Whether you are a seasoned competitor or undertaking your first Olympic Distance triathlon, you do need to plan your nutrition and hydration needs for this type of event. You might be able to get away without consuming energy drink or gels during a sprint distance triathlon, but it isn’t recommended for longer events.
While the distance of the Olympic (or Standard) triathlon – typically a 1500km swim, 40km bike and 10km run – means that while managing your nutrition and hydration correctly during the race itself is less critical to your ability to finish than in a long course race such as an Ironman or 70.3, it is still very much an endurance sports event. Racing for between two and four hours will require you to top up your muscle glycogen levels during the race itself to perform to the best of your ability.
You’ll need to consume carbohydrate in the form of simple sugars like glucose and fructose and starches such as maltodextrin (a chain of glucose molecules). Including fat or protein in your race nutrition at this distance isn’t recommended as you will be racing at a relatively high intensity. You need a fuel source that is broken down into energy as quickly as possible, and that source is carbohydrate. So, stick to energy drinks, gels, chews and bloks, jelly babies or possibly energy bars with a high carb but low fat and protein content. Dried fruit could be an option if you prefer real food but take care to wash it down with water. The form of carbohydrate has been shown in research to make little difference to performance1, so choose what you prefer or tolerate best. Your body can absorb up to 60g of glucose per hour, or up to 90g of a 2:1 glucose/fructose combination.2 Prior to your race, calculate your carbohydrate needs based on your expected finishing time, using a minimum of 30g and a maximum of 60g per hour. 90g per hour is likely to be too much at this race distance.
Whatever your chosen energy source, it is critical that you practise using it during training, particularly during race-intensity sessions, to check how well you can tolerate it. Brick sessions are ideal for this. If you do experience stomach issues, try another brand (eg one without fructose, which can cause problems for some people) or take on smaller amounts more frequently. Remember to wash gels and chews down with water straight after you have taken them to help move them through your digestive system efficiently. Or use gels that are already diluted with water, sometimes known as “isogels”.
Your glycogen levels will start to run low between 60 and 90 minutes into the race, and you should start topping them up well before that. Waiting until you feel your energy flagging is too late! The best opportunity for refuelling is on the bike, as your digestive system functions more effectively while your upper body is in a relatively still riding position than when you are running, and you are less likely to experience gastro-intestinal distress. Also, due to the time taken to absorb what you consume, you won’t see much benefit from consuming carbohydrate in the last 20-30 minutes of your race. It is best to plan for most of your carbohydrate to be consumed on the bike, in the form of an energy drink, or gels or chews plus water, perhaps topping up with one gel just prior to reaching a water station in the early to mid-stages of the run or using the energy drink provided on the course. Start your refuelling soon after you get on the bike. You may also want to take a gel about 15 minutes before the swim start.
It is also important to remain hydrated. You will need to take on between 400 and 700ml of fluid per hour, depending on the temperature and your personal sweat rate, drinking every 15-20 minutes.3 Remember that it is important not to over-drink due to the risk of developing hyponatremia, or low sodium levels in the blood, a serious medical condition. Check that your chosen sports nutrition products have some added sodium. Choose those with a higher amount if you know that you sweat heavily. It should not be necessary to take salt tablets at this race distance. Learn more about hydration for endurance sports in my blog here.
Here’s an example of a fuelling plan for an Olympic distance triathlon: if you think you will complete the race in three hours, you should be looking to consume between 90g and 180g of carbohydrates and between 1.2L and 2L of water during that time. This might mean drinking two 500ml bottles of energy drink with a 6% glucose/maltodextrin solution while on the bike for two hours (60g of carbs plus 1L of water), then topping up with an energy gel containing 30g of carbs during the initial stages of the run, washed down with 250ml of water. You may also need to consume further water (up to 750ml) while running depending on the conditions, eg temperature, and your thirst.
Everyone has different fuelling and hydration needs, so these can only be very general guidelines. Experiment in training to see what works for you and which products you prefer. If you are planning to use the drinks and gels provided on the course, practice with these brands to make sure that you can tolerate them. But, most importantly, don’t forget to plan a nutrition and hydration strategy for your Olympic distance triathlon event.
Jo Scott-Dalgleish BSc (Hons) is a BANT Registered Nutritionist, writing and giving talks about nutrition for endurance sport. Based in London, she also works as a Registered Nutritional Therapist, conducting one–to–one consultations with triathletes, distance runners and cyclists to help them eat well, be healthy and perform better through the creation of an individual nutritional plan. To learn more about these consultations, please visit www.nutritionforendurancesports.co.uk
1 Guillochon M & Rowlands DS. Solid, gel, and liquid carbohydrate format effects on gut comfort and performance. Int J Sport Nutr Exerc Metab. 2016. Dec 20: 1-21 https://www.ncbi.nlm.nih.gov/pubmed/27997257
2 Cermak NM & Van Loon LJ. The use of carbohydrates during exercise as an ergogenic aid. Sports Med. 2013. Nov; 43(11), 1139-55 https://www.ncbi.nlm.nih.gov/pubmed/23846824
3 M Ryan. Sports Nutrition for Endurance Athletes. Velopress (Boulder, Col), 2012 (3rd ed.).p153