Long swims bring their own fuelling puzzle: cold, no easy feeding, and hours of effort. Here's how to solve it.
Long swims bring their own fuelling puzzle: cold, no easy feeding, and hours of effort. Here's how to solve it.
Long-distance and open water swimming present a distinctive fuelling challenge. You may be in the water for hours, feeding is awkward and has to be planned around feed stops or support, the cold increases your energy demands, and your stomach can be unpredictable when working hard horizontally in cool water.
Solving this puzzle is what allows long-distance swimmers to keep going strong rather than fading or, worse, running into trouble far from shore. Here is how to approach fuelling for long swims.
Because feeding during a long swim is limited and awkward, starting with full glycogen stores is even more important than in some other endurance sports. A carbohydrate-rich meal a few hours beforehand, with a top-up closer to the start, gives you the biggest possible reserve to draw on.
For very long swims, the pre-event carbohydrate loading principles of endurance sport apply in the day or two before. The better fuelled you start, the more margin you have before feeding becomes critical.
Swimming in cold open water increases your energy expenditure, as your body works to maintain temperature on top of the effort of swimming. This raises your fuelling needs relative to a warm pool session of the same duration, something long-distance swimmers must plan for.
It also means that running low on fuel in cold water is not just a performance issue but potentially a safety one, as energy and warmth are linked. Adequate fuelling supports both your pace and your ability to keep functioning in the cold.
In long swims, feeding usually happens at planned feed stops, often with support from a boat or the shore, where you take on carbohydrate quickly before continuing. Easily consumed options like carbohydrate drinks and gels work best, since you need to feed efficiently without treading water for long.
Plan your feed schedule in advance, aiming to take on carbohydrate regularly rather than waiting until you feel depleted. Practising your feeding routine in training swims is essential, as doing it efficiently in open water is a skill in itself.
Swimming hard in a horizontal position in cold water can make the stomach sensitive, so what and how you feed matters. Stick to easily digestible carbohydrate options you have tested, and avoid anything new or heavy that might cause problems mid-swim.
As with all endurance fuelling, rehearsal is key. Practising your exact feeds in training swims lets you find what your stomach tolerates when swimming, so nothing is a gamble on the day of a long swim.
Even surrounded by water, long-distance swimmers can dehydrate, and taking on fluid at feed stops matters. Carbohydrate drinks conveniently serve both fuelling and hydration, and in warmer open water or very long swims, attention to electrolytes becomes relevant too.
Plan fluid alongside fuel at your feed stops, since both are limited by the same constraints and both matter for finishing a long swim strong.
For open water and long-distance swimming, start fully fuelled, account for the extra energy demand of cold water, plan and rehearse your feeds with easily digestible carbohydrate, manage your stomach carefully, and take on fluid at feed stops.
Long swims reward planning and rehearsal above all. Solve the fuelling puzzle in training, and you can focus on the swim itself when it counts.