There’s nothing quite like an early morning run to make you feel like you’re starting your day on the right foot. Running early is a great way to get some cardio in while you’re still refreshed and at your best after a good night’s sleep. Ideally it should be a workout that leaves you feeling more energized later in the day after you’ve recovered as well as being a good way to burn off the excess calories you might have had last night; for example, that unexplained ice cream sandwich that “accidently” found its way into your mouth ten minutes before you brushed your teeth and went to bed. Yep, that’s the one. A morning jog paired with a good tracker to monitor the calories you’ve burned may go a long way to handling these little occasional slip ups we all have. But so far there isn’t a tracker which can settle the age old running question: Should I eat breakfast before I go running or not?

Like most things there’s a lot of conflicting advice online, some of it even from the same sources. A website will state that running before you eat is a surefire trick to get the maximum out of your workout and then later in the year they’ll post a different article positing that the complete opposite is true. So which is it?

In order to gain some credible information on the subject and hopefully settle the debate for good we spoke with Melanie Pearsall, RD, CDE, a Registered Dietician and clinician at the Massachusetts General Hospital Revere Health Center.

Personally, I find I run better having something to eat beforehand. I run better, faster, and for longer. Am I burning off as much weight as I could if I opted to skip breakfast until after I run?

Melanie Pearsall, RD, CDE: In general to fuel performance you need to eat enough carbohydrates (CHO) through your day on a daily/frequent basis. The CHO will be stored in your liver and muscles to be used for fuel during activity. If you do not eat a reasonably consistent supply of CHO both on workout day and non-workout days more than likely your workouts will suffer or not be maximized. Exercise longer than an hour done at modest intensity will burn both fat and blood sugars for fuel but in different proportions the longer and more intense the workout is. People who under eat and workout thinking they will just burn their fat stores generally workout less effectively and at lower rates which means they burn less calories overall. Your body will burn both CHO and fat all the time in exercise – just at different ratios – starting with a higher proportion of glycogen used first then after sustained activity it will change to burning more fat to keep you going.

The proponents of running on empty seem to think that running before breakfast allows their body to burn a greater percentage of fat for fuel during vigorous exercise, instead of relying primarily on carbohydrates. Is there any truth to this?

MP: If you can’t run as long or as hard or continue to increase your intensity because you don’t eat enough then in the long run you won’t be burning a lot of fat for fuel if you can even get to the point of the workout when your body starts burning more fat than CHO. This is because your body burns both fuels all the time and the quicker you transition to burning a higher proportion of fat depends on how fit you are in general as well as the time and intensity of your run.


So unless it’s a really vigorous run that’s longer than an hour I’m not really going to be burning a higher proportion of fat for fuel?

MP: Here again I think it is intensity and time. If you do a high intensity exercise for a long time maybe you can burn a lot of calories and yes get to burning fat but this is usually not the case with running. It’s generally a long interval steady state ( LISS). And quick intensive exercises like sprinting use a lot of glycogen first not fats primarily.

So what sort of breakfast should I choose before a run?

MP: Pre workouts – consume light CHO based meal 2-3 hours before working out with a bit of protein. An example would be a small banana and peanut butter and/or 6-8oz of low fat milk. The closer to the workout the lighter the meal should be for digestion.

How important is it to eat something after I’m done running?

MP: Post workout – requires an approximate one hour timeframe for replenishment of your glycogen stores and protein to repair micro-tears in your muscles (making them bigger and stronger). Around 15-30 grams of carbs with 7-14 oz of protein – again modest amounts. I might add here that people who also don’t eat breakfast at all to burn more fat generally overeat later therefore defeating the purpose, at least that’s common in my experience! The hour or so timeframe is critical as the body is primed to take in those nutrients right then for use. It is ineffective to do this hours later.

So next time you get up early and throw on your running shoes and favorite tracker know that you’re probably not doing yourself any favors by skipping a light breakfast before heading out and hitting the pavement. Food is not the enemy. In fact it’s a vital part of being healthy and an essential component of running to stay in shape. Your body is a powerful machine. Fill up the tank before you take it for a ride.