Consistency is necessary for progress in almost anything!
If you're having trouble staying consistent, then it might help to practice "adaptive excellence." Aim high, but always appropriately. Listen to your body. Often, less is more. You don't have to run all the time. Run-walk builds fitness too.
Consistency is not so much a physical challenge as a mental one. The brain rules all. It's not your calves that will get your body moving. It's your thoughts.
Stay the course, my friend. Run long and run healthy!
My run today :-)