Hot Tub or Sauna: Which is Better for You? Study Reveals the Truth

The Battle Between Hot Tubs and Saunas: A Scientific Look

For centuries, humans have turned to heat therapy as a way to relax and improve their health. The ancient Greeks practiced therapeutic hot baths as early as 1000 BC, while sauna bathing in Finland dates back over 7,000 years. Today, the debate continues: which is better, a hot tub or a sauna? Recent research conducted by a team of scientists at the University of Oregon has provided some intriguing insights.

The Study and Its Findings

Jessica Atencio, a doctoral student in human physiology, led a study published in the American Journal of Physiology that compared the effects of hot tubs, traditional saunas, and far-infrared saunas on the body. The primary focus was on core body temperature, a key indicator of how heat therapies impact health.

Atencio used core temperature pills—essentially ingestible thermometers—to measure changes in participants’ bodies during each session. The results showed that hot water immersion in a hot tub had the most significant effect on raising core temperature. This increase in body temperature can lead to lower blood pressure, improved immune function, and enhanced vascular health.

Interestingly, the study also found that only hot tub immersion produced beneficial inflammation responses, suggesting it may have unique health advantages over other forms of heat therapy.

Surprising Results

While the hot tub's effectiveness in raising core temperature wasn't entirely unexpected, the findings regarding traditional saunas were surprising. Despite being hotter than a hot tub, traditional saunas caused minimal changes in core temperature. Atencio noted that this was contrary to expectations, given the higher temperatures typically associated with saunas.

How the Experiment Was Conducted

The testing took place at the Bowerman Sports Science Center, a state-of-the-art facility located in Hayward Field. The center focuses on sports science and is not intended for recreational use. The study involved 20 participants, evenly split between men and women aged 20 to 28 who regularly exercised. Each participant experienced all three types of heat therapy in separate 45-minute sessions.

Atencio explained that starting with a young, healthy population is standard practice for initial studies, with future research planned for different groups.

Implications of the Results

Heat therapy, like exercise, raises core body temperature, but it doesn’t cause muscle contractions. While exercise remains the top non-pharmacological method for reducing disease risk, heat therapy could serve as an alternative for those unable to exercise.

The increased blood flow from elevated core temperature is beneficial for arterial and vascular health. Research has shown that long-term use of heat therapy can reduce the risk of various conditions, including vascular diseases, high blood pressure, and neurocognitive disorders.

Atencio’s study suggests that hot tubs might offer even greater benefits due to their more substantial impact on core temperature. Although the study focused on short-term effects, the findings imply potential long-term health advantages.

Future Research and Developments

Atencio is set to complete her Ph.D. in the 2025-26 academic year. She has been part of Professor Christopher Minson’s lab for five years, where she worked on comparative studies of heat therapies. While she isn’t planning further experiments on heat therapies at the university, other graduate students are continuing this research.

One ongoing project explores whether sauna use can reduce inflammation in individuals with endometriosis. Minson, who has studied heat therapies for over two decades, believes that heat therapy can contribute to improved health when done in moderation.

A New Direction

In an unexpected twist, Atencio’s dissertation focuses on the harmful effects of prolonged heat exposure. Her research will examine the impact of heat on kidney, vascular, and cognitive functions in both young and older adults. Using the Bowerman Center’s environmental chamber, she will simulate a heat wave lasting six hours.

This work aims to expand understanding of the effects of climate change-driven heat waves, highlighting the importance of heat safety.

Conclusion

The study by Atencio and her team offers valuable insights into the health benefits of different heat therapies. While traditional saunas have long been popular, the evidence suggests that hot tubs may provide more significant physiological benefits. As research continues, the potential applications of heat therapy for improving health and addressing modern challenges like climate change remain promising.