About 20 miles a week would be very low for a professional runner, and a serious amateur race-runner would probably be doing more. But it’s risky to increase your mileage too quickly.

If you’re not currently following a training program, you’d probably get more benefit from starting to follow a structured program than just increasing mileage. There are different systems in the body which benefit from running at different speeds: e.g. short sprints build your leg muscles, 3 minute intervals build your maximum aerobic capacity, 20 minute hard sessions improve your ability to clear lactate from your blood. If you find a training plan it will give you a variety of different paces to help you build different systems.

What extra data fields do you want on your watch?

I want an “Am I actually dying?” screen that has a big green N. Unless I’m actually dying, in which case it has a red Y and gives me the last rites.

Also a screen that tells me how much time I’ve lost in worse posture and aerodynamics from looking at my watch too much…

I don’t pay much attention to Garmin’s Wild Guess At VO2 Max score, but when I look back, I see that after I upgraded to a different watch model it instantly dropped 8 points. Am I morally entitled to add 8 points to it forever in future?