Ketones.
When you work out intensely for long enough, you burn all your glycogen (sugar) reserves, so your body starts to burn fat instead.
When burning fat, one of the byproduct is ketones, and it gives you this weird taste in your mouth.
This phenomena can also happen if you are diabetic and low on sugar, or if you follow a keto diet.
Intense exercise causes an increase in blood pressure on the small blood vessels in your respiratory system. These blood vessels leak tiny amount of blood, which you can then taste when you exhale.
In a normally healthy person this isn’t a huge concern.
Read more here:
https://wexnermedical.osu.edu/blog/metallic-taste-workout
And here:
https://www.menshealth.com/fitness/a19521687/6-weird-things-that-happen-to-your-body-when-you-run/
Latest Answers