Theory and practise of fuelling and pacing long rides

As a follow up to a recent post on energy levels for cycling, I tried to measure how much I consumed during a recent 120 miles TDF stage (120 miles, 7hrs on bike, 7hrs 30min in total, including 30 mins to fix mechanicals and take photos.)

Firstly, it’s very difficult to remember how much you are eating. Even with the best of intentions, it’s hard to keep track of how much you’ve eaten / drunk.

One very rough rule of thumb is if you are drinking 400ml of energy drink per hour (30g of carb )- you  need to be taking one additional 30 gram energy bar / gel per hour. If you keep an eye on your elapsed time, whenever another hour passes, take another bar / gel and check what you have drunk. This way you don’t have to count so much, but just to remember to take something on the hour.

From memory and empty energy wrappers, I think this is what I got through in the 7.5 hours on the bike.

  • 3 litres of energy drink 4 * 750ml bottle (varying concentrations) usually a bit weaker than recommended = 180g
  • 2 energy gels * 25g = 50g
  • 7 or 8 energy bars * 30-35g = 255 g (inc 2* protein recovery bars towards end of ride)
  • 1 banana * 25g = 25g

total 500g of carb / 7.5 hours = 66.3 grams an hour.

  • If I counted correctly, I was fairly close to the 60-70 gram limit for absorbing carbohydrate. I never bonked, though my climbing muscles got exhausted after 2,500 + metres of going uphill. No amount of powerbars can change this.
  • If I was racing, I would be eating less energy bars, and would be relying on just energy drink and gels.

Pacing on rolling terrain

If you want to manage a 7 hour ride, it is best to pace yourself. But, for a route like the TDF stage, that doesn’t mean a constant power – because it would take you forever to get up some of the hills. There’s also a lot of freewheeling down them.

One interesting thing that stood out, is that when you’re going along a rolling road, you can look down at your power meter, and you’re doing 350 watts (I have an FTP of around 300 watts) – You’re doing a huge power output, when you thought you were just taking it fairly steady. Yesterday I spent a lot of time above anaerobic threshold (more than 15 mins of greater than 370 watts). No wonder I was shattered for the last climb of the day.

One thing I would suggest is be careful of rolling terrain, use you’re gears liberally. You will definitely want to increase power going up hills, but for the rolling terrain, it may be best to avoid those surges of power into anaerobic threshold – save that for the really steep long climbs.

Don’t just look for the big climbs, be prepared for rolling terrain. I was a bit surprised at how hilly that route was.

3 thoughts on “Theory and practise of fuelling and pacing long rides”

  1. Hi!

    I’m loving the recent articles on fuelling(and tdf routes!), it’s an area I have little knowledge on and hard to find decent numbers on. I was wondering if you carried those 4 water bottles with you or purchased/used a tap while you were out? If so how did you transport your carbohydrate powder?


    • Hi, I had 2 water bottles, and carried 2 sachets of energy powder. It’s useful to buy energy powder in individual sachets as well as big tubs. In Leyburn, I bought 1.5 litres water and refilled the 2 water bottles.

  2. Hello Tejvan

    Really love the blog – it’s a great read.
    The articles on nutrition have been very informative.

    I notice that you’ve got a picture on 9 Bars on this article.
    I like 9Bars but when I compared the amount of carbs they contain with other bars I was surprised they were relatively low. And as you measure your carb intake so accurately, I just wondered which bars you have decided to use please?

    When buying mine, I try to get bars with a high carb % but a low sugar % so have been favouring the CNP Flapjack – even though it’s not half as tasty as a 9Bar!

    Here are some comparisons based on 100g:
    Carbs 29.2g
    Sugar 26.2g

    CNP Flapjack
    Carbs 51.3g
    Sugar 6.9g
    Polyols 13.7g

    SIS Go energy bar
    Carbs 67g
    Sugar 27g

    PS I first noticed your name when looking at all the Strava climbs round where I live in Hebden Bridge..! Come on, give us mere mortals a chance!


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