Think that big cup of coffee in the morning will keep you awake all day. Not so, say researchers at Rush University.

Scientists at the college recently studied the best way to use caffeine contained in coffee and other beverages if the goal is to stay awake.

They concluded that people who take small amounts of caffeine regularly during the day do a better job of avoiding sleepiness and perform well on cognitive tests. And they do it without affecting their nighttime sleep habits.

The research team – which included members from Rush University Medical Center, Brigham and Women’s Hospital and Harvard Medical School – studied how caffeine affects sleepiness.

The group proposed that shift workers, medical residents, truck drivers, and others who need to stay awake would get a bigger boost from frequent low doses of caffeine instead of one big gulp in the morning. That method, they said, leads to caffeine levels that fall the rest of the day.

“I hate to say it, but most of the population is using caffeine the wrong way by drinking a few mugs of coffee or tea in the morning, or three cups from their Starbuck’s grande on the way to work, James Wyatt, PhD, a sleep researcher at Rush, said in a statement. “This means that caffeine levels in the brain will be falling as the day goes on.”