Stair-climbing machines, such as the StairMaster, are designed to simulate the act of climbing stairs in a controlled environment. By the very nature of the movement involved, these machines can offer you a low-impact cardiovascular workout that could produce many positive effects on your health and body image. There is a strength element involved in the act of walking up a never-ending flight of stairs, though, which has led some to wonder whether or not their StairMaster could be giving them bulky legs. While there are many benefits of this type of exercise, muscle bulk isn't one of them.
Origin of the Myth
When you use a stair-climbing machine, your legs are put under a large amount of repetitive stress for fairly long periods of time. To meet this challenge, your body begins to pump more blood to the working muscles so that they have all the fuel they need. This means that the blood vessels in your legs dilate to make room for the excess blood, and your muscles may even swell in response to the flood of nutrients. For a brief period after your workout, then, your leg muscles may look bigger. This increase in size is only temporary, though.
What Really Happens
As previously mentioned, the StairMaster is a piece of cardiovascular exercise equipment. As such, the targets of a workout on this machine are primarily your heart and lungs, improving your endurance. Since the large muscles of your legs are involved, you will also burn large amounts of calories, which, in turn, will help you lose weight. This reduction in body fat will include fat from your legs, making the muscles more visible and toned.
How Muscles Grow
Building bulky muscles, on the other hand, requires a very different approach. Your muscles much be consistently and progressively challenged over long periods of time. Additionally, a specialized diet needs to be followed that will fuel muscle growth. Bulky muscles do not happen overnight, and stair-climbing machines simply do not provide the resistance needed to produce lasting growth.
If You Want Bulk
While many people avoid exercises that they believe will produce bulky muscles, in some cases that's the entire goal of a workout. If muscle growth is your goal, stick to heavy, compound exercises such as the squat and deadlift. These lifts allow you to progressively add more weight while engaging large amounts of muscle fibers. In addition to building your muscle size, using all of those muscle fibers will burn lots of calories and help you lose weight.