Sentence 1: John went to a new gym to work out. 
 Sentence 3: A pretty girl was on the treadmill 
 Sentence 4:  John lifted more weight than he ever had before 
 Sentence 5:  John was sore for a week afterwards! 
 Option 1: The gym only allowed men. 
 Option 2: He hadn't exercised in a long time and wanted to ease his way back in.