No, not necessarily....
There are times when people do have a smell of ammonia when they are working out. It's an odor that seems to permeate the nose, and others may not necessarily smell this either. It's normal.
I think (personally) that the ammonia builds up in the blood when you spend an extended amount of time exercising. If you think about anaerobic exercise (or even long endurance events requiring lots of oxygen), when you are in an anaerobic state, you have a decreased amount of oxygen in your system, and at the same time, you are trying to exhale out the carbon dioxide and increase your oxygen intake (the easy explanation). You will breathe faster to make this happen (hyperventilate), but eventually, you will have to slow down, as the lactic acid levels in your body rises to the point where you are unable to take in enough oxygen to perform.
Keeping this in mind, if you look at the typical reaction in your body, ammonia is formed from the breakdown of amino acids. Normally, this excess of ammonia is converted to urea and excreted through urine in the body. The simple formula is:
2 ammonia+ 1 carbon dioxide= urea + water
There are some people who have an excess of urea, which is excreted through the sweat glands.
So, it could be a normal process, or it could be a signal that you are experiencing some kind of renal (kidney) problems. A simple solution way to figure out if there is a urea buildup is to check your skin. I've heard (and read) that there will be a crystal-like solid substance (may look like salt) forming on the skin after sweating during a workout- when urea is sweated out of the sweat glands onto the skin and makes contact with oxygen in the air, the urea is converted back to the ammonia, which could lead to the smell you are experiencing.
The best thing you can do is see a doctor, because if you think you are having some kidney failure, early intervention is the best way to keep this problem under control. They can test your kidneys and determine if you really need to be concerned. I wouldn' t panic in the meantime unless you had a reason to. In the meantime, be sure to drink a lot of water and be alert of any symptoms that may suggest renal failure. I doubt any of you guys are headed in that direction, though. Do you guys (experiencing this smell) eat a lot of protein?
Koffee