Forget your morning coffee - spend 10 minutes walking up and down some stairs instead.
It sounds like a nightmare to anyone who's struggling to get fired up after a mid-week night out.
But according to new research, that little bout of exercise will do far more for your energy levels than if you were to take the elevator while slurping on a soda or a cappuccino and saves you some money.
"We found, in both the caffeine and the placebo conditions, that there was not much change in how they felt," said Patrick J O'Connor, a professor in the department of kinesiology at the University of Georgia who co-authored the study.
"But with exercise they did feel more energetic and vigorous.
"It was a temporary feeling, felt immediately after the exercise, but with the 50 milligrams of caffeine, we didn't get as big an effect."
One can of Diet Coke contains 42mg of caffeine, while a latte contains around 77mg.
The study aimed to simulate the hurdles faced in a typical office setting, where workers spend hours sitting and staring at computer screens and don't have time for a longer bout of exercise during the day.
For the study, participants on separate days either ingested capsules containing caffeine or a placebo, or spent 10 minutes walking up and down stairs, about 30 floors total, at a low-intensity pace.
Professor O'Connor wanted to compare an exercise that could be achieved by people in an office setting, where they have access to stairs and a little time to be active, but not enough time to change into workout gear, shower and change back into work clothes.
"Office workers can go outside and walk, but weather can be less than ideal. It has never rained on me while walking the stairs," said Professor O'Connor.
"And a lot of people working in office buildings have access to stairs, so it's an option to keep some fitness while taking a short break from work."
Study participants were female college students who described themselves as chronically sleep deprived; getting less than six-and-a-half hours per night.
To test the effects of caffeine versus the exercise, each group took some verbal and computer-based tests to gauge how they felt and how well they performed certain cognitive tasks.
Neither caffeine nor exercise caused large improvements in attention or memory, but stair walking was associated with a small increase in motivation for work.
Professor O'Connor added that there is still much research to be done on the specific benefits of exercising on the stairs, especially for just 10 minutes.
But even a brief bout of stair walking can enhance feelings of energy without reducing cognitive function.
"You may not have time to go for a swim, but you might have 10 minutes to walk up and down the stairs."