<img src="https://images.immediate.co.uk/production/volatile/sites/30/2020/08/swimming_1-e2fb4c3.jpg?quality=90&resize=620,413" srcset="https://images.immediate.co.uk/production/volatile/sites/30/2020/08/swimming_1-e2fb4c3.jpg?quality=90&resize=360,239 360w, https://images.immediate.co.uk/production/volatile/sites/30/2020/08/swimming_1-e2fb4c3.jpg?quality=90&resize=180,119 180w, " sizes="(max-width: 620px) 100vw, 620px" width="620" height="413" class="wp-image-435434 alignnone size-landscape_thumbnail" alt="Woman swimming" title="What to eat during a swim" /> <p>When should you start refueling during swimming sessions, and what should you refuel with? Elite sports nutritionist James Collins answers all your questions about poolside nutrition.</p>
<p>If you are training to swim competitively, longer swims may require you to fuel during your session. If you’re a recreational swimmer it’s unlikely you’ll have to worry about eating during a swim, though you might want to consider hydration.</p>
<p><strong>Next, discover what to eat before a <a href="/howto/guide/what-eat-swim" target="_blank" rel="noopener">swim</a> and <a href="/howto/guide/what-eat-after-swim" target="_blank" rel="noopener">after a swim</a> as well as the <a href="/howto/guide/fitness-fat-burning" target="_blank" rel="noopener">best exercise to burn fat</a>, <a href="/howto/guide/how-stay-hydrated">top tips on staying hydrated</a> and <a href="/howto/guide/how-much-protein-to-build-muscle">how much protein you need to build muscle</a>.</strong></p>
<h2>What about refuelling during a swim?</h2>
<div class="image-handler__container image-handler__container–aspect" style="padding-bottom: calc(100% / 1.501210653753);">
<picture>
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=298%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=598%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=898%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1198%2C799 4x" type="image/webp">
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=298%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=598%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=898%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1198%2C799 4x" type="image/jpeg">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1063%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1417%2C945 4x" type="image/webp">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1063%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1417%2C945 4x" type="image/jpeg">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=403%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=808%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1213%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1618%2C1079 4x" type="image/webp">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=403%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=808%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1213%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1618%2C1079 4x" type="image/jpeg">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=553%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1660%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=2214%2C1476 4x" type="image/webp">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=553%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1660%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=2214%2C1476 4x" type="image/jpeg">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=619%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1858%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=2478%2C1652 4x" type="image/webp">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=619%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1858%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=2478%2C1652 4x" type="image/jpeg">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=406%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=814%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1222%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1630%2C1087 4x" type="image/webp">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=406%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=814%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1222%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1630%2C1087 4x" type="image/jpeg">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=1666%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?webp=true&quality=45&resize=2221%2C1481 4x" type="image/webp">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=1666%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=45&resize=2221%2C1481 4x" type="image/jpeg">
<img class="wp-image-880423 align size-landscape_thumbnail image-handler__image image-handler__image–aspect no-wrap js-lazyload" srcset="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" data-src="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Sports-drink-9ee7d63.jpg?quality=90&resize=619%2C413" width="620" height="413" alt="Woman drinking a sports drink" title="Sports drink">
</source></source></source></source></source></source></source></source></source></source></source></source></source></source></picture>
</div>
<p>As it’s difficult to eat during a swim, the focus should be on <a href="/howto/guide/what-eat-swim" target="_blank" rel="noopener">fuelling before training</a> to maintain your energy. For endurance training (over an hour) or high-intensity sessions, taking on small amounts of carbs may help to maintain performance. The focus of these should be around carbohydrate-electrolyte sports drinks (or gels), which are rapidly absorbed in the gut.</p>
<p>New <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936414/" target="_blank" rel="noopener">research</a> shows that even taking on small amounts of a carb-based sports drink or using it as a mouth rinse, helps to activate the brain and potentially improve motivation – this may be a useful strategy for later in your swim, when you can’t face taking on too much. As the response is very individual, if you choose to use these products be sure to practice this strategy during training.</p>
<h2>How do I stay hydrated?</h2>
<p>Staying hydrated is an important consideration when swimming, as often temperatures in the pool and out are warm and humid. This makes sweat loss (and overall hydration status) difficult to determine, as swimmers are already wet from the pool. However, you should bear in mind that if you lose as much as <a href="https://pubmed.ncbi.nlm.nih.gov/28508338/" target="_blank" rel="noopener">2% or more of your body mass</a> (e.g. 1kg for a 50kg athlete) through fluid loss, this may negatively affect <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207053/" target="_blank" rel="noopener">performance and concentration</a>, and put additional strain on your body making training feel harder.</p>
<p>Regular swimmers should try to <strong>estimate their sweat rates</strong>. This is easily done by weighing yourself (in minimal clothing) before and after a swim (following towelling down), then subtracting any fluid consumed. Every 1 kg lost = 1 litre in sweat (e.g. 1 litre lost from a 120minute swim). For every 1kg lost:1.5litres of fluid needs to be replaced (to allow for continued losses post session). A basic rehydration strategy may then be developed to replace fluid losses after training.<br>
Don’t forget to listen to your body, and drink according to your thirst. The body’s physiology is tightly regulated so when there is excess sweat loss (affecting blood levels) the thirst mechanism is triggered.<br>
Together these measures should help exercisers develop an appropriate strategy to stay hydrated, given one size doesn’t fit all.</p>
<h2>How often should I drink during my swim?</h2>
<div class="image-handler__container image-handler__container–aspect" style="padding-bottom: calc(100% / 1.501210653753);">
<picture>
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=298%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=598%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=898%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1198%2C799 4x" type="image/webp">
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=298%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=598%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=898%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1198%2C799 4x" type="image/jpeg">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1063%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1417%2C945 4x" type="image/webp">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1063%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1417%2C945 4x" type="image/jpeg">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=403%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=808%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1213%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1618%2C1079 4x" type="image/webp">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=403%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=808%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1213%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1618%2C1079 4x" type="image/jpeg">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=553%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1660%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=2214%2C1476 4x" type="image/webp">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=553%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1660%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=2214%2C1476 4x" type="image/jpeg">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=619%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1858%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=2478%2C1652 4x" type="image/webp">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=619%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1858%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=2478%2C1652 4x" type="image/jpeg">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=406%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=814%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1222%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1630%2C1087 4x" type="image/webp">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=406%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=814%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1222%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1630%2C1087 4x" type="image/jpeg">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=1666%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?webp=true&quality=45&resize=2221%2C1481 4x" type="image/webp">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=1666%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=45&resize=2221%2C1481 4x" type="image/jpeg">
<img class="wp-image-880424 align size-landscape_thumbnail image-handler__image image-handler__image–aspect no-wrap js-lazyload" srcset="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" data-src="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Swimming-9da445e.jpg?quality=90&resize=619%2C413" width="620" height="413" alt="Woman lane swimming" title="Swimming">
</source></source></source></source></source></source></source></source></source></source></source></source></source></source></picture>
</div>
<p>Before your training session drink 500ml of water, about two hours before getting in the pool. This will allow any excess to be passed as urine. Then, if tolerated, take small sips over the course of the session to help keep levels topped up.<br>
A small amount of dehydration isn’t a problem, the body can tolerate this – which means rehydrating during your swim may only be necessary if you complete a long or particularly heavy training session.</p>
<h2>What are electrolytes and where can I get them?</h2>
<p><a href="/howto/guide/what-are-electrolytes-and-do-i-replenish-them" target="_blank" rel="noopener">Electrolytes</a> are found in the blood, sweat and other fluids and have an important role to play in maintaining fluid balance within the body. Sodium is the most important electrolyte for hydration while others include potassium and chloride. Electrolyte levels are tightly controlled by the body, but may, along-with fluid, be lost in sweat and therefore need to be replaced.</p>
<p>Drinking large volumes of water on its own may just pass straight through the intestines and be lost as urine but by incorporating electrolytes your body will be able to absorb and retain the fluid, thus maintaining hydration.<br>
Electrolytes are found naturally in food, and are also found in sports drinks and gels, which are an easy way to absorb and retain fluid during training.</p>
<h2>Can I continue to drink caffeine and alcohol in moderation during my training?</h2>
<div class="image-handler__container image-handler__container–aspect" style="padding-bottom: calc(100% / 1.501210653753);">
<picture>
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=299%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=599%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=899%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1199%2C799 4x" type="image/webp">
<source media="(max-width: 320px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=299%2C199, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=599%2C399 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=899%2C599 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1199%2C799 4x" type="image/jpeg">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1064%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1418%2C945 4x" type="image/webp">
<source media="(max-width: 375px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=354%2C236, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=708%2C472 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1064%2C709 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1418%2C945 4x" type="image/jpeg">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=404%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=809%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1214%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1619%2C1079 4x" type="image/webp">
<source media="(max-width: 425px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=404%2C269, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=809%2C539 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1214%2C809 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1619%2C1079 4x" type="image/jpeg">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=554%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1661%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=2214%2C1476 4x" type="image/webp">
<source media="(max-width: 589px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=554%2C369, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1107%2C738 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1661%2C1107 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=2214%2C1476 4x" type="image/jpeg">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=620%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1859%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=2478%2C1652 4x" type="image/webp">
<source media="(min-width: 992px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=620%2C413, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1239%2C826 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1859%2C1239 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=2478%2C1652 4x" type="image/jpeg">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=407%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=815%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1223%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1631%2C1087 4x" type="image/webp">
<source media="(min-width: 768px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=407%2C271, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=815%2C543 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1223%2C815 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1631%2C1087 4x" type="image/jpeg">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=1667%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?webp=true&quality=45&resize=2222%2C1481 4x" type="image/webp">
<source media="(min-width: 590px)" data-srcset="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=555%2C370, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1110%2C740 2x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=1667%2C1111 3x, https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=45&resize=2222%2C1481 4x" type="image/jpeg">
<img class="wp-image-880425 align size-landscape_thumbnail image-handler__image image-handler__image–aspect no-wrap js-lazyload" srcset="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" data-src="https://images.immediate.co.uk/production/volatile/sites/30/2024/04/Coffee-8072edf.jpg?quality=90&resize=620%2C413" width="620" height="413" alt="Espresso being poured from a machine" title="Coffee">
</source></source></source></source></source></source></source></source></source></source></source></source></source></source></picture>
</div>
<p>It’s better to cut out (or cut down) alcohol around heavy training sessions, as this may interfere with the body’s maintenance of blood glucose and recovery (including sleep quality) after training. If you are going to enjoy the odd tipple, have it after your post-training recovery.<br>
After a lot of bad press, research suggests some caffeine, taken at the appropriate times, may actually be a <a href="https://pubmed.ncbi.nlm.nih.gov/12834577/#:~:text=It%20improves%20performance%20and%20endurance,reduces%20fatigue%2C%20and%20enhances%20alertness" target="_blank" rel="noopener">positive inclusion for performance</a>. If you are a regular tea or coffee drinker, these drinks will contribute to your daily fluid intake and in smaller amounts don’t dehydrate, as we had previously thought.</p>
<p>The stimulatory effect of caffeine is often employed by elite swimmers to help <a href="https://pubmed.ncbi.nlm.nih.gov/20888549/" target="_blank" rel="noopener">make training feel easier</a>.</p>
<p>Now you know what to eat and drink during your swim, get the rest of your training nutrition right:</p>
<p><a href="/howto/guide/what-eat-cycling" target="_blank" rel="noopener">What to eat before your cycle</a><br>
<a href="/howto/guide/what-eat-during-cycling" target="_blank" rel="noopener">What to eat during your cycle </a><br>
<a href="/howto/guide/what-eat-after-cycling" target="_blank" rel="noopener">What to eat after your cycle</a><br>
<a href="/howto/guide/what-eat-swim" target="_blank" rel="noopener">What to eat before your swim</a><br>
<a href="/howto/guide/what-eat-swim" target="_blank" rel="noopener">What to eat after your swim</a><br>
<a href="/howto/guide/what-eat-your-run" target="_blank" rel="noopener">What to eat before your run</a><br>
<a href="/howto/guide/what-eat-during-your-run" target="_blank" rel="noopener">What to eat during your run</a><br>
<a href="/howto/guide/how-recover-after-your-run">What to eat after your run</a></p>
<p><em>This page was reviewed on 8 March 2024 by Kerry Torrens</em></p>
<hr>
<p><em>As a sport and exercise nutritionist, James Collins regularly provides comment and consultation within the media and maintains a role of governance within health & nutrition in the UK, where he sits on The Royal Society of Medicine’s (RSM) ‘Food and Health’ Council. He was heavily involved in advising Team GB in the run up to the London 2012 Olympic games, and now towards Rio 2016.</em></p>