It’s entirely possible that the pre-race jitters are contagious, assuming those jitters are a mishmash of emotions including fear and anxiety.
Scientists have recently shown that the smell of fear is real. Humans emit pheromones, or chemical signals, that other humans can detect, and when it comes to fear, smelling someone else’s “alarm pheromone” can activate the parts of your brain associated with it, potentially making you anxious or scared or nervous yourself.
A study demonstrating this infectious nature of fear was published in 2009 and funded by the U.S. Army, leading Wired writers to speculate about the development of fear sensors and fear bombs that could incapacitate an enemy with dread. According to the Guardian, the lead author of that study said her findings “indicate that there may be a hidden biological component to human social dynamics, in which emotional stress is, quite literally, 'contagious.'"
To make matters worse, another study, published in 2012 in the journal Chemosensory Perception, showed that anxiety can boost your sense of smell, upping the likelihood that you’ll detect the fear in your fellow competitors if you’re already anxious.
If you’re prone to pre-race jitters, enjoy the expo, but don’t stick around too long. And if you’re racing or bunking with equally restless friends, take comfort in knowing that being a bit nervous can actually improve performance. The Yerkes-Dodson Law, a psychology concept developed more than a century ago, states that people perform best when a little stressed. (Too much stress, however, and your performance will suffer.)