As a Titleist Performance Institute Medical Provider I get asked the question, “How do I improve my driving distance.” The answer from my perspective as a movement and musculoskeletal expert is that you have to have a combination of flexibility and stability. The body is made up of regions that are meant to be very mobile, think of your shoulder, and other regions that are meant to be stable, think of your low back. Stability is often attained by strengthening key regions of your body that help to generate power and help transfer that power into the ball.
The gluteus maximus is a muscle that is very active in the forward swing which is the phase from the top of the backswing until when the club is horizontal. Studies have shown that for a right handed golfer there is 100% activity in the right gluteus maximus muscle.
A simple exercise to help strengthen this muscle is below. The top picture is your starting position and the bottom is your ending position. You can perform 10 to 15 repetitions and hold the end position for 5 to 10 seconds. This is a great way to strengthen your glutes which will allow you to hit the ball further!