Regarding fitness and serenity, yoga sounds great but im not comfortable with the spiritual side?

yoga appeals to me in a sense that it promotes fitness, flexibility, de-stressing and taking a step back from the busy world. However i don't particularly want to go all out as a lifestyle choice and follow the spiritual side to the practice. Is it possible to simply follow the fitness positions, learn to relax and meditate without involving the religion-like emphasis that comes with it? Or is their an alternative to yoga that gives you the stress releasing and fitness benfits without the 'dodgy' philosophy behind it?