The fitness pill builds strength endurance.These days there are pills for just about everything. If you can't sleep, take a pill. If you're unhappy, take a pill. What about if you're overweight and you don't have time to exercise? A new fitness pill may soon be available. Scientists are developing a pill that provides the same benefits as exercise. According to a BBC report, the fitness pill will "build muscle, increase stamina, and even burn fat.