Upper body strength in sports depends on the ability to transfer force from the lower body and core. Try to throw a baseball or serve a tennis ball without using your lower body. The power difference will be dramatic.
Strength and power come from the ground up, which is the primary reason why coaches and other experts agree that functional training is the most appropriate kind for improving sports performance [learn more about the advantages of functional training here].
Green Bay Packers linebacker AJ Hawk, who could be a difference-maker on the field in Super Bowl XLV, developed his functional upper body strength with the Alternating Landmine. This powerful exercise is initiated from a triple extension movement—a simultaneous flexion of the hips, knees and ankles. The force then travels up through the core to the upper body, finishing with the arm through the Single-Arm Press.
This exercise has no doubt helped Hawk improve his already-impressive tackling skills. Hit the weight room like Hawk to improve your throwing, tackling and other upper body sports skills.

• Assume athletic stance holding top end of weighted bar with right hand at chest level
• Lower into quarter squat and explode up through hips, knees and ankles
• Drive bar forward with arm as forcefully as possible and release
• Catch bar with left hand and immediately perform again, continuing in alternating fashion
• Repeat for specified reps

Sets/Reps: 4×5 each arm