Because i've been mostly nerding for the last two years i started doing pushups a few weeks ago to open my shoulders. I was amazed it started to hurt so quickly because I can do a seires of 80kg weight lifting and that doesnt hurt my shoulders/shoulder blades NEARLY as much as 40 pushups. Also i've been running 5-10km almost every day now for the last four months but it seems whenever I play Stepmania/Dance Dance Revolution it starts to hurt the front of my shins as in the muscles there were overused. Altho there are no muscles in the front of the shin between the bone and the skin