75 Hard fitness challenge draws expert warnings as toned-down versions gain traction

An extreme, all-or-nothing fitness regimen is going viral again as millions seek rapid weight loss and mental toughness through its relentless daily rules. But as health experts warn the intensity may be unrealistic for many people, lighter versions of the challenge are also picking up steam.

Fueled by social media buzz and dramatic celebrity transformations, the viral 75 Hard challenge, created in 2019 by entrepreneur and podcaster Andy Frisella, requires participants to follow a rigid lifestyle regimen "without compromise."

The rules include two 45-minute workouts each day — one outdoors — a strict diet with no cheat meals or alcohol, a gallon of water daily, 10 pages of nonfiction reading and a daily progress photo. Miss a single task in the 75 days, and the challenge resets to day one.

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"The mental changes are 100x greater than the physical changes," Frisella says on the challenge’s website. "This isn’t another temporary Band-Aid program," he promises.

Supporters say the program builds discipline and accountability and has given many participants a clean slate at the start of the new year.

Experts, however, warn that extreme doesn’t always mean effective, especially for long-term weight loss and health.

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"Any program that promises weight loss needs to take you into a calorie deficit," said Dr. Milica McDowell, a Montana-based exercise physiologist and doctor of physical therapy. "If you are burning more calories than you are consuming, yes, you will lose weight."

But she cautioned that the results often don’t last.

"The challenge with the 75 Hard workout is that when you stop doing it — which would mean burning fewer calories — and you do not change your eating and drinking behaviors, it is likely that whatever weight you lost during the challenge will come right back," McDowell told Fox News Digital. 

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"I do not consider this to be a sustainable way to lose weight," she said.

The Cleveland Clinic also says the program’s rigid, two-a-day structure may do more harm than good for people without a strong fitness base, particularly those with chronic medical conditions. Even drinking a gallon of water a day may be excessive for some people, depending on body size and health needs, it notes.

Medical professionals also urge caution for people with joint or heart problems, no exercise background, a history of eating disorders, or already demanding schedules.

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For those drawn to 75 Hard’s structure, experts suggest modifying the program to suit individual needs.

Variations like "75 Medium" and "75 Soft" have emerged that dial down the intensity with fewer workouts, more relaxed diets and simpler habit targets designed to be more sustainable.

"A softer start lowers the activation energy for behavior change [and] reduces all‑or‑nothing thinking," Fatima Cody Stanford, an obesity medicine physician scientist at Massachusetts General Hospital and Harvard Medical School, told USA Today.

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The approach can reduce the risk of injury, exhaustion and people quitting altogether, Stanford said.

"I think people are realizing it's OK to be gentle with yourself," Morgan Manning, a 26-year-old media and marketing professional from New York City, told USA Today. 

Her TikTok video announcing she was trying the "soft" version received over 60,000 views.

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"These versions feel more human," said Jesse Ramos Jr., a certified personal trainer and owner of BBT Fitness NYC. "They allow people to build discipline without burning out, getting injured or hating the process," Ramos told Fox News Digital.

"Fitness shouldn’t feel like punishment," he added.

Experts agree that consistency matters more than intensity when it comes to long-term weight loss and health.

Robin DeCicco, a certified holistic nutritionist from New York City, previously told Fox News Digital that she encourages clients to focus on sustainable habits like simply moving more, eating more whole foods and drinking more water than they were before, rather than following rigid rules.

"Healthy habits that change into long-term behaviors are what make people healthier into the future," DeCicco said.