It seems the more I ride, the hungrier I get. I feel I could eat all the time. I go on 30-40 mile rides several times per week, with hills on my Hybrid Sirrus Elite Disc. I've probably gained 5 lbs in the last 6 months to 205lbs. It feels like when I was a swimmer in high school and ate a big meal after practices. Is this normal for a 64 yr old?