Expert: Ken Alan - 8/21/2010

Question
I read somewhere that for an average guy of about 5' 8" and 170lbs they will burn 100 calories per mile while running 5 miles per hour. Is that accurate? If so, how can I calculate how many calories I burn when running? I am 195lbs and 5' 11" and although I can run an average 5 miles per hour I do slow down and walk periodically when running. Do people who weigh more burn more calories when running? Also do people burn relatively more or less calories when they increase their speed beyond 5 miles per hour? How does that all work?

Answer
100 calories per mile is a fairly accurate estimate of energy expenditure, plus or minus a few calories.  Interestingly, this is true whether you cover a distance of one mile running at 5 mph, 10 mph, or 3 mph.  It's the time it takes to complete the task that is different.  Walking at 3 mph takes 20 minutes to go one mile.  Running at 10 mph takes 6 minutes to go one mile.

Since you weigh more than the average man, you likely burn calories at a slightly higher rate.  The only way to calculate is to get to an exercise physiology lab where they would assess your oxygen consumption while running to determine an accurate caloric burn for you.  People who weigh more do burn more calories when running (or any cardio exercise) granted the distance and speed are the same compared to people who weigh less than you.  Fitness level also influences energy consumption, as does age, environmental conditions, and medical status.  As you increase speed when you run, you will burn calories at a higher rate per minute, because you are exerting more effort.

Hope this helps.  Glad you're doing physical activity.  Keep it up.