Amazon.com : PYHIGH Indoor Cycling Bike Stationary …

Basically I used my Polar H7 heart monitor chest strap (for Android) and paired it with the Polar Beat application. As you can see I started the workout in the blue warm up zone. The app computes your maximum heart rate based on the “220 minus your age” formula. So if you’re 30 your standard maximum heart rate is 190 beats per minute (bpm).

https://www.amazon.com/PYHIGH-Cycling-Exercise-Stationary-Training/dp/B07BSBBZPJ