I gave the 6-6-6 walking challenge a proper test, and the verdict splits in two: the number is arbitrary marketing, but the three things it quietly bundles together are exactly what the research says works

The 6-6-6 walking challenge has spread widely online, and it arrives wrapped in the usual promise of transformation in a matter of weeks. The fair way to judge something like that is not to try it for a viral seven days and file a verdict, but to give it a pr…