Onetrack1000: How to Prepare Your Body For a Running Event By Justin Reid-Simms


Running Event London

We recently spoke to Justin Reid-Simms, a Certified Nutritionist, Running Coach & Personal Trainer about the best ways to prepare and nourish your body for a running event like the OneTrack 1000. Here’s the advice he had to give to help you in the week before:

Practical Guidelines

via. Asker Jeukendrup

  • Make sure you start the exercise with sufficient muscle glycogen. Sufficient means high stores, but these stores don’t need to be extremely high. Extremely high glycogen stores are also broken down faster.
  • For trained individuals, this can be achieved by eating carbohydrate-rich for 2 days before a race, while reducing glycogen use (reducing training).
  • Because training is reduced and therefore, energy expenditure is reduced, higher carbohydrate intake should not be the result of just eating more. It should be the result of emphasising carbohydrate sources and reducing fat intake. Very often carb loading and overeating seem to be confused by athletes.
  • There are many different ways to achieve high glycogen stores. The type of carbohydrate appears to have little or no effect, both solid and liquid carbohydrate sources seem to have the same impact.
  • A carbohydrate intake of 5-7 g/kg per day appears to be sufficient in the majority of cases (with low energy expenditure).

Running Event London - Carb Recommendation

As a guideline to carbohydrate intake during exercise, you can’t go far wrong with the evidence outlined here. A carbohydrate drink can be an effective way to boost your performance on track if you know your energy intake hasn’t been high throughout the day. As you look to go longer, it’s time to think about sweets, gels and energy drinks to improve your performance. 

Thinking about Onetrack1000?

Take a quick look back to that carbohydrates recommendations chart. That might seem like a lot of carbs for a 10K or a Half Marathon but I've included a link to an article by Asker Jeukendrop as afterthoughts on carbohydrate intake and its relationship to finishing time for marathoners.

Briefly summarised - The study showed that the runners who have a science-based nutrition plan were an average of 4.7 percent faster than those that ran with a self-selected intake. You can read more about it here

Onetrack1000 is a running event in London taking place on the 1st of September 2019. If you'd like to know more, please don't hesitate to get in touch via the contact form or on 

Justin Reid-Simms is a Certified Nutritionist, Running Coach & Personal Trainer. Find out more about him at or get in touch @alamerathletic / @houseofcardinal



Bergstrom, J., Hermansen, L., Hultman, E., and Saltin, B. Diet, muscle glycogen, and physical performance. Acta Physiol Scand. 71: 140-150, 1967.

Jeukendrup and Gleeson Sports Nutrition Human Kinetics Champaign IL, 2010

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