I need to know if it would be ok to do 3-5 reps of high weight on flat bench to increase my power and strength on my bench?
yea, and eat more
Um... why woudlent it be?
Being a strong teenager means nothing.
My wrists hurt, but some people don't have wrists to be sore. My knees have tendinitis, but some people don't have legs to get tendinitis in. I seem to be going backwards with training, yet some people can't even walk let alone lift 400 pounds on a daily basis.
Dust out the vagina, and keep on lifting.
heavier weight + lower reps = higher strength increase
If you are looking to increase strength, do a search for the 5 x 5 routine