75 Hard vs 75 Soft vs your own 90 days

Three formats, one honest question: which set of rules will you still be following in week nine?

This page lays out what each one actually asks, where the rules come from, and what health professionals have said about the strict end of the scale. Everything factual is linked at the bottom.

75 Hard, as written

75 Hard is a fixed, single-author program. The official rules are five daily tasks, every day for 75 days:

• Follow a diet "geared toward YOUR GOALS", with "zero deviations, zero excuses, zero alcohol, and absolutely NO CHEAT MEALS".
• Two workouts a day, each a minimum of 45 minutes, and they must be at least 3 hours apart. One of the two must be outdoors, regardless of weather.
• Drink a gallon of water — a US gallon, 3.79 litres.
• Read at least 10 pages of non-fiction or educational material. Audiobooks explicitly do not count.
• Take a progress photo.

And the rule that defines it: miss any task, at any point, and you start over at day 1. In the official wording, it doesn't matter whether you're on day 2 or day 74.

Two details people get wrong. First, the 3-hour separation between workouts is part of the rules, not an interpretation — two sessions back to back don't satisfy it. Second, the program is explicitly not sold as a fitness challenge: the official page calls it a mental toughness program in capital letters. Weight loss is a side effect it doesn't promise.

Worth knowing if you're naming anything: 75 HARD is a registered US trademark of 44Seven Media, LLC (reg. no. 6176864, registered October 2020).

75 Soft, as it spread

75 Soft has no owner, and that turns out to matter.

It was posted to TikTok in April 2021 by Stephen Gallagher, an Irish fitness coach, whose framing was direct: "It's like the 75 Hard but for people who don't have time for two 45-minute workouts a day."

The most commonly published version, as Cleveland Clinic lists it:

• Eat well in general, and avoid alcohol except on social occasions.
• Exercise 45 minutes a day, with one day of active recovery each week.
• Drink 3 litres of water a day.
• Read 10 pages of any book — fiction counts.

And the structural difference, in Cleveland Clinic's own words: "If you miss one of these steps, take a break or try out an alternative approach — you don't have to start over."

Here is the catch nobody mentions. Because there is no official 75 Soft, published versions of the rules disagree. INTEGRIS Health, for instance, describes it as 45 minutes of exercise four times a week, up to three alcoholic drinks a week, and water measured as half your body weight in ounces. That is a materially different challenge from the Cleveland Clinic version, and both are presented as "the" rules.

So 75 Soft isn't really a program. It's a genre. Which is fine — as long as you write down which version you're doing before day 1, because otherwise the version you're doing will quietly become whichever one you managed that week.

Side by side

What health professionals have said about the strict end

None of this is an argument against being disciplined. It is what named clinicians have actually said when asked about 75 Hard specifically.

The water

Bethany Doerfler, a senior clinical research dietitian at Northwestern Medicine, told CNN plainly: "I do not recommend drinking this much water," warning of a risk of electrolyte imbalance, sodium in particular.

The arithmetic is easy to check. A US gallon is 3.79 litres of drinking water alone. The National Academies' guidance sets adequate total water intake — from all beverages and food — at about 2.7 litres a day for women and 3.7 for men, and notes that most healthy people meet their needs by letting thirst guide them. The NHS suggests 6 to 8 glasses of fluid a day, counting tea, coffee and milk. So the gallon rule asks you to drink, in water alone, more than the total-intake figure for either sex.

The training volume

Dana Santas, a certified strength and conditioning specialist who works with professional sports teams, in the same CNN piece: "The 75 Hard structure far exceeds the recommendations and doesn't provide any individualized guidance or programmed recovery." She points at overuse injuries, excessive fatigue and burnout as the predictable results of unclear intensity guidance combined with zero recovery days.

For scale: 75 Hard mandates 90 minutes a day, seven days a week — 630 minutes. The CDC's baseline recommendation for adults is 150 minutes of moderate activity a week plus muscle strengthening on two days.

The all-or-nothing rule

Matthew Sacco, PhD, a sports and performance psychologist at Cleveland Clinic, on the restart rule: "None of us are perfect, and the idea of being perfect, even for something like 75 days, is very difficult." On the toughness framing: "It speaks to this idea that we're supposed to be able to suck it up… But that's not a good long-term philosophy."

Doerfler goes further on the same rule, saying it "can contribute to binge eating, disordered eating patterns, negative body image and negative self-talk."

Katy Milkman, professor at Wharton and author of How to Change, adds the behavioural-science version: "The more friction you put between someone and execution of a habit the worse it is in terms of habit formation."

The daily photo

Sacco is the one clinician on record about this specific rule: daily progress photos can feed self-esteem and body-image problems, and he notes that physical changes "can take far more than just simple willpower" — meaning the photo often documents an absence of change for weeks, to someone who is looking hard for one.

Whether any of it is proven

There is no published controlled trial of 75 Hard. Cleveland Clinic's position is that there is little to no scientific evidence behind it and that the success stories are anecdotal. Dr. Milica McDowell, an exercise physiologist and doctor of physical therapy, told Fox News she does not consider it a sustainable way to lose weight, because when the 75 days end, so does the behaviour. In the same piece, Dr. Fatima Cody Stanford of Massachusetts General Hospital argues that softer versions reduce all-or-nothing thinking and lower the activation energy for change, cutting the risk of injury, exhaustion and quitting.

What the habit research actually says

The number everyone quotes comes from a real study: Lally, van Jaarsveld, Potts and Wardle, How are habits formed, European Journal of Social Psychology, 2010. Volunteers performed a chosen behaviour daily for 12 weeks. UCL, the authors' own institution, summarises it: on average it took 66 days for the habit to form, with individuals ranging from 18 days to a projected 254.

Two caveats that popular retellings drop, both noted in this review of the paper. First, the 66-day figure is a median across the subset of participants whose data actually fitted the expected curve — around half didn't. Second, and more awkwardly for every restart rule ever written: in that data, a single missed day reduced automaticity by less than half a point, and scores recovered quickly.

There is also evidence that rigidity itself is the problem. Westenhoefer and colleagues (2013) followed 106 women over six months and found that flexible restraint was associated with more weight lost and better maintenance, while rigid restraint was associated with less weight lost and with attentional bias toward food and body-shape cues.

So what should you actually do

Take the honest reading of all of the above: no format is validated, and the strictest one has the most named clinicians raising their hands. Which means the choice between 75 Hard, 75 Soft and your own 90 days is not a choice between a correct answer and two wrong ones. It is a choice about which set of rules you will still respect at 23:40 on day 51.

Design it yourself and you get three things the branded formats can't give you: rules that fit your job and your knees, exceptions written in advance instead of invented under pressure, and no obligation to pretend a stranger's water target is medicine.

What you don't get is someone else's authority to hide behind. That's the whole trade.

Which brings us to the position this site actually holds, and we'll state it plainly even though it undercuts our own strictness: the format matters far less than whether you negotiate with yourself. Two workouts or one, a gallon or three litres, 75 days or 90 — none of that is what breaks people. What breaks people is discovering, on a bad Tuesday, that the rules were always negotiable, and that the person doing the negotiating is also the person who wants to go to bed.

Our own restart rule is strict, and you have just read a body of research that doesn't obviously support it. We keep it anyway, for a reason that has nothing to do with habit-formation curves: a rule you can reinterpret isn't training anything. But we'd rather you knew what the evidence says than found out later that we'd skipped it.

Write the rules once, while you're rested and honest. Then stop having the conversation.

If you want to see exactly how that plays out in the awkward cases — half a habit, a forgotten log, a sick day, a flight across time zones — that's what the restart rules page is for. And if you want a tool for your own 90 days, Snurko is a one-screen, free and open-source app that does the counting and nothing else; it launches in January.

Sources

• Andy Frisella, What is 75 HARD? and the 75 HARD program page — official rules and framing.
• USPTO registration 6176864, 75 HARD, 44Seven Media LLC — record.
• TODAY, via Yahoo, What is the 75 Soft challenge? — origin and Stephen Gallagher's quote.
• Cleveland Clinic, What Is the 75 Soft Challenge? — the most-cited ruleset.
• INTEGRIS Health, How to implement the 75 Soft challenge — a materially different ruleset.
• CNN, Should you try the 75 Hard challenge?, March 2026 — Doerfler, Santas and Milkman quotes (syndicated copy).
• Cleveland Clinic, The 75 Hard Challenge — Matthew Sacco, PhD.
• Fox News, 75 Hard challenge promises weight loss — McDowell and Cody Stanford.
• National Academies, Dietary Reference Intakes for water; NHS, Water, drinks and your health.
• CDC, Physical Activity Guidelines for Adults.
• Lally, van Jaarsveld, Potts & Wardle (2010), How are habits formed, Eur. J. Soc. Psychol. 40(6), 998–1009; UCL summary; review of the study's caveats.
• Westenhoefer et al. (2013), Cognitive and weight-related correlates of flexible and rigid restrained eating behaviour, Eating Behaviors 14(1), 69–72.