Polar is known worldwide for their precise heart rate monitors. Scientific studies use Polar equipment to accurately measure heart rate. That is why Polar wearables are suitable choices for athletes who value heart rate measurements. With Polar sports watches, you measure your sports performance in addition to your heart rate and with Polar activity trackers, you mainly measure your daily activities. Although the heart rate monitors of Polar sports watches are good, a heart rate belt is always more accurate. For a very accurate measurement, you pair a sports watch and a heart rate belt.