28 February 2020

Expert advice: How to eat for a triathlon, part 1 – before

June 6, 2016

It’s peak triathlon season, so here’s some great advice if you’re planning to take on a triathlon this year. Getting your nutrition right can make all the difference to your race preparation and performance. In this blog post we tap into the expertise of  Dr Matthew D Campbell, Dr Lauren Duckworth, Dr Andy King and Oliver Shannon from Leeds Becket University and Olympic hopeful Tom Bishop.


For Olympic distance races such as the ITU World Triathlon inLeeds where you might be competing for over two hours, swimming, cycling and running a combined distance of over 51 km places a huge demand on your body. However, knowing how to “fuel” appropriately will allow you to capitalise on your hard work during training, perform optimally on race day, and recover quicker after the chequered flag.

With the three different disciplines, the beauty of triathlon is that you can adapt your fuelling for each leg of the race – but, how much of what and when?

Before the race

Many of us have heard of “carbohydrate loading”, but this is more than simply eating pasta for dinner the night before competition. In the days leading up to the race as the amount of training is reduced, try to maintain your energy intake, specifically the amount of carbohydrate.

For Olympic distance competitions, take 7-8 g of carbohydrate for every kilogram that you weigh over the course of 24 hours preceding the race. (i.e. ~530 g spread throughout the day for someone weighing ~70kg). This will be adequate to ensure your muscles have stored enough energy.

Everyone has different levels of tolerance towards eating before exercise, especially swimming, so it is important to trial what works for you. In general, try to consume around 150g of carbohydrate and allow 2-4 hours to digest a larger meal before your swim. You could maybe have a smaller carbohydrate snack 30 minutes to 2 hours before the race.

Complex carbohydrates (such as porridge, muesli, wholegrain toast, eggs, yoghurt without sugar) give a slower release of energy and should be the focus of main meals before an event.


Simple carbohydrates (fruit juice, sugary snacks, jam sandwich etc) are quickly broken down to provide immediate energy, making great snack options for a short sharp boost before, during, and after a race.

Some athletes take a number of supplements leading up to the race, such as caffeine and nitrate (usually in the form of beetroot juice). Caffeine has been shown to improve endurance performance when taken in a moderate dose. A cup of coffee 2 hours or so before the race should be sufficient to give you that edge. Research at Leeds Beckett suggests that using beetroot juice, which is rich in nitrate, can also help performance when taken up to 3 hours before exercise. Beetroot juice is readily available and about 70 ml of a concentrated shot may provide you with an additional advantage.

Tom Bishop: “I eat a good high carb breakfast such as porridge about 4 hours before. I have a coffee and a small snack 2 hours pre-race. Then I sip at a sports drink, until one hour to, when I have a gel and a sip at water before the race. I also take 140ml a day of concentrated beetroot juice for the five days before the race.”

Read part 2  – what to eat during the event

Dr Lauren Duckworth, Sportsister
The Women’s Sports Magazine

Dr Lauren Duckworth is a Senior Lecturer in Sport & Exercise Nutrition, working within the Carnegie Faculty at Leeds Becket University.




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