If you like to dig deeper into the stats on your best smartwatch, there’s a strong chance you may have come across one called VO2 Max. It can be called something different on different smartwatches. On the Apple Watch, it’s known as 'cardio fitness', while on Fitbits, it’s referred to as your 'cardio fitness score'.
VO2 Max is a fitness metric that has been around for some time, but if you’ve been grappling with what it actually is, what it tells you, and whether you should care about it, we’re going to clear things up for you here. This is the lowdown on the key fitness metric, and why it might be something you should take more notice of.
