Rawr! (Also: METS demystified!)

This week is getting off to an awesome start. After resting yesterday (serious resting--there was even a nap in there!), I was ready to kick off the training week with a fab four-miler today. The weather was kind of yucky--40°, light rain, and some wind, about the same conditions I had for my race last weekend--so Betsy and I went to the gym. It wasn't very busy, so I hopped on a treadmill in the hopes I could get all four miles in without getting booted off. (There's a 30-minute time limit, but it's enforced only when it gets busy.)

After warming up and gradually increasing the pace, I settled in at 5.8 mph (10:19 pace per mile) for the first two miles. To my delight, it felt pretty easy and my heart rate was staying relatively low, so I decided to kick it up to 6.0 mph (10:00 pace) for a mile and see how it felt. It actually felt great. Yes, I was doing some work, but I was able to keep a relaxed stride and hit a nice groove at that pace. I distinctly remember breathing hard trying to maintain 5.3 mph on the treadmill less than three months ago, so today felt particularly sweet. I kept up the 6.0 mph pace for two whole miles!! My heart rate hit 171 at one point, but my anaerobic threshold must be going up because I honestly didn't feel like I was working that hard. Seeing some payoff from all the hours I've been putting in is so, SO sweet!! I finished 4 miles (including the initial warmup) in 43:16 for a 10:49 pace.

My treadmill puts up some statistics while I'm running, and one of them has always mystified me--in the right-hand corner, it has a number called "METS." When I am working hard, this number is 9-10 or slightly higher. I think it was 10.19 while I was running my ten-minute miles. Every time I get on and see that number, I think, "What is that?" followed by "That would be a good subject for a blog post!" And then I promptly forget about it by the time I get home.

But no more! Today I'm going to tell you what METS are (other than a baseball team, of course). METS stands for "metabolic equivalent of task." It is supposed to be a measure of how strenuous something is compared to your resting metabolic rate (RMR). Sitting quietly is by definition equal to your RMR, so sitting around like a lump has a METS of 1.0. (By the way, RMR is defined by a consumption of oxygen equal to 3.5 ml O₂·kg^-1·min^-1.) An activity that doubles your metabolic rate from your RMR, like walking very, very slowly, would have a METS of 2.0. Running twelve-minute miles has a METS of about 8.0. So an activity with a METS of 10.19, like my fast running today, means that I am consuming ten times the oxygen I would normally use at rest. So for me, running at 6.0 mph is ten times as strenuous as sitting around like a lump.

Wow, that makes me feel even more badass.

Here's a nice article about METs that includes a calculation for figuring your target METS rate:

• For women, MET level = 14.7 - (0.13 x your age in years)
• For men, MET level = 14.7 - (0.11 x your age in years)

According to that, my target METS is 9.0, so I am going above and beyond by hitting 10.19. Woot woot!