Sitting in a hot tub, also known as a jacuzzi, has become a popular activity for relaxation and potential health benefits. Some people claim that using a hot tub can help with weight loss. But is there any truth to this? Let’s take a closer look at the evidence.
How Do Hot Tubs Work?
Hot tubs are designed to hold warm water, usually between 98-104°F, that immerses most of the body up to the shoulders. This warm water can cause several physiological responses:
- Increased heart rate – Being immersed in warm water causes an increase in heart rate similar to light exercise. A typical 30 minute hot tub session can increase your heart rate by 30-50% over resting.
- Increased blood flow – The heart pumping faster circulates more blood to the muscles and skin. Peripheral blood vessels will dilate allowing more blood flow.
- Increased metabolism – As more blood circulates through the body, your metabolism may increase slightly because your tissues are working harder.
- Sweating – Being immersed in hot water causes sweating, which can result in temporary water weight loss after a hot tub session.
- Relaxation – The warm water can help relax muscles and joints, which some believe may have benefits like reduced inflammation.
So in summary, hot tubs cause an increase in heart rate, blood circulation, sweating, and metabolism – all of which may temporarily increase calorie burn. But does this lead to any lasting fat or weight loss over time?
Does Using a Hot Tub Burn Calories?
Yes, using a hot tub can burn some extra calories versus resting. But the amount of calories burned is generally not very high.
Some estimates suggest a 150 lb person may burn approximately:
- 80 calories in a 30 minute hot tub session
- 120 calories in a 45 minute session
- 160 calories in a 1 hour session
To put this in perspective, that’s about the same calories burned during a leisurely walk. And it’s far less than more intense exercise like jogging, swimming laps, or an exercise class which can burn 300+ calories in an hour.
So while you can burn some extra calories in a hot tub, it’s generally not considered an effective fat loss or weight loss strategy on its own. The calories burned are just too low compared to other forms of exercise.
Water Weight Loss
Some proponents of hot tub use for weight loss point out that you can temporarily lose several pounds of water weight after a hot tub session.
This is because immersion in hot water causes sweating and excretion of fluid through your skin and lungs. It’s possible to lose around 2-3 lbs of water weight, but this is only a temporary effect.
Within several hours after leaving the hot tub, you’ll naturally rehydrate by drinking fluids and eating food. So any water weight lost initially comes right back.
For lasting weight loss, you need a loss of body fat, not just temporary water weight fluctuations. And hot tubs on their own don’t lead to significant fat loss.
Relaxation and Stress Reduction
Some believe that the relaxation benefits of hot tubs may aid weight loss indirectly.
It’s true that hot tub use can lower stress hormones like cortisol. Over time, lower cortisol may potentially make it easier to lose weight.
But the relaxation benefits only last temporarily after each hot tub session. Overall stress levels and cortisol return to normal afterwards when engaging in daily activities.
So any anti-stress or cortisol benefits of hot tubs are unlikely to lead to major differences in fat burning over the long-term.
As mentioned earlier, being immersed in warm water does increase your metabolism slightly during the hot tub session.
But studies show this after-burn effect wears off quickly. Your resting metabolism returns to normal within 1-2 hours after using a hot tub.
The temporary increase in metabolism from hot tub use is too small and short-lived to make any meaningful impact on fat burning over the long run.
Some advocates believe hot tubs may suppress appetite, making you eat less throughout the day.
But research has not found strong evidence for this. Any minor appetite changes seem to be temporary and unreliable for weight loss.
Overall, relying solely on hot tubs for appetite suppression is unlikely to produce significant weight loss results. Managing your diet through proper portion control remains far more important.
Using a hot tub before bedtime may help some people fall asleep faster and improve sleep quality. Better sleep could then potentially aid weight loss.
However, for many people, hot tubs may also have the opposite effect. The stimulation of warm water and increased heart rate can make it harder to wind down at night.
The effects of hot tubs on sleep seem highly individualized. So improved sleep is an unreliable benefit for the majority of people.
The warmth and massage effect of hot tub jets may temporarily reduce inflammation in joints and muscles. Some believe this could improve the ability to exercise and aid fat loss.
However, studies show inflammation reductions are minor and transient after each hot tub session. Any anti-inflammatory benefits are unlikely to substantially improve exercise ability or meaningfully impact weight over the long-term.
Based on the evidence, it’s clear that hot tubs do not provide meaningful weight or fat loss benefits for most people. The increase in calorie burn is negligible, and any other proposed benefits are minor or temporary at best.
While relaxing in a hot tub can certainly feel good, it should not be viewed as an effective way to lose weight and burn fat.
To lose weight sustainably, focus instead on proven strategies like eating in a calorie deficit, increasing cardio and strength training exercise, reducing stress, and improving sleep quality through daily lifestyle habits.
Summary of Hot Tub Benefits For Weight Loss
Here is a summary of the potential benefits of hot tubs for weight loss, and an evaluation of the evidence:
|Potential Benefit||Evaluation of Evidence|
|Increased calorie burn||Burns minimal extra calories, similar to light walking. Not sufficient for significant fat loss.|
|Water weight loss||Causes temporary water weight loss of a few pounds. Weight returns once rehydrated.|
|Relaxation and lower cortisol||Stress reduction is temporary. Unlikely to affect fat burning over the long term.|
|Increased metabolism||Metabolism boost wears off within 1-2 hours. No lasting effect.|
|Appetite suppression||No strong evidence that hot tubs reliably reduce appetite for weight loss.|
|Better sleep||Improved sleep is unreliable and highly individualized.|
|Reduced inflammation||Anti-inflammatory effects are minor and temporary.|
Despite hot tubs being a popular activity, most experts agree that they provide minimal meaningful benefits for weight loss:
Dr. Christopher Still, MD, Geisinger Obesity Institute:
“While immersing your body in the hot water of a spa may provide some relaxation, it won’t help you lose weight. Sweating out excess water does not equate to weight or fat loss.”
Karina Cunanan, RD at Good Housekeeping:
“The truth behind hot tubs aiding weight loss is murky. The benefits are inconsistent and minor for most people. Sitting in a jacuzzi is no replacement for traditional diet and exercise required for sustained fat burning.”
David Prologo, MD, Cleveland Clinic:
“Using a hot tub lacks hard clinical evidence for significant weight loss. Theories about reducing inflammation or cortisol are largely speculative. For meaningful fat loss, create a calorie deficit through your nutrition and activity habits.”
Hot Tub Use Recommendations
Based on the evidence, here are some recommendations around using hot tubs for weight loss:
- Don’t rely solely on hot tubs for fat loss – the benefits are minor and unreliable for most people
- View hot tubs as an aid for relaxation and recovery, not weight loss
- Keep hot tub sessions under 30-45 minutes to avoid overheating
- Stay well hydrated before, during, and after using a hot tub
- Avoid using hot tubs immediately before bedtime if they disrupt your sleep
- Focus on proven diet and exercise strategies for meaningful, long-term fat loss
Other Benefits of Using Hot Tubs
While hot tubs may provide minimal benefits for weight loss, they can offer other benefits like:
- Temporary relief of muscle soreness
- Reduced pain from conditions like arthritis
- Improved circulation
- Calming, meditative experience
So used properly, hot tubs can certainly enhance your overall wellness – just don’t expect them to replace proper nutrition and exercise for fat loss.
The Bottom Line
Sitting in a hot tub may burn a few extra calories and offer some other proposed benefits, but it is ineffective as a weight loss strategy for most people.
Lasting fat loss requires a sustained calorie deficit, increased physical activity, and healthy nutrition – not relying on hot water immersion alone.
If you enjoy using a hot tub, there’s generally no harm in occasional use. Just have realistic expectations when it comes to meaningful impacts on body weight and fat.
Any minor benefits are temporary and do not replace traditional diet and exercise. Those remain the cornerstones for effective, long-term weight management for the majority of individuals.