How to Fuel for the Great North Swim

Written by XMiles - the Sports Nutrition Retail Partner of The Great North Swim.

Whatever distance you have chosen, smart fuelling plays a big role in how strong, comfortable and confident you feel in the water. Swimming places unique demands on the body, and nutrition is often overlooked because eating and drinking during swims is not always straightforward. That makes planning ahead even more important.

Understanding the demands of open water swimming

Open water swimming is different from pool swimming. You are exposed to cooler water temperatures, variable conditions and longer continuous efforts with limited chances to refuel. Even in cooler water, your body is working hard and using significant amounts of energy and fluids.

Longer swims rely heavily on carbohydrate stores, while shorter distances still benefit from being well fuelled to support pacing, focus and technique. Getting your nutrition right helps maintain energy levels, supports body temperature regulation and reduces the risk of fatigue setting in too early.

Fuel the day before your swim

The day before the event is about preparation, not overloading. Your goal is to top up energy stores and stay well hydrated without feeling heavy or uncomfortable.

Focus on meals built around complex carbohydrates alongside moderate protein and familiar foods you know sit well with you. Avoid experimenting with anything new or unusually rich. Eating little and often through the day can help maintain steady energy levels.

Hydration matters just as much. Sip fluids regularly and include electrolytes if you are prone to heavy sweating or cramping.

Pre-swim nutrition on race morning

On the morning of your swim, aim to eat something light, high in carbohydrate and easy to digest. The timing will depend on your start wave, but most swimmers feel best eating around two to three hours before getting into the water.

Good options are foods that are low in fibre and fat, helping them digest comfortably. If nerves affect your appetite, liquid calories such as smoothies can be easier to manage than solid food.

Closer to the start, a small top-up snack such as an energy bar can help if you have a long wait between breakfast and your swim time. This keeps blood sugar levels stable without feeling overly full in the water.

Fuelling during the Great North Swim

For shorter distances, most swimmers can rely on their pre-swim fuelling alone. Once swims extend beyond around 60 minutes, energy management becomes more important.

Longer swims and SwimRun events may include opportunities to refuel at designated points. These moments are vital for maintaining energy, concentration and stroke efficiency. Quick, easily digestible carbohydrate sources are usually the best choice during the event.

If you are racing more than once over the weekend, nutrition between swims is just as important as fuelling during a single effort. The amount you eat depends on how much time you have before your next swim. Short gaps call for light snacks like an energy gel or chews, while longer breaks allow for more substantial meals that include carbohydrates and some protein.

Recovery after your swim

Once you leave the water, recovery should start straight away. Swimming places stress on both muscles and energy stores, even if it does not always feel as demanding as running or cycling.

Aim to take in carbohydrates to replenish glycogen and protein to support muscle repair within the first hour after finishing. Some swimmers prefer liquid recovery options like a recovery drink immediately after, followed by a balanced meal later on.

Hydration is often underestimated after open water swimming. Even though you are surrounded by water, fluid loss still occurs through sweating and breathing. Replacing fluids and electrolytes helps restore balance and supports recovery, particularly if you are swimming again later in the day or the following morning.

Distance matters

Your fuelling strategy should reflect the distance you are swimming.

Shorter swims benefit from good preparation and recovery rather than in-water fuelling. Middle distance swims require careful timing of meals and possibly a small top-up beforehand. Longer swims demand a clear plan for energy intake and our Nutrition Calculator can help keep performance consistent from start to finish.

Training is the time to practise this. Use long training swims to test what works for you so race day feels familiar and predictable.

Fuelling for the Great North Swim does not need to be complicated, but it does need to be intentional. Eating well the day before, choosing the right pre-swim meal, planning energy intake for longer swims and prioritising recovery afterwards all contribute to a stronger, more enjoyable experience in the water.

For more information, visit the XMiles website here.