My 16 year old daughter has been wearing the pto airmesh knee braces on both knees for about a year. She plays sports year roun

My 16 year old daughter plays sports year round.  She has been wearing the pto airmesh knee brace on both knees for about a year.  She noticed that her endurance seems to be much worse when wearing them in a heavy practice.  During volleyball she does pretty good but when basketball season starts ata times she experinces rapid heart rate and chest and shoulder pain about 4 min. into game.  We have had her checked out with a Cardiologist and lab work and she tests fine.  Im wondering if this brace might be making that much of a difference in her endurance.