The other day I was training someone and after having them do a set of 20 burpees they commented “That was so mauch harder than when I did them in gym class!” after I got over my initial shock that a gym teacher actually had the kids doing exercises we talked a little about the differences: 1. I made him do a full pushup each rep. 2. I made him try and touch my ceiling each rep. In other words I made him put effort into each rep. There is a big difference between doing burpees with a half assed pushup and a little hop at the top and doing a full crisp rep and a powerful leap like you mean it. Its like jumping rope: Its great for little kids singing songs at the park and for pro-boxers getting ready to go 10 rounds with the champ…It’s all in the effort!