When i have long books--although i've never had a 1000 pg book

--- i just go till i feel tired & then close my eyes and do some deep breathing & releasing any tension i might feel in the shoulders. Then i just start up again from that point.
You could probably do 500 pgs w/o any hassle. Then take a 5 minute break & then do the next 500.
With that many pages, i'd really make it a point to listen to MS paraliminal before sleep.
good luck & be sure to ask very clear questions on that material so you can get to needed info faster.