TCW illustrated field note · 05
4 × 4 cardio, clearly explained
One interval structure. Several ways to move.
The guide, in text
01 · Warm up
10 minutes of easy-to-moderate movement.
02 · Work
4 minutes at a challenging, controlled effort. This is not an all-out sprint.
03 · Recover
3 minutes of easier movement between work intervals.
04 · Repeat + cool down
Complete four work intervals, with three recovery intervals. Finish with 5 easy minutes. Total: 40 minutes.
Choose your equipment
Incline walking, a stationary bike or a fan bike can use the same timing. Match effort to fitness; machine settings are not interchangeable.
Build toward it
This is vigorous exercise, not a required starting point. Begin more easily if you are new; discuss suitability if you have symptoms or a medical condition. Stop for chest pain, dizziness or severe breathlessness.
Sources + context
Source review: September 2026. Illustrations explain concepts; they do not verify products or replace individualized advice.