Look into the review mirror when you’ve started and stopped following workout routines. What were the obstacles, issues or problems you rammed into that made you stop? Both temporarily and for good.
There’s likely a reoccurring obstacle that keeps terminatoring your efforts. Getting injured or ill, not having time, work, kids, free Margaritas…
What actions would reduce the chance of that same obstacle blocking your path next time?
You might not be able to eliminate the obstacle. But perhaps you can prepare for it.