Tag: cardio exercise

By Jenna Carrow 11 December 2025

What Is the 321 Rule in Fitness? A Simple Guide to Balanced Workouts

The 321 rule in fitness is a simple, science-backed routine: 3 days of strength, 2 days of cardio, and 1 day of active recovery. It’s perfect for beginners and busy people who want lasting results without burnout.