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 know 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.

Research has shown that a free-weight, all-PowerBlock dumbbell program produces high levels of strength and size. These results can be accomplished even with high-intensity workouts as short as 12-30 minutes. Perhaps the best thing about dumbbells is that they can easily be incorporated into a home gym.

The Most Effective 18-Minute Home Training Blast

You can do over 100 functional exercises with the PowerBlock dumbbells in combination with an adjustable bench. A workout of just under 20 minutes can be adequate to build strength and size in just six weeks. Perform this workout twice per week, spaced out to allow several days in between workouts (e.g., Monday and Thursday, or Wednesday and Sunday).

On Thursday do the same workout as above, but only do 6-8 reps, and increase the weight. Start with incline presses. Substitute either triceps kickbacks or one-arm extensions for triceps instead of the curls for biceps. Don't forget to work your abs and lower body and do some aerobics during the week as well.