Will I Get Big Leg Muscles From Walking?

Walking Tones Lean Muscle, Doesn't Add Bulk

Treadmill Walking at the Gym
Treadmill Walking at the Gym. skynesher/Creative RF/Getty Images

Do you worry that walking will give you even larger legs? This is a worry for some women, who may have heard that using incline on the treadmill or walking outdoors on hills will build leg muscles. It may also be the hope for those who want to grow their leg muscles.

But you need only take a look at a hikers and mountain climbers to see that this can't be the case. You might wonder how such lean legs can get them to the summit.

Look at the starting lineup for a marathon and note the tiny legs on the men and women. If walking and running led to big leg muscles, these people would look very much different.

Slow Twitch Muscles Are Lean, Not Big

Endurance exercise such as walking builds slow-twitch muscle fibers which are used for sustained activity. These fibers are not the ones that body builders aim to create for big, showy muscles. They use specific programs of progressive overloading, lifting heavy weights for only seconds at a time, to make their muscles grow. Meanwhile, aerobic exercise such as walking, running, and cycling builds slow-twitch muscle fibers and long, lean muscles overall.

What Makes Your Legs Larger

If your legs are already larger than you want, it is probably due to stored fat rather than muscle. If you've ever gone on a diet and lost 20 pounds or more, you will be amazed at how your body shrinks in areas where you didn't realize you had stored fat.

Meanwhile, you might not get the results in the areas you wish would shrink. Your body might prefer to keep fat on your thighs and hips rather than your stomach, or vice versa.

When you exercise your leg muscles, they will grow a little, but you will mostly see the effect immediately after exercise as the muscles swell to bring in nutrients and expel waste.

This effect goes away after 30 minutes to an hour. As the muscles recover, they build new fiber and also use it more efficiently. The result is unlikely to be visible as a larger muscle, but rather a leaner, toned muscle.

If you exercise enough and watch your diet, you will lose fat as you gain muscle. Overall, your legs can get smaller and leaner. If you lose enough fat weight, you begin to see the lean muscle defined. Body builders go on very strict diets so they have less body fat covering their muscles. But remember the marathon runners, they also have very low body fat but their leg muscles are not bulky.

How Bodybuilders and Skaters Get Huge Thighs

Sprinters and speed-skaters may have large muscles, but they are engaging in short sprints with explosive muscle action that relies on fast-twitch muscle fibers. Their hard work can result in larger muscles. But when you see them in the Olympic Games you are seeing unique human physiques, not what happens from a few treadmill incline sessions per week.

Body builders have to work very hard with strength training to build large muscles. Their diets are very strict to reduce body fat so the muscles are more defined.

How to Slim and Tone Your Legs

To get slimmer legs, you need to reduce your body fat.

You must burn more calories per day than you eat. It is difficult to do that with exercise alone, although that is part of the equation. Your workouts will build lean muscle that is necessary for health and fitness.

Cardiovascular exercise such as brisk walking, running, and cycling will result in burning stored fat if you sustain it for more than 40 minutes. But you need to carefully watch your diet to ensure you really are eating fewer calories than you burn each day.

Increase Your Walking Workout to Tone Your Legs

Personal trainer Lorra Garrick suggests this workout change to build lean muscle and burn fat.

Increase the speed. If you have been walking at 3 mph, boost the speed to 3.5 and then 4 mph. You may have to do that for only a couple of minutes at a time at first until you build your speed walking technique and capacity.

You can also vary the incline to increase the intensity of your workout. By walking or running uphill, you will challenge your muscles in new ways as well as burning more calories at the same speed. You can measure how effective that is by noting your breathing intensifying and your heart rate being raised. Aim to get from the moderate intensity zone into the vigorous intensity zone during your workout in intervals.

If you've been holding onto the handrails of your treadmill, it's time to let go. Stop holding onto the treadmill so you have good walking and running form and burn more calories per minute.


Nicholas Ratamess, Brent Alvar, Tammy K. Evetoch Terry J. Housh, W. Ben Kibler, William J. Kraemer, N. Travis Triplett. Progression Models in Resistance Training for Healthy AdultsMedicine & Science in Sports & Exercise: March 2009, Volume 41, Issue 3, pp 687-708.

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