I mostly workout alone but that's the reality of time management. If I had my way it would be with someone else. Time goes more quickly and on the days that I'm not motivated to walk, my workout partner, can give me a nudge.
I like David's post at davidadewumi.com:
"Partner Up: Find someone who is in (slightly) better shape that is going solo — or find a group of friends to train with. Coming together is a beginning. Keeping together is progress. Working together is success."
or
"Motivation = Decision before Action. A journey of a thousand miles begins with a single step.” –Lao...