Infrared sauna

  (Redirected from Waon therapy)

Infrared sauna also called infrared therapy or Waon therapy uses infrared heaters to emit infrared light experienced as radiant heat which is absorbed by the surface of the skin.[1] Saunas heat the body primarily by conduction and convection from the heated air and by radiation of the heated surfaces in the sauna room. Because of this, infrared therapy is not considered a sauna by Finnish sauna societies.[2] Nevertheless, "Infrared Sauna" and "Infrared Therapy" are respectively a methodology and a terminology in the application of the infrared electromagnetic field spectrum to the human body.

The interior of an infrared therapy room.


A 2018 meta-analysis of nine clinical trials found that five weekly sessions of infrared sauna for 2 to 4 weeks, was associated with a significant reduction in brain natriuretic peptide (BNP — a marker of heart failure progression) and cardiothoracic ratio (an indicator of heart enlargement), and improved left‐ventricular ejection fraction, but no significant effect on left‐ventricular end‐diastolic diameter, left atrial diameter, systolic blood pressure, or diastolic blood pressure.[3]

Waon (Japanese: "soothing warmth") therapy is a form of IR sauna developed in Japan, used for patients with chronic heart failure and other conditions.[4] Waon therapy has been reported to improve many indicators of heart function, including cardiac output, stroke volume, ejection fraction, while also having benefits in vascular function including decreased vascular resistance and blood pressure.[4][5] In a 5-year open-label trial, patients receiving Waon therapy in addition to usual care experienced a decrease in cardiac death and rehospitalisation after cardiac events compared to patients receiving usual care alone.[6]

Some infrared therapy proponents claim that the IR is an effective method for considerably raising the rate of energy expenditure in the body. Proponents typically quote the Journal of the American Medical Association stating: "A moderately conditioned person can easily sweat off 500 grams in an infrared room, consuming nearly 300 kcal, which is equivalent to running 2–3 miles. A heat-conditioned person can easily sweat off 600–800 kcal with no adverse effects. While the weight of the water loss can be regained by drinking water, the calories consumed will not be." However, this conclusion drew significant criticism, at least because it implies that individuals living in warm climates, where liters of sweat are generated per day, would require hundreds or thousands of additional kilocalories to survive, which is known not to be the case.[7][8]

There are claims of detoxification which lack scientific evidence.[9]

The prevalence of serious health claims associated with infrared saunas has prompted some regulatory agencies to issue public safety warnings about the use of these devices. There were fears that patients may refuse conventional medical treatments in favour of infrared sauna therapy.[10]


  1. ^ Naik S (21 September 2008). "Infrared Radiation". Retrieved 12 December 2013.
  2. ^ Rice C (12 July 2017). "Don't Call it Sauna". Sauna Digest. Medium.
  3. ^ Källström M, Soveri I, Oldgren J, Laukkanen J, Ichiki T, Tei C, et al. (November 2018). "Effects of sauna bath on heart failure: A systematic review and meta-analysis". Clinical Cardiology. 41 (11): 1491–1501. doi:10.1002/clc.23077. PMC 6489706. PMID 30239008.
  4. ^ a b Miyata M, Kihara T, Kubozono T, Ikeda Y, Shinsato T, Izumi T, et al. (October 2008). "Beneficial effects of Waon therapy on patients with chronic heart failure: results of a prospective multicenter study". Journal of Cardiology. 52 (2): 79–85. doi:10.1016/j.jjcc.2008.07.009. PMID 18922381.
  5. ^ Cho GY, Ha JW (June 2010). "Waon therapy, can it be new therapeutic modality in heart failure patients?". Journal of Cardiovascular Ultrasound. 18 (2): 43–4. doi:10.4250/jcu.2010.18.2.43. PMC 2920462. PMID 20706567.
  6. ^ Kihara T, Miyata M, Fukudome T, Ikeda Y, Shinsato T, Kubozono T, et al. (April 2009). "Waon therapy improves the prognosis of patients with chronic heart failure". Journal of Cardiology. 53 (2): 214–8. doi:10.1016/j.jjcc.2008.11.005. PMID 19304125.
  7. ^ Dean W (August 1981). "Effect of sweating". JAMA. 246 (6): 623. doi:10.1001/jama.1981.03320060027013. PMID 7253113.
  8. ^ Searle AJ (January 1982). "Effects of the sauna". JAMA. 247 (1): 28. doi:10.1001/jama.1982.03320260016012. PMID 7053434.
  9. ^ Beever R (July 2009). "Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence". Canadian Family Physician. 55 (7): 691–6. PMC 2718593. PMID 19602651.
  10. ^ "Infrared saunas not authorized to treat any medical conditions". Health Canada. Public Health Agency of Canada. 4 July 2019.