And people are creating their own spins on the challenge, trying gentler versions like 75 Soft and 75 Mom, or abbreviated versions (Earle, for instance, is in the midst of a 30 Hard challenge).

Emily Macek, 25, a category analyst in New York, first tried the 75 Hard Challenge as a way to manage her personal health.

Many of them test mental toughness, dedication and stamina, and the ever popular 75 Hard challenge is no exception. The #75HardChallenge hashtag has more than 1 billion views on the platform ...

This year, it’s the ’75 Hard’ challenge’ – with variations such as’ 75 Soft’ and ’75 Medium’ following closely behind. The 75 Hard challenge actually isn’t new at all.