German medical researchers concluded one session of Far Infrared Radiant Heat Therapy for over 1 hour can have significant reduction of blood pressure thanks to persistent peripheral vessels dilation. They also noted that blood viscosity was improved. After 1 hour of far infrared radiance, there is a significant decrease of blood pressure, cardiac ejection resistance, total peripheral resistance and significant increase of heart rate, stroke volume, cardiac output and ejection fraction. In simple terms; it places demands upon the cardiovascular system, making the heart pump harder and producing a drop in diastolic blood pressure.

Infrared Heat and Coronary Effect Finnish researchers, reporting on the regular use of saunas state "there is abundant evidence to suggest that blood vessels of regular sauna-users remain elastic and pliable longer due to the regular dilation and contraction" of blood vessels induced by sauna use.

A group of hypertensive patients was studied using far infrared saunas, to carefully evaluate the effects on the circulatory system. With each infrared session, there was a decrease of blood pressure, cardiac ejection resistance, and total peripheral resistance in every subject. There was also a significant increase of heart rates, stroke volumes, cardiac outputs and ejection fractions. The researchers cite these last three effects as evidence that stimulation of the heart during infrared induced hypothermia is well-compensated, while the prior list of effects show clear detail of the microcirculatory changes leading to the desired result of lowering blood pressure.

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 raining 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 a hypothalamic-induced increase in both heart volume and rate.  This beneficial heart increases in heart rate, cardiac output and metabolic rate.  As a confirmation of the validity of this from 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 aerobic 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.