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.”

As a certified exercise physiologist, I’ve heard many stories like Chastain’s, and they’ve made me realize that we need to be doing a much better job at welcoming people of all sizes into movement without making assumptions about them.

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.

[Why you should stop trying to lose weight]

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, 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.”

Larger folks are excluded from fitness marketing, other than the dreaded “before” picture. Fitness equipment, including bike seats and some apparel, is often not sized to fit larger people comfortably. “I’m training for my first Ironman race,” Chastain says, “and there’s only one wet suit that fits my body. While I can find workout gear in my size, many folks larger than me cannot, and everything is in basic black.”

Those who have persevered and managed to build up serious fitness routines have said they are tired of always being seen as a beginner who should only be on the elliptical machine to lose weight, when they might be able to do more challenging weightlifting moves than thinner exercisers. 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.

Wherever the negative messaging comes from, people internalize that stigma, which can lead to exercise avoidance or overtraining. Instead of seeing weight as a problem, consider that weight stigma poses a bigger threat to developing long-term exercise routines.

How to help

Everyone can reduce weight stigma by reducing body shame. Start by treating all exercisers the same, and don’t assume anyone’s goal is weight loss. Reinforce a positive, self-care mind-set, especially when someone shares any kind of frustration with past exercise experiences. An empathic “I’m sorry that happened to you” can go a really long way in offering support. Keep in mind that even a small show of respect can make a big difference.

Fitness professionals should provide a plan that’s safe, interesting and sustainable, with a focus on building strength, stamina and flexibility. And a crucial part of showing people they belong in fitness is visibility. A fellow trainer once told me that she should quit because she was too big to be taken seriously by clients and peers. I disagree. I think her presence is necessary and the fitness industry needs to hire a more diverse set of trainers, coaches and weight-inclusive professionals to create a true culture of wellness.

“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.”

Rebecca Scritchfield is a District-based dietitian, certified exercise physiologist and author of the book “Body Kindness.”