1万稳定补天上岸:Polars new fitness watch analyzes your recovery when sleepingPolars new fitness watch analyzes your recovery when sleeping There arent that many fitness watches that try to really fold sleep into the equation when it comes to coaching guidance. Can the $$230 Polar Ignite answer the call?Polars intriguing new sleep tracking system, called Nightly Recharge, calculates a Sleep Score for overall sleep quality, but also measures ANS (Autonomic Nervous System) recovery by calculating heart rate variability, heart rate and breathing. Both measurements combined determine how Polars fitness app calculates the intensity level your next days workouts should be at.Then, a coaching system called FitSpark claims to advise on training regimens based on what your Nightly Recharge results are. According to Tom Fowler, president of Polar USA, it could be possible that youd get a good Sleep Score but not score well on ANS recovery, and as a result, your body may not feel as well recovered.Compared to Polars larger ultra-long-life GPS watches, the Vantage V and M, the Ignite is a lot slimmer, and has normal-feeling watch straps. Its also meant to be worn all the time, especially while sleeping.The Ignite battery life should last about 20 hours with GPS and heart rate tracking on, or five days of tracking without GPS. I havent worn the Ignite yet to test its claims out.