On a recent Sunday night, Liz Paul was tired. She'd worked in the morning, spent a full day with her family and she did not feel like going out for her daily jog.
"I tweeted out, 'Well, it's 9 p.m. on Sunday and I didn't work out,'" she says, "I really shouldn't go run in the dark should I?"
The response was immediate. The network of people Paul is relying on to help in her battle to lose weight chimed in with advice. Some tweeted back, "Yes, get out and run." Others offered alternatives like a video workout.