My work buddy named Steve gave me a set of Roller Trainers. OMG, what a great workout. It forced me to engage my core, keep a high cadence and high speed, good pedal stroke, and minimal upper body movement. Basically, forced me to have good form. I videotaped my first try at it. The first 10 minutes consisted of falling down alot. The next ten was holding onto the armchair with one hand and trying to hold steady. Then I got the hang of it and did 10 minutes solid. Good times! Can’t wait to try it again!