Fitbit Has Finally Solved the Cardio Problem.
Cardiovascular fitness has received a significant upgrade in the new Fitbit app, which Android users can try out starting this week in “public preview.” (This is the same preview that gives you access to an AI-powered fitness coach, which I tested yesterday, and the results were puzzling .) Cardiovascular fitness will now be tracked weekly, making it much easier for the app to provide intelligent recommendations.
What is (and was) cardio?
The Cardio Load feature is Fitbit’s attempt to guide you toward the right amount of exercise. Obviously, a beginner shouldn’t immediately jump into hour-long intense workouts, and someone training for a marathon shouldn’t slack off without reason. Cardio Load is an attempt to set an amount of exercise that’s neither too much nor too little.
Many athletes and coaches use some kind of model to calculate exercise volume: whether it’s runners counting up their miles in a spreadsheet, or a coach listening to their gut and saying, “Let’s take it easy today.”
Fitbit uses an approach with the amusing name TRIMP (“TRaining IMPulse”), where every minute of elevated heart rate is counted toward your cardio load, with higher heart rates being considered effort. You can read more about this calculation here .
Why cardio was confusing
The idea sounded good: Fitbit would calculate your required cardio load each day based on how much you exercised. You could tell the app whether you wanted to improve your fitness or just maintain it, and it would adjust its metrics accordingly.
But for many people, these numbers never made sense. They fluctuated from day to day, often failing to meet the patient’s actual needs based on their medical history and health status. Many users found that the recommended cardio load was constantly increasing, with rest days signaling they weren’t training enough.
Examples of Reddit threads from r/fitbit include titles such as ” Cardio is confusing me ,” ” Cardio, I hate you ,” ” Cardio isn’t real ,” ” Cardio isn’t just wrong, it’s dangerous ,” and ” Fitbit, either fix cardio or ditch it .”
Why the new feature might be better
Google explained that it is implementing a fairly simple solution: calculating cardio recommendations on a weekly basis rather than a daily basis. The cardio recommendations themselves will not change.
Ultimately, alternating between hard days and easy or rest days is normal, and any exercise management recommendations should accommodate this. Google also notes that background activity levels (like how much you walk while grocery shopping) also increase your cardio load, making it more difficult to meet daily recommendations.
The new version of the Fitbit app now features a big donut at the top of the screen, reflecting your progress toward your weekly goal. After a couple of quick runs, I was already 41% closer to my weekly goal. There’s even a graph showing where I’m at and where I’m overshooting my goal. It’s much clearer.