I was being too aggressive with my rest periods. Today I remembered this quote from S&S:
"Rest long enough between sets to assure no drop-off in technical proficiency, get-up strength and swing power."
....
More relevant excerpts from S&S:
- "Once you are doing all the sets with a heavy weight, work on dominating it. Then slowly compress the rest periods."
- 'Remember Dr. Hatfield’s “cardio” training instructions to a power athlete: “an all-out effort... maximum contracture against submaximal resistance."'