Infra Red Sauna>

Cardiovascular Benefits

While the moisture on the surface of the skin evaporates and cools the body, a number of other changes occur in the body to release the heat as quickly as possible. The heart beats harder and faster , pumping more blood through the dilated blood vessels, achieving the conditioning benefits of continuous exercise.

Passive Cardiovascular Conditioning Effects

The Infrared Thermal System makes it possible for people in wheelchairs, or those who are otherwise unable to exert themselves, or who won't follow through on an exercising and conditioning program to achieve a cardiovascular training effect. This also allows for more variety in any ongoing training program. "Many of us who run do so to place a demand on our cardiovascular system, not to build big leg muscles. Regular use of a sauna may impact a similar stress on the cardiovascular system, and its regular use may be as effective, as a means of cardiovascular conditioning and burning of calories, as regular exercise." - Journal of the American Medical Association 8/7/81.

Due to the deep penetration, over 1.5" into the skin, of the infrared rays generated by the Infrared Thermal System, there is a heating effect deep in the muscular tissues and the internal organs. The body responds to this deep-heating effect via an hypothalamic-induced increase in both heart volume and rate. This beneficial heart stress leads to a sought-after cardiovascular training and conditioning effect. Medical researches confirm the use of a sauna provides cardiovascular conditioning as the body works to cool itself and involves substantial increases in heart rate, cardiac output and metabolic rate. As a confirmation of the validity of this form of cardiovascular conditioning, extensive research by NASA in the early 1980's led to the conclusion that infrared stimulation of cardiovascular function would be the ideal way to maintain cardiovascular conditioning in American astronauts during long space flights. Blood flow during whole-body hypothermia is reported to rise from a normal 5 ~ 7 quarts per minute to as much as 13 quarts per minute.

"The 1980's was the decade of high-impact aerobics classes and high-mileage training. Yet there was something elitist about the way exercise was prescribed. Only strenuous workouts would do, you had to raise your heart rate to between X and Y, and the only way to go was to go for the burn. Such strictures insured that most 'real' exercisers were relatively young and in good shape to begin with. Many Americans got caught up in the fitness boom, but probably just as many fell by the wayside. As we've reported, recent research shows that you don't have to run marathons to become fit - that burning just 1,000 calories a week is enough. Anything goes, as long as it burns these calories." - Wellness Letter, 10/90, University of California, Berkeley.

From The Journal of the American College of Cardiology

March 6, 2002 (Volume 39, Number 5)

Repeated Sauna Treatment Improves Vascular Endothelial and Cardiac Function in Patients With Chronic Heart Failure

Kihara T, Biro S, Imamura M, et al
Journal of the American College of Cardiology. 2002;39(5):754-759

Rationale and Design

This group previously showed that thermal therapy by dry sauna improved clinical variables and cardiac output in congestive heart failure (CHF) patients. In the current study, the investigators sought to determine the mechanisms of this improvement and the effects of thermal therapy on endothelial function.

Twenty patients with CHF class II or III and mean age 62 ± 15 years were studied. The mean ejection fraction was 38 ± 14%. The patients were placed supine in a 60-degree C infrared-ray dry sauna for 15 minutes and then removed and kept at bed rest with a blanket for an additional 30 minutes. Sauna therapy was performed once a day 5 days a week for 2 weeks.

Symptoms were evaluated with a self-administered questionnaire, and patients were divided based on their responses of improved or no change. Fasting blood was obtained to evaluate neurohumeral factors, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and tumor necrosis factor (TNF). Endothelial function was evaluated using a noninvasive ultrasound method to determine hyperemic response in the right arm and response to sublingual nitroglycerin.

Results

All enrolled patients completed the study. Clinical symptoms improved in 17 of 20 patients and were unchanged in 3. Two-week sauna therapy significantly increased the %FMD (flow-mediated dilation) in the improved group but not in the unchanged group. BNP concentrations were lower after 2 weeks of therapy but ANP and catecholamine levels were unchanged. The left ventricular end-diastolic dimension decreased significantly compared with baseline. There was a significant correlation between the change in %FMD and the improvement in BNP (P < .0005).

Editor's Comment

It is known that CHF patients have impaired endothelial-dependent vasodilatation and the proposed mechanism for this is decreased peripheral vascular production of endothelium-derived nitric oxide. Endothelial function in CHF can be improved with ACE inhibitors, physical training, and vitamin C. This study showed that 2 weeks of sauna therapy also improved endothelial function and decreased the BNP. BNP levels are an important marker of cardiac status and prognosis in heart failure, as highlighted by several recent studies. The sauna therapy also reduced systolic blood pressure. The precise mechanism by which sauna therapy improves CHF is not clear from this study, but the authors hypothesize that sauna therapy acutely causes vasodilatation, which leads to upregulation of eNOS protein in the endothelium. Clinically, it is worth commenting that sauna therapy may be widely applicable to CHF patients and could also be used in patients incapable of exercise.