I haven’t read all the responses, but the last one from Jill rings true for me too. I think we’re all somewhat hardwired for certain things in life. A person’s preference or ease with particular times of day has a lot to do with his/her biology, body rhythms, hormones, personal and professional schedules and demands, etc…
That said, if you truly have no other time to run, then you might want to consider doing it in the morning. It doesn’t mean you’ll be able to convert yourself to a morning person, but you will get your workout in…I would hope some of those helpful endorphins would kick in for you!
Now, if you find yourself fighting all sorts of negative self-talk, why not consider something that is not so intense or time-consuming first thing in the morning? Maybe a short yoga or muscle conditioning routine, like 15-20 minutes in the morning, and a run some other time?? You may need to experiment with different activities and times before you find the combination that works best for you.
I guess you have to find within yourself a compelling reason to rise early and exercise.
Behavior change is possible. It’s challenging but possible. No offense intended with the following statement, however, it is not as though you are trying to change a behavior that requires a clinical approach.
Write down on a piece of paper the pros and cons of rising early and exercising and ask yourself whether the manner in which you are approaching engaging in physical activity is effective.
If you find that it is not, then, I would set a goal of a maybe getting up early in the morning, let’s say 15 earlier and start with stretching. Make that a habit and build from there.
I hope this is of help to you.