so i'm planning to start karate soon and feel confident with my strength and endurance but my flexibility is AWFUL. i don't think i've ever been able to touch my toes with my legs straight at any point in my 17 year life. my arm and shoulder flexibility is fine, but my hamstrings and such are horrible. i was wondering if there is like a 20-30 min workout regiment that is geared solely towards drastically increasing my flexibility. thanks.