First for me is my Withings graph (past 18 months shown.) To anyone looking to either gain or lose weight you pretty much need a scale and I love that the Withings scale syncs over wi-fi and allows you to view the results on iOS.

Second is my Lift streaks for exercise and eating well. When I cheat I know how long its been since last I cheated. It's awesome reinforcement.

What works for you?

Lift (lift.do) has been the best source of meaningful metrics for me lately.

Prior to that, it was my times/weights with various crossfit workouts or exercises. I loved seeing my times go down and weights go up.

I have been meaning to take body measurements for a long time, but have never done it. Have you? If so, motivating? Seems like they would be pretty slow moving.

Yeah - so body fat % is obviously a compelling metric but it's annoyingly hard to come by. The Withings scale measures it but I don't quite believe the result or even necessarily the trend. Doing measurements with skin calipers is really hard to do by yourself.

I think one of the reasons crossfit is so successful for folks must be the scorekeeping inherent to it.