Carbs per hour required to fuel your Ultra Marathon

One of the biggest questions I get asked when it comes to fuelling is, “how much energy in the form of calories, which is primarily in the form of carbohydrates, should I be consuming on an hourly basis?” And this is really going to differ from individual to individual.

This will be based on the digestive system function, in other words the tolerance levels that your digestive system can tolerate of that particular carbohydrate. The kinds of carbohydrates that you’re utilising. Some are limited in absorption; some can be absorbed at a much higher rate. And then a combination of carbohydrates, which we call ‘multiple transporter carbohydrates’, can actually increase the rate of absorption when it comes to carbohydrate ingestion.

So, these are some of the things that need to be taken into account. But what can you do to work out and calculate exactly how much you require per hour? It’s quite simple. You need to look at two things.

Number one, you need to look at what keeps your energy levels stable during a training session so that you can take it to race day. And number two, you also need to look at what your tolerance levels are. And the way to do that is to build up the volume of carbohydrates over time and see what that tipping point is.

Work out your carbohydrate tipping point

Now the tipping point is the point at which you have digestive comfort and maximum energy levels, the two need to be aligned. The minute you get gastro-intestinal distress, in other words you’re getting discomfort in the digestive system from ingesting carbohydrates, you need to lower the amount that you’re ingesting because your body is not able to tolerate it. And that is how we find the tipping point.

So, the best thing to do, and this is what I recommend to most athletes, is to start off low and build up over time and see what that tipping point is. For some people the cut-off might be 40g per an hour, some might be 60g per an hour, some might be in between. And there are some athletes that consume much larger amounts, but it really is based on what an individual can tolerate and that’s quite important.

Why you have to drip feed (your carbohydrates)

So, you need to be testing this during training. Each week you should be ingesting carbohydrates in a couple of your sessions and seeing what works for you and it also needs to be a regular feed. In other words, once you’ve found how many grams of carbohydrates you will be consuming per an hour, you need to then clock feed and make sure that you take that volume hourly. You cannot disperse it too far apart; you need to be consistent with the feed. We call this ‘drip feeding.’

Drip feeding is feeding on a regular basis and making sure that you accumulate the volume of carbohydrates that you require on an hourly basis in order to maximise your energy levels and provide you digestive comfort. So, try it in training and once you find the output works for you, take it to race day, bank it, don’t change anything, stick to the nutrition fuelling plan.

If you missed the previous episodes in our Ultra Marathon Fuelling Series...

Episode 1 ↠ A BIG mistake people make close to Comrades Marathon

Episode 2 ↠ How to know what (if any) fuel to take for your session

Subscribe (It's FREE) to our YouTube channel to be the first to view our latest and greatest video content.

Products to help you get your Carbs in...

A Simple & Effective Single-Source Multi-Hour Super Endurance Race Strategy Nothing Else Needed – Just Go.

Meet sn uncomplicated fuelling strategy that will see you finish your race feeling strong and absolutely satiated! 32Gi® Race Pro is so easy on the gut you would hardly believe you had been pushing yourself for so long! To top it all off, it will enhance your recovery post-exercise.