I just returned from skiing with some buds who never train physically. We would walk up stairs and they would be winded while I could just keep going. Why then, do they just fly down the hills and I struggle??? I have been skiing for 10 years and have taken many a private lesson. I have completed 2 iron-man triathlons,train physically 3-4 times per week and noticed that while I am skiing, my feet are sore. super sore the next day. This is not from my boots as they are custom Sure Foot boots, but more that my intrinsic foot muscles, calves and quads are just beat!... I am obviously over working myself as i ski and am getting frustrated. I have great balance and feel that I am just working too hard. I would appreciate any advice from an upper level skier.