I recently got into a discussion with someone new to trail running on an online forum. His biggest gripe was that he was an ex football player (bigger guy) and he was really struggling with his fuel intake on his long runs.

The problem he was having is that he felt like he was eating and drinking constantly on his runs, but no matter what he did he was bonking when he hit the 5 hour mark!

He was training for a 50K trail race. After a few questions it sounded like he had put good time in feet, lots of strength training, ticking all the boxes but was worried on all his longer training runs he was just running out of juice at the end.

We nailed it down to a fuelling issue and he was asking what he should eat . He was aiming for around 90 grams of carbs per hour but after the first few hours was getting sick of trying to get 4 gels an hour down. He liked mixing in solid foods and his stomach held up well BUT he was still totally zapped when he went over 4 hours.

"What liquid calories are you using?" I asked

"Liquid calories? What do you mean I just drink water." He replied

BINGO. We had got to the source of the issue.

Nailing down your liquid calorie intake is crucial to success in any ultra distance trail race.

I have written previously about why I advocate for using soft flasks to keep strict count of how many liquid calories you are consuming per hour.

This isn't some magical thing I have stumbled across either. Listening to Courtney Dauwalter being interviewed after her DNF at Hardrock 100 she had developed a new plan and strategy for UTMB that same year.

Working with a nutritionist to combat the stomach issues that saw her drop at Hardrock they had decided she would switch to purely liquid calories from 70 miles on. Courtney (doing Courtney things) ended up winning that UTMB race and afterwards said she felt her stomach going and match the switch to purely liquid calories earlier than the originally planned 70 miles mark.

It is important to point out not all liquid calories are the same. Different concentrations and amounts sit differently with different people so this is definitely something you are going to want to nail down in your training.

Personally, between aid stations I aim for 66 carbs/hour in a 500ml water pouch (INFINIT endurance electrolyte mix being my brand of choice) combined with a Maurten Gel. that gets me close to 90 grams an hour and seems to work well with my stomach.

So make sure you dial in your liquid nutrition for that next longer effort. If you have any comments or suggestions what works best for you drop a post on our trail running forum.

Check out more from Moretrail

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Ditch your bladder and switch purely to soft flasks to nail your next race hydration plan!