If I'm honest I struggle with many of the yoga poses too, but the idea is really to bend as much as you comfortably can rather than perfectly match the poses. Once you take that approach it's a lot less daunting. I think the benefit comes from making the effort to actually use all of your joints regularly. Daily routine and biking simply doesn't achieve that for me. Not consistently anyway. I don't actually think I'm getting any more flexible, but I have no aches, pains or stiffness in my joints and I haven't lost any flexibility over the years. Still can't touch my toes without bending my knees!