In rallies the shots are so fast that sometimes my body can't keep up with the tempo. Like for instance if they constantly smash and move me to corners my body (or sometimes even my eyes) can't follow it. What sort of ways (such as particular exercises) can i do to get used to fast paced rallies?
Multi-shuttle drills are a great way to force a fast pace when training. In some cases, you might even want to speed the shuttle up by tipping the feathers inwards to get an even faster pace.
also drives a lot, and try to always return to the center of the court, there you can move to all the court with lees movements
do the following 2 vs 1 drill. you have two friends that can only stand in the fore and mid-court areas. they can only lift and push the shuttle to the mid and rear-court areas of your side. you have to cover the mid and rear-court, and you can do drops and light smashes only. basically they'll just move you around the rear half of the court as you return the shuttle back to the two individuals. this will simulate two players picking on the rear court individual in the attack-defensive positions.