial compliance.

Do Saunas Help Eliminate Toxins from the Body?

One of the major problems of living in our industrialized modern world is the high exposure to pesticides, heavy metals, plastics, phthalates and other chemicals. Most of our produce is sprayed with herbicides, hygiene products can be contaminated with aluminum, seafood can have high levels of mercury and cookware can leech toxins into our food. What’s worse, the very air we breathe can be polluted and filled with noxious fumes. It’s been estimated that 92% of the world’s population breathes polluted air.

The Hubbard protocol uses sauna combined with exercise, niacin and supplemental oils to eliminate persistent organic pollutants (POPs) and improve clinical symptoms in subjects exposed to them. In general, studies find a 25-30% decrease in POP levels in fat tissue and blood by heat-induced sweating. This has also been shown to increase IQ, neurocognitive function, work-related ableness and quality of life.

What is the Difference Between Infrared and Traditional Saunas?

Infrared (IR) saunas may provide additional unique benefits due to the delivery of infrared waves. Infrared waves are invisible and are a natural makeup of sunlight, although they have a longer wavelength than visible light. There are three types of infrared (IR) waves: near-infrared, mid-infrared, and far-infrared, the last of which can potentially improve endothelial function.

Traditional wooden saunas raise body temperature through the use of convection heat (heating the air around you), whereas infrared saunas warm up your body partially through this mechanism but also by heating you from the inside out. IR saunas heat deeper into the tissues, where they stimulate collagen synthesis and activate mitochondrial energy production. Infrared wavelengths also increase eNOS beyond any effect from increased core body temperature, suggesting that IR saunas work not only because of the rise in heat but by their infrared waves.

Regardless, both saunas meet the minimal effective dose for improved immunity and hormesis, but the hotter it gets, the more you end up being able to endure the heat.

Nasal hyperthermia can immediately relieve symptoms of the common cold and improve its course.

In conclusion, sauna and other hyperthermic therapies including inhaling hot air through the mouth and nose may have profound effects on immunity. Additionally, health benefits for sauna sessions may include maintaining good cardiovascular health, insulin sensitivity and stress resistance. Heat exposure also improves type-1 interferon activity, which play a critical role in combatting viruses and preventing their replication. Sauna sessions have been used for decades as a possible means to prevent and reduce symptoms of common colds, influenza, and pneumonia.

Cold Exposure and Immunity

Cold shock proteins (CSPs) are multifunctional RNA/DNA binding proteins that repair misfolded proteins and RNA. CSPs are represented by cold shock domains, which include about 70 different amino acids that bind to DNA.

The most predominant one in humans is the Y-box protein family, out of which Y-box protein-1 (YB-1) is a potential target in cancer therapy. Other CSPs in humans are Lin28, calcium-regulated heat-stable protein 1 (CARHSP1), PIPPin, and are upstream of N-RAS (UNR).

Cold shock proteins and adaptations to colder temperatures have been found to have several health benefits, including increased gene expression. Here are the most profound examples:

• Cold shock protein YB-1 is important for embryonic development and survival. Upstream of N-RAS (UNR) maintains a state of pluripotency for embryonic stem cells, which means they will be able to differentiate into any other tissue cell based on demand. This serves as a signal about the conditions of the particular environment in which the fetus finds itself in, thus preparing for it in advance before birth.
• Cold therapy might help with neurodegenerative disease by blocking neuronal apoptosis and inflammation. Poor oxygenation in the brain of newborn babies is often treated by cooling them to 33°C for three days. This reduces damage to the brain and increases survival.
• Cold may decrease arthritic inflammation. Patients with arthritis experience significantly less pain after taking a daily 2-minute cold shower for a week. This can also be an amazing tool for reducing muscle soreness or other pains. However, typically, cold therapy should not be used shortly after exercise, as it can blunt the adaptive hormetic benefits. In fact, sauna therapy or heat after exercise, actually increases the benefits of exercise by further enhancing the hormetic response.
• Shivering and lower temperatures activate brown adipose tissue, which improves mitochondrial functioning, increases metabolism and thermoregulation. Metabolic rate and energy expenditure get raised with cold therapy. Exposure to cold stimulates lipid metabolism, burns white fat, and decreases triglycerides. Both shivering and non-shivering thermogenesis increase uncoupling protein 1 (UCP1) or thermogenin that promotes stress adaptation, redox balance and browning of white fat into brown fat.
  • When obese men are put in a cold room (58˚F) for 6 hours a day, their metabolic rate increases by 14% after 10 days. In another study, 11 lean men were in a 67˚F room wearing a cooling vest for 90 minutes and their metabolism increased by 16.7% just 30 minutes later, with fat burning rising by 72.6%.
  • UCP1 expression in skeletal muscle mitochondria is considered to increase lifespan in other species. This is thought to be due to the prevention in the formation of reactive oxygen species (ROS). Things that promote UCP1 are exercise, fasting as well as cold and heat exposure.
• Cold exposure increases norepinephrine or adrenaline, which promotes attention span, alertness, and improved mood. Three weeks of cryotherapy has been shown to improve mood and anxiety in people with mild depressive disorders.
• Lower temperatures increase adiponectin, a protein that helps with blood sugar management. The cold promotes glucose uptake by stimulating a glucose receptor called GLUT4 and has been shown to have potential in those with type-2 diabetes. In one study of type 2 diabetics, sitting in 58˚F for 2-6 hours a day improved insulin sensitivity by 43% after 10 days. In other words, turning down the thermostat may turn on insulin sensitivity.
• Winter swimming reduces uric acid and increases glutathione. These are the body’s most powerful detoxification and antioxidant systems. However, it does create oxidative stress and lipid peroxidation in the short-term, but we then adapt to this acute stressor. That’s why the hormetic benefit has to include recovery.
• Exposure to cold stimulates the immune system similar to exercise and strengthens immunity. A daily contrast shower for 30 days led to a 29% lower self-reported work absenteeism due to sickness in healthy adults.

However, cold therapy also has negative side-effects that we should be aware of as hormesis works in a dose-specific manner:

• Cold immersion before exercise reduces maximum power output and performance in elite level cyclists. Prior to working out, it is actually better to have your muscles warmed up to prevent injuries.
• Post-workout cold exposure might block the muscle building signal and adaptations to resistance training. It is basically going to suppress the inflammation that gets created during exercise that you need for growth. That’s why it’s not ideal to be taking cold showers or ice baths right after working out.
• Although it doesn’t appear that the cold directly suppresses immunity, it can do so when you’re already stressed out or over-exerted. High intensity exercise has been shown to decrease immune functioning in the short term. If you drain your body’s adaptive resources with additional cold exposure, you might just predispose yourself to getting sick. Getting exposed to the wind or a draft may also increase the likelihood of catching a cold.
• Viruses seem to be more stable in cold and dry environments, enabling them to survive for longer. Influenza strands break out more in the winter, which is why they come in seasons. Human rhinoviruses replicate at a higher rate at temperatures below 37°C or 98.6°F. That’s why constantly being cold or suffering from low body temperature, as found in those with hypothyroidism, could make it easier for viruses to remain alive. This is just another reason why having a functional metabolism and good thyroid function are important. But no one stays in permafrost, unless you live in the Arctic, and brief episodes of a cold shower or winter swimming may not be an issue. It could strengthen immunity because of reasons discussed earlier as long as you’re coming from a recovered healthy state.

Both the cold and heat share similar properties when it comes to hormesis, reducing inflammation, improving cardiovascular health and thermoregulation. However, heat therapy is the clear winner over cold therapy, specifically in regard to having more evidence and less potential for side effects.

It’s also possible that cold therapy directly after heat therapy could inhibit some of the benefits, similar to inhibition of some of the benefits after exercise. On the flip side, winter swimming combined with saunas has been shown to increase lysosomal enzymes, which is associated with autophagy and removal of dysfunctional cell particles, but we don’t know if either alone would have been better. Rewarming after exposure to the cold induces autophagy so there may be benefits to cold shocking first and then heat shocking. Cold-shock proteins raise a protein called LC3, which is linked with autophagosomes and autophagy.

Huberman

Temperature: Cold & Hot Gonads

Temperature and day length are linked. Our biology evolved to these variables being correlated.

Ice baths and cold showers can have a positive effect on testosterone. There is a rebound of vasodilation after the cooling. More infusion of blood into the gonads as they are heavily vascularized. GnRH comes from neurons that start off in the nose, during early development, migrate into the hypothalamus, then the axons extend into the pituitary and release GnRH. Lots of vascularization here too. GnRH can then stimulate follicular-stimulating hormone, luteinizing hormone, which is released into the bloodstream. They reach the ovaries and testes and enter via the vascular system, but the dilation or constriction is modulated by neurons. The best way to shut a neuron down is to cool them. When the gonads are warmed up, they hyper-vasodilate and allow blood back in at excessive levels, leading to increased testosterone levels indirectly.

Excessively high heat is bad for the testes and sperm production. Heat alters the location and function of proteins that promote motility.

Cold Showers, Ice Baths, Cryotherapy

Shot of adrenaline in a cryochamber or cold bath, stimulate vasoconstriction (hard to get rid of heat), if it is truly cold and you are completely submerged the vasoconstriction won’t matter.

Palms, soles, and upper part of face have AVAs that can shunt blood from the arteries to veins, bypassing the capillaries, the nutritive vessels with high resistance.

Boundary Layers

If you are still while in a cold bath, you develop a boundary layer. A boundary layer is where the still water that is in contact with your skin is coming into equilibrium. If you move around, you’ll feel cold again.

Cooling Before Aerobic Activity to Enhance Performance

Aerobic activity that you can sustain, will benefit from cold showers before as it increases the capacity of your body mass to absorb excess heat. Longer to get to the sweat point. Can increase speed or endurance depending on their running style.

A few minutes in the shower is plenty. If you are in too long, your body will shut of the heat loss to keep your temperature from going below normal.

Anaerobic Activity Locally Increases Muscle Heat

The temperature of the muscles will increase during exercise (local effect). During rest, heat leaves the muscle but not very fast. It needs blood flow to do so, which is not being pumped much during rest. Heat production can go up 50-60-fold during anaerobic activity, but blood flow cannot.

Temperature Gates Our Energy Use

Most of the energy from our food is lost from heat. Individual muscles can reach hyperthermic limits before the body overall, to prevent core hyperthermia and messing with bodily systems.

An enzyme that is critical for getting fuel into mitochondria is temperature sensitive. It shuts off at a certain temperature, preventing fuel supply to mitochondria and exercise can no longer continue.

Local Versus Systemic Fatigue: Heat Is Why We Fail

There will still be a fatigue curve if you try to do an exercise in a different area. Systemic fatigue will contribute to the increased speed and reduced intensity of the new area.

The fatigue issue is not just the reduction of glycogen, the temperature is likely to be the cause. You can always cool off and go back to do more reps.

Cooling Off: Most Methods are Counterproductive

The body is a good insulator, it requires blood flow to cool off, rather than chucking a cold towel or ice pack on your neck.

Preoptic interior hypothalamus is considered our thermostat. Input form the body surface will be sent to the thermostat. Cooling the body surface only serves to trick the thermostat rather than solving the heat/fatigue issue. Cooling the core may even vasoconstrict your blood vessels, impairing overall heat loss.

Blood flow to the brain comes mostly from the carotid arteries and the vertebral arteries. If you put a cold towel around your neck, you are putting a cold stimulus into the brain making you feel cooler than what you are.

Exercise-Induced Brain Fog

A rise in temperature decreases cognitive capacity.

Hyperthermia

Thermal afferent information also goes to the somatosensory cortex. The information reaching the hypothalamus is a more integrated/average reading.

Symptoms of heat stroke – vasoconstriction, stop sweating, exhausted, miserable, cardiac drift.

People sometimes overcome this feeling by pushing harder.

Best Body Sites for Cooling: Palms, Foot Pads, Upper Face

Glaborus skin (no hair). We evolved these blood vessels to shunt blood across. Grabbing a glass, you can see the hand going white from shutting off blood flow in your palm. If you are bicycling on a hot day, you don’t want to squeeze the handle bars too hard, as it will limit your performance.

If you want to maximize your heat loss, don’t wear gloves or shoes.

Cooling Your Brain via The Upper Face; Concussion

The blood that perfuses these blood vessels in the face, returns in the venous supply to the heart. When you overheat, the direction of the blood vessels reverses. So, the cool blood from the facial region goes back in to cool the brain.

So, squeezing cool water on your head in between fights will actually help to cool the brain.

For injury to the brain, decrease swelling by decreasing heat.

Extraordinary (Tripling!) Performance by Cooling the Palms

Dips: Cooling to increase work volume. 40 dips and decreasing across sets. Over a few days of practice with hand cooling in between sets, he doubled performance by doing more reps and sets. Resulting in 300 dips at the end of the month (tripled performance).

Enhancing Recovery, Eliminating Soreness w/Intra-workout Cooling

DOMS from microtears when we extend workout capacity volume. DOMS go down in experiments with these cooling techniques.

Multiple Sclerosis: Heat Sensitivity & Amelioration with Cooling

Enhancing Endurance with Proper Cooling

They were doubling the endurance on the treadmill with continuous cooling. Even though they were working in a hot room.

Cool Mitt, Ice-Cold Is Too Cold, 3 Minutes Cooling

Arteria is the cool mitt technology. Standardized for 3-minute stints.

Ice cold is too cold as it causes vasoconstriction.

How You Can Use Palmer Cooling to Enhance Performance

Frozen blueberries/peas or a can passing back and forth.

To make sure there is no vasoconstriction you can get somebody to come feel your hand to see if you’ve vasoconstricted (cold hands).

Radiation, Convection, Heat-Transfer, Role of Surface Area

If I put my hands by a fire – radiation.

Convection – cool breeze/ wind chill factor.

Convection of heat exchange requires something like a liquid medium on the other side of your hands/feet. A solid surface won’t turn the temperature over well. You can use ice or cool packs though.

Cooling the hot blood heading towards the core rather than the blood that is close to it (axilla or groin).

Hypothermia Story, Ideal Re-Heating Strategy

Heating up a hypothermic person: If you’re under anesthesia you’re vasodilated, when you come out you are hypothermic and you vasoconstrict. Making it difficult to get heat in.

Take an arm, put it in an environment wrapped in a heating pad with negative pressure, pulling more blood into the limb, getting it heated, and heating the rest of the body.

Back to core temperature in 8 minutes instead of the usual 2-hour recovery.

You can go hotter on the glaborus skin as it takes the heat away faster. Hot water bottle on the hands and feet.

Paw-lmer Cooling for Dog Health & Performance

Getting dogs to stand in a body of water to calm down.

Warming Up, & Varying Temperature Around the Body

You can warm up on a cold day by wearing a knit cap and getting rid of it afterwards. If you can decrease heat loss from the head it will help. The ability of mitochondria to produce energy can be impaired at lower temperatures. Varies in different parts of the body.

Tympanic temperature is probably one of the better measures.

Cooling-Enhanced Performance Is Permanent

Less DOMS, better performance, actual gains to performance afterwards.

Anabolic Steroids versus Palmer Cooling

Anabolic steroids allow people to train more because they recover faster. Anabolic experiment (bench press studies) has a rate of 1% improvement per week. Palmer cooling had 300% in a month.

Female Athletic Performance

Same results with females.

Shivering & Cold, Metabolism

Deliberate shivering without cold happens with a fever. A good way of increasing metabolism.

Studies of Bears & Hibernation, Brown Fat

Bears go down to about 33 degrees. They also shiver. Ground squirrels can go down to the environmental temperature. When animals come out of hibernation they shiver like crazy. At cold temperatures they are essentially shut down and can’t shiver so they compensate after (once they reach about 15 degrees). They use brown fat at those lower temperatures. Big patches around the heart for survival in these animals.

Brown Fat Distribution & Activation in Humans

Brown fat is distributed amongst other fat tissues (not as discrete as the scapula thoughts).

Ice on the scapula/spinal cord, by the vertebral arteries, cold source to the brain, hypothalamus thinks it is cold, shivering.

Consistently exposed to cold to increase brown fat.

Brain Freeze, Ice Headache: Blood Pressure, Headache

Roof of the mouth is close to the hypothalamus. Vasomotor change/ increase in blood pressure.

Some people seem to feel that heating their palms helps to rid themselves of migraine (preliminary/anecdotal).

Very hot peppers can cause thunderclap headache and death in some

Fidgeters, Non-Exercise Induced Thermogenesis

Hyperthyroid people vs hypothyroid people display these movement examples.

How Pre-Workout Drinks, & Caffeine May Inhibit Performance

Jittery -> increase NEAT.

The muscle releases adenosine, which causes the blood vessels to open up. Caffeine is an adenosine receptor blocker. May impair performance.

Sleep, Cold, Warm Baths, Screens, & Socks

CBT gets more attention now. Increasing sleep hygiene, regularity, no screens, relax – don’t work up to bed, bath before, cooler environment. Stay cooler because it is easier to thermoregulate.

Put the glabular surfaces out of the bed to help thermoregulate. Socks promote thermal comfort, which is why we all wear them.