Eating on the Bike – How Much is Enough?

One of my clients who is training for Ironman USA in July emailed me today:

Biked today. Felt great. Did 50 on the TT bike. Was able to maintain a pretty good overall avg. Lots of “Pathletes” out there today as you can imagine. Some are pretty wide and hard to get around. At least they are out exercising. So I did the brick and bonked about minute 21 on the run. Not sure why. I did quick numbers analysis. On the bike I burned about 2130 cals, I took in approx 360, avg about 120 per hour. Is that enough or should I try and up the calorie intake on the bike. My own fault for not grabbing anything when I got off the bike and I forgot to grab a gel for the run.

First off, I’m excited to read this because he took the time to estimate what he burned and how much he consumed so that he can correlate to what happened - i.e. he bonked on the run.

My answer back was that he needs to eat more on the bike. I recommended that he replace between 30-40% +/- of the calories lost. This percentage is both a function of what his stomach can tolerate – too much and it will just sit in his stomach – and intensity. For a relatively easy training ride, he should be able to take in and tolerate more calories than in an International triathlon for example. I also recommended that grab a gel in between the bike and run.

Next time he rides long, he’ll be sure to take in more and see how that works. Since it’s early March, he has plenty of time to test different consumption amounts to determine what he should and shouldn’t be able to consume on race day.

As we used to say at Capital One – “Test and learn.”

Live life richly and boldly!

David

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David B. Glover
Writer, Athlete, Coach and Race Director
Author of Full Time and Sub-Nine
Personal Web: www.davidglover.net
Business Web: www.enduranceworks.net

© 2009 David B. Glover