I run, lift, and do heavy Colorado trails at high heartrate levels. I find exercise makes it generally more difficult to sleep. Has been a problem for years, only get real sleep on my rest days.
That looks like FUD from somebody who's living depends on blogging FUD. Of course, it's possible to train too hard, but this is very bad advice for the average (slightly overweight, not very active) person. If you worry about training too much, go talk to a sports physician and take a cardiac stress test. Or just run so slowly that you can breathe through your nose only.