If you’ve ever experimented with working out and eating healthier for the sole purpose of losing weight, then you’ve probably come across the phrase “fasted cardio.”
Fasted cardio refers to working out in the morning without eating beforehand and rumor has it that it can help you burn fat and lose weight quicker.
Is your bowl of oatmeal making the difference for you when it comes to losing a few pounds? We did some digging to figure it out once and for all.
What Is Fasted Cardio?
Fasted cardio feeds off the assumption that you’ve had all night plus the morning without consuming food prior to a workout. According to BodyBuilding.com,
“Fasted cardio in the morning is effective because as you sleep and fast overnight your body conserves its precious carb stores and leans toward mobilizing fat for fuel. The story doesn’t end here, however. Your body also breaks down amino acids into glucose overnight, so fasted morning cardio mobilizes more fat and potentially more amino acids for fuel, which isn’t ideal if building muscle is your primary goal. This isn’t a huge problem as long as you consume a fast-digesting protein like whey, along with some slow-digesting casein, after your cardio.”
For those of us who don’t speak science, the theory behind fasted cardio is that you burn more fat and in turn, lose more weight if you don’t eat before hand because your body thinks it’s starving to death and wants to use fat for energy instead of the carbohydrates you consumed the day before.
Whereas that might sound a tad bit dramatic, your body’s survival instincts are so strong that it thinks it’s starving to death…basically all the time. This is why many experts recommend eating several small meals throughout the day. When you stop eating in order to lose weight, you may see a drastic reduction in water weight to begin with, but in the long-term, your body will actually hold onto carbohydrates and start breaking down fat and muscle instead to provide the energy your body needs.
While this may sound appealing to some, it’s not even close to being healthy and as soon as you begin eating normally, your body will bounce back and then some. This is what frequently happens when people yo-yo diet, a cycle where people lose weight quickly using unhealthy methods and then most often gain the weight back with a few additional pounds.
Does Fasted Cardio Work?
Like many things, it depends on who you ask.
According to a study published in the British Journal of Nutrition in 2013, your body will burn fat faster during fasted cardio. In this study, 12 healthy males completed four exercise trials and gave blood panels which indicated that fasted cardio does have an effect on insulin and energy levels.
However, the study also presented evidence that you will burn the similar amounts of fat after eating a carb-dense breakfast while also gaining muscle in areas that are already fat-free in your body. Translation: eating breakfast before you work out equals major gains.
And while this study does indicate that fasted cardio leads to burning fat faster, it also showed that not eating breakfast before working out leads to an imbalance of energy and fat levels in the blood throughout the day and a lack of an appetite when it comes to later meals, neither of which are positives for your health regardless of whether you’re looking to make gains or lose weight.
To make things even more confusing, this article published in the Journal of International Society of Sports Nutrition in 2014 refutes the study published by the British Journal of Nutrition.
In this study, 20 healthy young females were assigned to two different control groups — one that ate before exercising in the morning and one that didn’t. The good news is that both groups showed significant weight loss after a month of nutrition counseling and exercise. The bad news is that neither group outperformed the other in weight loss — meaning that eating before or after working out didn’t make a big difference.
Should I Do Fasted Cardio?
Our conclusions is that fasted cardio can be an effective tool to burn fat, but isn’t necessarily the most effective tool for getting healthy.
So many variables affect our body’s ability to lose weight. For example, breakfast isn’t a bad thing, but don’t expect to lose weight if your first meal of the day consists of sugary pastries or frosted cereal. Regardless of your fitness goals or what time of day you work out, your breakfast should be healthy and well-rounded with appropriate portions of protein, complex carbohydrates and healthy fats regardless of whether or not you plan on working out. You can check out some of our favorite healthy breakfast ideas here.
To make things simple — if you’re looking to build muscle through your workouts, eating breakfast beforehand is probably a smart idea. If you’re looking to slim up and burn fat, try fasted cardio and see how you feel. What’s most important is doing what works best for you and your body.