Walking is great exercise, but will it build muscle? What to know

Because walking is an aerobic exercise, many think of its health benefits as being cardiovascular alone. While that's certainly one of the top advantages of walking, the exercise offers a host of other proven benefits as well. These include arthritis relief, improved sleep, reduced stress, a boosted immune system and improved glucose control. "There is emerging evidence that walking also lowers the risk of depression and the development and progression of Alzheimer’s disease and other related dementias," says Roger Fielding, PhD, leader of the nutrition, exercise physiology and sarcopenia team at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.

Another lesser-known benefit of frequent walks is that the movement can help with toning and muscle growth. 

How does walking build muscle?

While walking builds some muscle, it isn't the big, bulky muscle mass that comes from spending a lot of time in the gym. Rather, walking creates a leaner muscle tone throughout one's body, particularly in lower muscle groups.

Muscles grow after being stressed enough to break down in the first place. This requires the body to repair the microtears by strengthening and reinforcing the area around them. While walking won't break down muscles the same way weight training does, it can break down muscles in some muscle groups, causing them to tone and grow over time. This is especially true for people who may not exercise as frequently, for those who walk for longer periods of time, and for people who work to target muscle groups through more demanding walking practices. 

Beyond strengthening muscles, walking can also help maintain the muscle mass one already has. "Muscle loss, called sarcopenia, happens with age," explains Michael Fredericson, MD, director of the Physical Medicine and Rehabilitation division of Stanford University. "But regular exercise, including walking, can help reduce its effects."

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Which muscle groups does walking build? 

"Walking primarily works the muscles in your lower body," says Austin "Ozzie" Gontang, PhD, a licensed psychotherapist and the director of the San Diego Marathon Clinic. Such muscles include one's quadriceps, hamstrings, calves, and glutes. "Walking also works the muscles in your core abdominals and back muscles," adds Gontang.

The degree to which these muscles grow will depend on several factors including one's gender, age, and body mass, existing muscle strength, and whether one is walking on an inclined path or not. "Walking uphill increases the intensity of your workout and is a way to put more stress on your muscles, which is the best way to build them," explains Gontang. 

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How often should you walk? 

The Centers for Disease Control and Preventions recommends a "moderate-intensity aerobic activity (such as brisk walking) for 150 minutes every week." That's the equivalent of about 30 minutes each weekday. 

One's walking workout can be improved by carrying weights, interval training or increasing one's speed. "Walking is a great place to start," says Gontang, "but you could also try carrying a backpack with some weight in it to increase the intensity of your workout and make it more challenging." 

It may also be helpful to combine walking with other forms of exercise. "In one small study, older adults participated in a 10-week exercise program of either walking or walking plus resistance training," explains Fredericson. "Both groups showed improved muscle mass in thigh muscles. However, participants who also did resistance training showed greater improvement."