Yes! I agree the HIIT research is great and very interesting and impactful - they designed and implemented an intervention with a control group and measured oth

Yes! I agree the HIIT research is great and very interesting and impactful - they designed and implemented an intervention with a control group and measured other correlative variables including muscle biopsies. And as you say the results are actually useful for getting some people that don't have the time or inclination to run marathons. I would certainly distinguish this kind of research from the many redundant retrospective observational studies (often with self-reported exercise activity levels) of the kind linked in the original post.