Not all cardio workouts come in perfect 30-minute chunks of time. Sure, a long workout at the gym is great for focus and creating peace of mind, but fitting that in every day can be difficult.
That is why it is good to know that different "doses" of aerobic activity are beneficial. A five-minute stair climb and a brisk walk around the block both count as exercise even though you are not at a gym sweating continuously for a half hour. I have a friend who jumps on her elliptical when she is cold and works out out until she is warm. The she gets off the machine, goes about her day, and repeats her mini workout next time she feels chilly.
While five increments of exercise might not improve your endurance for running a marathon, I think every stair climb will help you run hills. Regardless, you are working your heart and lungs, which is a good thing. Besides short bursts of exercise are beneficial. For all you desk-bound readers, I encourage you to get up and move throughout your day, especially on the days you cannot make it to the gym. Everyday activities do add up and the most important thing is that you're staying physically active.
Did you workout today? If not did you go for a walk or take the stairs instead of the elevator? Tell me in the comment section how you stay physically active throughout your day.