It really depends on the population you want to work with. If you’re mainly working with the senior population, I would look at ACSM, ACE, or NASM before NSCA – I’m sure others in the room can add to that list. The NSCA is more geared towards sports training and conditioning – that’s who I’m certified with – and I don’t even work with athletes! A friend and colleague of mine has great website geared towards personal trainers and certification information – www.joe-cannon.com. Check it out – it’s a great resource and I highly recommend it! Good luck Noreen.