Estimated Maximum Heart Rate Is a Starting Point
The American Heart Association gives an estimated maximum heart rate of roughly 220 minus your age. For a 30-year-old, that is about 190 bpm. Individual differences mean it should not be treated as the same as a maximum measured through testing. If you have heart disease or take medication that affects your heart rate, ask a healthcare professional about your target range.
Start by Distinguishing Moderate- and Vigorous-Intensity Ranges
A general reference range is about 50–70% of estimated maximum heart rate for moderate-intensity exercise and about 70–85% for vigorous-intensity exercise. Many exercise apps divide these into five zones, but the boundaries and names vary by service. Do not assume that the name “Zone 2” represents the same intensity everywhere.
Use the Talk Test Alongside the Numbers
During moderate-intensity exercise, you may breathe and have a faster heartbeat but still be able to talk, although singing is difficult. At vigorous intensity, it is difficult to say more than a few words without pausing to catch your breath. If your device reading is very different from usual, slow down and first check the sensor fit and how your body feels.
Lower Zones Can Also Help With Weight Management
At low or moderate intensity, fat may account for a higher proportion of the energy used during exercise. That does not mean your body only uses fat after exercising in a particular zone for more than 30 minutes. Changes in body weight are influenced by overall activity, diet, and sustainability together.
High-Intensity Intervals Are Not a Fixed Prescription
There is no single correct answer for the duration and number of repetitions in interval training, which alternates between high-intensity and recovery periods. If you have limited exercise experience, build a foundation with walking or light aerobic exercise first, then add short high-intensity intervals. Do not try to reach a target heart rate by pushing through pain or unusual symptoms.
Compare Measurements Under the Same Conditions
You can count your wrist pulse for 30 seconds and multiply it by 2 to convert it to beats per minute. Wearables can be inaccurate depending on movement, skin contact, and device type. Compare trends during the same exercise in similar conditions, and do not interpret a single reading as a medical diagnosis.