Fasted cardio is having a moment. Wake up and do your exercise before breakfast, so the theory goes, and your body will forced To burn fat, because there will be no food left in your stomach to use for fuel. But does fasting before a workout really make a difference to your weight or your health? Not the way you think. Let’s take a look at the science.
What is Fast Cardio?
“Fasted” cardio does not require some kind of extreme starvation protocol. That means doing cardio when you haven’t eaten recently. The most common way to do fasted cardio is to work out first thing before breakfast since you’ve been fasting overnight. (The word “breakfast” also comes from the fact that it’s the first thing you eat breach Yours fast.)
Cardio It refers to any movement that you can perform rhythmically for minutes or hours on endsuch as jogging, cycling, swimming or using gym machines such as a stepper or elliptical. So if you’ve ever gone for a morning jog without breakfast first, you’ve already done fasted cardio.
Does Fasted Cardio Help You Burn Fat?
In a limited, technical sense: maybe. In a real-world, big-picture sense: no.
Remember we are all burning fat all the time, Just exist. How do you think your body stays alive all night while you sleep? It burns some of your fat stores, knowing that you will eat more food during the day and that fat can be replaced.
In other words, there is a difference between burning fat and to lose Fat We burn fat and replace it continuously throughout the day; Burning fat does not mean losing fat. We just to lose Fat is when we don’t eat enough to replace all the fat we burn.
Ultimately, you don’t need to pay attention to what fuel your body uses at what time. If you really want to get into the details, your body also has carbohydrate stores (called glycogen), and when you do fast cardio you burn those stored carbohydrates—so not all of the energy you use comes from fat.
What Science Says About Fasted Cardio
Scientists have tested the possibility that fast cardio can burn fat, which in turn can lead to fat loss. Unfortunately, the results are pretty clear that fast cardio doesn’t help people lose weight.
in This 2014 study20 women were put on a calorie-restricted diet (which would help them lose weight), and did one hour of cardio three mornings per week. Half of the women got the shake before their cardio session, and half got the shake after. Members of each group ate the same total number of calories per day.
The results? Both groups lost a similar amount of weight. Fast cardio provided no additional benefit.
It’s also unclear whether fast cardio causes fat gain burning. A 2018 meta-analysis 38% of studies on fasted cardio found more free fatty acids in the bloodstream compared to fed cardio; That means the fat was burning. But a 2011 study actually found that people who ate before doing cardio had a higher rate of fat burning. Based on these results, I wouldn’t trust fasted cardio to burn more fat, much less lose it.
What do you think so far?
Disadvantages of fast cardio
The biggest downside to fasted cardio is that you will always perform better during a workout when you are fed. You’ll be able to push harder, work longer, and feel less tired doing it. If you find exercise tiring, a A pre-workout meal, snack or even a sports drink It can change.
Longer sessions will especially benefit from eating beforehand. It is well known among endurance athletes that marathons, all-day bike rides and long hikes benefit from a massive supply of calories, mainly in the form of carbohydrates. If you exercise for more than an hour at a time (some say more than 90 minutes) you should not only exercise beforehand, but Bring fuel with you to eat on the go.
At the extreme, going without food during exercise can make you feel dizzy or have a headache (especially if you’re pregnant or have medical problems that can affect your blood sugar). It can also mean “hitting the wall” after a few hours—the point where you reach the point where your body doesn’t have enough stored carbohydrates to sustain the level of effort you want to put forth. (This is more of a problem for marathoners than casual joggers, so don’t let that scare you if you’re looking to fuel up for a short morning run.)
While fasting can make cardio sense
Even if I sing Continuously In addition to pre-workout carbs, I do a lot of fast cardio myself. I’m not for the fat burning benefits; I do it because I jog in the morning and I don’t want to worry about finding time to eat beforehand.
Doing cardio on an empty stomach may make sense if:
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Your stomach is sensitive and you may feel nauseous if you eat right before a run.
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You won’t have time to eat beforehand, and your workout will be shorter or easier anyway.
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You have a limited calorie budget for the day, and want to save your carbs for later (before an evening weightlifting workout, perhaps).
In these cases, I would skip the pre-workout meal only if your cardio session is relatively short or easy. Longer sessions still require fuel. If stomach upset is an issue, consider eating a few hours earlier—or even eating dinner or a midnight snack before a long or hard morning run. It’s also worth exploring if there might be small snacks, like a banana or a swig of sports drink, that can give you some fuel before your run without triggering your stomach issues.
