Heart Rate for Fitness

Use these pages to calculate zones and plan aerobic training with practical intensity guidance.

Fitness + heart rate: a simple workflow

Pick a zone model, calculate a target range, and then validate it with perceived effort and real training outcomes.

Step 1: calculate zones

Use Karvonen (HRR) to get personalized targets from resting HR + max HR.

Step 2: validate with perceived effort

Heart rate is a helpful constraint, but hydration, heat, sleep, and stress can shift readings. Use it alongside how the workout feels.

Fitness HR FAQ

Q:Should I train by heart rate or pace?

Both can work. Heart rate is useful to control effort (especially for easy days). Pace is useful for planning structured workouts. Many runners use pace targets and keep HR as a guardrail.

Q:Why does my heart rate drift up during a steady run?

Cardiac drift can occur due to heat, dehydration, fatigue, or overpacing. Slow down and hydrate; for Zone 2, staying controlled is the goal.