Why do my feet smell so bad when wearing travel shoes? What is the difference between foot sweat and sweat from other places?

Travel shoes are less breathable than other shoes and become very moist after being worn for a long time, causing the feet to secrete a large amount of sweat, causing sweaty feet.

The composition of sweat produced by the feet is the same as that of other parts, mainly water, and a small amount of inorganic salts, fatty acids and urea. But because the bacteria on your feet break down these substances and release some gases, your feet smell bad.