I think I may have a handle on what is going on. I have significantly upgraded my cardio over the last 2 weeks. Prior to that I would do 3-30 minute sessions a week (primarily bike). Lately I have been doing 6-7 days a week for 45-60 minutes followed by a 30 minute bike ride at night and also 3 1-1.5 hr weight training sessions a week. My body fat 2 weeks ago was running 35-36%. Today it measured at 31%. I guess I'm building muscle since I'm not losing weight.