From Japanese walking to 75 Hard: what the science really says about viral fitness trends

YAKOBCHUK VIACHESLAV/Shutterstock

If TikTok fitness advice is to be believed, you should be interval walking like the Japanese, hanging from a pull-up bar every day and committing to a 75-day challenge with no rest days.

Some of these trends are grounded in scientific research. Others are built on shaky claims or misunderstandings of how the body actually adapts to exercise.

Social media has made fitness advice more accessible than ever. But a review has raised concerns about the accuracy and quality of online fitness content...