Connect IQ app - Live Suffer Score gives you a second-by-second answer to a tricky question: How hard are you trying?
Strava analyzes how much time you spend in different heart rate zones and measures total activity effort with a simple rating: The deeper you dig, the longer you can hold on, the higher your Suffer Score.
Live Suffer Score is pre-installed on the Forerunner 735XTand works with all Connect IQ-compatible devices. And if you want to see your Suffer Score after your run is over and track scores over time, you better go Premium (https://www.strava.com/premium/analysis/suffer-score) – the ultimate Strava experience.
Be sure your Garmin and Strava heart rate zones are the same. Live Suffer Score requires a built-in optical heart rate sensor or a paired heart rate monitor.