I started CF in 2011 in Highschool. I was a cc runner at a mid 17-minute 5k. But doing more than 5 wall ball shots at a time was impossible, and I used a 12lb ball as a scale. The issue was not loading or reps, it was that my cardio system was not tuned for anything other than running. Then, Karen would take me 12-minutes. Now I have almost halved my Karen time and only lost 3-minutes off my 5k. That is a good trade. Not to mention a deadlift that went from 165lb to over 405lb doing only a heavy day one or two times a week. #crossfitworks