Imagine my surprise when I found out getting a degree in exercise science required a lot of MATH!

I thought it was all going to be gym shorts and sweat.

Instead it was cadavers, metabolic calculations, and weird tools like an “open circuit spirometer.”

Oh well, at least I got to wear the shorts

Someone asked on my facebook wall: “How many more calories will I burn walking hills?”

Awesome question.  Short answer: Lots.  Long answer: See below.

The formulas below come from the American College Of Sports Medicine’s Resource Manual for Guidelines for Exercise Testing and Prescription.  Don’t get a copy unless you’re a super-geek like me.

Here’s the formula for figuring out how many calories you burn while you’re walking:

VO2 (ml/kgxmin) = (0.1xS) + (1.8xSxG) + 3.5ml/kgxmin

VO2 is oxygen uptake.

S is speed in meters per minute. (Conversion 1mph=26.8m/min)

G is fractional grade in decimal form.  (9%grade is 0.09)

Ok, so let’s figure out the difference in oxygen uptake for a 150 pound person walking at 2.5mph on a flat versus the same person walking up a 10% grade.

2.5miles/hour x26.8m/min = 67m/min

Flat VO2=(.1×67) + (1.8x67x0) + 3.5 = 10.2mL/kgxmin

Hill VO2=(.1×67) + (1.8x67x.1) +3.5 = 22.26mL/kgxmin

Ok, even without converting into calories burned we can see that walking up a 10%grade makes us use more than TWICE as much oxygen.  Something is going on.

Our 150 pound person weighs 68.18 kilograms.

Flat: ((10.2×68.18)/1000)x5 = 3.47 Calories per minute

Hill: ((22.26×68.18)/1000)x5 = 7.59 Calories per minute

So over a 30 minute walk choosing an incline will burn about 125 MORE Calories than walking on a flat.

If you have a treadmill, bump up the incline.  If you’re outside, get up to where there’s a view.