My Fitbit Air test revealed the flaws of calorie counting with a health tracker - here's why

Key Points:

• The Fitbit Air provides generally accurate heart rate data comparable to the Polar H10 chest strap, especially during steady-state cardio like treadmill workouts, with under 2.5% error in heart rate metrics.
• The Fitbit Air shows a lag in detecting rapid heart rate changes compared to the Polar chest strap, particularly during transitions such as starting to run or during strength training intervals with quick intensity bursts.
• Calorie burn estimations by the Fitbit Air are less reliable, underestimating calories by approximately 12% during treadmill sessions and up to 31% during strength training, highlighting challenges in accurately calculating energy expenditure from heart rate data alone.
• Wrist-worn trackers like the Fitbit Air inherently have delays in capturing heart rate fluctuations due to their distance from the heart, making them less suitable for users needing precise real-time heart rate monitoring during workouts.
• Overall, the Fitbit Air is recommended as a reliable general health tracker for heart rate monitoring but should be used cautiously for calorie tracking or detailed exercise intensity analysis.