Should we be running long distances, mileage, marathons? I personally think that the increase in cortisol stress hormone and risks on joints from running outweigh the benefits... If you stress your joints with thousands/millions of reps what impact does that have on your joints, tissues, ligaments over time? If you were to bike for 20 minutes at a slower pace (60rpm's) that would be l,200 reps... Think about doing 1200 push ups or squats... It makes you think about it differently. Me personally, I have done cardio exercise for 20+ years and it hasn't lowered my blood pressure.
Is there another way to get cardiovascular benefits without running? I believe that breathing exercises, meditation, Isometric Resistance Training can have more impact or influence than traditional cardio.
Check out these interesting articles about long distance running...
Jim Fixx was a runner that died at 52 while jogging... https://en.wikipedia.org/wiki/Jim_Fixx
NIH study states "The marathon running population does not constitute solely persons with excellent cardiovascular health." https://www.ncbi.nlm.nih.gov/pubmed/3298928
A Runners World Article Heart Risk? Marathon Runners have increased artery plaque and What to know about running and your Heart https://www.runnersworld.com/heart/what-to-know-about-running-and-your-heart
Thoughts and comments?