In this era of fitness trackers, we have easy access to our heart rate at any given moment. Every so often, a number catches your eye as it flashes on your Garmin or Apple Watch while you're sitting ...
How can you calculate it? It's all about hitting different ... experts say you should be getting to 50% to 70% of your maximum heart rate. Intense or strenuous exercise is about 70% to 85% of ...