Know your Minimum Calories per Hour (MCPH)

By: B Frank

How Many Calories Should You Consume Per Hour During Exercise?

For over 38 years, I've been exploring the question: How many calories per hour should you consume during exercise—whether it’s for 1, 3, 6, or even 12 hours? 

The answer is simple: Less is best.

Many athletes struggle with this question, especially given the widespread myths and misinformation out there. Back in the 1980s, when Hammer first began, the trend was to recommend 400–600 calories per hour. But that advice has proven to be 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 prolonged exercise. Consuming too many calories too quickly often leads to digestive distress, poor performance, or both.

Today, some are still pushing high-calorie fueling strategies, often based on questionable research.

For example, studies promoting 90–100 grams of carbohydrates per hour (that’s 360–400 calories) were done under conditions that don’t reflect real athletic efforts. Subjects exercised at very low intensity (50% of max effort), and not all could even finish the tests.

The reality is: during 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.

What’s the right amount?

A good starting point: about 1 calorie per pound of body weight per hour.
That usually means:

• 100–180 calories per hour for most athletes

• Slightly higher (~200+) for larger individuals or those with very fast metabolisms

This range supports performance while:

• Avoiding gastrointestinal distress

• Reducing cramping risks

• Encouraging fat metabolism for long-lasting energy

Trying to consume 360–400+ calories per hour goes against how the body works. The liver can only convert about 1–1.5 grams of carbohydrate per minute into usable energy, equaling roughly 240–270 calories per hour at most. Trying to exceed this leads to discomfort, not better performance.

The bottom line:

Find your MCPH and stick with it. You'll feel better, perform better, and avoid the unnecessary complications of high-calorie strategies.

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

Hammer on.