The benefits of exercising on an empty stomach
Do you ever exercise on an empty stomach? Opinion is divided on the topic of "fasted" training, so let's look at the benefits of exercising before breakfast.
"Never skip breakfast". "Fuel up for your workout". We're often led to believe that it's inadvisable - or even impossible - to do any form of exercise without eating beforehand.
Is this really true? Or are there actually some surprising benefits to working out without eating first?
Exercising on an empty stomach (or "training in a fasted state", to go all fitness-speak on you) is big news in the health and fitness world. The benefits range from better fat loss, to improved hormonal output, to better uptake of nutrients in the meals you eat after exercise. It's not an approach which will suit everyone, of course. But it's definitely worth considering if fat loss, muscle gain, body composition and athletic performance are your goals.
What are the benefits of exercising on an empty stomach?
Give your hormones a helping hand
As you already know, your body's hormones have a massive part to play in everything from how you digest your food, to how you build muscle, shed fat and perform in the gym. Hormones are at the centre of it all. The surprising news is that short periods of fasting, and training on an empty stomach, won't damage your hormonal activity at all. In fact, it may even optimise it. Leading to better gym sessions, a leaner body, and a healthier you!
When your body is in a fasted state, with an empty stomach, this prompts a huge array of hormonal activity. The most significant are better insulin sensitivity and increased growth hormone levels along with improved testosterone in both men and women. Eating less often encourages the body to release insulin less often, too, and this makes us more sensitive to it when it is released - ultimately making fat loss easier and improving over all health. Short periods of fasting boosts the body's output of growth hormone (GH), the wonder-hormone which is responsible for muscle gain, fat loss, bone density and general health. Lastly, whilst training fasted doesn't have a direct impact on testosterone levels, it does create the perfect environment in the body for testosterone to do its thing (which, by the way, including more lean muscle mass, less body fat, higher energy levels, less chance of depression and even minimising heart health problems). This goes for both men and women.
Boost your exercise and workout performance
Depending on the kind of exercise you do, it could actually make perfect sense to train on an empty stomach. If your morning workout is high intensity cardio (HIIT), long slow cardio (such as powerwalking) or weight training, read on…
Combining these kind of fat loss, muscle gain workouts with short periods of fasting creates an anabolic hormonal environment, encouraging all those positive hormones we just mentioned, and letting your body release more fat for fuel whilst building serious amounts of lean tissue.
Endurance athletes could consider fasted training, too. Some endurance athletes like to train without eating a solid meal first, because training on an empty stomach can improve the way in which our muscles store glycogen (fuel), ultimately leading to an easier time during your next long race.
Improve the way your body handles food
Ironically enough, training on an empty stomach has a positive effect on how your body deals with the next meal you do eat. Training fasted teaches your body to partition, digest and use nutrients and macros more efficiently. So, when you do get your post-workout meal down the hatch, the carbohydrates, proteins, fats and micronutrients will get shuttled quickly to exactly where they're needed.
Are there any downsides or risks?
Like any approach to nutrition or exercise, it's your call. THere's no one-size-fits-all and you know your body (and schedule) better than anyone. There aren't any risks to training on an empty stomach, but it's not for you if:
- you suffer with low blood pressure or dizzy spells
- your exercise session involves very long periods of endurance cardio
- you didn't eat well (or enough) the previous day
- you have a history of eating disorders or disordered eating
- you prefer to eat small regular meals
- you wake up hungry and hate the feeling of exercising with a rumbling stomach!
Who should - and shouldn't - consider training in a fasted state?
What time of day do you work out? If you train in the morning, it could work for you. But if you need to train after work or in the evening, it's probably not the best strategy.
What was the last meal you ate? Was the most recent meal you eat sufficient in calories, macronutrients and micronutrients? Or was it a cheat meal, takeout or junk food?
How hydrated are you? Hydration is key. Make sure you drank plenty of water the previous day, and be sure to drink water (ideally with electrolytes and/or BCAAs) before your fasted workout.
What kind of training are you doing? Training on an empty stomach is best suited to HIIT cardio, intervals, low intensity cardio such as walking, or intense weights sessions.
Want to give it a go? Here's your fasted-training strategy:
Wake up and drink at least 500ml water to hydrate
Sip on a black coffee or espresso as you get ready
Prepare a large bottle of water with added electrolytes and/or BCAAs (branch chain amino acids)
Get your post-workout meal, shake or snack ready
Hit the gym, track or workout studio
Warm up well
Drink plenty of your big water bottle during your workout
After training, aim to eat (ideally carbohydrates and proteins) within the hour
And keep hydrated….
Monitor how you feel, how well you recover, how you sleep that night and how your body responds to fasted training