Posted in Triathlon
Image of Wiggle staff member Tim Wiggins

I had an embarrassing moment the other day. I had been driving for a while ignoring the petrol light, thinking I could “squeeze in one more trip up the road before I stop and fill up”. Not so. That last trip was one too many and I had the pleasure of pushing the car the few blocks up the road to the petrol station…

The same thing has happened to me a few times during races. I’ve been slack with my nutrition and ended in a world of pain in the last few kms without barely enough energy to shuffle on. So much for the sprint to the finish line!

The common mistake? Not fuelling properly… In the car it was obviously petrol, for the race my problem was a shortage of carbohydrates. And, without enough carbohydrate to fuel my muscles during intense exercise, I came to an abrupt halt, ’hit the wall’, ‘bonked’, and was engulfed by that horrible feeling of fatigue.

As an athlete (weekend warrior all the way through to elite triathlete), focusing on carbohydrates is key to giving your body the fuel it needs to push through a hard session or race and the energy you need to get through your day.

Foods are classified as carbohydrates because when you eat them, they are digested and broken down into glucose (the simplest form of sugar) before being absorbed into your blood stream. Glucose is then transported around your body and either used for fuel or stored in your liver and muscles as glycogen (lots of glucose molecule stuck together just like an old-fashioned candy necklace you used to get in your show bag). When we exercise, our body pulls these stores of glycogen from the muscles and liver and uses them to get us moving.

Carbohydrates are found in all starchy foods (grains, cereal, bread, rice, pasta, potato, sweet potato and corn) and sugary foods (fruit, dairy, sweets, honey and sugar). Day-to-day the amount of carbohydrate you'll need to eat will depend on your weight and training schedule but the table below from the AIS will help to give you an idea of how much you may need.


Light Low-intensity or skill-based activities 3-5g per kg BW per day
Moderate Moderate programme with ~1 hour of exercise per day 5-7 g per kg BW per day
High Endurance programme with moderate to high intensity exercise for 1-3 hours per day 6-10g per kg BW per day
Very High Extreme commitment with 4-5 hours per day of moderate to high intensity exercise. 8-12g per kg BW per day


So, if you weigh 70kg and are training for an olympic distance triathlon (doing 1-3 hours of training per day), you’ll need anywhere between 420 and 700g of carbohydrate each day. It’s often more food than you think! The following example day gives approximately 500g carbohydrate:


  • Breakfast: 2 cups flakey cereal with 1 cup milk and a banana and a small glass of juice (125g)
  • Morning Tea: regular coffee and 2 wholemeal crumpets with honey (70g)
  • Lunch: A large chicken and salad roll (50g)
  • Afternoon Tea: 2 cups of fresh fruit salad with 200g yoghurt (75g)
  • Dinner: 1.5 cups rice with a beef and vegetable stir-fry (75g)
  • Supper: 1 cup fruit crumble with 1 cup custard (75g)


Carbs are particularly important around race day. You need to make sure your stores of glycogen are fully stocked before you start, and you top up during your race so you can power through to the end. Keep an eye out for our upcoming ‘Eating to win’ series on race day nutrition where I’ll discuss what and when to eat for racing.

It’s essential to tailor your carbohydrate intake to the training demands of your day - eat more carbohydrate on heavy training days and less carbohydrate on lighter days or rest days. If you overload on carbs, you’ll be overloading on kilojoules (or calories) and will end up having to carry extra weight around in your race! To make sure you get it right, see a sports dietitian who can help to tailor a specific plan for you based on your training programme.


Zoe Wilson smiling

Zoe Wilson is Wiggle’s new Australian nutrition blogger – Zoe is a triathlon-mad Accredited Practising Dietitian with a keen interest in sports nutrition. Most of all, she loves making nutrition concepts easy for any old person to follow. Find her at