One of the most controversial topics of conversation in the health and fitness industry is;
“Should I eat before I workout?”
I have heard many opinions on this topic, which includes the idea that you may burn more fat on an empty stomach. Most people want to know whether they should plan to do one or the other in the hope that it may improve their results. As usual, there are pros and cons to both of these approaches, and ultimately, I feel like you need to do what feels right for your body. Some of us can eat right before a workout and feel amazing, whereas others can’t even stand the sight of food before a workout. But is there necessarily a certain way that will make you lose fat faster?
Let’s take a look at the ‘does training on an empty stomach burn more fat?’ debate. Some people think that jumping out of bed in the morning should immediately be followed by a cardio session before you even think about breakfast. The idea stems from the fact that glycogen, a stored carbohydrate, is often depleted in the morning. So after a night without eating, your body could potentially burn a greater percentage of fat as your store of carbohydrates, its preferred energy source, is not easily available. While reduced glycogen stores may help your body to prioritise or burn more fat, if they are completely depleted, this can potentially be bad for your body and may even use muscle for energy. This is something we DO NOT want, as muscle is what gives you definition, shape and tone! Usually by this stage, you're also not feeling that great either.
As most of us have a meal a few hours before getting to sleep and with the busy lives we lead, we may not always get the recommended 8 hours of shut eye, the likelihood of completely depleting your glycogen stores while sleeping is pretty slim. This means if we were to do cardio first thing in the morning, glycogen would still be in our bodies, allowing us to burn fat (safely) and maybe even more of it.
So how does our body burn fat?
Without going into too much detail, what you need to know is that fat is stored in special tissue called adipose tissue in various locations throughout the body. In order for fat to be burned (i.e. used for energy), it must first be freed from this adipose tissue. To do this, fats must first be converted to triglycerides and released into the bloodstream. This process is called lipolysis, which is kickstarted in the first few minutes of your workout!
Once the fatty acids (triglycerides) are in your bloodstream, they are delivered to your muscles, where they will be oxidised (burned) for energy. Yay! However, the important thing to remember is that fat is a complex structure and oxygen must be present in order for it to be broken down.
If you don’t 100% understand this process, the most important thing to remember is that lipolysis is not the step that determines your body’s fat burning ability, but how much oxygen is available to help break down that fat.
"So, should I eat before a workout or not?"
It is important to understand that if you have eaten a large meal before your workout, a portion of your blood is potentially being diverted away from your working muscles to the digestive system to help process your food. As blood is your body’s oxygen delivery system, this means that there is a high likelihood that there will be less oxygen available to your muscles, which can reduce your body’s fat burning capabilities. Alternatively, if you haven't eaten a meal beforehand, science also says that this has no significant impact or change on your body's ability to burn fat. If you are anything like me, training on an overly full stomach may leave you feeling a bit sick but training completely on empty isn't amazing either! By training on an empty stomach or after a light meal, means that your body is not preoccupied with digesting huge amounts of food, but instead is able to deliver large amounts of oxygen to your muscles and potentially burn more fat. Also, if you're using any supplements, with less interference in your digestive process these can essentially be absorbed faster.
Now I’m not saying that everyone should train on an empty stomach and I am also not saying that you should eat a huge stir-fry first either. One way is not significantly better or worse than the other. Science shows that ultimately there is no huge or significant benefit from making either choice. More directly, it is important to listen to your body and do what makes you feel comfortable. If you want to eat before your workout, as a suggestion I would recommend reaching for light foods, like apples or a few nuts. Not only are these easy to digest, but they are also ready to consume so you can grab them on your way out the door! If you like to train after dinner, it could be a good idea to wait a few hours after eating to allow for digestion.
In conclusion, it is important to base whether or not you eat before your workout on how you feel, as I've said above, don't feel pressured to do one or the other based on obtaining a better result. If training on an empty stomach makes you feel ill and lacking in energy, then you may find that grabbing something small will allow you to put in more effort and go harder!
Listen to your body and do what works best for you!