Here’s an interesting excerpt from Supertraining which I dug out…
“Special attention must be paid to the prescription of general heavy resistance exercises. They enable the athlete to reach the necessary level of absolute strength, to provide general physical conditioning and to train the neuromuscular system non-specifically. However, it is undesirable to use them extensively during specialised training phases, since they can diminish speed and explosiveness. High volume strength loads used after a phase of specialised jump training can substantially reduce the existing level of explosive strength.”
The key here to note is “specialised training phases.” Maximal strength is key for nearly every athlete, since your explosive strength will never equal that of your maximal strength- eg, you’ll never jump squat what you can squat. However, if speed training is entirely neglected, there may be a drop in explosive strength. Early in the offseason this may be an option as there is plenty of time to regain and increase explosive strenght to a higher level before competition.
Basically, to me it very much argues for the conjugate or complex methods of periodization where everything is trained at once with varying emphases.