I'd say the back injury and weight gain has your core weaker than normal. I have a history of back problems and whenever I have a flair up it takes awhile to recover and rebuild my core strength. And until then, I really don't feel confident or comfortable doing anything athletically. But when I'm healed up and feeling strong again, snowboarding (especially presses and such) feel so much more effortless. And I agree with donutz... I turn 34 tomorrow and I'm riding better this season than I ever have. It's great to hear you are still progressing at 55. Gives me hope!