From the start, running was my main calorie-burn exercise of the Social Diet. I'm a plodder, but 4 miles of plodding burned enough calories to keep the daily ledger in balance, and it delivered a nice chunk of steps toward the 10,000-a-day goal.

Then, recently, I decided  to pick up my pace. This happened after signing up for the MapMyRun app while I was in New Zealand. MMR maps any run or walk with a GPS-enabled phone. It also reveals other people who have run your route and their times (and it suggests routes—handy in a foreign city).

So I started using MapMyRun, at which point the app confirmed what I already knew: I'm Pokey McSlowFeet out there.

Back home, I was running a 9-plus-minute mile over the 4-mile hilly route. Curiously, though, I was running the same slow pace over a flatter 4-mile route. This suggested room for improvement. First, I increased the flatter route to a 6-mile run. Then, a couple of weeks ago, I decided to pick up the pace and came in at an  8:48 mile. The following week I decided to pick things up a bit more, and came in at 8:18. Then I set a goal: By summer, I wanted to run it at an under-8-minute pace. Then, this weekend, I ran it at 7:52. That's almost a minute faster, per mile, simply by paying attention.

The 7:52 pace will amuse any serious runner, but it left me pretty spent. Any further improvement will require some training, and I don’t want to get hurt, so give me a few months.

Shaving almost a minute off each mile with just a couple of weeks' attention reinforced the power of apps: Data can motivate. It also made running more fun. Now, along with the sounds of my favorite podcasts (currently "The Bugle," with John Oliver, and "Hardcore History," with Dan Carlin), I hear, whispered in my ear, each minute: my total time, my split time, my pace … and I run faster.