I have made excellent gains in the past from only working out once a week though for like 2 hours and it was mostly deadlifts and presses.I was the strongest those days,always wanted to get back into it but been lazy lol.
deadlifts 10x 6-8
military press 6x5-6
power cleans 6x5-6
db press 6x6-8
weighted pull ups 10x 3-4
curls 6 x8-10
I think I became soo efficiant at recruiting more muscle fibers and gained soo much strength that I became overtrained even from that once a week workout because of the intensity and volume,The next few days I would be toast but when I recovered I was at 100% and stronger.