Coach David Roche's advice for how to find and set your heart rate zones for heart rate based trail running training.

The year 2025 is a “perfect square year” because it’s the product of a number multiplied by itself – 45×45=2025, a phenomenon ...

Optical illusions challenge eyes and brains with hidden numbers in complex patterns. This test features a 6-digit number blended into colorful swirls, exploiting visual perception tricks.

Here are 25 of my favorite products, plus some tips and tricks, to help get you started with journaling — but remember, there’s never a wrong way to do it.