Principle of Training Specificity
Train the way you play. Lift fast and explosively for maximum carryover to explosive athletic movement. Every rep should be as fast and explosive as possible.
Getting super strong and grinding out big weights will make you good at just that being strong but slow. Training at higher percentages or at high RPEs or reps left in the tank will necessitate a slow down in bar speed will negatively impact explosiveness.
Also related to specificity of training your exercise selection is vital: what you neglect is as important as what you work on. Powerlifting is fun but the bench does not carryover to sprinting much. Inherently explosive movements like the power clean, clean and jerk, snatch, kettlebell swing etc. are perfect for you.
Excessive upper body mass does little for you. It’s just more weight to be accelerated. Force = Mass x Acceleration. Therefore adding non functional mass on randomly without improving force generating capacity leads to poorer performance in explosive movements.
Greater muscle mass has the potential for greater force production potentially resulting in increased power output or explosiveness. This does not happen by itself and is no guarantee like the example above where you get stronger but slow so you are unable to potentiate force production into power. You must actively drive this process.
To this end you should always be programming in sport-specific power work. I use the word programming because, as you’ve experienced, if you’re stupid with the volume/frequency you can end up injured. Explosiveness is a trait and should be trained as seriously as strength if not more so.
Like sport specific power work, technique in sprinting with and without the ball, change of direction/deceleration, jumping etc. should be a staple of your training. Good technique equals running faster and jumping higher. Bad technical equals inefficient running and jumping nowhere near your potential performance.
Probably hire a specific coach for athletic performance or football and stop talking to powerlifters unless you want to be pro in powerlifting too. Maybe bench less and sprint more. Maybe spend more time on the field than in the gym than you are currently doing. Throw in some power cleans.
Good luck Comrade
