You're ready to get out and hit the trail to get in shape and burn a little fat. But how fast you should go depends on your fitness status and goals. Walking and running both use large muscle groups in repetitive contraction and release. You can get the benefits of aerobic exercise from each one. Understanding how they differ and the reasons to make a choice between them will help you to work your workout more safely and efficiently.
Mechanics and Moves
Walking and running both propel you from one place to another, expending energy, stretching and strengthening muscles, and stressing knee and ankle joints. But the mechanics of each activity, while largely similar, exhibit a few distinct differences. Walkers typically strike the ground heel first and lock their knees. Runners land on the forward part of the foot and keep the knee joint soft and flexible. Runners experience more knee injuries than walkers because more muscles work harder to support the knee at foot strike and push-off. Walkers use the soleus muscle in the calf to push themselves forward, sending energy from the leg to the torso. The soleus runs down the back of the leg, from the knee to the heel. It flexes the ankle, pointing your foot downward when your knee is bent. On the run, the soleus works along with hip and knee extensors to deliver energy to both the leg and the torso.
Walking is nearly as automatic as breathing. If you are mobile, you can -- and do -- walk anywhere and all the time. When walking becomes your exercise program, you need to step up your game. You'll benefit from sturdy shoes that encourage the proper foot strike and stabilize the ankle joint. A forgiving surface is kinder to your joints than asphalt or concrete, and a brisk pace works your heart and other muscles harder, giving you more fitness benefits. Regular walkers develop stronger bones and calmer minds, leading to lowered stress. A walking program is gentler than running for rehabilitating injury or exercising when you are out of shape. And walking speed is a longevity indicator. Researchers at the University of Pittsburgh, in a 2011 report published in “The Journal of the American Medical Association,” found that how fast you walk after age 65 can correlate with how long you live.
Reasons to Run
Running is an aerobic activity and delivers all the usual benefits of raising your heart rate during a regular exercise program. Running increases bone mass, strengthens joints and muscles, and lowers blood pressure, anxiety levels, cholesterol levels, and the risks for heart attacks, strokes, diabetes, several cancers, osteoporosis, depression and age-related memory loss and dementia. Select supportive running shoes and a trail surface that absorbs some of the impact of foot strike. Warm up and cool down adequately, and rest appropriately between long runs, to avoid burnout or injury. One exceptional difference between walking and running is that in running, for just a fraction of a moment as your feet leave the ground, you take flight.
A 2012 study published in the “Journal of Obesity” counted caloric intake at a buffet for runners and walkers after an hour of exercise. The runners had much higher levels of appetite-suppressing hormones called peptides in their blood than walkers and ate almost 200 calories less than they burned while running. The walkers, with no boost in peptides, consumed 50 calories more than they had expended. Runners burn more calories in general than walkers, even when they travel the same distance. A 156-pound runner burns about 112 calories per mile compared to a walker's 89 calories.
And the difference is sharper when you factor in the after-burn, the extra calories you continue to use as your body returns to its resting metabolic rate after exercise. A California State University study, published in the “Journal of Strength and Conditioning Research” in 2012, found that runners took longer to return to resting metabolic rate than walkers. Runners burned about 46 extra calories during the 30 minutes after exercise, compared to just under 22 calories for walkers.
- Journal of Biomechanics: Differences in Muscle Function During Walking and Running at the Same Speed
- Runner's World: Running v. Walking: How Many Calories Will You Burn?
- Natural Running Center: Walking vs. Running: Why These Gaits Are Not the Same
- The New York Times: Is It Better to Walk or Run?
- Harvard Medical School Health Publications: Research Points to Even More Health Benefits of Walking
- Runner's World: The Benefits of Running
- Runner's World: 6 Ways Running Improves Your Health
- Journal of the American Medical Association: Gait Speed and Survival in Older Adults
- Journal of Obesity: Influence of Running and Walking on Hormonal Regulators of Appetite in Women
- Journal of Strength and Conditioning Research: Energy Expenditure Comparison Between Walking and Running in Average Fitness Individuals
- Photo Credit Comstock/Comstock/Getty Images