One of the most common questions I get as a runner and Nutrition Consultant is, “what should I eat before a run? Should I eat at all?”. As much as I want to give a straight answer to this question, the reality is that the answer is more of a gray area.The reason for this we’ll discuss right here, focusing only on what you should know if you want to run before you eat.
There are both benefits and risks when considering running on an empty stomach. To find out the best solution for you, try to decide which side of the spectrum you stand on and approach it individually.
Benefits of running on an empty stomach
It eliminates the risk of digestion issues.
Unfortunately, many runners, especially beginners, find it hard to eat anything before a run. Everyone’s gut is different, and it takes some time to find out what to eat before a run if you could eat at all. If you decide not to take breakfast/ snack before your run, at least you know that you don’t need to worry about too many restroom stops. You also won’t have to think about potential stomach cramps, vomiting, or nausea.
It helps you burn fat
Since your body is running after a fast (let’s assume your last meal was your dinner, and it has been at least 8 hours), and carbohydrates levels are low, it’s assumed that it will draw from your fat stores. If you are going for an easy run and trying to lose some weight, running on an empty stomach can boost your fat loss. Moreover, in general, low-intensity activities burn more fats because you stay in an aerobic state, where your body prefers fats for fuel.
It may help your body become more efficient and economic
Since you are running on low (calories), your body will eventually adapt to that state and learn how to become more efficient while you run. This means that you may start running at a higher speed, needing fewer carbohydrates to maintain that speed. Thus, you will be more fat adapted. A lot of Kenyans practice on an empty stomach as well, and they are definitely one of the greatest runners in the long-distance running world. If you are not a fan of eating before a run, there is a good perspective on why you should continue doing so.
Risks of running on an empty stomach
It is not ideal for hard running days
Having low energy before a workout that requires a lot of energy (meaning you are burning too many calories), is not a good idea. If your glycogen is close to depleted, you will use fats as fuel. This is great unless you have to run fast because your body relies on carbohydrates to fuel your intense work, and if you don’t have much of those (for example, after a fast), you will feel sluggish and unable to cope with the pace. This is also the reason why you see runners using carbohydrate gels and drinks during marathons.
It can increase muscle-loss
When you wake up in the morning, your cortisol levels hit their highest. The cortisol hormone is responsible for your stress response and controls your blood glucose levels. But cortisol promotes the breakdown of muscles. So when you also have no energy in the morning, your body is more likely to break muscles to receive more carbohydrates as fuel (yes, your body can make up carbs that way!), especially when training hard.
It is not recommended if you have certain conditions
Fasting is not something that everyone should practice. Because running on an empty stomach can easily lead to low blood sugar, people who have diabetes or Addison’s disease may put you at risk.
In addition, if you feel fatigued or you usually have low blood pressure, having a snack may make you feel better and help you work out for longer.
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