If you’re talking about long term working out, motivation will not cut it. It has to be determination/making it a habit. Like - “Time to take a shower”, “time to workout”.

But working out doesn’t mean you have to push yourself till you feel like puking. Start small, do 10 squats at lunch and another 10 when you finish your work day for e.g… Do something you find fun, not something that’s just “well running is exercise so I guess I have to do that”