I had an opportunity to try out the weight belt this past year. I slowly increased the weight to a few of my swimmers that were on the edge of making huge cuts. It worked beautifully. My 200 IMer went from 2:05 to 1:58; his 100 breast went from 1:05 to 1:00. Very exciting. Both swims were his first Sectional cuts. My sprinter went from 22.89 to 21.73. Now that is a huge drop and his 1st Sectional Cut, too. This kid only swims high school (max 8 hour/week) and trains only 2 additional workouts (75-90 min) each week. Both boys were very happy with results. Their parents - even more happy. That makes my life as a coach blissful!