Deload weeks for meditation I like to go to the gym and lift weights. If you do that you are recommended to take deload weeks where periodically you lift lighter weights or less frequently or both. It's meant to be very beneficial.

Could the same be said for meditation practice? Has any teacher / book recommended something similar? Could periodically taking it easy (less frequently or shorter sits) benefit the practice generally? The advice I've seen seems to be the opposite i.e. the answer to poor meditation is more meditation. That kind of thing hasn't worked for me in the past and has actually caused me to go from poor meditation to no meditation.

I do appreciate lifting weights and meditation are different though.
Tibetan lineage teachers usually say, meditation should be like spending time with a best friend. You meet joyfully, you spend time effortlessly, and you separate easily, knowing you can't lose each other and will meet again soon. 

Don't try to squeeze too much value out of that meeting, because you don't want to burden your friendship and turn it into a job.

When you turn meditation into a job your mind will secretly hate it. Instead, turn it into a vacation from all neuroses.