I was wondering the importance of powerlifting techniques when training for sports. Is it necessary to change exercises every 3 or so weeks. Also, is it a good idea to use powerlifting technique on the bench, squat and deadlift. for examle tucking elbows in, bringing bar to lower chest and pressing in a straight line in the bench press rather than having the elbows slightly out and pressing in a j movement.
Absolutely. Everyone in high school is usually lacking in absolute strength.
The way a powerlifter benches is more efficient and safer. It will save you from unecessary shoulder rotation and get you in a tight setup where injury is less likely to occur.
Obviously, you don't have to get wider than the rack when you squat, but low bar squats are great for posterior chain emphasis, important for athletic performance.
As for the deadlift (and this goes for squatting too), it is important to learn proper and safe techniques period. There is not as much of a "PLing" dead though, especially if you're pulling conventionally.
Read the articles by Dave Tate, Robertson, and Cressey. Also check out WSSB by DeFranco once you have read about methodology and exercise setups.
These articles have helped me immensely to become a more efficient and stronger lifter. Best of luck to you.
I agree with Bear that high schoolers are generally lacking in maximal strength and technique is paramount. The powerlifts can be good for this, but make sure to include full ROM leg (full squats for example), shoulder/arm (OH press), and back (chinups, facepulls) movements as well. A lot of kids in high school are just learning how to move with their newly growth-spurted bodies, so they should learn to be strong in all positions (the safe ones anyway).
Good advice on the articles too.
I completely agree with Mr. Bear. I also wanted to address the question about changing excercises every three weeks. There is no set "rule" that three weeks is the limit for accessory moves. However, the point is to change the excercises as our bodies, just like with anything else, will adapt and you will get to a point where you are not progressing with a movement anymore. So, changing things up is crucial but for some people that might mean three weeks for others it might be less or more. I typically change things up every 3-4 weeks.