Have you ever wondered why sauna bathing feels so good? Or why it’s supposedly so healthy? As a child, I didn’t like the steamy, hot air and couldn’t fathom what adults enjoyed about taking a sauna. Today, I’d love to have one at home, especially in winter. View points change. =)
The word “sauna” is of Finnish origin, apparently the only Finnish word that made it into the English language. Merriam-Webster defines it as: “A Finnish steam bath in which the steam is provided by water thrown on hot stones; also : a bathhouse or room used for such a bath.” The recommended temperature is 80 – 100 °C (176 -212 °F) at face level and 30 °C at floor level. The air has a relative humidity of 10-20% (Hannuksela & Ellahham 2001). A usual sauna bath consists of several short stays between 5 and 20 minutes, interspersed with cooling-off periods, and followed by adequate fluid intake.
Sauna bather cooling off the natural way.
In Finland, sauna bathing follows a long traditionof thousands of years (Hannuksela & Ellahham 2001), as reflected by an estimated two million (often private) saunas among a population of about 5.2 million people (Kenttaemis & Karkola 2008). Hot steam bathing is not exclusive to Finland and Skandinavia, however, but an old practice of different cultures around the world. Known as sweat lodge in North America, as temazcal in South America, as banya in Russia, and as oukup in Indonesia, among many others, the concept is the same, although methods may differ in humidity levels, heat generation, and purpose. The cleansing effects of sweating has been used in hygiene rituals since ancient times and later in medicine of the Persians, Romans, and Greeks since the 8th century BC (Kowatzki et al. 2008).
So while sauna bathing is an old, traditional practice the world over for cleansing and rejuvenating the body, what does current science say about its health benefits? How often should we enjoy a sauna? What’s the best practice, and are there pitfalls to avoid while sauna bathing? Let’s take a look.
How the body reacts to sauna bathing
Cardiovascular effects
Within a few minutes, skin temperature rises up to 40°C, and sweating sets in fairly quickly. We lose up to 0.5 l of sweat during a typical sauna bath (Hannuksela & Ellahham 2001). Skin blood flow, heart rate, and cardiac output increase, whereas blood flow to internal organs and muscles decreases. Blood pressure may remain unchanged, increase, or decrease (Hannuksela & Ellahham 2001).
Despite these acute, transient cardiovascular changes, most healthy people, including children, tolerate sauna well, as do most patients with hypertension, stable angina pectoris, coronary heart disease, or prior myocardial infarction (Hannuksela & Ellahham 2001, Roine et al. 1992).In fact, regular sauna bathing twice a week lowers the blood pressure in patients withhypertension (Laukkanen et al. 2015, Nguyen et al. 2005).
Despite a very small fraction of the population dying during sauna (Rodhe & Eriksson 2008), the risks of myocardial infarction, coronary death, and sudden death are lower during sauna bathing than during other daily activities (Hannuksela & Ellahham 2001), and a recent prospective study in male sauna bathers found that long, hot sauna baths were associated withfewer deaths from heart attacks, strokes, various heart-related conditions, and other causes(van der Wall 2015). This is also echoed by Basford et al. (2009), who stated that “the question arises whether this prohibition on sauna bathing is overly restrictive. It may be that not only are safety concerns needlessly limiting the activities of people with CHF [chronic heart failure], but also that excessive caution is preventing the use of a potentially beneficial modality. This study suggests that systemic sauna bathing at moderate temperatures may be safe and well tolerated by people with CHF”. Two previous papers arrived at the same conclusion, saying that repeated sauna use not only improved cardiac function and clinical symptoms in chronic heart failure patients (Kihara et al. 2002), but also increased their sense of wellbeing and exercise tolerance (Miyamoto et al. 2005). Note that saunas used in these latter studies were modified to 60°C.
Along similar lines, Gayda et al. (2012) reported that even a single Finnish sauna bath induces changes in the autonomic control of the cardiovascular system in patients with untreated high blood pressure, as evidenced by increased sympathetic and decreased parasympathetic drive. It would be interesting to see how regular sauna use would pan out for these patients, as long-term sauna bathing has been shown to lower blood pressure and enhance left ventricular and endothelial function in men (Lim 2015).
Effects on the lungs
Sauna bathing decreases lung congestion and improves lung function (Hannuksela & Ellahham 2001). People with chronic bronchitis and asthma reported improved breathing.
Effects on the skin
Regular sauna bathing causes no harm to the skin and may benefit people with psoriasis (Hannuksela & Ellahham 2001). Sweating also allows the body to eliminate heavy metals like nickel, copper, mercury, aluminium, and chromium, among other toxins (Cecchini & LoPresti 2007, Hohnadel et al. 1973). Sauna does not cause drying of the skin (Hannuksela & Ellahham 2001) and renders it soft and smooth. People who enjoy sauna regularly adapt to this by downregulating their ionic excretion through urine and sweat, thereby retaining more salts compared to irregular sauna bathers, pointing to a training effect in sweat production (Kowatzki et al. 2008). People with acne may benefit from sauna bathing, as regular sauna decreases facial sebum levels, a major contributing factor to the presence of acne. Future studies will also address the potentially positive effect of sauna in atopic dermatitis patients (Kowatzki et al. 2008).
All up, research suggests that regular sauna bathing exerts a protective effect on epidermal functions, a stimulating effect on skin blood circulation, and no negative effects on skin hydration. Regular sauna use might indeed be beneficial for dry skin conditions (Kowatzki et al. 2008).
Effects on fertility & pregnancy
Sauna bathing does not influence fertility (Hannuksela & Ellahham 2001). Generally, sauna poses no threat to healthy pregnant women. However, women experiencing pregnancy complications should discontinue sauna bathing (Hannuksela & Ellahham 2001).
Effects on common cold prevention
Sauna seems to decrease incidence of the common cold, but not to significantly affect duration and severity once contracted (Ernst et al. 1990). It also seems to take some time (c. three months) for regular sauna bathing to extend a cold-preventive effect (Ernst et al. 1990).
Effects on headaches
Great news for people suffering from regular headaches! Sauna may be part of your solution: a recent New Zealand study found participants experienced relief from chronic tension-type headaches after adhering to an eight week sauna regimen, bathing three times a week for 20 minutes. Headache intensity decreased by 44%, approximating or exceeding the success of medications and other treatment methods (acupuncture & physical therapy). This positive effect registered six weeks into the intervention. The authors concluded: “These results show that regular sauna bathing may provide a promising non-pharmaceutical, self-directed management option that requires minimal medical input” (Kanji et al. 2015).
Effects on athletic performance & recovery
Pilch et al. (2013) found that a sauna bath induces higher thermal stress in untrained subjects compared to athletes, who exhibit a more efficient transport of heat, earlier onset and higher intensity of sweating. People who habitually sweat (e.g. eager sauna bathers, athletes, people working in hot environments) should consider replenishing trace elements, as frequent sweating may lead to their loss and a possible deficiency (Hoshi et al. 2001).
Athletes also show a stronger response in their immune system to the heat stress induced by sauna: their white blood cell (neutrophil, basophil, lymphocyte, monocyte) counts increase. Observed changes in the white blood cell profile suggest a faster mobilization of cells in the first line of immune defence in athletes compared to untrained people after a sauna bathing session. Thus, “sauna bathing could be recommended for athletes as a means of enhancing immunological defence” (Pilch et al. 2013).
Sauna may also be useful for recovery from athletic performance: Lee et al. (2012) found that both full immersion bath and mist sauna (at 40°C) induced recovery from muscle fatigue. Endurance performance of sub-elite runners also increased after three weeks of post-training sauna bathing (Scoon et al. 2007). And Stanley et al. (2015) add that post-exercise sauna bathing may offer a time efficient means by which to stimulate heat acclimation in athletes required to adjust to different climate zones.
For those who prefer to visualize themselves healthy and well over going to the gym: you may potentiate your efforts by sauna bathing! Gryka et al. (2014) found a positive effect of sauna on people’s lipid profile, similar to the effect obtained through moderate-intensity physical exercise. They also concluded that sauna bathing may represent an alternative method in prevention of atherosclerosis for people with dysfunctional motor organs. (If you thought I was kidding above in regards to visualizing, you may enjoy this read or this post, which both touch on the incredible power of our mind. =) )
Effects on rheumatic disease
Sauna may alleviate pain and improve joint mobility in people suffering from rheumatoid disease. Patients with chronic neuropathic pain also reported pain relief (Hannuksela & Ellahham 2001).
Effects on wound healing & sutures
Despite the popular and persistent belief that sauna bathing (heat & sweating) enhances wound swelling and may predispose to postoperative bleeding, thus negatively affecting wound healing, scientific evidence for this is apparently lacking (Papp & Alhava 2003). As a rule of thumb, patients who can return home within three days of surgery can likely enjoy sauna bathing with sutures. This includes small traumatic wounds, wounds after excisions for cutaneus of subcutaneus lesions, scar revisions, and all other wounds where late postoperative swelling is unlikely (Papp & Alhava 2003).
Sauna and cerebral palsy patients
Iiyama et al. (2008) found that cerebral palsy patients not only enjoyed sauna, but also benefited from it, as they showed improved peripheral circulation during and after sauna. Theirs was an adjusted regimen of 15 minutes at 60°C (dry infrared sauna).
No comments:
Post a Comment