Who has the best forehand in tennis? Federer.
Who has a scrawny body made to look weak by numerous WTA players? Federer.
It's 90-95% technique. If you want more ummph, you can put on 20 pounds o muscle and maybe get about 2 mph...or, you can learn to hit the ball with a loose grip, good rotation, using your legs, out in front, etc, and probalby get 10 MPH more out of your shot. It's not a coincidence that tennis players are skinny in comparison to most professional athletes.
3.5 player. Equipment: Prince NXG OS, hybrid kevlar mains/poly crosses 50 lbs