Why Do Swimmers Eat so Much?


If you’ve ever felt like your stomach is a bottomless pit after an hour in the pool, you’re not alone. Swimming is a demanding exercise that can leave you feeling hungrier than you would after the same amount of time running.

We’ll go over why that is and what you can do to better prepare yourself for your next swim.

Why Do Swimmers Get so Hungry?

Swimming is a very demanding aerobic exercise that requires a lot of energy. Many major muscle groups are engaged when swimming, especially if you consistently mix up your strokes. However, overall energy expenditure as it relates to body mass is actually lower in swimming than it is in other similar sports like running.

So while it may utilize more muscle groups, this does not correlate with the total energy needed (Source).

Sometimes the temperature of the water can have an impact on your overall hunger, too. During a challenging workout, your blood flow will be primarily focused on releasing heat from the body. In other words, your digestion is put on hold, which can suppress your overall feeling of hunger.

However, swimming in a pool that is below the normal body temperature won’t cause this same effect. That’s because the blood flow isn’t focused on releasing body heat, so your stomach will continue its digestive processes as usual, leading to an intense feeling of hunger once you exit the pool. (Source)

How Many Calories Burned Swimming 30 Minutes?

On average, swimmers can expect to burn around 250 calories for every 30 minutes of swimming. This will vary depending on the swimmer’s weight and overall athletic ability, plus the type of swim stroke they’ll be doing. Here’s a useful table to get a general idea of how many calories you can burn while swimming, depending on your weight:

 Body WeightRecreational Swimming, 30 minutesVigorous Swimming, 30 Minutes
125 pounds180 calories burned300 calories burned
155 pounds223 calories burned372 calories burned
185 pounds266 calories burned444 calories burned
Calories Burned While Swimming Vs Body Weight (Source)

In addition to the intensity of the swim session, the swim stroke can make a noticeable difference in calorie burn. For example, 30 minutes of the breaststroke can burn around 372 calories while the butterfly would burn closer to 409 calories in the same amount of time.

Knowing which stroke you’ll be primarily focusing on can help you better prepare for your fuel needs ahead of time.

Why Does Swimming Burn so Many Calories?

Swimming is a full-body exercise that has the added benefit of water resistance, making it easier to burn more calories over time. You can generally expect to burn more calories swimming than you would running the same distance because it’s easier to consistently maintain a higher heart rate while swimming . (Source)

That’s partially due to the water resistance, but it can also be due to the low-impact nature of swimming, making it more gentle on your body.

It also takes more effort for the body to stay afloat by kicking than it does to take steps when running, adding to the overall calorie burn.

Can Swimmers Eat Whatever They Want? (Ideal Meals Listed)

Technically, anyone can eat whatever they want, but different goals require different nutritional needs. While swimmers can burn through a lot of energy during their workouts, they’re better off fueling themselves with nutrient-dense foods most of the time in order to maintain their challenging routine and grow as an athlete.

Swimmers will want to focus on both pre-workout and post-workout nutrition in order to achieve optimal performance and avoid potential injury.

Before Swimming

Aim to eat at least one hour prior to swimming in order to have enough fuel for your workout. If you swim early in the morning and don’t have time to consume a full meal, opt for something easily digestible like a banana or energy bar. (Source)

If you have more time, here are some recommended pre-workout foods:

  • Whole Grain bread
  • Pasta
  • Nuts (best if unsalted)
  • Peas
  • Oats or porridge
  • Beans

After Swimming

You’ll want to replenish your energy stores after swimming and promote the recovery process. It can be very tempting to devour whatever is in sight, so it’s important to set yourself (and your body) up for success. Here are some healthy, replenishing options to choose from:

  • Chicken
  • Baked sweet potato
  • Fruit
  • Yogurt
  • Protein bars

How Do I Stop Overeating After Swimming?

There are two things you can do to avoid overeating after swimming: eat enough before the swim and prepare your meals in advance.

If you swim without having enough fuel in the first place, you’re only going to end up more hungry. You’ll also likely be more exhausted, making it extra challenging to cook up something healthy.

Instead, you’ll stop at whatever fast food joint is on your way to your next stop. While it may satisfy your hunger, it probably won’t help much for your recovery. That’s where meal prepping comes in.

Look at your schedule for the week and figure out how many pre and post workout meals you’ll need. You should also consider how intense the swims are likely to be so you can prepare larger meals for those days.

Pre-workout meals can be something as simple as a banana and a granola bar. For your post-workout meal, you’ll want something a bit more substantial. Prep a bunch of brown rice or pasta, bake up some diced sweet potato, and top it with chicken. Portion this out into however many meals you’ll need.

You’ll also want to make sure you’re feeling properly throughout the day, even if you won’t be swimming. Eating well can help your recovery and will leave you feeling ready and energized for your next activity.

Bottom Line

Swimming is an energy intensive but low-impact activity that can leave you with a nearly insatiable hunger.

Make sure you’re prepared with healthy, easy-to-eat foods for before and after your workout in order to maintain optimal performance and avoid injury.

Aprill Emig

Based out of Duluth, MN Aprill loves to write about the outdoors, education, and all forms of adventure. You can find her mountain biking, running, or playing roller derby.

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