question re BMR and exercise

BMR stands for Basal (or sometimes Basic) Metabolic Rate and is the number of calories it takes to maintain your brain functions and organs... Basically it's what you would consume if you just laid in bed all day.

RMR stands for Resting Metabolic Rate and is what you would burn if you sat around all day watching tv. It is used sometimes because it's easy to measure, easier than BMR. (You breath into a machine for ten minutes to get your RMR. Some gyms have these machines and charge around $50-75 for this test.)

The formulas on the web that give you a BMR are an estimate assuming you are average for your weight, height, sex and age. The number you get may or may not be your true BMR. I find all the sites except MFP to give a number that is too high for most people. If you use an online BMR and still have trouble losing, it might be worth it to get your RMR tested.

Once you have a reasonbly accurate BMR, there are several approaches to figuring out your daily calorie allowance. One is to pick your lifestyle multiplier based on your daily activities, not including exercise. Then you set a calorie goal that is around 500 lower than that plus whatever you burn in exercise that day. So if your calorie goal is 1500 and you burn 500 calories at the gym, you eat 2000 that day.

The other way is to factor in your exercise as part of your multiplier. That's what I do. With my job, my lifestyle is sedentary but with my exercise, it's moderately active. So that's what I told MFP when I set my goals. Then I don't eat my exercise calories every day but eat that average amount every day. This works better for me for several reasons. First, some days I can burn 2000 calories with exercise (like yesterday -- completed a triathlon so I was out there for 4 hours and 20 min working hard the whole way). There just isn't any way I can eat 2000 calories in a day let along 2000 calories plus whatever my daily allotment is. The other reason is that sometimes on days I exercise intensely, I am only slightly more hungry that day, but the next day I am also more hungry. So spreading it out means I'm not forcing myself to eat way more than I feel hungry for one day and way less than I feel hungry for the next day.

A caution about eating your exercise calories: most machines at the gym and most online formulas as NOT accurate. If you are going to eat everyone of your exercise calories, then you should get a Heart Rate Monitor IMO. Those will estimate your calories burned using your heart rate and are much more accurate. Or some people just eat a portion of their exercise calories instead to give themselves a cushion.