Is it true that i should wear thick clothes such as a hoody while doing cardio to sweat more? Or is it just water weight that gets put back on when you drink? I have heard both.

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    If sweating made you thin, the American South would not have an obesity epidemic.
    – wdypdx22
    Commented Mar 11, 2011 at 19:16
  • I wear a trash bag on my torso then a shirt over that and then a hoodie with a beanie. I get a good sweat going. Does it help? I don't know. I do see significant drops on the scale (obviously due to water loss) but it's temporary. However, sweating is good for your body to get rid of toxins. It makes me feel better so I do it. One would think since most suppliments use caffine to increase body temperature to burn fat it would make sense that wearing clothes would have the same affect. Commented Mar 11, 2011 at 22:48
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    Definitely only losing water weight. The other problem is, because your body can't wick away heat through sweat you're also at a higher risk of heat exhaustion from working out. Commented Mar 20, 2011 at 20:10

7 Answers 7


It will make you sweat more. Sweating more means you will need to drink more. It doesn't help you lose fat faster, if that is what you're asking.

  • people say your heartrate increases as you sweat, and so you lose weight faster.
    – user358
    Commented Mar 10, 2011 at 19:29
  • @fullyinsance: That seems to be assuming that your heart is what is burning most of the calories. But that is an incorrect assumption. You're legs are burning most of the calories (assuming your running or something). Commented Mar 10, 2011 at 19:32
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    If you heart rate does increase as you sweat, and the hoodie does make you sweat more, your heart rate would increase by wearing a hoodie. However, you state that you want to lose fat, so now it depends what your rate is at before you put on the hoodie. If you heart rate is under 55% of your MHR, you may consider putting the hoodie on, because you would get closer to the ideal fat burning zone. However, if your heart rate is already above 60% of your MHR, you would not want to put on the hoodie, as you would get further away from the fat burning zone. Commented Mar 10, 2011 at 19:58
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    @Andrew: the whole point of the % of MHR is to work at a specific level. If you are working at less than 55% of your MHR, you should work harder, not put on a hoodie. Commented Mar 11, 2011 at 14:02

Currently there is not a lot of research in human studies on the effects of high ambient temperature and increased energy expenditure. As is pointed out in another answer, the artificial inhibition of the cooling mechanisms of the body by wearing either many layers or heat trapping clothing will negatively impact the length and quality of exercise sessions.

There is a study (With the caveat that it was funded by an energy drink company) that shows an unnamed commercially available thermogenic drink (Monster/Rockstar type) does have an effect on lipolysis, attributable to the already known effects of caffeine and EGCG (The active ingredient in green tea). That study can be found here. (Also of interest, near the end of the first paragraph in the discussion is a suggestion that EGCG also alters food digestability).

There are two studies that I found suggesting that high ambient temperatures actually slow down, rather than speed up metabolisms and subsequent energy expenditure. This study using Zucker rats (Lab rats specially bred for obesity research) shows in this graph that metabolism and energy expenditure markedly drop with increases in ambient temperature, for both obese and non obese rats.

This study on male weasels shows a similar curve. There is an associated decrease with both low and high ambient temperatures, with a peak in the "nominal" range, falling off even below the lower temperature curve as the temperature increases. There is also a suggestion found here that in endothermic animals, being unable to dissipate body heat is a limiting factor as well, which is a new theory called Head Dissipation Limit. This theory suggests that energy expenditure is limited by the ability of the subject to dissipate heat.

The HDL hypothesis has somewhat been validated, as there have been studies on the effects of cold on energy expenditure, and as this study shows, cold environments tend to increase lipolysis in humans.

The common misconception that wearing lots of clothing increases weight loss is a correlation error, in that people wear a ton of clothes, sweat a lot, and mistakenly think that the water weight they have lost is equivalent to fat weight lost. This is reinforced by the common practice of boxers, wrestlers and other athletes that need to make weight being shown exercising in many layers.

While there has not been a definitive study on high heat environments and the effects on lipolysis in humans, there is quite a bit of evidence that metabolism and energy expenditure both decrease in response to high heat environments, which is the opposite of what you want when trying to reduce fat.


If pure weight loss is what youre after ( and I mean just kg/pounds, not fat loss), then that extra hoodie could help you.

Amy Nutt makes a great point about heat and weightloss. Sweating helps body get rid of the salts. And as we know, salt, besides making our food taste different, has the side effect of lessening the water throughput of your body. In other words, it keeps the water inside the body, therefore increasing, or certainly not lessening, your bodyweight.

And if we assume, that you are on a good diet, there should be quite a small intake of salt, so there will be initial gains, but not in the long run. It may help you loose those first couple of kg/lbs that people are so ecstatic about, but will not help your weight loss in the long run.

  • i do want to lose fat.
    – user358
    Commented Mar 10, 2011 at 19:36
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    @fullyinsane Then that extra hoodie will do you no good. Commented Mar 10, 2011 at 19:37
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    I love how you said ...making our food taste 'different' instead of 'better' lol. Perfect. Commented Mar 11, 2011 at 22:43

For any given fitness level, you can burn more energy the better you can dump the waste heat into the environment. The amount of energy you can burn on the long run is going to by determined by the heat transfer coefficient.

Your maximum body temperature, the temperature of the environment, the thermal properties of your clothes, and your body area define a maximum sustainable rate at which you can dump heat into the environment (taking also in to account how much sweat can still evaporate from your clothes). The more clothes you are going to wear, the less heat per unit time you'll be able to dump into the environment. The amount of work you can perform will then also drop, so the total amount of energy you can burn per unit time will go down.

  • Yes. I was going to say something similar but in less technical terms: If you are wearing warm clothes, then you will be less comfortable and you will be prone to overheating, which means you won't be able to exercise with as much intensity as might otherwise, which means you will burn less calories.
    – Dangph
    Commented May 30, 2014 at 5:05
  • Plus, the experience will be less fun, and if something is less fun, then you will tend to do it less often.
    – Dangph
    Commented May 30, 2014 at 5:06
  • A lot less fun! When I'm travelling and have to use the hometrainer or treadmill at the hotel, I already suffer a lot from this problem. Usually the treadmill does have a fan, but it's not the same as running outside. A lot of sweat and after the exercise it feels like I've done nothing at all. Commented May 30, 2014 at 12:56

I have seem bodybuilder wearing loads of cloth for their cardio workout just before a competition. They do it to minimize the water body which will in a lean and trained body cause the muscles to appear more defined.

This, however, is not healthy. Your body regulates the temperature by sweat that evaporates from your skin and cools the body down (You can cool down a drink in summer by wrapping it in a wet newspaper and put it in the sun - same effect).

Sweating more will do not do anything because your body will just be carving for more water after your workout. So wear whatever you are comfortable with.

  • They do it before competition to 1) Drop weight quick for weigh ins (in applicable sports) and 2) for body builder competitions - help remove water from the skin (in addition to taking diuretics) so their skin looks very thin and you can see all of their cuts. Commented Mar 11, 2011 at 22:45

Sweating is one of many body responses to higher temperature, and begins when other responses are working to maximum efficiency, such as vasodilation (dilation of capillaries close to skin) and the increase in heart rate, both working to cool the body.

An increase in cellular respiration performed by the body's cells, is needed to fuel these systems, and the hotter the body is the more the body must work to maintain a satisfactory temperature. Obviously there are many more factors to consider when exercising such as water intake and the types of exercise being performed, but if applied appropriately, wearing thick clothes during cardio WILL provide better weight loss results.


Sweating helps detox sodium overload. I've been told by many athletic trainers that when eating too much sodium, which is common for a lot of people, it can not be released out of the body other than through sweat. If you do not go out on a sweaty workout after eating too much sodium, you will become bloated due to the fact that people believe drinking water will help detox away the sodium. water weight is developed due to over levels of sodium. That's why people wear thick clothing. To help with too much sodium intake.

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    You've been told wrong. "Detoxifying" in all it's forms is snake oil bro-science at its worst. And bloating/water weight can come from many different sources, only one of which could be sodium.
    – JohnP
    Commented Apr 9, 2015 at 15:08