KNOW YOUR MINIMUM CALORIES PER HOUR (MCPH)

BY B. FRANK

How many calories should you consume per hour during exercise?

For more than 38 years, I’ve explored one key question: how many calories per hour should you consume during exercise — whether it lasts 1, 3, 6, or even 12 hours?

The answer is simple: less is best.

Many athletes struggle with this, largely because of long-standing myths and bad information. Back in the 1980s, when Hammer first started, the common recommendation was 400–600 calories per hour. We now know that approach is unrealistic — and, frankly, harmful.

Yes, you might burn that many calories, but that doesn’t mean your body can absorb or use them efficiently during long exercise. Taking in too many calories too quickly often leads to digestive upset, worse performance, or both.

Even today, some people still push high-calorie fuelling strategies, often based on questionable research.

For instance, studies promoting 90–100 grams of carbohydrate per hour (around 360–400 calories) were carried out under conditions that don’t match real athletic efforts. Participants exercised at very low intensity (about 50% of maximum effort), and not everyone could even finish the tests.

In real-world endurance exercise — where your heart rate and energy output are much higher — your body simply can’t process that many calories effectively.

That’s why I developed the Minimum Calories Per Hour (MCPH) approach.

So what’s the right amount?

A solid starting point is about 1 calorie per pound of body weight per hour. For most athletes, that works out to:

• 100–180 calories per hour
• Slightly higher (around 200+) for larger individuals or those with very fast metabolisms

This range supports performance while also:

• reducing the risk of stomach and gut problems
• lowering cramping risk
• encouraging fat metabolism for steady, long-lasting energy

Trying to consume 360–400+ calories per hour goes against how the body actually works. The liver can only convert about 1–1.5 grams of carbohydrate per minute into usable energy, which equals roughly 240–270 calories per hour at most. If you try to push beyond that, you’re more likely to get discomfort than better performance.

The bottom line

Find your MCPH and stick to it. You’ll feel better, perform better, and avoid the unnecessary problems that come with high-calorie strategies.

Less is best. Start low, adjust if needed, and keep it simple.

Hammer on.