While exercise is something nearly everyone should do, we need to work out with moderation. If you exercise too long and too hard without sufficient recovery, you risk injuring yourself. That’s where Polar’s $499.95 Vantage V2 fitness watch comes in; it will help you track recovery time.
Source: Polar’s $500 Vantage V2 Fitness Watch Will Tell You When to Skip Leg Day – Review Geek