When I had my bike fit, the fitter pointed out that I should feel like I am on a tripod (butt, feet, hands) and that none of those points should feel like they are carrying more weight than the others. What was interesting to me was how he helped me understand that the head/neck was the key pivot point. Depending on where my head was, every one of the other three points changed in terms of balance. I don't know if you can have someone video you while you ride, but that might be helpful. Other things to check are that your handlebar width is correct so you aren't pushing your shoulders together (too wide), and that your seat is the proper distance forward; if it is too far back you will carry more weight on your hands. If you haven't had your fit checked, maybe that's a good step, instead of assuming it is all (lack of) conditioning.