Like Dr. William Donald Kelley before us, Dr. Nicholas Gonzalez and I always recommended soaking in hot water. Our patients with a more acid metabolism would be told to add a mixture of Epsom salts and baking soda to the water. Those with a more alkaline metabolism would add vinegar. But the value of baths was emphasized for all.

    Since saunas have become somewhat more affordable, I have switched to recommending either a sauna or a soak. And I believe that both are beneficial. But a recent article in the peer-reviewed literature would suggest that the low-tech procedure is actually superior.

    In this study, participants completed three bouts of passive heating with hot water immersion, traditional sauna, and far infrared sauna, separated by at least one week. The researchers collected data about many different parameters, as described in the paper.

    Hot water immersion led to the greatest physiologic response. It also caused the most discomfort. For this part of the study, the water in a hot tub was heated to 40.5 C, or about 105 F. Since a hot tub was used, the water temperature would stay constant, unlike in a bathtub.

    Participants spent 45 minutes in the water, longer than I would want to spend. Water loss through sweat, calculated by measuring weight before and after the intervention, was highest in hot water immersion. The hot water soaks were tolerated fairly well in the study participants, all healthy adults, but for a population with health problems, I would recommend lower temperatures and shorter times. For my patients, please follow the directions you were given, and let me know if you have questions. For all others, discuss with your physician before implementing.

    The researchers did not discuss the quality of the bathwater, which would affect which intervention is most valuable. If the water is not particularly pure, then contaminants might be absorbed through the skin, which would make me lean towards recommending the sauna or a shorter soak.

    But it was certainly good to see that the least expensive, most accessible option was effective in this study. And I am encouraged that the study was done at all.