# How to use METS to estimate additional caloric expenditure and weekly recommendations

I have a question regarding metabolic equivalents for exercises (METS) that I've been unable to google an answer to. It seems that it's either so incredibly obvious that it doesn't make sense to ask it, or that its not relevant, or some other reason.

Disclaimer: From what I've read, METS are estimates and the true energy requirements for an exercise will vary based on lean body mass, fitness, etc. Let us assume that walking 2.5 MPH is 3 METS. Also assume that the resting/base metabolic rate is 1 METS (By some definitions). I also realize that analyzing this much is a bit silly - eat less, move more to lose weight. I'm simply interested in the mathematics.

I would like to calculate the number of ADDITIONAL calories burned from an exercise. I find this extremely relevant, and I'm surprised I can't find this in the articles I've read online. Say you are calorie counting and are supposed to have 2000 calories per day. You walk at 2.5 MPH for 1 hour, consuming 3 METS of energy. What that says to me, is that by walking you have burned 2 ADDITIONAL METS than you already were by sitting on the couch. I for one am not interested in the total number of calories burned by the activity from a weight loss standpoint, those are already factored into my diet. I am interested in "How much EXTRA am I burning" from doing this.

A silly yet hopefully helpful example is that we are recommended to get at least 7.5 MET Hours per week of exercise to reap the benefits of exercise. That means you can sit on the couch for 7.5 hours and accomplish this, right? That's 1.0 METS. I mean think about it, say you're sitting on the couch and brushing your hair. That's a 1.2 METS activity. So you do that for ~6 hours and you're good? What I'm getting at is it sounds like you need to subtract 1 MET from the exercise to get the "net METS" or the number of ADDITIONAL energy expenditure over resting metabolic rate. For example, subtracting 1 from sitting on the couch is 0 net METS. Great, that means we're not exercising and can't contribute to our weekly 7.5 goal. Or, with hair brushing on the couch, subtracting 1 from the 1.2 and you get 0.2 METS. You'd need to brush your hair for 37.5 hours to get 7.5 MET hours with that exercise.

So if walking at 2.5 MPH is roughly 3 METS of energy TOTAL energy expenditure , then 2 METS is what the exercise is actually adding to your energy expenditure over resting (sitting on the couch).

Now that I've hopefully explained my case, lets get down to specific questions.

1. If you look up the METS for an exercise, that would be the TOTAL energy expended (Resting/Basal metabolic rate (1 MET) + the extra energy), correct?
2. There are two calculations for calories. One are the total burned by the activity, one is the extra burned by the activity over sitting on the couch. Can you calculate the latter by simply subtracting 1 MET from the total METS of the exercise?
3. For the weekly recommendation of MET Hours, are you supposed to subtract 1 from your exercises? So if walking 2.5 MPH is 3 METS, instead of walking 7.5/3 = 2.5 hours, should you instead walk 7.5/(3-1) = 7.5/2 = 3.75 hours? After all, you're only doing 2 more METS than sitting on the couch.