Definition: Walk-working is using a treadmill with a work station.

Over the years, Angela Leitner’s lower-back pain got so bad she could sit for only 30 minutes at a time. She had tried everything from steroid injections to physical therapy, but nothing worked. Her doctor told her she could have spinal fusion, but it would mean the end of an active lifestyle that once included running.

Leitner, 29, had another idea. She went for a walk.