Welcome back to Just Curious, Strong Women’s weekly series exploring all the random health and fitness questions you’ve always wondered about but never got the answers to.

This week, we’re exploring why some people feel so tired after a swimming session, and how best to recover when you’re left feeling exhausted.

Swimming is one of those forms of exercise that never seems to get its moment in the spotlight. It’s great for so many things, including our hearts, joints, bones and lungs. Oh, and it’s also low impact, making it suitable for those rehabbing an injury and for people looking to boost their fitness and longevity.

But some people find that swimming really takes it out of them, leaving them feeling a bit sleepy and tired for the period after a session. We’re not just talking about a kind of ‘I need a coffee’ tired, either – it’s that kind of tiredness where your eyelids feel heavy and you’re suddenly aware of how much energy goes into picking your feet off the ground.  

Because it’s so low impact compared to running and strength training, this exhaustion can catch people off guard. So, why does swimming have this effect on you, and what are the best ways to recover from a swimming session when you’re feeling tired? We asked the experts to share their thoughts.  

There are several reasons why a dip in the pool can make you feel sleepy, all of which add up to create the fuzzy, exhausted feeling that comes after a good swim.

1. Physical demand

Swimming may be low impact, but that doesn’t mean it’s low effort. “Swimming engages nearly every muscle in your body, and unlike running or cycling, the water’s resistance increases the effort required,” explains personal trainer Claudia Kwayosa. “This makes it a full-body workout, and after such exertion, your body naturally craves rest.”

All the muscle contractions involved in swimming – especially a high-effort stroke like backstroke or butterfly – can also lead to your muscles becoming fatigued, which is why you might feel both physically and mentally tired after a swim.

2. Water temperature

Even if you’re not going cold water swimming, most pools won’t be as warm as the human body (37°C), so the water will have a cooling effect. This can cause your core temperature to drop, so your body has to work harder to maintain equilibrium.

“Swimming in cooler water can sap your energy as your body works harder to stay warm,” Kwayosa says. “Once you are out, the drop in body temperature can mimic what happens before sleep, making you feel even more tired.” 

It’s the same reason why a warm bath before bed can help you sleep better – cooling your core temperature, whether through time in the pool or a warm bath that makes your blood vessels dilate and release heat, acting as a signal to your body to start producing melatonin and prepare for sleep. 

3. Calming effect

Getting into the flow during a swimming session can make it an incredibly meditative experience, leaving you feeling more relaxed and sleepier afterwards.

“The rhythmic breathing and repetitive movements of swimming can trigger the parasympathetic nervous system, the one responsible for relaxation and recovery,” Kwayosa explains. This means strokes where you move your head in and out of the water – breathing as you rise out and holding your breath as you go under – can be particularly therapeutic.  

Because swimming is such a full-body workout, you want to make sure you’re giving your body everything it needs to recover afterwards.

1. Hydrate, hydrate, hydrate

Spending time in the pool can leave you dehydrated – so giving your body the hydration it needs should be your first step.

“Swimming can dehydrate you more than you realise because you are in the water and do not feel yourself sweating,” Kwayosa explains.

2. Refuel

Just like you would after any workout, you need to refuel after swimming. This should follow soon after your rehydration to give your body the fuel it needs to recover.

“Have a snack or meal rich in protein or carbohydrates,” Kwayosa recommends. “Something simple like a banana with peanut butter or a protein shake works wonders.”

3. Stretch it out

If your muscles feel particularly tired after a swim, gentle stretching is a great way to encourage blood flow to the area, kickstart the recovery process, and ease tension.

“Swimming is hard work, but with the right recovery routine, you will feel refreshed and ready to dive back in,” Kwayosa adds. 

Images: Getty