Determined to win the 90 day challenge at my gym

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I signed up for a 90 day challenge at my gym last Saturday. Who ever loses the biggest percentage of weight Nationally wins $5,000 and a spa vacation in California. So far so good, down 12.5 pounds in 9 days. Staying under 1000 calories everyday and burning atleast 700 on the eliptical is tough but I am willing to do what I need to. Would love to be friends with like minded people who have over 100 pounds to lose so we could motivate each other and comment on each others food diarys and exercise. My goal is to lose 90 pounds in 90 days and of course win the National prize.