Just got back in to running after number of years so compression tights completely new to me. First pair I ordered was small my normal size, fit really snug didn’t feel uncomfortable although very tight. Second pair was medium as most people seem to say order size up. Wasn’t as tight easier to pull on and more comfortable around the top part, not as squished! But my legs seem to be aching more after the run in the medium size. Could be coincidence? Is the tighter ones the best way to go to prevent muscle fatigue?