When Ragen Chastain set the Guinness World Record for the heaviest woman to complete a marathon, she said she hoped her record would soon be broken "to increase visibility of what larger people can do."

As a self-identified "fit fatty," Chastain is an advocate for the rights of people to engage in physical activity at any size. She and a growing number of others are shedding light on ways in which our society upholds barriers to movement among the overweight and obese. 

"Fat people have to endure unwelcomed comments, judgments and exclusions that can discourage our participation in fitness," says Chastain, who weighed 288 pounds when she set the record in 2017. "We should be able to work out without being body-shamed." 

Many folks who eschew regular workouts have said they are really avoiding the recurrence of painful past experiences, such as fellow gym-goers blatantly mocking them, trainers saying their physical efforts weren't good enough and street harassment for simply taking a walk outside. One new mother described to me her wonder that the glares she experienced ceased only when she had a newborn in tow. 

The prevailing myth about overweight and obese people is that if they just worked harder, they would become thin, but that's actually not a typical outcome. Jennifer Kuk, a kinesiologist and associate professor at York University, says, "Weight management science is very complex, and much of how the body responds to weight-loss attempts is outside human control." 

On any typical day, higher-weight people may have to put extra emotional labor into getting mentally prepared to take on our appearance-driven fitness culture. Even a locker-room comment of "I've seen you here a few times. Keep up the good work!" can feel condescending. 

In the age of "tough love" training ushered in by the likes of Jillian Michaels and "The Biggest Loser," most of the professional fitness industry has rendered itself ill-equipped to truly provide what many people at higher weights desire, including modifications; diverse, enjoyable training plans; and goal-setting outside of weight reduction. 

Louise Green, a personal trainer and author of "Big Fit Girl," thinks the fitness industry needs an overhaul at the education level.

"Often, modifications aren't offered because there's a lack of understanding as to when one may be needed," she says, "like loading the knee joint in lunging or prescribing exercises that require the client to get up and down off the ground, paying attention to wrist pressure in body-weight exercises, and sensing when body weight is a sufficient load."

Higher-weight runners complain that running stores assume they are there for walking shoes and the only clothing options that fit are hats and fuel belts. Even race events often limit participant shirts to sizes, only going up to extra-large.

"The single most important factor that needs to change is the systemic bias against higher-weight people," Kuk says. 

Chastain adds: "While it is not an obligation for anyone at any size to have to engage in physical activity, it's important progress to create spaces that welcome those who do for everyone's physical and mental health."