What Are The Health Benefits Of Cold Exposure?

Welcome to my blog post discussing the health benefits of cold exposure.

You may also be interested in these two blog posts on sauna therapy – the combo works a treat!

• Optimise Health With Sauna Therapy At Home: click here.
• Sauna Therapy, A Key Health Hack: click here.

Winter swimming may increase body tolerance to stressors and achieve body hardening. When practiced by individuals who are in good general health adopting a regular, graded and adaptive mode, winter swimming seems to confer cardiovascular (CV), and other health benefits.

Cold Exposure And Depression

A case report described a 24-year-old woman with symptoms of severe depression and anxiety. The patient had been treated since the age of 17, and the symptoms did not respond to conventional therapies, including Fluoxetine or Citalopram. After the birth of her daughter, she wanted to be free of medication and symptoms. For this purpose, a novel intervention comprising of a weekly program involving cold water swimming was developed. This resulted in an immediate improvement in mood after each swim and a sustained and gradual reduction in the symptoms of depression. The intervention ultimately led to a reduction in medication use and then finally to a discontinuation of the medication.

After one year of therapy with cold water swimming, she was medication-free. Due to the increase in catecholamines, cold water swimming could be a treatment for depression as it activates the sympathetic nervous system and increases the concentration of norepinephrine and β-endorphin (6).

Does Cold Exposure Boost The Immune System?

We found significant changes in hemoglobin concentration, the number of red blood cells, the hematocrit index and mean corpuscular volume of red blood cell and the percentage of monocytes and granulocytes after the winter swimming season. The response to cryogenic temperatures was milder after five months of winter-swimming. The obtained results may indicate positive adaptive changes in the antioxidant system of healthy winter-swimmers. These changes seem to increase the readiness of the human body to stress factors (8).

Changes in uric acid and glutathione levels during ice-bathing suggest that the intensive voluntary short-term cold exposure of winter swimming produces oxidative stress. We investigated whether the repeated oxidative stress in winter swimmers results in improved antioxidative adaptation. The baseline concentration of GSH and the activities of erythrocytic SOD and Cat, were higher in winter swimmers. We interpret this as an adaptative response to repeated oxidative stress, and postulate it as a new basic molecular mechanism of increased tolerance to environmental stress (9).

How Long Do We Need To Be In The Cold?

Well it partly depends on how accustomed you are to being in the cold, and how cold it is.

It is interesting to note that the ice swimmer only spends a few minutes immersed in cold water, however, the short exposure duration is still sufficient to illicit a measurable physiological response. For example, blood tests performed immediately before and after a 150 m winter swim at 6 °C showed that the leukocytes (neutrophil granulocytes, lymphocytes and monocytes) increased significantly in the blood due to the cold, so that protection against inflammation and respiratory infections can occur. Another study also showed an increase in leukocytes and monocytes, which was seen as a sign of an improvement in the body’s response to stress. However, the clinical significance of these findings is still uncertain (6).

What About Heat And Cold Exposure?

One paper (1) concluded that, although acute warm and hot temperatures are stressful for humans, the human body also adapts physiologically to repetitive heat sessions, leading to improved heat tolerance and ultimately also decreased mortality and reduced risks for brain disorders such as dementia and Alzheimer’s disease. Therefore, similarly to hypoxia or altitude, heat or cold stress could also be applied as an independent or adjunct therapy to exercise and physical activity to maintain or improve human health, particularly among those people who do not want to or cannot exercise.

It seems that the best benefits in cardiovascular and all-cause mortality will, however, be obtained by increasing physical fitness combined with sauna bathing, highlighting the fact that several lifestyle habits affect human health.

What Causes The Health Benefits Of Cold Exposure?

When entering a cool environment, the human body will adjust to maintain heat balance. Heat balance can be restored via two strategies:

• Reducing heat loss
• Increasing heat production.

Heat loss is minimised by cutaneous vasoconstriction, which decreases heat transfer from the core to the skin and other distal parts of the body.

On the other hand, heat production can be increased by non-shivering and shivering thermogenesis. Shivering especially is a very efficient way to produce heat.

Peak shivering intensity can increase heat production close to five times over basal metabolic rate.

Numerous hormonal and nervous system adaptations contribute to the adaptation to cold that occurs in experienced swimmers. From the cardiovascular health point of view, one of these mechanisms can be called cold-induced vasodilation, which means that, after initial exposure to cold and resulting vasoconstriction in limbs, a period of vasodilation is observed that enables the return of warm blood to the fingers and other distal body parts.

It is known that this periodic cold-induced vasodilation reflects a vasodilation in both muscle and cutaneous vasculature. It is likely to stimulate shear stress-mediated improvements in vascular function leading to better health of the peripheral circulation.

It is also likely that repeated extreme temperature variations such as sauna bathing and ice-cold swimming are particularly strong mediators of this effect. When an individual returns to the sauna after a swim in ice-cold water, this effect is evidenced by a feeling of swollen hands and legs together with strong pulsation sensations as blood flow is strongly stimulated by these extreme variations in temperature.

Cold water and ice swimming require preparation, acclimatization and more importantly, cold water immersion experience and should be undertaken only with appropriate supervision in order to avoid injury or death. Even in the most experienced ice swimmers, cold water immersion carries risk (6).

Summary

The health benefits of cold exposure are clear then.

Cold water swimming (ice, cold and winter swimming) is an exciting new discipline and further research is required to fully understand the health benefits of its undertaking (6).

It’s pretty simple isn’t it? We should be consciously exposing ourselves to ‘the elements’ knowing that we are building our resiliency by doing so.

References

1. Effects of heat and cold on health, with special reference to Finnish sauna bathing: click here.
2. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure: click here.
3. Cold-induced thermogenesis in humans: click here.
4. Cardiovascular diseases, cold exposure and exercise: click here.
5. Pregnancy, cold water swimming and cortisol: The effect of cold water swimming on obstetric outcomes: click here.
6. Cold Water Swimming-Benefits and Risks: A Narrative Review: click here.
7. Winter Swimming: Body Hardening and Cardiorespiratory Protection Via Sustainable Acclimation: click here.
8. Winter-swimming as a building-up body resistance factor inducing adaptive changes in the oxidant/antioxidant status: click here.
9. Improved antioxidative protection in winter swimmers: click here.
10. Gender-related effect of cold water swimming on the seasonal changes in lipid profile, ApoB/ApoA-I ratio, and homocysteine concentration in cold water swimmers: click here.