I would just like to say that I find calorie burn information deceptive and ineffective, bordering on misinformation, considering it is an estimate off an equation even if you are hooked up to a VO2/CO2 analyzer.
It’s like telling everyone to get on a 2000 calorie diet–assigning a specific number to a generic, abstract idea. These ‘burn’ numbers aren’t exact at all. For example, in this National Heart Lung and Blood Institute slide show, it says you can “walk leisurely for 1 hour and 10 minutes to burn 400 calories based on a 160 lb person.”
Does that differentiate between what you would have used in an hour and 10 minutes without exercising at all? Does this 160 lb person have 130 lbs of lean mass (18.75% body fat) or 145 lbs of lean mass (9.4% body fat)?
The leaner person can use more calories during exercise because they can exercise more intensely. At a given pace though, they may burn fewer calories than the not-so-lean person because they are more efficient at that given pace.
Different people use calories differently, nor does exercise “burn calories” as much as it “increases caloric needs,” and is highly dependent on the amount of muscle mass and intensity the person can perform said exercise efficiently. As I have blogged about before (Diet or Exercise posts), exercise alone is NOT an effective way to lose weight. Great for maintaining weight though.
I’ve worked with people on the physical training side of things long enough to know that people don’t lose any weight (actually they gain weight) with exercise alone independent of diet changes, especially when people are struggling to reach the recommended 150 minutes a week goal for aerobic exercise, based on the Physical Activity Guidelines for Americans.
Is the take home from this sort of message: “Heck, I guess I can’t eat that because I sure won’t ever exercise that much!”? If that’s the message they are trying to give, then ok, but I think many RDs give out the message of “How does this food fit in your overall eating plan?” I think bringing in the exercise component based on wishy-washy calorie numbers just confuses people nor is it accurate.