…For many years serious athletes and bodybuilders have known that free weights build muscle size, strength and power faster than any other form of resistance training. Today’s smart bodybuilders are also acutely aware that the process does not take as much time as many have erroneously believed and that, by using dumbbells (because they DO require balance), the whole process happens more quickly than with machines or even free-weight barbells. Nearly all serious bodybuilders use free-weight barbells and dumbbells almost exclusively to do their ominous thing.
…Over the last 12 years, ongoing American University Athletic Department and PE Research has verified that a free weight, all- PowerBlock dumbbell program produces high levels of strength and size. These great results were accomplished even with very short (as little as 12-30 minutes duration), high intensity workouts.