I know this is predominantly a high impact series but I just couldn't resist and bought it anyway since I'm looking for more shorter workouts to add to my ever expanding collection. I usually modify any high impact moves to low impact (due to knee issues) but can tolerate a smidge of high impact. Would love to hear from anyone who does this series who is in a similar predicament and successfully modifies. I really hope my CTX doesn't become a dust-collector!