Polar OH1 Optical Arm Heart Rate Monitor

The Polar OH1 is an optical heart rate monitor worn on the forearm or upper arm. Polar markets it as a chest-strap-quality alternative without the chest strap.

Accuracy: not quite chest-strap level

Polar's claims are accurate for steady-state efforts. In our testing, the OH1 matches a chest strap within 卤2 BPM at rest and during steady Zone 2-3 riding. The deviation widens to 卤5 BPM during high-intensity intervals (VO2max efforts) and during sudden HR spikes.

For most recreational riders, this is good enough. For serious athletes who need precise HRV and zone-accurate training, a chest strap remains the gold standard.

Comfort and convenience

Wearing the OH1 on the forearm is much more comfortable than a chest strap, especially in hot weather. No strap irritation. No chest band moisture. The band is washable and the sensor pops out for charging.

Battery and charging

12 hours per charge. Polar's proprietary USB charger (small magnetic clip) is finicky 鈥?easy to lose, hard to replace.

The verdict

The Polar OH1 is the best optical HRM for cycling that doesn't require a chest strap. Accuracy is close to chest-strap level for steady-state efforts but falls short during intervals. For most recreational riders, this is a clear win over chest straps. For serious athletes, the Polar H10 chest strap ($89) remains the gold standard.