HydroBlog March 23, 2020

Combating COVID-19: Practical Suggestions

Hydrotherapy Research

The effectiveness of hydrotherapy treatments for various conditions has been confirmed through research findings, especially in the areas in which it is most commonly utilized as a treatment modality.  But beyond this, some fascinating discoveries have been made about the effectiveness of certain hydrotherapy treatments to improve conditions which have not conventionally been treated with it, such as chronic diseases, pneumonia and cardiovascular conditions.    In this section we will take a look at significant findings in the field of hydrotherapy research.


Discussion of compelling research on immune system benefits of hydrotherapy with some evidence of possible reduction in COVID-19 cases in countries where frequent use of contrast therapy is used (hot and cold, such as sauna ending with cold, or hot and cold shower). Presented by Roger Seheult, DM (Board Certified in Internal Medicine, Pulmonary Disease, Critical Care, and Sleep Medicine).


1. Hooper PL. Hot-tub therapy for type 2 diabetes mellitus [Internet]. N Engl J Med 1999 Sep; 341(12):924-5 Available at: http://www.nejm.org/doi/full/10.1056/NEJM199909163411216

  • This study found that immersion in heated pool water of 37 to 40 degrees resulted in reductions in blood glucose levels, medication and weight. It was hypothesized that insulin-mediated glucose uptake may be facilitated by increased skeletal muscle blood flow related to the warm water immersion. Responses to the article highlight the importance of using extreme caution with hydrotherapy for patients with diabetes, especially in regards to the contraindication of foot soaking or using hot water on the feet; http://www.nejm.org/doi/full/10.1056/NEJM200001203420318

 2. Elliot D, Gilkes L. Australian Physiotherapy Association Aquatic Group - Diabetes Information Pack 2010 [internet]. World Confederation for Physical Therapy. London (UK) WCPT, 1951 – [updated 2012 Jan 10; cited 2013 Feb 10]. Available from: http://www.wcpt.org/node/37485

  • This article highlights several aquatic physiotherapy research reports that indicate improvement of blood glucose levels (BGL) related to pool exercise. Aquatic physiotherapy is typically done in warm water. Under the same section of the article a discussion of precautions for these clients is also made, including the issue of predisposition to burns at much lower temperatures than would usually be expected, as well as hypoglycemia related to the BGL lowering effects of the exercise session. It mentions that BGL levels were shown to be up to 27% lower after a session of aquatic physiotherapy.

 3. Saeki Y. The effect of foot-bath with or without the essential oil of lavender on the autonomic nervous system: a randomized trial. Complement Ther Med. 2000 Mar;8(1):2-7. PubMed PMID: 10812753 Available at: http://www.ncbi.nlm.nih.gov/pubmed/10812753

  • In this Japanese study investigating the effects of hot foot bath on the autonomic nervous system, it was found that according to spectral analysis parasympathetic nerve activity was significantly increased during the foot bath. The study design was a randomized crossover controlled study and the intervention involved women soaking their feet in hot water for 10 minutes with or without lavender oil. Electrocardiogram, fingertip blood flow and respiratory rate were recorded, and spectral analysis of heart rate variability was used to evaluate autonomic function.

4. Komamura K. Appendicular thermal therapy for heart failure. Nihon Rinsho. 2009 Mar; 67(3):637-43. PubMed PMID: 19280944 Available from: http://www.ncbi.nlm.nih.gov/pubmed/19280944

  • This Japanese study assessed the effects of steam foot bath in 4 male patients with cardiomyopathy and congestive heart failure awaiting heart transplantation. Findings included that the grade of mitral regurgitation tended to decrease while endothelial function significantly increased, so it was concluded that steam foot bath therapy may be safe and beneficial for patients with endstage heart failure awaiting transplantation (that would be assuming they are not diabetic, in which case the use of heat to the feet would be contraindicated).

5. Kluger N. Sauna: cardiac and vascular benefits and risks. Presse Med. 2011 Oct;40(10):895-9. PubMed PMID: 21414742 Available from: http://www.ncbi.nlm.nih.gov/pubmed/21414742

  • This article in French discusses in the English abstract in regards to the question of whether sauna bathing is safe for those with cardiovascular pathologies. It acknowledges the fact that it is considered to be safer for patients with such conditions to avoid sauna bathing, but also cites that clinical studies have shown sauna bathing to be safe among patients with stable heart conditions such as hypertension, coronary disease, and stable controlled chronic heart failure. It also refers to Japanese preliminary studies that seem to show some benefits for patients with chronic congestive heart failure.

6. Allison TG, Miller TD, Squires RW, Gau GT. Cardiovascular responses to immersion in a hot tub in comparison with exercise in male subjects with coronary artery disease. Mayo Clin Proc. 1993 Jan;68(1):19-25. PubMed PMID: 8417250  Available from: http://www.ncbi.nlm.nih.gov/pubmed/8417250

  • Regarding the question of the safety of hydrotherapy for those with cardiovascular conditions, a study from the world-renown Mayo Clinic indicated that the passive heating that occurs during soaking in a hot tub was less stressful to the body than light exercise among 15 men with clinically stable coronary artery disease. Dr. Thomas Allison was quoted by the LA times discussing the research by offering the precaution that water temperatures should not exceed 104 degrees Fahrenheit, and the time should not exceed 15 minutes. LA times article available from; http://articles.latimes.com/1991-10-06/news/ss-76_1_hot-tub

7. Yoon SJ, Park JK, Oh S, Jeon DW, Yang JY, Hong SM, Kwak MS, Choi YS, Rim SJ, Youn HJ. A warm footbath improves coronary flow reserve in patients with mild-to-moderate coronary artery disease. Echocardiography. 2011 Nov;28(10):1119-24. PubMed PMID: 21854441 Available at: http://www.ncbi.nlm.nih.gov/pubmed/21854441

  • Another study highlighting the recent trend in discoveries of potential benefits for individuals with stable cardiovascular conditions is this one from Korea which showed significant increases in diastolic coronary flow and improvements in coronary flow reserve related to a warm foot bath among 21 patients with mild to moderate coronary artery disease.



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Because Hydrotherapy Interest Group is committed to continual improvement in seeking to provide accurate information on www.hydroreference.com, we invite anyone who is aware of pertinent information, current research about hydrotherapy or conditions effected by hydrotherapy to please contact HIG.

It should be noted that hydrotherapy treatments can result in serious injury or complications under some circumstances. Prior medical advice should always be sought and extreme caution taken when performing any kind of hydrotherapy treatments for individuals with chronic diseases or decreased skin sensitivity. Hydroreference.com does not recommend the use of hydrotherapy for any condition without prior consultation with a physician or qualified healthcare provider.