national association of sports medicine. (which i think is the best one you can get without having to have a 4 year degree in sports science). ACSM if you are. Other respected certifications include ISSA, ACE.....and a hand full of others. I also have a online certification which i used to legally say i was certified ( ) to start working through AFTA (american fitness training of athletes).
Sage
"im the greatest scienitifically inclined mind since einstein"
Mod @ gaining-mass.com
Mod @ massnation.com