Ammonia Smell During Exercise on Ketogenic Diet – Q&A

Question: My question relates to the pungent smell of ammonia in my sweat during a hard work out, seems to start about 45 minutes in and gets stronger from then. This started very soon after the diet. I have recently started a high protein slow carb diet,am drinking between 3 and 4 litres of water a day (currently 180lbs with 21% body fat)have plenty of energy and feel alert and well.  From your work I gather this could be the result of ketosis and burning protein and fat for energy?

Two questions please:
1. Is this OK?
2. Is there anyway to eliminate the smell?

Answer: This is a fairly common report on very low-carbohydrate/ketogenic diet (defined, once again, as any diet containing less than 100 grams of carbohydrate per day), a report of a fairly strong ammonia smell in the sweat during exercise.  As I discuss in detail in my first book The Ketogenic Diet this ammonia is produced due to the ultimate breakdown of ATP to ADP to AMP and ammonia.

This appears to occur more readily when muscle glycogen is depleted (as occurs with the combination of of a very low-carbohydrate intake along with training) and may be part of the increased protein requirements that have been known to occur with endurance training (this is discussed in detail in The Protein Book).  I would mention that it appears that this ‘protein breakdown’ is not actually coming from the breakdown of skeletal muscle itself; rather it’s from the breakdown of BCAA (branched-chain amino acids) within the free amino acid pool.

So is this ok?  So long as dietary protein intake is sufficient, I don’t see this as being any real problem.  The effect is slight in terms of the absolute amount of protein being broken down (in terms of grams) and so long as protein intake is sufficient, there shouldn’t be any detrimental effect other than the smell.

And how do you get rid of the smell?  Well, either wear strong deodorant or raise your carbohydrate intake above the ~100 g/day cutoff point so that you’re not in ketosis.  That’s really all I’ve got solution wise since it’s just one of those biochemical processes that is going to occur during long-duration workouts on a ketogenic diet.  All the best!

(Visited 13,274 times, 15 visits today)



The Ketogenic Diet

For Any Questions You Have About Low-Carbohydrate Dieting

Low-carbohydrate/ketogenic diets have been surrounded in controversy since they first became popular. The Ketogenic Diet: A Complete Guide for the Dieter and Practitioner is the only book to examine the diet from a purely scientific viewpoint; with over 600 references on low-carbohydrate diets there is no more comprehensive resource on the diet, what it does, and how to use it (if you so desire).