That Swimmer’s Appetite – Nutrition for Triathlon Swimming

Swim nutrition in triathlon often gets forgotten, as for the majority of triathlon distances, the only nutrition taken on board is completely accidental! However, when it comes to any endurance swim races or key swim sessions, nutrition should absolutely be considered to optimise performance and training adaptions. Also, who could talk swim nutrition without also covering off on the insatiable appetite afterwards!

Hydration in and out of the water
Although our sweat losses while swimming go unnoticed, it is important to consider the factors that are influencing how much you are losing while in the water. Swimming outdoors in cooler water means that you may not be losing too much fluid during a session and only really need to drink to thirst to maintain fluid requirements (assuming you have entered the session well-hydrated).

If swimming in indoor or heated pools, this environment can up regulate the sweat response and lead to you having quite a significant sweat rate without even realising it (think about those times you seem to be unable to stop sweating after a hot swim session). With this in mind, have a bottle of fluids on the pool deck with you and utilise breaks between sets to optimise hydration. Depending on the length and goals of the session, this may be water, electrolytes or carbohydrate-containing sports drink.

Even more important than this acute hydration around specific swim sessions, is the chronic hydration over the day. As swim sessions are often early morning, hydrating pre-session can be a challenge. As such, plan fluid intake the day before the session and ensure that your recovery strategies after any afternoon sessions are optimised. When losses are high in and around sessions, the addition of electrolytes may help to retain fluid and further help enhance hydration.

Post-Swim Session Recovery
In the life of a triathlete, swim days often also mean double-training days – this makes recovery an increasing priority. In the 30-60 minutes after your session, aim to eat a quality snack or meal that focuses on getting in both protein and carbohydrate.

Protein will kick-start the muscle recovery process and carbohydrates will start the muscle glycogen refuelling process – particularly for any upcoming training sessions. Being organised and timely with your recovery food early, will help ensure you aren’t playing catch-up with nutrition later and hopefully mean you are better fuelled for your next training session!



Appetite Control
I’m sure I’m not the only one who finds my appetite increases exponentially following a swim session! If you are with me on this, it is important to have some tools in your toolbox to manage this increase that is a common issue amongst both triathletes and swimmers. Handy nutrients to manage appetite are protein; fats and fibre, along with making sure you are keeping your fluids up.

Therefore, try to limit overeating temptations following a swim session by keeping high-quality meals and snacks close by to choose from. This can be made easier by:

  • Timing your breakfast to follow soon after your morning swim session – instead of just having a coffee and hoping that will be enough to get you through the next couple of hours until you can find some food.
  • Preparing your evening meal the night before so you know that you can eat as soon as you get home from an afternoon swim. This ensures that you tick both recovery and appetite, while also prevents any ‘emergency’ takeaway stops on the way home.
  • Keeping a stash of quality, long-life snacks in your training bag. Some favourites might be quality muesli bars, fruit, dried fruit and nuts.

Protecting your Immune System
Swimming combined with heavy training can increase the risk of illness. With this, many supplements and nutritional strategies will continually be suggested to keep you illness-free during your training and race preparation. The latest research emerging shows that one of the most important strategies to protect the immune system is to keep well fuelled with carbohydrate during the key training sessions. Consuming sports drink during and a small snack afterwards (see the point on recovery), helps to limit the stress on the immune system – particularly during periods of heavy training. This principle can also be used in other hard and long training sessions outside of the pool.

Fuelling your swim on race day
The swim in triathlon comes with challenges that are not experienced in the ride or run. The primary hurdle, of course, is the inability to eat or drink during the swim leg of a triathlon (well not efficiently anyway!). Of course, race day strategies are going to vary depending on your swim distance, as you may be swimming for anywhere between 10 to 120 minutes!

For any swim going beyond 90 minutes, it may be worthwhile to consider taking nutrition in during the event. However, for swims less than 90 minutes you will only need to consider your nutrition needs both before and after the swim. Before race day, it is therefore important to consider the swim distance, expected swim time, history of gut upset or bonking and foods you can tolerate around swimming.

If you are unsure about these, this is when an experienced sports dietitian can be super helpful (and quite the handy investment!).



For swims less than 30-40 minutes
These events will not deplete all your fuel stores. So, although you will want to optimise pre-race nutrition, you will be able to utilise fluid and food on the bike to refuel and rehydrate for both the bike and run legs.

For swims approaching the 60 minute plus mark
This is a long time in a race environment to go without any fluid or nutrition, so entering the race well hydrated and eating enough pre-race is key. Ensure that you are eating adequate amounts for your pre-race breakfast and snacking on sports foods and drinks in the lead up to the race start.

Once you finish the swim, you then need to start the refuelling process as soon as possible. However, with your heart rate often approaching threshold at this point, make sure what you plan to have in the race has been trialled at a specific brick session during training. Things to consider are what you will be able to physically stomach post-swim (will you be better with solid foods, gels or sports drink?), what the bike course is like coming out of T1 and what you plan on carrying on the bike with you.

Distance Swimming Events (> 2hours):
Although this is not relevant for most triathlon distances, it is worth mentioning the nutrition needs for open water swimming events that many of us may book in over summer as both a training and racing opportunity. Distance swimming events will often incorporate feeding and hydration stations into their courses, so make sure you checkout aid station placement and support personnel opportunities before race day.
Ideally, you will want to feed at 15-25 minute intervals during the swim so that you can focus on taking in small, frequent amounts. Options to include (depending on what support you have available) may be a sports drink, water, gels and whole foods that are easy to get down (and handed to you!) such as bananas.


Alicia Edge

Alicia is an Advanced Sports Dietitian with an online sports nutrition business, Compeat Nutrition. She is also a mum and triathlete, so advice extends beyond the basics and is instead focused on providing effective and achievable nutrition for both training and racing.

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