Good question. The threshold that the Apple Watch uses for exercise is probably slightly lower than gold-standard measurement techniques, but I am very active nonetheless. It helps that I am a single woman in my 20s, no kids and I quit my full time job in the spring/summer to focus on my PhD, so my schedule is really flexible. I also walk a lot and I walk really fast (so it is all registered as exercise), plus I bike 30-45 minutes most days, I started rowing this summer and just took up rock climbing. I use physical activity as a way to connect with others, I participate in a lot of "challenges" and movement is absolutely essential for my mental health so I prioritize it as much as possible. Most people don't have the kind of spare time/flexibility that I have, though, so that needs to be acknowledged.