Hot tubs are a highly desirable backyard luxury, but are they really worth it? Our…
Sauna vs Hot Tub: Top Benefits for You from Each One
Find out the real benefits provided by a hot tub or sauna, and decide which, or both, is best for you.
To unwind, reduce stress, and improve overall health, many people turn to saunas and hot tubs. Both have a lot going for them, but they each work in unique ways and may be better suited to certain people or situations. A 2025 study published in the American Journal of Physiology compared hot tubs (hot water immersion), traditional saunas, and far infrared saunas, revealing that hot tubs elicit the greatest thermoregulatory, cardiovascular, and immune responses. This article explores the fundamentals of saunas and hot tubs, including how they operate and the advantages they provide, incorporating the latest research to help you decide which is the best fit for your lifestyle.
Table of Contents
Show
What is a hot tub?
A hot tub is a large spa filled with warm water and massaging jets, perfect for indoor or outdoor relaxation. Typically made from acrylic or fiberglass, hot tubs can seat multiple people comfortably. Keep in mind that hot tubs have higher running costs, so check out our guide on “How Much Does it Cost to Run a Hot Tub?”
What is a sauna?
A sauna is a small, well-insulated room or structure equipped with a heat source, such as a fireplace, stove, or heater. The two main types are traditional dry saunas, which heat the air to high temperatures, and infrared saunas, which use infrared heaters to generate heat directly absorbed by the skin. While often associated with Finnish culture, saunas are enjoyed worldwide.
Common Benefits of Hot Tubs and Saunas
Improved heart and blood vessel health
Research, including the American Journal of Physiology study, shows that hot tubs and saunas benefit heart health. The heat causes blood vessels to dilate, improving blood flow and lowering blood pressure. Hot tubs, in particular, elicit the greatest increase in cardiac output (+3.7 L/min) and reduction in blood pressure compared to traditional and infrared saunas, making them especially effective for cardiovascular health.
Burn calories passively
Both saunas and hot tubs can help burn calories passively. Sweating in either environment burns calories, and raising your core body temperature may produce heat shock proteins, boosting metabolism. The study found that hot tubs cause the largest increase in core temperature (+1.1°C), potentially enhancing calorie burn compared to traditional (+0.4°C) and infrared saunas (no significant increase), making hot tubs a stronger option for passive calorie burning.
Pain relief and muscle recovery
Saunas and hot tubs can ease sore muscles, joint pain, and inflammation. The heat relaxes tense muscles, while hot tub jets provide a massage-like effect to relieve stiffness, making both excellent for recovery after a long day or workout. Hot tubs may offer superior relief due to their hydrotherapy jets and the significant core temperature increase observed in research.
Quality of sleep improvement
Both saunas and hot tubs may improve sleep quality. A session in a sauna or hot tub before bedtime can reduce stress and promote relaxation, helping you wind down and fall asleep faster. The greater physiological response from hot tubs may enhance this relaxation effect.
Relaxation
For unwinding, saunas and hot tubs are top choices. The combination of heat, massaging jets in hot tubs, and the tranquil atmosphere of either can alleviate stress and anxiety, creating a perfect escape from daily pressures. Hot tubs may provide a more intense relaxation experience due to their significant thermoregulatory effects.
Diabetes
Studies suggest that saunas and hot tubs may benefit those with diabetes. Sauna use can improve insulin sensitivity, while hot tubs may lower blood sugar and enhance vascular health. The stronger cardiovascular response from hot tubs, as shown in the study, may offer additional benefits for managing diabetes.
| Benefit | Sauna | Hot Tub |
|---|---|---|
| Arthritis & Joint Pain | Relaxes muscles and improves circulation with dry or infrared heat. | Hydrotherapy jets and significant core temperature increase target joints, reducing stiffness and inflammation. |
| Sore Muscles | Heat eases muscle tension and promotes recovery. | Massaging jets and higher core temperature provide targeted relief for soreness. |
| Back Pain | Improves blood flow to reduce discomfort. | Weightlessness, jets, and greater physiological response alleviate pressure on the spine. |
| Weight Loss | Sweating burns calories and may boost metabolism (minimal core temperature increase). | Greater core temperature increase and jet stimulation enhance passive calorie burn. |
| Heart Health | Dilates blood vessels, moderately lowering blood pressure. | Significant increase in cardiac output and blood pressure reduction enhance circulation. |
| Sleep Quality | Promotes relaxation for better sleep. | Soothing jets, warmth, and stronger physiological effects help you unwind before bed. |
Hot Tub or Sauna for Arthritis and Pain Relief
If you’re dealing with arthritis, back pain, or sore muscles, both hot tubs and saunas can offer relief, but hot tubs may have an edge. The American Journal of Physiology study found that hot tubs (hot water immersion at 40.5°C for 45 minutes) produce the largest increase in core body temperature (+1.1°C), enhancing blood flow and muscle relaxation compared to traditional saunas (+0.4°C) and infrared saunas (no significant increase). Hot tubs provide hydrotherapy through massaging jets, targeting specific areas of discomfort, easing joint stiffness, and reducing inflammation associated with arthritis. The warm water also supports your body, creating a weightless sensation that takes pressure off aching joints. Saunas use dry or infrared heat to relax tense muscles and improve circulation, which can alleviate back pain and soreness, but they lack the targeted massage and significant physiological response of hot tubs.
Sauna vs Hot Tub for Weight Loss
Curious about whether a sauna or hot tub can help with weight loss? Both can contribute to burning calories passively, but hot tubs may be more effective. The study showed that hot tubs increase core body temperature by +1.1°C, significantly more than traditional saunas (+0.4°C) and infrared saunas (no increase), potentially boosting metabolism through heat shock proteins. Hot tubs also encourage calorie burn through warm water and jet stimulation, while saunas promote sweating for modest water weight loss. Neither replaces exercise or a healthy diet, but hot tubs may offer a slight advantage for passive calorie burning due to their greater thermoregulatory impact.
Infrared Sauna vs Hot Tub
When comparing an infrared sauna to a hot tub, the choice comes down to heat type and physiological impact. Infrared saunas use radiant heat to penetrate the skin directly, offering a gentler experience at lower temperatures (typically 120–140°F) compared to traditional saunas. However, the study found that infrared saunas (45–65°C for 45 minutes) produced no significant increase in core body temperature, limiting their cardiovascular and metabolic effects. Hot tubs, immersing you in warm water (100–102°F) with massaging jets, provide hydrotherapy and a significant core temperature increase (+1.1°C), enhancing circulation and relaxation. If you prefer a dry, gentler heat experience, an infrared sauna might suit you; for a powerful, spa-like physiological boost, a hot tub is the better choice.
Thermoregulatory and Cardiovascular Effects
Core Temperature and Sweating
The American Journal of Physiology study compared the thermoregulatory effects of hot tubs, traditional saunas, and infrared saunas. Hot tubs (hot water immersion at 40.5°C for 45 minutes) increased core body temperature by +1.1°C and caused the greatest sweat loss, thanks to water’s high thermal conductivity and reduced evaporative cooling. Traditional saunas (80°C for 3 × 10 minutes) raised core temperature by +0.4°C, while infrared saunas (45–65°C for 45 minutes) showed no significant increase. Hot tubs provide the most significant thermoregulatory challenge, making them ideal for those seeking intense heat therapy.
Cardiovascular Strain
The study found that hot tubs elicit the greatest cardiovascular response. Hot water immersion increased cardiac output by +3.7 L/min and reduced blood pressure significantly more than traditional saunas (+2.3 L/min) and infrared saunas (+1.6 L/min). The combination of water’s thermal load and hydrostatic pressure enhances blood flow and reduces systemic vascular resistance, mimicking moderate exercise. This makes hot tubs particularly effective for improving heart health, especially for those unable to exercise regularly.
Immune System Benefits
Inflammatory Response
Hot tubs may offer unique immune system benefits, according to the study. Hot water immersion increased interleukin-6 (IL-6) levels post-heating, indicating an acute inflammatory response similar to exercise, which may help reduce chronic inflammation with repeated use. Neither traditional nor infrared saunas triggered this response, likely due to their minimal impact on core body temperature.
Immune Cell Activation
The study also showed that hot tubs increased cytotoxic T cells (CD8+) and natural killer (NK) cells 24 and 48 hours post-heating, enhancing immune surveillance. These changes were not observed in traditional or infrared saunas, suggesting that hot tubs’ significant core temperature increase drives a stronger immune response, potentially benefiting overall health with regular use.
Benefits of Sauna Time
Detoxification
Saunas, particularly traditional ones, promote detoxification through intense sweating induced by high temperatures. While hot tubs also cause sweating, the study showed they produce greater sweat loss, but saunas’ dry heat is more effective for flushing toxins and chemicals from the skin.
Skincare
Saunas may provide cosmetic benefits for the skin. The dry heat opens pores and sheds dead skin cells, leading to clearer, healthier-looking skin. Hot tubs, due to their water-based environment, offer fewer skincare advantages compared to saunas.
Sanitation
Saunas are often easier to keep clean than hot tubs. Hot tubs require regular cleaning and maintenance to prevent germ buildup, while saunas, with their dry environment, typically face fewer sanitation challenges.
Aromatherapy
The dry heat of a sauna enhances the fragrance of essential oils, offering therapeutic benefits through aromatherapy. In hot tubs, the presence of water diminishes the effectiveness of aromatherapy compared to the dry environment of a sauna.
Safety
Saunas may be safer than hot tubs in some respects. Hot tubs pose risks like accidental drowning or slips due to water, while saunas, with their dry heat and lack of water, eliminate these hazards.
Advantages of Hot Tubs
Hydrotherapy
Hot tubs provide hydrotherapy massage, unlike saunas. Their jets deliver a massage-like experience, helping to relieve muscle tension and pain. The study highlights that hot tubs’ significant core temperature increase enhances these benefits, making them superior for targeted pain relief.
Improved digestion
Soaking in a hot tub may benefit digestion. The warm water can relax the stomach and intestines, aiding digestive processes for some users. Saunas, lacking water, don’t provide the same digestive advantages.
Weightlessness
Hot tubs offer a sense of weightlessness, floating effortlessly in warm water. This is especially beneficial for those with arthritis or joint pain, as it reduces pressure on muscles and joints, amplified by the significant physiological response observed in research. Saunas, without water, can’t replicate this experience.
Superior style
Hot tubs can add a touch of luxury to your home. With various sizes and designs, they can be a stunning addition to any backyard. Saunas, often more compact and understated, may not offer the same aesthetic appeal, especially outdoors.
Read our guide on how to choose a hot tub for tips on design and making your hot tub look amazing.
Social time with friends and family
Hot tubs are ideal for socializing, whether with friends, family, or a partner. Their spacious design encourages group relaxation, unlike saunas, which are typically more intimate and less conducive to social gatherings.
How Do Saunas and Hot Tubs Work?
Dry saunas
Traditional dry saunas heat the air to high temperatures, typically 150–175°F, encouraging sweating to rid the body of toxins. The study used a 3 × 10-minute protocol at 80°C, resulting in a modest core temperature increase (+0.4°C), promoting relaxation and circulation.
Infrared saunas
Infrared saunas use infrared heaters to emit heat absorbed directly by the skin, typically at 120–140°F. The study found no significant core temperature increase at 45–65°C, suggesting limited thermoregulatory impact compared to hot tubs or traditional saunas.
Hot Tubs
Hot tubs maintain water temperatures of 100–102°F, with jets creating a massaging effect. The study confirmed that hot tubs at 40.5°C for 45 minutes significantly increase core temperature (+1.1°C) and cardiac output, enhancing blood flow and muscle relaxation.
Does a Hot Bath Have the Same Effect as a Sauna?
Wondering if a hot bath can replicate the benefits of a sauna or hot tub? While a hot bath can relax muscles and reduce stress, it falls short of the full experience. Saunas deliver intense dry or infrared heat, promoting detoxification, though infrared saunas showed minimal physiological impact in the study. Hot tubs offer hydrotherapy and a significant core temperature increase (+1.1°C), which a bathtub can’t match. A hot bath is a budget-friendly alternative, but for targeted health benefits like arthritis relief, cardiovascular health, or immune support, hot tubs provide a more powerful experience, followed by traditional saunas.
Which Should You Pick?
Choosing between a sauna and a hot tub depends on your personal preferences and health goals. The American Journal of Physiology study highlights that hot tubs offer the greatest thermoregulatory, cardiovascular, and immune benefits, making them ideal for heart health, pain relief, and immune support. Saunas, especially traditional ones, are better for detoxification and skincare due to their dry heat.
If you prioritize intense physiological benefits, hydrotherapy, or socializing, a hot tub is likely the better choice. For gentler heat, detoxification, or easier maintenance, a traditional sauna may suit you, though infrared saunas showed limited impact. Both require regular maintenance and involve upfront costs, with saunas generally cheaper initially and hot tubs offering long-term health benefits.
| Factor | Sauna | Hot Tub |
|---|---|---|
| Initial Cost | Generally lower, starting at $5,000–$9,000 for basic models. | Higher, typically $7,000–$19,000 depending on size and features. |
| Maintenance | Minimal; occasional wood or heater replacement. | Regular water testing, chemical balancing, and filter cleaning. |
| Installation | Simple for portable models; indoor saunas may need ventilation. | Requires electrical setup, water supply, and a stable base. |
| Space Requirements | Compact, fits small rooms or outdoor spaces. | Larger footprint, needs deck or concrete pad. |
Ultimately, the choice between a sauna and a hot tub is yours. Both can enhance your health and well-being in unique ways, but hot tubs stand out for their superior physiological impact, as shown in recent research. Weigh your options carefully to find the best fit for your lifestyle.
Check out our best hot tub brands guide or call us today to get help choosing the best equipment for your home.
Are You Still Feeling Overwhelmed?
Call 888-884-3742 or Fill Out the Form Below to Contact Us Today!
About The Author:
Richard Horvath
Hot Tub & Spa Expert
Richard has been in the hot tub & spa industry for years. As a long hot tub & swim spa owner himself, Richard has a passion for helping homeowners create their dream backyard.
