Logging METs Metabolic Equivalents with the BodyMedia Armband

A feature of the BodyMedia Armband is its ability to measure METs Metabolic Equivalents of Task. It’s a fairly simple measurement that indicates how hard you are working for your body size. It is expressed as a ratio so it can change as your body size changes and give you an idea of your level of fitness. A lot of people don’t know what it is, let alone how to use it, and they don’t use that feature of the armband.

One MET is based on your average calorie burn per minute when you are at rest. It’s considered to be a rough estimation of your Resting Metabolic Rate, your calorie burn for a day of just generally laying around. That figure will be higher than your Basal Metabolic Rate which is the base calorie burn you expend to simply BE ALIVE and have all autonomic body functions up and working; you know, all the important stuff like oxygenating blood and brain activity. Obviously, the BodyMedia armband is going to be able to calculate this. Remember also that the armband is using body parameters that you enter and update as your weight changes. Put very simply, the MET is a measurement of multiples of that resting value. You’d be working at two METs when your calorie burn is twice your resting rate. Three to six METs is considered Moderate activity. Six METs is the general threshold for Vigorous activity. So again—and this is putting it very, very simply—if you average 1 calorie at rest, you’d be working at 6 METs if you are burning 6 calories per minute while exercising.

If you do a bit of Googling, you will find tables that list the METs value of various activities. These values are standardized by averages and most of us are not really “average.” Also remember that to achieve a particular per minute calorie burn, you have to be able to reach and maintain a numerical average that will be displayed by the BodyMedia armband. For example, for the last few days I’ve been hitting about 230 calories for a 30 minute session on the stair climber. That would be an average of about 7.6 calories per minute. The digital display I have will show calories per minute in real-time so I’ve been able to see that I burn about 1 calorie and change per minute when I’m just sitting quietly. I have been able to see that’s about what I burn when I’m sleeping, generally 1.2 to 1.4 calories per minute. Do the math on my cardio stair workout and I’m right around that 6 METs mark for “Vigorous” activity.

Blogging is not very hard work

The BodyMedia armband is going to log the time for Moderate and Vigorous activity and that’s very helpful to know! But there’s a better way to use this information. The armband lets you adjust the settings for YOUR threshold for what level of METs will be Moderate and Vigorous activity for YOU. Right now I’m seeing that I’m not hitting that 6 METs mark consistently for the full 30 minutes so I’ve adjusted the setting down. I want to see where my current intensity level is and work on building the time I can stay at that level. I will adjust the setting up little by little as I work toward increasing my workout intensity for a longer period of time.

If you’ve read my book or this blog, you know that I am all about learning from experience, seeing what works (or doesn’t) and putting it to use. What’s MY level of fitness? What’s an improvement for what I am doing? I believe we need and deserve to see a benefit from whatever we’re doing if we want to keep doing it. Motivation and inspirational sayings won’t get me on that stair climber every day—seeing real numbers as my stats change and feeling my conditioning improve WILL.