I don't care how fit you are, almost no one is running a 10k in 45 minutes at 60% of max HR. I'm sure in many cases more strenuous exercise is not detrimental,

I don't care how fit you are, almost no one is running a 10k in 45 minutes at 60% of max HR. I'm sure in many cases more strenuous exercise is not detrimental, but of course the public health recommendations are going to play it safe.