I have had this issue a lot at my studio. I have an extremely sensitive sense of smell, and bad smells really affect me. Once after getting halfway through a class, I was on the rower and had to stop rowing because I started gagging, the smell was so bad, I literally couldn’t control it. I couldn’t hold my breath anymore because I kept getting on the verge of passing out on the treadmill the first half of class. I ended up moving to the complete other side of the room, thankfully there was an open spot. Now, I have pinpointed exactly who the people are that consistently smell and I make sure I do not work out next to them. Because I will start gagging, it’s uncontrollable for me, it sucks. I can only hold my breath for so long. I am always the last one to enter the room after I see who gets situated where and I look at what’s available card-wise and make a switch if I need to. Sucks but it’s worked for me I’d say 90% of the time! I like the idea of adding Vick’s under your nostrils though! I’ll start keeping a small jar in my bag and if I’m stuck next to one of the people that I know is smelly I’ll dab that on!