The age old question: to become a better/faster runner, do you need to run faster or run longer?
In short, I agree with him. If you want to be your best, you better be doing a fair bit of both volume and intensity. The details of where that balance lie really depend on individual factors.
Feeling Fatigued? 3 Strategies to Combat Overtraining Steve Magness offers his thoughts on overcoming overtraining.
When should you hammer your workouts and when should you relax? Alex Hutchinson has some input on that. Don’t get too caught up in the details, though.
What is your optimal stride rate/cadence? Probably slightly faster than you naturally run but the benefit of increasing is so small it’s probably not worth worrying about.
How useful are sleep tracking devices? It should be no surprise that they are less useful than the marketing would suggest.
Lifting to Failure Isn’t Always Better Kind of like running, varying your intensity seems to be best. I’d also argue that it’s very infrequently best to give 100% effort in anything other than a competition.