As either a sport or recreational exercise, swimming has a lot of health benefits – no matter your age or fitness level. It is low (zero) impact on your joints, meaning that any long-standing pain or arthritis is soothed and unaffected, and the chance of injuries are much less than running or other jolting manoeuvres in different sports taking their toll on your body.
Why Does Swimming Make You Hungry?
But the question we are here to answer today is a little different. Those of you who have ever swam consistently for exercise will have noticed that, on leaving the pool, you are overcome with hunger. More so than simply being peckish, 40 minutes of moderate swimming can in fact make you ravenous! Well, there is actually a definitive science behind why swimming makes you hungry, and two very important reasons that contribute to it. So let’s deconstruct those post-crawl cravings and delve deeper into why does swimming make you hungry.
Reason #1: Cold Water - The Science of Appetite Suppression
It’s not a widely known fact this, but temperature heavily influences your appetite. In any given cardiovascular exercise – running, cycling, cross-training – you obviously get hotter as the workout intensifies. This causes blood flow in your body to transmit heat to your skin, which is then expelled as sweat – which then serves to cool you down. All very rational and relatable thus far, right? Well, when you’re in a swimming pool, the water temperature is (on average) 10+ degrees below your core body temperature. This means that, unlike running or cycling, blood flow isn’t rushing to the surface of your skin in the same way. Instead, it maintains its focus upon your internal organs – namely your stomach – which means normal function can be maintained as you workout. So even though regular high intensity workouts can suppress appetite because the stomach is running in ‘stand by’ mode – swimming is actually excluded from this.
So whether you swim at low or high intensity, the main reason you feel hunger afterwards is that your stomach has never stopped working in the way that it does when you do other exercises. This just serves to accelerate and amplify the feeling of hunger when you finish your lengths.
Reason #2: Calorie Burn & Energy Replenishment
This next big reason behind why swimming makes you hungry is a little more conventional and obvious. Think of your body like a steam train from the good old days. To keep that train running, the furnace has to be constantly stoked and filled with fresh coal. When the coal runs out, so does the power and the movement. This is what food (specifically calories) is to our body. Without them, we would grind to a halt on the tracks and be unable to move. This is exactly why you might feel lethargic and tired if you don’t eat for a long period of time. Swimming as an exercise is one of the few that truly engages most muscles in your body. You use your arms, legs, hips and core - all at once - in order to move and stay afloat. Not only that, if you are swimming with your head underwater, your regulated breathing enhances lung capacity and affects the oxygen levels feeding your muscles. Minute-for-minute, you will be hard pressed to find a better full body workout that burns more calories than swimming does in a 30 to 45 minute period. Going back to the steam train analogy, the more calories you burn, the more energy you expend.
Naturally your body’s healthy reaction to this is to replace the lost energy to maintain function – and we do this by eating. Food is our fuel, and swimming demands a lot of fuel. Together with the water temperature, these two reasons are why you are feeling exceptionally hungry post-pool workout.
We hope this has answered your question on why does swimming make you hungry and you now understand the science behind being hungry after swimming. It is an incredible workout if you suffer from sore joints or chronic pains but still wish to get in a good cardio session – just make sure you refuel with some healthy fruit or natural carbs afterwards to keep energised for the rest of the day.