What is a Heart Rate Monitor (HRM)?

A Heart Rate Monitor tracks how fast your heart is beating. This data is essential for Heart Rate Zone training, ensuring you are training at the right intensity (e.g., easy enough for recovery or hard enough for VO2 max).

Types

1. Chest Strap: Worn around the chest. Detects electrical signals from the heart. Considered the gold standard for accuracy, especially during intervals.
2. Optical Sensor: Built into the back of most modern GPS watches. Uses light (LEDs) to detect blood flow changes in the wrist. Convenient but can be less accurate during high-intensity or cold weather runs.
3. Arm Band: An optical sensor worn on the bicep/forearm. A middle ground between chest strap accuracy and wrist comfort.

Why Use It?

"Running by feel" can be deceptive. An HRM gives objective data on your body's stress level.