“Daddy, You Smell Like …Pee”

That’s what my son said to me upon returning from my long run on Monday. Want to know something? He was right!

I’m sure I didn’t smell exactly like urine but, as you may or may not know, there is ammonia in urine and ammonia is the stuff responsible for the strongest odour we can smell in that particular liquid.

But why did I smell like pee after my run?

The answer is that there was ammonia in my sweat. This is explained nicely at Devine Sports:

Your body produces ammonia everytime you run hard. Whether you smell it or not is a different story, but your body produces it on every long, hard run.

The reason this happens is ammonia is a by-product of protein metabolism. When you run hard and long, your body burns protein and carbohydrates for fuel. When the carbs are burned off (or when there aren’t adequate carbohydrates), the distinctive ammonia smell presents itself.

The fact that ammonia is produced on every run doesn’t mean the smell is noticeable afterward. Usually the smell is only present when there is the carb deficit. This increases the ammonia levels in your muscles and the ammonia is then picked up by your blood and carried to your respiratory system. When this occurs, you can usually smell it. In addition, some of the ammonia will show up in your sweat which makes the odor even more noticeable.

The smell usually isn’t anything to worry about. But if it persists, you probably aren’t taking in enough carbohydrates. If you emphasize carbohydrates before, during and after running and the ammonia smell is still around, you should get checked out by a physician.

This isn’t dangerous at all. But it is a not-so-subtle warning from your body that it needs more carbs (rather than more protein) to burn on long and hard training runs.

The solution is easy: Eat more carbohydrates to fuel your muscles. Especially if you’re running longer than an hour or two your muscles crave carbohydrates which burn easier than protein. You can also do this by taking in in carbohydrates while running.

Simply drink a cold sportsdrink (which has carbohydrates) every 15-20 minutes while running. If your carbohydrate intake is adequate to fuel your running, the ammonia smell should disappear. Your body will still be producing ammonia, but you probably won’t be able to smell it.

So it looks like I need to eat more veggies.

Now if only someone could help me figure out why I sometimes smell like a pine-scented car freshener.

Posted by Mark Iocchelli on November 10, 2006
Filed Under: Nutrition, Science and Research