Instagram fitness stars are becoming ubiquitous.

Without even needing their own gym, these trainers manage to cultivate enormous followings.

But that might come at a cost.

One of New York’s most well-known trainers spoke to Business Insider about the possible dangers of jumping on board with an Instagram fitness plan.

“There’s a lot of misinformation,” David Barton, who famously had his own chain of gyms (though he is no longer associated with them, for reasons he won’t disclose) and currently runs the New York City-based TMPL, recently said to Business Insider. “Now, with social media, there’s even more.”

“I think it’s a great thing and a terrible thing,” he said. “It’s great that people get inspired. I think if somebody can get inspired to exercise that’s fantastic.”

One problem is that Instagram stars can look great in photos for myriad reasons.

“I think seeing somebody who looks great and looks great because of a million factors — one of which [may be] they may just have looked great before they ever stepped into a gym because of their genetics,” he said.

“”I may not know what I’m doing teaching you and it works for me [and I] haven’t hurt myself’,'” Barton said, speaking as though he was someone who might be a social media fitness star. “‘And I chose the right parents so my shape is dynamite.'” He said that what some of these people on Instagram are doing may not be safe, but it works — as in, some people see results —  because they’re working out with intensity. (Too -intense workouts have also been subject to criticism).

“There are some popular fitness trends people are getting hurt doing,” he said. He said that some people doing certain exercise programs and look great doing it, “because they are one in 100 [people] who are not predisposed to injury doing this thing. The other people, though, “they’re now not exercising because they’re home icing their knees.”

Barton’s not the only trainer to speak out against the dangers of social media. When Business Insider spoke to Kelly Ripa’s trainer, Anna Kaiser, earlier this year, she warned of similar problems, pointing to how some of these trainers do not even have credentials.

It’s impossible to ignore, though, the positive sides to Instagram fitness: it’s gotten people to be inspired about fitness, and as BeachBody CEO Carl Daikeler told Business Insider earlier this year, it makes people accountable. Celebrity trainer Autumn Calabrese of the popular 21 Day Fix diet and workouts also said how it’s helped cultivate community, inadvertently making for a savvy and subtle marketing tool.

“Social media has kind of made it easier to come together,” she said to Business Insider in an April interview. “I think that they say, ‘ misery loves company’ and — not that it’s miserable to work out and — well, maybe it is for some people —  but the fact that they have other people to hold them accountable and to say like, ‘great job,’ ‘did you push play?,’ way to get those work outs done!,’ and they have other people that they can share those results with and other people cheering them on — it sells the product itself.”

So, yes: Instagram can be an excellent marketing tool. Look no further than emergence of trainers like Kayla Itsines, of the Bikini Body Guides and Sweat with Kayla app, who has well over 5 million followers and the most profitable fitness app of the past year, and the slew of similar Instagram trainers like her: Anna Victoria and her Fit Body Guides, Karena Dawn and Katrina  Scott of Tone It Up. 

Additionally, Barton is aware that there is a lot of good information out there — it’s just that it all gets jumbled together.

“So the thing about Instagram is it’s just not controlled. No one’s looking [and asking] ‘who is this person?'” He said. “There’s some experts out there but it’s hard for people to really know a[if they’re] listening to somebody with good information, is it based on science?”

It’s easy, though, to fall victim to photos of washboard abs, especially when people are looking for an easy fix to get similarly sculpted stomachs.

But unfortunately for people looking for a shortcut, he says, “there is not a magic bullet.”

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