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The 75-day challenge, explained

A 75-day challenge is a fixed set of daily habits you repeat for 75 days straight. Three versions dominate: 75 Hard, the strict original; 75 Soft, the sustainable one; and 75 Medium, the community middle ground. This guide covers what each actually requires and where their rules disagree.

Last updated 2026-08-16 · Glow75 editorial

The three versions at a glance

Rule75 Hard75 Soft75 Medium
Workouts2 × 45 min, one outdoors1 × 45 min, one recovery day a week1 × 45 min, no rest days
Water1 US gallon (3.8 L)3 litresHalf your bodyweight in oz
DietAny structured diet, followed exactlyRoughly 90% healthy eatingYour plan, on 90% of days
AlcoholNone for 75 daysSocial occasions onlyUsually limited, not banned
Reading10 pages non-fiction, physical book10 pages, any book10 pages, any book
PhotoEvery dayDay 1 and day 75 (common variant)Every day
If you slipRestart at day oneKeep goingKeep going, hold 90%
AuthorAndy FrisellaStephen Gallagher, April 2021No single author

Which one to pick

The honest filter is not how disciplined you are — it is what your next eleven weeks look like. Open a calendar and find the trips, weddings, deadlines and birthdays that fall inside the window, then choose the version whose rules survive them.

The failure mode nobody warns you about. Most people do not fail a 75-day challenge on willpower — they fail it on arithmetic. Two 45-minute workouts, a gallon of water and ten pages is roughly two hours a day, every day, for two and a half months. If those two hours do not exist in your week right now, the version that fits is the one you will still be doing in October.

Where the published rules disagree

None of these challenges has a governing body, so “the rules” means “the rules as most commonly published”. That matters more than it sounds, because the versions have genuinely drifted:

On each page we say which version we are describing and where it came from, rather than presenting one retelling as canon.

The seasonal one: the Winter Arc

From October the 75s get a rival. The Winter Arc runs from 1 October to New Year — roughly 90 days — and inverts the format: instead of five rules someone wrote for you, you write three to five of your own and hold them while the year winds down, entering January ahead instead of starting there. No restart clause, no owner, a different bet entirely — the comparison is in Winter Arc vs 75 Hard, and there is a neat trick for running both: 75 Hard started on 18 October finishes exactly on New Year's Eve.

How these pages are sourced

75 Hard rules are reported as published by the program itself, which describes it as a mental toughness program and not a fitness challenge. 75 Soft is attributed to its creator with the date it appeared. Where a rule is contested, we say so instead of picking the version that makes a neater table. Glow75's own Home Edition plans are adaptations, and they are labelled as adaptations wherever they appear.

These are not medical guidelines. Both of the demanding versions involve daily training with no rest days and a fixed water target, and neither was designed around your health history — the footer disclaimer on every page is there for a reason.

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