Hi, yeah, they are supposed to reduce muscle vibration and soreness and assist in compressing the chest which helps regulate breathing - this should be mean less time in recovery.
I've used Nike tops that compress and they seem to increase my ability to run for longer and feel less fatigued afterwards - i've tried wearing these on different days / lengths of run and the results do seem to bear out that the compression does help.
I ran my 1stHalf Marathon 2 weekends ago at Silverstone.
I've trained over 12 weeks, gradually increasing time/distance without any injuries or pain. I have had a weeks rest since the event but ran 3.5 miles Tuesday and the sides of both of knees now hurt (feels like bruising).
Could you offer any idea as to what I may have done or what may have caused this pain?