Maintaining weight but want to lose more

calund06

I am 5'4", 57 year old ( 58 in September) female weighing 154 lbs. From April 2011 to March 2012 I lost 94 lbs and have gone from 40+% bf to 26.5%. I started using MFP this past May and log my food as well as exercise. I exercise 5-6 days a week---usually 15+ mile bike ride at 10.8-11.7 average speed and usually burn 500+ calories. I wear a HRM in order to have as accurate calorie info. possible. 2 days a week I do cardio and strength training for about 45 minutes and burn 250-350 calories. I sometimes do bike ride on same day as the cardio strength training which of course ups my calories burn.

I would like to get my weight down to 147 so that my BF% would be a bit lower. When I updated my profile about 2 months ago I used active for activity level and that I wanted to lose 1/2 lb a week which gave me a net calorie goal of 1580. I eat healthy diet with lean proteins and lots of fruit and vegetables, whole grains and low fat dairy. I am often slightly under my net calorie goal and almost never over yet my weight seems to be plateaued---I weigh first thing every morning to monitor my weight and over the past 14 weeks my weight has fluctuated betweem a low of 152 to high of 156.

I feel terrific and truly believe that I am the healthiest that I have ever been but I would like to get to my 147 goal and then be able to maintain that weight. I understand that weight fluctuation of 3-5 lbs is completely normal but why cant I get past this plateau? Any help/suggestions would be appreciated.