“If you're low on carbs, the body will kick in more stored fats for fuel. But due to low energy, you may not run as hard or as long. And after your run, your metabolism may slow due to your semi-fasted state.
Running on an empty stomach can help your body burn fat as fuel, which can be beneficial for weight loss goals. But if you're doing a longer, more intense workout, running on an empty stomach can be risky. Without enough fuel in your system, you might experience dizziness, fatigue, and even fainting.
It is not recommended to workout if you don't have food in your system, as the body needs energy from food to sustain physical activity. Exercise can be taxing on the body and without proper fuel, you may experience weakness, fatigue, and decreased performance.
No matter the type of run or workout, you'll need to eat something prior. “Exercising muscles prefer glycogen — stored carbohydrate in your muscles — which is especially important to maintain a high intensity and sustain longer duration workouts,” Kelly Jones, MS, RD, CSSD, LDN, says.
Food is fuel for runners. But eating a large meal too soon before going out for a run can lead to digestive problems like cramping or diarrhea. Instead, try to wait at least three hours after a meal before going for a run.
So, running on an empty stomach helps our muscles use fat for fuel. This habit is great for burning more fat. By exercising without blood sugar, our body learns to use stored fat. This allows us to run longer and perform better, thanks to the energy from fat.
What the research says. A beta-analysis from 2017 looking at five studies on fasted versus fed exercise concluded that working out fasted does not result in greater weight loss or changes in lean muscle mass or fat mass.
Unfortunately, the answer is no. Although it's easy to assume – or hope – that regular exercise will burn away any unhealthy food choices, that's not the case.
For many people, daily runs can translate to overtraining, which means higher risk of overuse injuries and fatigue. But for experienced runners with a proper program and an established routine, running every day can provide a sense of consistency and progress.
"I normally don't recommend runners go for a run on an empty stomach due to blood sugar and energy level concerns," Garcia said. "Starting a run fasted can induce hypoglycemia symptoms, make a runner feel sluggish, and can negatively impact their recovery time."
However, the good news is that running is one of the best forms of exercise to lose belly fat, and there are even a few small tweaks you can make to your regular running schedule to deliver a sustained fat burning boost.
Going for a run without eating anything prior can not only negatively affect your workout, but it can also make the experience less enjoyable.
Water or Sports Drink
They contain electrolytes and carbs that facilitate water absorption and help prevent fatigue. The added sodium helps your body hold onto fluid and prompts you to drink. Water is great anytime. Use sports drinks on runs 60 minutes or longer.
Running on an empty stomach forces the body to tap into its fat stores for energy. When glycogen levels are low, the body resorts to burning fat as fuel. This can be advantageous for runners aiming to improve their body composition or enhance their fat-burning capabilities.
However, a 6-8 mile run with no calories beforehand is totally doable (9-12 kms). We always encourage our athletes to have a glass of water before they go out for their run, whether they eat or not, because you usually wake up slightly dehydrated.
If you want to improve or maintain your cardiovascular fitness, then running on a treadmill is fine. However, if you're training for a race or want to see greater benefits in terms of muscle tone, then running outside is the better fit for you.
This method advocates that 80% of your training should be easy and the remaining 20% should be hard. The exact split of easy to hard runs depends on several factors, including the number of runs you do each week, your personal fitness level and any training you do outside of running.
Running 2 miles a day has many health benefits and can be very motivating. And since it's easier to sustain than other running plans, it's a good way to get you moving every day.
If you go running regularly, you'll start getting a runner's body. This is pretty amazing! Your body is adjusting its shape and the location of muscle mass to suit your new hobby. In many ways, the benefits of getting a runner's body outweigh most of the disadvantages.
Being leaner but not necessarily lighter can improve your performance because lean muscle mass generates more power and speed. But be careful not to drop your body fat too low. So, ideal race weight is the place where your body can work optimally and sustainably.
“As soon as you consume enough calories to give your body energy to do anything, that brings you out of that fasting state because your body has been given fuel to work with,” Cording says. Basically, having any amount of calories means you're rolling the dice with leaving your fasting state.
Work Out. After some time has gone by, work up a real sweat: Run, lift weights, play basketball. It's best to wait at least 3 to 4 hours after a big meal. It will burn off some of those extra calories.
That plan is called the 30-30-30 rule. It's a simple but catchy idea that encourages you to eat 30 grams of protein within 30 minutes of waking up and then get 30 minutes of low-intensity exercise. The 30-30-30 rule now has millions of followers on TikTok.
At present, the only proven way to increase fat oxidation during exercise is to perform regular physical activity. Exercise training will up-regulate the enzymes of the fat oxidation pathways, increase mitochondrial mass, increase blood flow, etc., all of which will enable higher rates of fat oxidation.