Working out indoors can be uninspiring: the fluorescent lights, the gym playlist running on loop, the same view every day. For a change of scenery, head to your local park for this equipment-free, full-body workout. All you need is a bench and a patch of grass. “We tend to be so serious about workouts in our adulthood, viewing them as a ‘have-to-do’ versus a ‘get-to-do,’” said Nikki Fraser, an exercise physiologist in Toronto who has led outdoor fitness classes for 20 years.