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 (n =12 each). Peak oxygen uptake was higher in the climbers after the intervention (P = 0.003), suggesting that stair climbing snacks are effective in improving cardiorespiratory fitness, although the absolute increase was modest.