Do fasted workouts help you lose body fat? This is one of the most common assumptions about fasted exercise. However, the general consensus among experts—researchers as well as trainers and coaches—seems to be that fasted exercise doesn't result in more fat loss.
Running fasted has been proven to burn fat rather than glucose stores. But there's also a far higher muscle breakdown so your performance will likely be impaired as protein break breakdown is also increased compared to in a non-fasted state.
No, running on an empty stomach at a given intensity burns the same amount of fat as being full at the same intensity. Some people think running on an empty stomach in the morning is the first thing they do, but this has more to do with the amount of exercise they do and the food they eat.
Research has shown that there is no difference in body-fat loss between fasted and fed cardio. Fasted cardio may burn more fat during the time of the actual workout but less the rest of the day, whereas non-fasted cardio may burn less fat during the workout but more throughout the day.
It is generally advised to eat before running. This provides the fuel your body requires to workout safely and effectively. Stick to light to moderate running if you prefer to exercise on an empty stomach. If you start to feel lightheaded, take a rest.
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.
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.
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.
After hepatic glycogen stores are depleted, the body uses adipose tissue and protein for energy. The liver has an active role in the metabolism of fats as it is the main oxidizer of triglycerides. In more extreme versions of fasting, where fat sources have been expended, the body breaks down skeletal muscle for energy.
Our data shows 20.7% of users opt for a 16-hour fast or more with a fat-burn rate of 42-46%. The 16:8 fasting ratio often involves skipping breakfast and not eating your first meal until midday.
With 5K races, you need to achieve a fine balance with your diet. You want to ensure you don't overeat; you also want to avoid starting the race on an empty stomach. We recommend having a small, easily digestible meal or snack at least 1–2 hours before the race to avoid stomach cramps.
But opting for it on an empty stomach makes the stress hormones go even crazier. The best thing to do if you're new to fasted running and must do a workout at the end of your no-food period is to keep your runs relatively short (not more than 1,5h) and easy. Otherwise, you risk hitting the wall or even feeling dizzy.
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.
Running faster is a more efficient workout, burns more calories per minute, and it builds more muscle strength. If that's what you're looking for, as well as anaerobic exercise benefits, faster runs may be right for you.
What is the most effective fasting time window? Fat burning typically begins after approximately 12 hours of fasting and escalates between 16 and 24 hours of fasting.
The research is clear that training in a glycogen depleted state does increase your ability to oxidise fat. Unfortunately there is no research showing that changes in fat oxidation translate into performance benefits as yet. To fully understand the potential benefits of train-low strategies we need more research.
When it comes to nutrition advice via social media, trust me, I've heard worse. The 30-30-30 method refers to consuming 30 grams of protein within 30 minutes of waking, followed by 30 minutes of low-intensity exercise. Biologist Gary Brecka describes the diet on TikTok, which now has more than 17 million views.
4-Hour Body Diet: Health Risks
Restricting entire food groups could lead to deficiencies in certain vitamins and other nutrients, including vitamin D and calcium (found in dairy) and B vitamins such as folic acid (found in grains and fruit).
Some examples of low-intensity workouts are walking, bicycling, swimming, rowing, yoga, tai-chi, and resistance training. Such activities improve blood flow, prevent muscle wasting, and prevent falls and injuries.
If you're looking to maximize your running performance, the evidence is clear that those who run fasted do not outperform those who are fueled. Consider the big picture, if you're the type of runner who is injury prone, experiences fatigue, or struggles to recover, make fueling before every run a priority.
Simple and Complex Carbs
Simple carbohydrates, like a handful of HIGH5 Energy Gummies or a ripe banana, are ideal for a quick energy boost at the start of the race, and they're also good to use throughout the run. They provide readily available fuel for that initial burst of speed and sustained energy during the race.
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.