There are hundreds of different diets out there, and the internet is constantly coming up with new ones. Some are harmless and can genuinely help you get in shape, while others are unhealthy or even dangerous.
Recently, users have been actively discussing the 75 Hard Challenge. Thornhill Day takes a closer look at what this strategy is and what doctors think about it.
The Core Idea
The 75 Hard program offers a radical way to reset your life and change your habits. It combines physical exercise, diet, and intense discipline training.
The concept was introduced in 2019 by American entrepreneur Andy Frisella.
Here are the main rules of the program:
Follow “clean” eating and stay within your calorie target, with no cheat meals.
Drink at least 3.7 liters (one gallon) of water every day.
Complete two 45-minute workouts daily, one of which must be outdoors.
Read 10 pages of a non-fiction book every day.
Track your progress daily.
All rules must be followed for 75 consecutive days. If you break even one rule, you must start over from day one. Alcohol is strictly prohibited, and the conditions of the program cannot be changed.
Some participants add extra rules. For example, they wake up at 5 a.m., or stick 75 notes on the wall and remove one for each successful day.
The expected outcome? Over 75 days, participants are supposed to build discipline, form new healthy habits, improve physical fitness, and lose weight.
People who have tried the program admit that following such strict rules is extremely difficult. But according to the creator, that’s exactly the point.
“There are never perfect conditions in life. You will always have to do things you don’t want to do,” Frisella has said.
What Experts Think
On social media, many people claim that the program completely changed their lives, and some are happy with the results. However, experts warn that the trend has some serious drawbacks.
First, 75 days is a relatively short period. Most people will notice some results if they follow strict rules, but major changes take time. Weight loss isn’t always fast, and building significant muscle mass in this timeframe is unlikely.
There’s also a high risk that once the challenge ends, people will revert to old habits as work, social life, and family responsibilities take over. The program doesn’t allow for a gradual transition, making it difficult to integrate these habits into everyday life long term.
Fitness trainer Emma McCaffrey notes that the program can be especially dangerous for beginners and for women over 40. For these groups, it may lead to burnout or injury.
“Real, sustainable transformation doesn’t happen in 75 days. It happens through gradually increasing load on your own terms — in a way that’s healthy and realistic for your life,” she explains.
The program also offers no rest days, increasing the risk of injury and exhaustion, according to Daily Mail.
“Without rest days, the body can’t repair microtears in muscle tissue, which can lead to chronic fatigue, tendinitis, or stress fractures rather than strength gains,” McCaffrey adds.
Experts are also concerned about the hydration rule. Trainer Rachel Sacerdoti says that most people don’t need to force themselves to drink that much water.
Negative reviews are already appearing online. Irish blogger Aoife Claussen shared that she was hospitalized last year while attempting the challenge — her body gave up on the third day.
