Even as someone who loves exercise most of the time, I still totally believe in this approach to start/get out of a slump:

Make it an appointment that’ll cost you something if you miss it.

Book a class that’ll cost you a no-show fee. Make an exercise date with your most flake-intolerant friend. Join the almost-too-expensive gym if you can swing it and let your budget bully you into going. Tell your mom you’re going to FaceTime her from the walking trail and give her permission to express her grave disappointment if you bail.

You don’t win points for being the Most Intrinsically Motivated Exerciser. Just do whatever you have to do to get it done