People tend to check in during these times:
Club One at Embarcadero's 13,500 sq. ft. facility offers award-winning amenities, supportive staff, and motivating programs conveniently located at the Embarcadero Center.
SF Weekly's Best of Winner 2012 - Reader's Poll - BEST GYM
Jim's spin class at 6am is awesome.
Get there before 6p and enjoy the place almost to yourself.
Take a yoga class with Terry! Tuesdays at 4:30.