If you've led morning classes or rehearsals, you may be familiar with those dancers who enter the studio carrying a coffee from the closest café, or whose floor stretches look, in part, like an excuse to stay horizontal—and perhaps you feel their pain. Denise Warner Limoli is familiar with this scene; she teaches 9 am ballet classes at Skidmore College. Sleepy dancers, she notices, tend to be slow on the pickup. “A dancer usually has very fast responses, and sleep-deprived dancers are a little slow to react," she says. “They don't learn assigned combinations quickly, or they make mistakes that they should not be making at their level of accomplishment."