Does more sweat mean more calories are burnt? Do Sauna Vests Really Help Slimming? | Hummingbird

Do Sauna Vests Really Help Slimming?

So how many days of social distancing for you already? Not many will be able to answer this question in 3 seconds because who keeps track of the dates when you stay at home all the time! If you are an introvert, home quarantine doesn’t make much difference to your daily life. However, if you are an extrovert, this may not be the case. Not being able to go out to the beach, pub, party or gym will very likely lead to cabin fever. Not to mention overeating caused by sitting on the couch and pouring in all those high calorie snacks. At the end of the day, you realize that you have gained weight because of overeating and lack of physical activities.

Despite the fact that our activities are limited due to COVID-19 at the moment, we know that summer will come, and we will be able to wear light clothes or bathing suits, go out and enjoy the sun again. Before that, some of us will want to tone our body, just like what we have been doing in normal years, starting usually at this time of the year. In order to make our body burn more fat, some of us will turn to products like what I am going to mention below – sweat shaper sauna vests

How Do Sauna Vests Work – According to Merchants

According to one of the merchants on Amazon, sweat shaper sauna vests have the following two functions: 

  • Increase body temperature, produce three times more sweat, help you burn more calories, for healthy prompt weight loss effect
  • Hot vest absorbs sweat quickly to leave you feeling dry and fresh outside

These sauna vests are made of neoprene, which is a kind of synthetic rubber. Traditional neoprene is a good insulator and can absorb water. However, can these vests really “increase body temperature”, produce more sweat and help burn more calories? Let’s take a look at these statements on a more technical standpoint one by one. 

Does More Sweat Mean More Calories Burnt?

Most people who wear sauna vests during exercise think the vests can accelerate calorie consumption by sweating more. Is it true? Let’s take a look at what determines how many calories are consumed for a specific exercise. As shown in the table below, the amount of calorie expenditure depends mainly on the type and length of the activity. There are also other factors like weight, age, sex, body size and body composition (e.g. muscle mass). Sweating is not one of the factors mentioned above.

Energy expenditure table | Do Sauna Vest Really Help Slimming? | Hummingbird

Note: 1kg=2.2lbs


more sweat doesn’t mean more calories are burnt!

What Exactly Do Sauna Vests Do – The Reality

First let’s introduce law of conservation of energy, meaning energy can neither be created or destroyed, rather, it can only be transformed from one to another. During exercise, a small part of body energy is used for physical function (25%-40%), and the rest is transformed to heat. Generated heat first will be dissipated by the environment via the skin, mainly in the form of sweat evaporation. As sweat evaporates, it takes away part of the heat from the body and turns into gas. Excess heat that cannot be dissipated will be stored in the body and increase the core body temperature.

As a media of absorption and insulation, a sauna vest on one hand adds resistance to sweat evaporation. So, instead of taking heat from the body and turning into gas, majority of sweat gets absorbed by the vest, which means only a little heat gets taken away from the body. On the other hand, excess heat is stored in the body and increases core body temperature.

In addition, as sweat mainly consists of water, with no heat dissipation, unevaporated sweat is just a waste of body water. The more you sweat, the more body water you waste, sometimes to an extent where dehydration can occur. Even if you lose part of the body weight due to sweating, it will bounce back after your body is hydrated again. 

Potential Harm Caused By Wearing Sauna Vests

High body temperature impairs muscle function and exercise performance, causes early fatigue. As mentioned above, length of an activity influences calorie expenditure. Shortened exercise time reduces calorie burnt. High body temperature can also lead to heat disorders. This includes muscle cramps, nausea, headache, even heat stroke. 

As you can see, sauna vests do not help slimming. They cut off heat dissipation during exercise and hinder performance to the point of limiting calorie expenditure and causing heat-related disorders. The functions, that merchants promote about sauna vests, do not exist.

Key Take Away

  • The amount of sweating is not an indicator of calorie consumption. Calorie can keep burning with no or little sweat.
  • Both aerobic and anaerobic exercise, be it strength training, HIIT or endurance training, can increase metabolic rate therefore burn more calories.
  • Body weight loss is determined by calorie deficit, i.e. calorie intake < calorie output. If your daily calorie intake has way surpassed your output, check out this article to see 4 Best Ways to Curb Food Cravings.
  • Focus should be less on exact body weight, more on body composition (muscle mass).
  • There is no PROMT, QUICK or FAST weight loss method. Start early and persistence is the only way to achieve a desirable body.

Leave a comment

Please note, comments need to be approved before they are published.