When my motivation disappears, i still keep pushing myself to get to the gym. Once you’re there, you know there’s only one thing to do and that is train.
Your thoughts become focused on the workout instead of drifting somewhere else. When I feel like my motivation is completely off, i try not to overthink it. I just push myself to get to the gym and take it from there.
Every time i’ve done that, it has worked out well, and the motivation always comes back.