Exercise On An Empty Stomach? Yes or No?

by Virginia Bain

A debate that has raged since the first weight was lifted: Is it better or worse to work out on an empty stomach?


Well, the truth is… different people work out best under different situations. Telling someone that they should or shouldn’t eat before training or cardio is like telling them what time of day to workout, or which diet is ‘The Best’ for them to follow. This does largely depend on the individual… but it is time to dismantle some old myths and learn some of the reasons how it can actually benefit you.

First off, contrary to popular belief - research has shown that eating many small meals throughout the day will not speed up your metabolism, skipping a meal won’t make you fat and exercising on an empty stomach will not nullify a workout. In fact, skipping a meal or two (also known as intermittent fasting) can be downright beneficial. An empty stomach triggers a cascade of hormonal changes throughout the body that are both conductive to building muscle and burning fat.

Exercise, especially intense exercise that uses a lot of muscles (think compound movements like deadlifts and squats) causes a big surge in testosterone—which is why it can make sense to combine exercise and fasting.

Many studies have found that training in a fasted state is a terrific way to build lean mass and boost insulin sensitivity, not just because of the nifty hormonal responses, but also because it makes the body absorb the post-workout meal more efficiently.

The two main significant effects of training in a fasted state are:

  • Improved insulin sensitivity

Put very simply, the body releases insulin (a hormone) when we eat to help us absorb the nutrients from our food. The hormone then takes the sugars out of our bloodstream and directs them to the liver, muscles, and fat cells to be used as energy later on. The trouble is that eating too much and too often can make us more resistant to insulin’s effects, and while poor insulin sensitivity ups the risk of heart disease and cancer, it also makes it harder to lose body fat. Eating less frequently (i.e. fasting more regularly) is one way to help remedy the issue, because it results in the body releasing insulin less often, so we become more sensitive to it—and that makes it easier to lose fat, as well as improving blood flow to muscles, and even curbs the impact of an unhealthy diet.

  • It Increases Human Growth Hormone

A good old-fashioned fast can promote muscle gain and fat loss comes down to growth hormone (GH), a magical elixir of a hormone that helps the body make new muscle tissue, burn fat, and improve bone quality, physical function, and longevity. Along with regular weight training and proper sleep, fasting is one of the best ways to increase the body’s GH: One study showed that 24 hours without food increases the male body’s GH production by 2,000% and 1,300% in women. The effect ends when the fast does, which is a compelling reason to fast regularly in order to keep muscle-friendly hormones at their highest levels.

Essentially, by depriving the body of nutrients and entering a workout in a fasted state, the workout is a greater stress on your body, which leads to greater adaptations.

In short, fasted training helps to ensure that carbs, protein, and fats go to the right places in the body and are stored only minimally as body fat.

Exercising on an empty stomach has been shown to be especially great for fat loss, and it’s even been shown that people who train while fasted become progressively better at burning fat at higher levels of intensity (possibly because of an increase in fat-oxidizing enzymes.)

So You Want to Fast Before Exercise?

Your Action Plan:

We know what you’re thinking. “I can’t handle intense exercise without food in my belly!”

Firstly, give yourself a little credit! You’re capable of more than you think with the right frame of mind. Secondly, there are several tips you can follow to help you out with this new approach to eating:

  • You can consume more than just water. Feel free to quell cravings and get an energy boost with black coffee, plain tea, caffeine pills, BCAA, Creatine or any kind of drink or supplement that’s virtually calorie-free.
  • Break your fast whenever you'd like. Many people like their first meal right after exercising, since the fast improves the absorption of the post-workout meal, but it’s actually no big deal if the fast lasts for a while longer. Even if you exercise in the morning and don’t eat until the evening, the wave of growth hormone you’ll be riding all day shouldn’t prevent any muscle loss however you decide to approach this, your body’s got you covered.
  • Eat as many meals as you'd like. Note: We didn't say as many calories as you like. But it’s not necessary to eat many meals throughout the day. Despite some long-held ‘Bro-Science’ that thebody can only absorb a certain amount of protein at a time, we're completely capable of digesting the day's intake in one big meal (of course, this doesn’t mean that you need to!).

Studies have shown that doing so results in no strength or muscle loss, and some have even shown that concentrating food intake into one or two meals each day can be a better way to build lean muscle mass. A lot of protein just takes longer to digest and be utilized, but it still gets digested. Even after eating a normal-sized meal, amino acids are still being released into the bloodstream and absorbed into the muscles five hours after eating. So play around with the feeding times and styles that work best for you.

The short of it: Metabolism and the digestive system are simply not as temperamental as some might believe.

The Takeaway

Eating is perhaps the most ingrained habit we have, and humans are well and truly creatures of habit.

Disrupting that habit by skipping a meal or two can be profoundly difficult for some people (particularly those who have wrestled with any form of disordered eating). It’s true that intermittent fasting takes some time to get used to as the body learns not to expect food so frequently. That discomfort usually does pass, but if fasting just isn’t for you, then there’s no need to keep it up—just don’t be afraid to try it out. IF is just one approach to health and fitness, and certainly not the only one that can get you results. In general, there is no need to eat before exercise. If you feel better when you do, then by all means, keep it up! However, if choking down a pre workout banana or oatmeal, is a dreary chore that you only do because it’s supposed to help you avoid muscle loss/fat gain/growing antlers, then it’s time to relax. You’re completely free to eat whatever you want. Just listen to your body—it’s got you taken care of.



Post by SiS Coach, Virginia

As a full-time Development Manager and mother of two teenagers, Virginia understands the need for a balanced and healthy lifestyle. Her passion for fitness began 15 years ago as a personal trainer. Since then, she has also gained certifications in holistic nutrition and sports nutrition. Virginia finds strength in being a SiS coach and empowering other women to live like the Power Women they are.


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