a certain muscle stretch

2

Hey There

Im 36 years old and decently strong but my stamina is diminishing. I have started doing your workouts about three weeks ago and feel different for sure. Im having trouble stretching a certain muscle that your leg routine hits hard and has hurt me for years. Im not big on muscle terminology but its the area above your bum cheeks and below your hip bones. just wondering if there are good stretches to work this area

Thanks

Mike