Some of my coworkers and I are trying out a 30 second per hour workout routine. We're having a hard time finding bodyweight exercises for the legs that really tax the system. I'd like it if we could start doing pistol squats, but some of the participants aren't able to perform them yet.
Is there a simple progression for pistol squats that can give my coworkers some efficacy for this advanced movement (and hopefully get them performing them before too long)?