Brian Frank here talking about a really important subject. “Got to get this off my chest before I explode," as the old headline used to read. For 36 years, I've been dealing with the question of how many calories per hour one should consume when exercising, be it an hour, 3 hours, 6 hours, or 12-hour multi-day events. Hint – Less is BEST!

This question vexes many athletes, and unfortunately, there is so much myth and misinformation surrounding it. The high-calorie crowd, as we call them, the experts of the day, were saying the same thing about how many calories per hour, with some going as high as 400, even 600! Silliness!

Maybe that's what you're burning. Doesn't really matter. You can't consume anywhere near that much. So, now we have a whole new generation of research, sort of. The outcome of a couple of questionable studies touting 60 to 90 grams an hour of carbohydrate is the basis for the "new" 60-90 grams per hour or recommended intake. Take a closer look at that research - Test subjects operate at 50% of max watts! What?

That's right. Participants are walking along at a 95 beats per minute heart rate, not so much. We're constantly exercising at a much higher heart rate than that.

You've probably tried higher calorie intake and had GI distress, plus all kinds of fun problems that go with it. So we invented this concept that less is best for optimal fueling in response to constantly dealing with athletes suffering from overconsumption of calories. So I have a little system I call the minimum calories per hour - MCPH.

MCPH is the number you want to know. You want to determine your minimum calories per hour that allows you to exercise at the limits of your ability and fitness, not slow down, and not suffer GI distress or any other cramping problems. It comes down to about one calorie per pound of body weight for most athletes.

That usually ends up being the sweet spot, plus or minus a few. So, for most athletes, we're talking 100 to 180 calories an hour. Nowhere near this 240 to 360 calorie craziness we're hearing. This high-calorie take also contradicts human physiology. We know that the human liver can return about 1 gram of carbohydrate per minute into Glycogen.
So there you go. Four calories per gram, times 60 minutes in an hour, equals a 240-calorie per hour theoretical ceiling. So why try to exceed that? And more to the point, why try to stuff so many calories down your throat when you just want to go pedal, swim, bike, run, whatever?
So do that and consume a lot less calories. You'll be happier, your stomach will be happier, and you can forget about all the high-calorie fuss and mus. So less is best. 100-180 calories an hour. One calorie per pound of body weight, and you'll be in the ballpark.