Do stair climbing exercise "snacks" improve cardiorespiratory fitness?

We investigated the effect of stair climbing exercise "snacks" on peak oxygen uptake. Sedentary young adults were randomly assigned to perform 3 bouts/day of vigorously ascending a 3-flight stairwell (60 steps), separated by 1-4 h of recovery, 3 days/week for 6 weeks, or a nontraining control group ( = 12 each). Peak oxygen uptake was higher in the climbers after the intervention ( = 0.003), suggesting that stair climbing "snacks" are effective in improving cardiorespiratory fitness, although the absolute increase was modest.