You're best pal rushes down the sidewalk at breakneck speed while you'd rather take your time. While metabolism may seem like a likely culprit for the difference in pace, this bodily function only affects the way you process energy from food, not your speed or effort during exercise. That said, your walking speed does affect metabolic rate, so ramping up your stride can increase calorie burning nicely.
In a nutshell, metabolism is an oxidation process that transforms food into energy. You use this energy, which is measured in calories, for vital functions like breathing and pumping blood, as well as any other physical activities. The number of calories you expend for basic life support is called your basal metabolic rate, or BMR. Your BMR, along with the number of calories burned for digestion and muscular activity, determine your total energy expenditure, which averages about 2,000 to 2,200 calories per day for most moderately active young women. When you eat more calories than you use, your body stores the extra as fat -- when you eat fewer calories than you expend, you lose weight.
Since metabolism doesn't play a role in walking pace, consider some other factors. In an interview with BBC News, Professor Richard Wiseman -- who headed a British Council study on the subject -- linked fast walking with a number of other traits including impatience, fast talking and wearing a watch. He noted that walking speed has increased about 10 percent globally, probably due to technological advances. Walking speed is also cultural, and people who grew up in speedier cities may be faster on their feet than those from slower-paced areas.
Walking and Calories
Having a faster metabolism may not add pep to your step, but picking up the pace while walking can increase your total caloric expenditure. Although you burn roughly the same number of calories per mile at casual and moderate paces, moving faster than 4 mph increases the calorie count because your heart and lungs must work significantly harder. Plus, by walking at a faster speed you can fit more miles into the same time frame. For example, in 30 minutes a 140-pound woman burns just 110 calories walking at 3 mph, but 123 calories walking at 3.5 mph because she's gone a longer distance.
While you can't fully control your metabolic rate -- women typically burn fewer calories than men, and your metabolism may slow with age -- you can help increase calorie burning with some lifestyle changes. Building more muscle with weights or resistance exercises like squats and lunges increases your metabolic rate slightly, and upping your level of physical activity increases your overall calorie burning. For optimal calorie expenditure, perform cardio activities like walking or jogging most days of the week, and frequently engage in non-exercise activities such as fidgeting at work or pacing during phone conversations.
- MayoClinic.com: Metabolism and Weight Loss: How You Burn Calories
- FamilyDoctor.org: Nutrition: Determine Your Calorie Needs
- Runner's World: Which Burns More Calories, Walking or Running?
- ExRx.net: Walk / Run Metabolic Calculator
- BBC News: What Walking Speeds Say About Us
- American Council on Exercise: Burn More Calories On the Job
- Stockbyte/Stockbyte/Getty Images