"Even though you can use a railing for assistance, the exercise of climbing stairs improves balance because you're needing to balance on one leg as you press into one leg and lift the other leg onto the same or next step," says Laura Flynn Endres, CPT, a California-based personal trainer who works with older adults.

Livestrong’s recent article, entitled “Want to Age Well? This Everyday Activity Improves Balance and Prevents Falls,” says that standing on one leg (as you do when climbing stairs) also helps strengthen a variety of muscles, including your core, glutes, quads and calves. However, the benefits of stair climbing don't stop there. Here are all the reasons you may want to skip the elevator and use the stairs.

1. It Builds Lower-Body Strength. Climbing moves your hip, knee and ankle joints, so the stairs can help strengthen all the muscles in your legs, including your quads, hamstrings, glutes and calves. You'll also work your hip flexors when you raise your leg, your gluteus medius [smaller glute muscle] to help keep you balanced, your lower back and abs as you lean into the stairs and the muscles of your feet — especially if your heel hangs off the step when you climb. Strengthening these muscles is important as you get older because age-related muscle loss can put you at a higher risk for falls.
2. It Helps You Maintain Mobility. This is critical to keeping your independence later in life. Mobility exercises help to keep your joints in top shape by moving them through their full range of motion. Climbing stairs can improve mobility because it requires the use of the ankle, knee and hip joints. It's a fairly dynamic exercise that requires power, balance and strength.
3. It Increases Your Cardiovascular Fitness. Climbing stairs itself is a cardio workout. That means it strengthens your heart and improves your aerobic capacity. Researchers of a small February 2017 study in the ​International Conference on Movement, Health and Exercise​ found that people who climbed seven floors twice a day, five days a week for a month and people who walked one mile on a treadmill for the same amount of time all saw improvements in their cardio fitness.
4. It Improves Bone Density. Contrary to what many think, your bones actually get stronger with exercise. Any weight-bearing exercise, such as climbing stairs, makes you work against gravity, conditioning your bones to take on load and, therefore, strengthening them, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. This helps prevent the risk of osteoporosis, a condition in which your bones become weak and brittle, which increases with age.

Reference: Livestrong (July 17, 2022) “Want to Age Well? This Everyday Activity Improves Balance and Prevents Falls”