<s>[INST] My daughter gets mottled skin on her legs with exercise, and says they get real heavy and feel tight like rubberbands and she can hardly move them.  And she feels like her heart is racing more than usual.  She is 17 and on a dance team and it happens with dancing.  Anything we should worry about? [/INST] Hi, I had gone through your question and understand your concerns. You shouldn't be worry about your girl as all these changes are common after heavy exercise for those who are not athlete before. I see similar case in my clinic, I advised this case to lessen heavy exercise for two weeks with gradual increase and to notice the frequency of recurrence of symptoms. I also prefer having NSAID when needed. </s>