How to fuel your triathlon training: Expert nutritionist tips to help you nail every session

Nutrition is a vital piece of the puzzle when it comes to unlocking your triathlon potential. But knowing how to fuel your training – the what, and the when – can be tricky.

In triathlon, transition is often called the ‘4th discipline’ of the sport. But we’d argue that it’s actually nutrition which should take that 4th spot. Because while a bungled transition might cost you a minute or two, max. Messing up your nutrition can be completely catastrophic. How many times have we seen athletes – pro and amateur alike – felled by the foe that is GI issues?

And it’s not just on race day either. Getting your nutrition wrong during the day to day training can seriously hamper your performance too. Whether it’s running out of energy and not being able to execute a session at the prescribed intensity. Bonking on a long ride and having to cut it short. Or at the more drastic end, consistent under-fuelling leaving you with the fall-out that comes with low energy availability and even Relative Exercise Deficiency in Sport (RED-S).

Getting your nutrition right can help you to unlock a whole new level of performance – and to feel far more energised in general. But with so much information out there, and – let’s face it – for most of us, not enough time between all the swimming, biking and running to actually take it all in. Knowing how to fuel your training properly can be far trickier than it might seem.

Expert tips to help you dial in your triathlon nutrition

To help you eat to perform and fuel your way to success, we caught up with expert sports nutritionist Dr Stefano Montanari to get his advice on how to fuel your triathlon training. From what to eat and when before sessions. The ideal forms of carbohydrates to keep you moving during sessions. And whether or not you need to be racing against the clock to get protein in immediately after a workout. Read on to get Stefano’s top tips.

Dr Stefano Montanari – Sports Nutritionist

Stefano is a nutritionist for Total Endurance Nutrition with an MSc in Sports Nutrition and a PhD in the field, actively practicing since 2017. He’s very passionate about his job, helping you overcome your challenges and achieve personal goals through personalised and sustainable nutrition plans. Whether you want to improve your body comp, recover from an injury or simply improve your nutrition to enhance your performance, he is keen to help you kickstart your nutrition journey to become a healthier and stronger athlete.

Should I train fasted in the morning? How to fuel your early morning training sessions

For many of us, early morning sessions are where we struggle the most with nutrition. Especially if we’re getting up before the sun to fit in a training session before work. So should we be trying to get some fuel on board first?

It depends on the training session, and on the individual says Stefano. “Before answering this question, you should ask yourself – what is the goal of your morning session? If you are going to train at low intensities to improve your engine and rely more on fat as a form of energy, then you can do your early morning session fasted.”

“But if your session is going to be moderate to high intensity/longer than an hour then you should consider having a carbohydrate rich breakfast first. For example, porridge with a banana and some honey. Or at least have a carbohydrate rich snack before heading out, like a slice of toast or a banana. This will allow you to maintain session quality and get the most out of your session!”

Some athletes struggle to get food down before early sessions without experiencing digestive discomfort, but your choice of fuel could be the culprit. “It’s important to choose a pre-training fuel that is easily digestible, such as a small snack (banana, dried fruits, crumpets with jam) or carbohydrate drink, to avoid discomfort during exercise. Practice to find what works best for you.”

Other reasons to eat before training sessions: RED-S and pre-race gut training

Stefano raised a key consideration, particularly for female athletes, when it comes to fuelling adequately before workouts.

“Relative Energy Deficiency in Sport (RED-S) is a common issue among endurance athletes, where chronic under-fuelling can lead to hormonal imbalances that hinder recovery, training adaptation, health, and performance. Female athletes are more susceptible to RED-S which can severely impact the production of oestrogen and progesterone, key hormones that have a profound impact on several physiological functions (from cardiovascular function to bone metabolism) as well as ensuring a regular menstrual cycle*.”

“Therefore, females athletes should always consider taking in some fuel in the form of carbs prior training to avoid long-term energy deficiency.”

*PMID: 32557402.

Training your gut

Alongside making sure you’ve got the energy to complete the session, taking in fuel before training can help to prepare your gut for fuelling during races with less chance of issues or discomfort.

“If you are a few months out from a competition, consuming foods ahead of training (and during) will help you train your gut so during your race day your stomach will be more comfortable digesting food while on the move.”

Fuelling during training – when to fuel and how much you need

While it can be tempting to save your energy gels exclusively for race day (they are expensive after all!) fuelling during training can be important to make sure you can complete the session with good quality, manage your overall energy intake and get your body used to taking on fuel during activity to avoid issues that can come with taking your stomach by surprise with a barrage of energy gels it’s not used to on race day.

So when do you need to start factoring in intra-fuelling? “Sessions lasting over 60 – 90 minutes require fuel during the workout to maintain session quality and prevent fatigue*,” says Stefano.

“High intensity sessions – such as sprints or interval training – which last less than one hour do not require food/fuel during the session. However, they will deplete glycogen stores quickly, therefore meals before and after the session are key to optimise performance and recovery.”

*PMID: 21660838

How much carbohydrate do I need – and what type?

The amount of carbohydrate you need to take in during a session will depend on the duration – which in turn also impacts the optimal ‘type’ of carbohydrate you should fuel with.

“The amount of carbohydrates you are aiming to consume per hour during a session will dictate the ‘best’ form of carbs,” says Stefano. “Sessions lasting 1-2.5 hours may need between 30-60g per hour of carbs*. In this case, simple forms of carbohydrate such as maltodextrin, glucose and glucose syrup will be perfectly fine to fuel your sessions.”

Combine glucose and fructose for optimal carb intake during longer sessions

“For sessions lasting longer than 2.5 hours, you want to start consuming both glucose and fructose. This is because our gut has a limited capacity to absorb glucose – no more than 60 grams per hour. And during exercise lasting more than 2.5 hours, you are looking to exceed this threshold for effective fuelling. Ideally aiming to reach approximately 90g/h*. Therefore adding fructose is essential to provide an extra source of energy that can be absorbed by a different mechanism.”

“A 2:1 ratio of glucose to fructose is often used in sports drinks and gels, which will be ideal if you are aiming to take in 90g/h. However, if you plan to push your intake to 110-120g/h or higher – some evidence suggests that a 1:1 or 1:0.8 ratio could enable your body to oxidise even more carbohydrates compared to the 2:1 ratio*.”

*References: PMID: 21660838 / PMID: 24791914 / PMID: 32403259

But what if I HATE energy gels?

Let’s face it, none of us are going to be ordering ‘the energy gel platter with extra fructose’ in a restaurant. But for some people, forcing down energy gels goes beyond a necessary evil and becomes an intolerable prospect. So what are your options if you really can’t keep the sticky gels down?

Stefano suggests that for some athletes, there are alternatives that can work well. “Options like energy bars, granola bars, dried fruit, sweets, chews or rice cakes provide carbohydrates in a solid form. For some athletes these can be easier to digest. Bananas are a great whole-food option for quick energy – and a medium banana provides around 20 to 30 grams of carbs.”

“Homemade energy balls made with oats, honey and nut butter can be a tasty and customisable alternative to gels, too.”

If you are choosing to fuel with real food, it’s important to look at the carbohydrate content to make sure you’re still taking on enough grams of carbs for the effort. Stefano also raises the importance of hydration: “I would still recommend bringing a water bottle with added electrolytes to keep you hydrated, especially during long workouts.”

Recovery nutrition: what’s more important, protein or carbs? And is there really a strict window to get the protein in post-workout?

While the fitness industry places a huge emphasis on protein post-workout, it’s important to remember that as endurance athletes – we’re depleting our glycogen stores as well as stimulating adaptive muscle damage during training. “After a workout, protein helps repair muscle and carbohydrates replenish glycogen stores – so both are important for recovery.”

And when it comes to timing, it’s actually carbohydrate that’s the most important. “While the fitness industry still often promotes that protein consumption is a must immediately following a workout. Current evidence suggests that we actually have more time to get our recovery meal or snack, as the body is primed to receive the nutrients for several hours post exercise*. Ideally we should aim for protein to be consumed at regular intervals throughout the day.”

“However, the carbohydrate intake post-workout is much more important.”

“Following a workout the first couple of hours are critical for carbohydrate consumption. During this time our muscles are primed to uptake the glucose and use it to replenish our glycogen stores.”

“This process will happen even if you consume carbs later on post-exercise but the replenishment will be at a slower and less efficient rate*. Therefore consuming carbs following an intense session is critical to speed up recovery, even more so if you have another session soon after.”

*References: PMID: 23360586 / PMID: 3132449

What should a good post-workout meal include?

If you’re time pressed, then you can consider supplementing your intake post-workout with a complete protein shake with added carbs (SIS REGO is a favourite here at TRI247!). But where time permits, Stefano recommends that your post-workout recovery meal includes “lean protein (e.g. chicken or tofu) with whole grains or fruit to support muscle repair and energy recovery.”

Read our article with nutritionist Harvey Fortis to learn more about balancing your macros for optimal performance and recovery.