My skin has become splotchy and the marks around my skin are bruise colored but it doesnt hurt its sometimes itchy and when i start to exercise my skin feels like theres little pins whats wrong?

My skin isn't really splotchy or anything, but when I haven't ran or worked out in a long time my legs feel like theres little pins there. Same with everythone else I know. It's your body trying to adaot to a work out