Struggling to stick with an exercise routine? New US research suggests that, just as when faced with challenges in other aspects of life, whether or not you can overcome obstacles in your workout regime could boil down to confidence.

"Almost 50 percent of people who begin an exercise program drop out in the first six months," said University of Illinois kinesiology and community health professor Edward McAuley, who led the research. His assumption? A lack of a quality he refers to as "self-efficacy," or "situation-specific self-confidence."