You're going to be moving around and sweating as you exercise, so comfort it key. Choose clothing that isn't restrictive of your movements, and if you're exercising outside, try and dress in layers so that you can easily remove an outer layer and maintain your body temperature. When selecting workout clothes, stick to fabrics that are breathable. Avoid cotton, which tends to get wet and heavy from sweat and then cold and smelly as it dries.c 

Make sure that the shoes that you will be working out in are no more than a year old. If you're running several miles on a daily basis, though, you should ideally change your shoes every six months. As shoes get worn, the soles break down, causing the shoes to go flat and lose support, increasing the likelihood of ankle, knee or back injury and shin splints.

If you're going to be doing a lot of running, head to a specialty store and choose a shoe that will give you joint stability. Cross-trainers are better for gym workouts because they have more lateral support.c 

When picking out a sports bra, choose one that supports you the best. This may mean trying on several styles until you find one that works for you. Test out doing a few jumping jacks or running in place in the dressing room to test the comfort level. It may seem silly, but it'll benefit you when you hit the gym.c 

It may seem vain to say that a key to a better workout is looking good, but if you have clothes you like that are specifically dedicated to exercising, you'll be more likely to get motivated to go to the gym. But skip the makesup, which can clog your pores, and jewelry, which can get in your way as you exercise.c