While barre and spin class are sure to get your heart pumping, don't underestimate the power of walking. According to a new study from Southern Methodist University, the current standards used to measure walking energy expenditure may greatly underestimate the amount of calories you're burning. The results are published in the Journal of Applied Physiology.
To identify an equation for predicting how many calories are burned during level human walking (walking on a firm, flat surface), the researchers used existing literature to compile a comprehensive data set. The set included 25 subject groups from 10 publications spanning 1960 to 2010, and each group encompassed a range of walking speeds and body sizes. The number of subjects per population group ranged from 5 to 42, and the mean age ranged from 5 to 40.
When the data set was tested using the leading standards, the standards predicted too few calories burned 97 percent of the time-likely because they fail to account for height and weight.
"Height essentially economizes walking, so the taller you are, the less energy it takes per pound to walk a mile, or the slower the rate you burn calories while walking at the same speed compared to someone who is shorter," Peter Weyand, co-author of the study, tells RealSimple.com.
Once they had identified the components needed for an accurate prediction, the researchers created a new equation that accounted for both height and body mass. To put it to use, measure velocity (distance divided by time) in meters per second, and height in meters:
Kcals burned per minute = (0.035 * body weight in kilograms) + ((Velocity^2)/Height))*(0.029)*(body weight in kilograms)
To determine the speed at which you walk, Weyand suggests walking on a treadmill, using a pedometer, or timing yourself as you walk along a known distance. The benefit? Being able to accurately estimate the rate at which you burn calories while walking could predict the intensity at which you're able to exercise, or determine whether you're able to perform a certain task.
"Burning calories is of major importance to health, fitness and the body's physiological status," Weyand said in a statement. "But it hasn't been really clear just how accurate the existing standards are under level conditions because previous assessments by other researchers were more limited in scope."