In what may be the biggest challenge to Whoop ’s dominance since the company first released its wearable in 2015, Google has just launched the Fitbit Air – an £85, screen-free wearable that doesn’t require a subscription to work. The fitness tracker was first teased in early April by NBA legend and Google’s performance advisor Stephen Curry . It’s the first new Fitbit tracker in almost three years. The Fitbit Air boasts a smaller, lighter design and focuses on passive, round-the-clock health tracking and recovery, rather than trying to replace a smartwatch . Intended to be worn day and night, the Fitbit Air monitors everything from heart rate and sleep to recovery metrics like blood oxygen, skin temperature and heart rate variability, with all data being fed into Google’s newly revamped Fitbit app, rebranded as Google Health. The new health platform now features a super-smart AI coach that creates tailored fitness plans that adapt to your real-time performance data.…