new study (University of New England) compared group exercise to individual exercise, and found that while the solitary exercisers studied worked out twice as long, those doing a group exercise class experienced significant improvements in all quality of life measures: mental (12.6%), physical (24.8%) and emotional (26%), with a 26% reduction in stress levels. Solitary exercisers reported no significant changes in any measure, except mental quality of life (11% increase).