Which Sports Produce the Most Sweat? What the Data Says

Maybe you’re one of the lucky ones; you can go out for a run mid-day and come back with a nice glistening look after an hour. Or maybe you come back looking like you went for a swim in the Gowanus Canal.

Whether you look like option A or option B has a huge effect on how much fluid you lose and how much fluid you need to consume throughout the day to rehydrate, and more importantly, to stay hydrated. Checkout our sodium guide for runners if you know you’re on that heavy sweater side.

Based on a new study, the sport you’re doing also plays a huge role.

The Sweatiest Sports: Overview

Have you ever wondered, as a runner, where running ranks amongst other sweat-inducing endeavors? Instant Hydration recently published a study showing the sweatiest sports, and you might be surprised where running landed.

Before we get too much into the weeds, it’s important to cover exactly why Instant Hydration put their efforts into this study and its importance now. First and foremost, it’s their business model. Second, and probably more important, we’re deep into one of the hottest summers on record. 

In California in particular, not only are we seeing temperatures as high as 75 degrees as early as 7:00 a.m., but humidity is regularly in the high 80s and low 90s if you go out early to beat the heat.

The Sweatiest Sports: Ranked

Surprisingly, Formula 1 registered as the sweatiest sport. The sweat rate of 1.89 liters per hour falls a little short of the sweat champion, Tennis, but the scant opportunities to drink while piloting one of the fastest land vehicles in the world leave F1 drivers with a fluid deficit of 2.5 liters over the course of an average 95-minute race.

Running came in 6th place overall, with a fluid deficit of 1.8 liters and a recommended replacement intake of 2.7 liters following a marathon, assuming you finish in the average time of 270 minutes.

Here’s Instant Hydration’s ranking of the top sweatiest sports:

1. Formula 1
2. Rugby
3. Tennis
4. Cycling (road race)
5. Lacrosse (field)
6. Marathon Running
7. Triathlon (Olympic distance)
8. Mountain Biking (Cross-Country)
9. Ice Hockey
10. Cricket

Taking into account the amount of sweat loss per hour, the total average duration of the activity,  and total fluid lost, Instant Hydration compared that against the amount of fluids that can be consumed during a given activity. They came up with a total fluid deficit and a recommended fluid intake to replenish your water levels. 

How Much Fluid Do You Lose (And Need To Drink)?

Here’s what the study found about how much fluid a person loses over the course of a 270-minute marathon, which is only second to a cycling road race:

• Average fluid loss: 4.28 liters
• Equivalent weight loss: 9.04 pounds
• Average fluid consumed: 2.5 liters
• Remaining fluid deficit: 1.8 liters
• Equivalent deficit: 3.8 pounds

The stud found the average fluid loss over the course of that 270-minute marathon came to 4.28 liters, second only to a cycling road race. If you convert this to imperial measurements, the average marathon runner will lose 9.04 pounds during a marathon. The loss can be offset with responsible hydration. During the study, participants took in an average of 2.5 liters, leaving a deficit of 1.8 liters, which converts to around 3.8 pounds.

I’m a bit of a nerd and like to be aware of these types of things, and I’ll often record a loss in water weight of 3 to 5 pounds after a long run of up to 2 hours, even while taking in electrolytes during my run. After my first marathon, I was still 6 pounds lighter than when I woke up after a full day of eating, drinking, and socializing afterward.

How To Make Sure You Stay Hydrated

Electrolytes are important for anyone in daily life, but even more so for athletes, as we tend to sweat out a lot of what we take in. Electrolytes help regulate muscle function, fluid balance, heart rhythm, and a host of many other important body processes. Here are some great ones:

• Calcium
• Magnesium
• Potassium
• Sodium
• Chloride

Coach Amanda did a rather thorough deep dive into the topic, along with a recipe for a homemade electrolyte drink.

Runners are clever creatures and will find ways to stay hydrated on long runs. I know of someone who would run a loop on their long runs, and they would stash a bottle of electrolytes hidden away in some bushes so they could make a quick hydration pit stop.

But if you’re the type that doesn’t want to leave your hydration up to the slim chance someone happens upon it and makes away with it, there are plenty of other ways to carry it along with you. 

As a site that has tested dozens, if not hundreds, of hydration belts and packs, we’ve got you covered, from hydration packs to handheld bottles. Checkout what our team approved after miles of testing.

What to read next?

• Iron Deficiency in Runners: Symptoms, Ferritin Levels, and Treatment
• 6 Unexpected Marathon Travel Tips For Your Best Race
• Breathing Trainers for Runners: Do They Actually Improve Performance?