title: Friends and Groups Matter When it Comes to Leisure-Time Physical Activity.
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D033062:Friends / Q000523:psychology*; D006126:Group Processes; D006306:Health Surveys; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009519:New York City; D012945:Social Values; D013177:Sports / Q000523:psychology*