I teach a circuit training class 2X a week at a corporate client. I've been working with the same core group of girls for about a year and a half. I've been talking to them about lifting heavy, pushing yourself harder. On Wednesday the girls had 30 seconds per exercise and my suggestion is that since its a short period of time perhaps we try to lift heavier. So as the girls moved through their stations they would comment on how heavy the last person lifted - wow, she did 80 pounds on the leg press! This one did 60 pounds on the lat pull down! And they took turns trying to keep up with each other. It was a great feeling to see them lifting heavier than 20-30 pounds, which is where they were when we first started working together. And they feel stronger too! It is an awesome feeling to be able to influence someone like that. I can't wait to see those girls again on Monday!