5 Essential Nutrition Tips for Triathletes

triathlon nutrition

There’s a reason why nutrition for triathletes is sometimes regarded as the fourth discipline in triathlon.

Picture this. Your training has been consistent for months, you’re fit and healthy and in the best shape ever – there’s no reason why come race day, you won’t have the race of your life.

Except you don’t.

You run out of energy and everything feels like a struggle. Or perhaps worse – you suffer from stomach cramping or other pretty undesirable gastrointestinal issues (did someone say portaloo!?).

It happens, and unfortunately – like everything else that comes with the demands of taking on a triathlon – there’s a process.

It’s not just nailing your race-day nutrition though. Nutrition is a vast science and getting it right during your training, both in off-season and in race season, is key to hitting your performance potential.

If you’re under-fuelling or not fuelling with the right foods, your training sessions will undoubtedly suffer. Which is both – demoralising for you as an athlete and has implications on your health, such as increased risk of potential injury or illness.

Here are our top 5 essential triathlon nutrition tips for athletes:

Stay hydrated

This sounds extremely obvious but your performance can be impaired even if you are dehydrated by as little as 2%. In fact, the capacity to perform high-intensity exercise can actually be reduced by as much as 45%, which will have huge implications on your performance both in day-to-day training and on race day.

During higher intensity or longer duration workouts, ensure you take on enough fluids and if it’s a session where you will sweat a lot, take a reliable electrolyte supplement. This goes for race day too.

Eat to train (and don’t train to eat!)

eating for training

Fuelling your training sessions well is key to facilitating better physiological adaptation to the triathlon training and therefore improvements in performance.

Typically, a higher intensity or longer in duration training session will require carbohydrates a few hours prior to training (such as oats for breakfast, for example). Depending on the session (usually anything in excess of 90 minutes), quick-release carbohydrates such as gels or energy drink will be required during the session.

Post-training, protein is essential within a 30-minute window to aid repair and recovery, as well as 1-1.2g of carbohydrate per kilo of body weight, to replenish the muscles.

On the flip side, it’s important not to over fuel as you will end up heavier and more sluggish.

Calculate your Basal Metabolic Rate (BMR) to work out your caloric needs, and factor in any training sessions you do to off-set the risk of a caloric deficiency:


BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)


BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

Shine on race day

race day food

On race day, it is essential to replace lost calories and fluids to ensure your body can meet the demands of the exertion you are placing it under.

Aim for 1g of carbohydrates per kilo of bodyweight per hour, and keep this consistent throughout the race.

Crucially, you will need to have enough fluid to convert the carbohydrate into energy otherwise it will result in gastrointestinal issues, which is never nice.

Aim for 750ml of fluid per hour.

During exercise the body diverts blood away from the digestive system and into the muscles, so training your body to cope with the ingesting of carbs is important, especially when you are racing at a higher intensity. Training is the ideal time to practice and perfect your fuelling strategy, so take on fuel during your longer/harder training sessions so you are used to it by the time you hit race day.

Stick to what you know

stick to nutrition you know

Both in training and racing, it’s often best to stick with what you know works well. On race day, always stick with the same breakfast even if it means taking your usual foods abroad with you. Some hotels don’t offer early race morning breakfast or they don’t have your usual foods available, and it’s not worth risking trying anything new on race day.

The same goes for your pre-race meal the night before – if you stick to something generic that is widely available, you will run less risk of not being able to find it in other countries that you may end up racing in.

In training and racing, consistency is really the aim of the game so fuel your training sessions using the same nutrition that you plan to use on race day (again, aim to take your gels and powders away to your race with you). Your body may not be used to what’s available on the course so it’s worth relying on familiarity to save your race.

Keep the immune system strong

fruits as healthy nutrition

Believe it or not, one of the biggest barriers to consistent training is getting ill. When you’re putting your body under stress your immune system is in an almost-constant suppressed state, so it needs every little bit of help it can get to ensure you don’t get run down.

One of the best ways to avoid getting ill is to diversify your diet as much as possible, especially when it comes to fruit and vegetables.

Aim for rich variety and colour to maximise micronutrient intake, and take gut-healthy foods such live yoghurt, kefir, miso and sauerkraut.

Foods such as berries, turmeric, ginger and chilli are known for helping to reduce inflammation which can also help to prevent injuries from occurring. You may also want to supplement with a multivitamin to optimise immune function, especially during the winter months.

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