Same here...but just think of it as the benefit from doing all of those very difficult workouts that Cathe makes for us. Because we're in such great shape, these workouts don't really amount to being strenuous. Have you tried Kick Punch Crunch? That is a great kickbox focused workout that has a lot of jump kicks and squats into kicks, and other moves that get the heart rate up to a nice range. The first part has a good segment of high intensity moves that certainly are not kick box related (high knees, hammer punches), but it segues into a kickbox workout that gets my heart rate up more than the STS MMA series.
Eva