Stair climbing is when you walk or run up a set of stairs using your feet, rather than an elevator or escalator.
Stairs are like a bunch of little hills stacked on top of each other that you need to go up or down to get from one floor to another in a building. When you climb stairs, you use your legs and feet to step up onto each step and lift your body weight up a little bit higher with each step.
It can be a good way to exercise because it gets your heart beating faster and makes your muscles work harder than just walking on a flat surface. Climbing stairs can help you get stronger and healthier. But, it can also be tiring if you do it for too long or if you go up a lot of stairs at once.
You should always be careful when climbing stairs, especially if they are steep or slippery. Make sure to hold onto the railing for support and take it slow and easy so you don't trip and fall. And remember, it's always okay to take a break and catch your breath if you need to.