Your ability to shift your weight in your golf swing is determined by how flexible and mobile your hips are. If your hips are tight or are limited in rotation, you won't be able to move them from side to side and shift your weight correctly in the golf swing resulting in loss of distance.

Stand in a shoulder width stance using a golf club for balance.
Lift one leg up so your foot is up in the air, hinging from your hip socket.
Swing your leg back and then forward, taking your hip through full range of motion.
Continuously swing your leg back and forward for 8 to 10 repetitions.
Return to the start position and repeat on opposite leg.
Do 8 to 10 repetitions on both legs.