As a recreational sport, golf was often looked at as a sport in which an individual did not need to be in top physical shape to excel. While a chiseled body is not required to play well, the dominance of Tiger Woods demonstrated the advantage that could be found by showing up with the vital muscles in a swing properly toned.
The primary muscles in the upper body that are used when performing a golf swing are the shoulders and back muscles. As with all muscles involved in the swing, it is important for the upper-body muscles to be both fit and flexible. Strength in the upper body allows the golfer to maintain control over the club as he winds it back, while flexibility allows for a deeper backswing without losing control of the club, which can occur when a golfer over swings. To work on building the upper body, basic exercises that do not require advanced machinery include push ups and pull ups.
Flexibility is essential in any golfer's core, even more so than in the upper- and lower-body muscles that contribute to the swing. An inflexible core will prevent a golfer from getting the proper turn in her swing, and can lead to a golfer being unable to bring the club back far enough to develop the proper momentum for striking the ball. Strengthening the abs will also allow the golfer to develop extra torque with her swing, increasing the momentum of the club head at the moment of impact. However flexibility through the core remains more important.
The primary lower-body muscles that are used to support the body throughout both the backswing and the down swing are the quadriceps muscles, which are responsible for providing balance and stability throughout the swing. A simple quad stretch is performed by grabbing the foot of the leg being stretched, and pulling the foot up toward the golfer's rear until a stretching is felt in the muscle. Build up quad strength by performing squats, a simple exercise that doesn't require any equipment. Step forward with one foot, lower the body until the opposite knee nearly touches the ground, then stand back up. For extra resistance, hold weights while performing squats.