The NASM or National Academy of Sports Medicine recommends that people do a minimum of 2 days of resistance or strength training per week. Regular resistance training can help you improve your strength, flexibility, coordination and agility. All things needed for a efficient golf swing.
When you train to get stronger, first, your muscles are better able to tolerate the movements and stresses the golf swing puts on your joints. Second, strength training makes you stronger to swing, not only faster, but also smoother and easier. And third, strength training may help prevent injuries so that you can keep playing the game longer and better.