I am a 44 year old male that have been a bit inactive the last years and am looking to get more fit. I have always been fond of running as a way to get some cardio, fresh air and reduce stress, but I am starting to get worried about my knees. One problem in this respect is that I am quite heavy (100 kg) although I have not much body fat.

I recently read "Your New Prime" by Craig Cooper. He is strongly opposed to long distance running for men over 40. In fact he advocates the 5k as an ideal bench mark distance as opposed to the marathon. That is if you can run the 5 km fast then you are healthy. If you can run the marathon fast you are not healthy. His reasoning is as follows: long distance running reduces musclemass and lower your testosterone levels. This is exactly the opposite of what you need since your muscle mass and testosterone levels decreases each year after 40.

This seems logical and plausible. I have verified his claims about muscle loss from age and long distance running from several other sources. However his suggestion about training towards the 5 k is not something I have found elsewhere. It sounds reasonable and practical but I have one worry: the force on knees and other joints increases with the speed. Not sure what is most dangerous for knees though: high volume or high intensity? The expression is high mileage knees, but on the other hand I would be worried about running a 100 m as fast as possible with little warmup in my age but not 20 years ago.

He also like so many other advocates high intensity training. There are lots of studies done in the last years showing how time effective this. Which is great, but high intensity sound possible dangerous. I have not seen any studies of possible harmful effect of hit such as possible irregular heartbeat.

  • 2
    I think there might be some debate as to whether or not running is actually bad for your knees. Furthermore, I think training for a 5K is a noble goal that will allow you to decide for yourself how to train. It’ll take some time to get to that level, and that will most likely dictate how you feel about running in general. I wouldn’t stress too much about “high intensity,” as it seems most cardiologists’ responses to any heart issue these days is to up the volume. I joke, but it is very often true. That said, it’s always best to ask one’s doctor before starting an exercise regimen of any sort!
    – Frank
    Commented Apr 25, 2018 at 0:17
  • Yes - the bit about running vs. walking is that while the impact is greater when running, it happens over a shorter period of time. And in general, older runners don't have bad knees. I think this may be a case of "wearing hats makes men go bald" - it isn't that running makes knees go bad, it's that bad knees make people so running. And furthermore, if you don't run, you may not notice that you have bad knees. Commented Apr 25, 2018 at 23:51

2 Answers 2


Running properly isn’t bad for your knees, but running in bad form certainly can be. As a matured human being, you should train like a matured human being. It doesn’t matter what age or sex you are, the only factors that might change the way you train are things like injuries, sickness, disabilities, etc (goals too). I read an article once that spoke of how much a person should run, and the expert in that article suggested that a person should only run as long as they can maintain the pace of an 8 minute mile (7.5mph). Read more on that —> https://breakingmuscle.com/fitness/the-8-minute-mile-standard

In general though, long distance running isn’t recommended unless you have a specific purpose in doing so. A nice HIIT routine with sprints (anywhere from 10-30 minutes) is more advantageous for cardiovascular endurance, and a walk (from 30 minutes and up) is easier on the knees and body in general. Long distance jogging just sort of takes the negatives of both sprinting and walking (physically demanding and time consuming respectively).

Like Mr. Cooper, I would also advocate high intensity training. I would suggest doing it 2-3 times a week and keeping it under 30 minutes. Doing sprinting intervals with jogging or walking in between in a great way to build up the muscles and endurance needed to go on longer jogs. If participating in long distance runs is a goal of yours however, I would suggest doing one sprint-centric HIIT routine and one long distance run a week. Running too often too soon and too much will cause your knees to wear out for sure even if you are doing everything in proper form.

The only danger in HIIT is doing more than your body can handle. If you have heart/lung problems, be extra careful, but try to build what you can regardless. If you feel like your heart is about to jump out of your chest, slow down or take a break. The more you do, the better you will understand your own limits and how to better push yourself beyond those limits (without harming yourself).


Short answer:

You should train like anybody else. Only thing what change with age is the error buffer. In other words, your body will tolerate less mistakes. So if you choose running (or any other activity), make sure that your body is prepared and you know how to do that correctly and safely.

Long answer:

  1. make sure that your mobility and strength level is sufficient for the activity you want to perform. In case of running the book Ready to Run: Unlocking Your Potential to Run Naturally (Kelly Starrett) is probably the best choice where to start acquiring informations on this topic.

  2. learn the technique of your chosen activity - the best approach is to find and hire the best available professional who can teach you

  3. choose some reasonable progression. For example, a gentle and generally successful approach is Maffetone method (https://philmaffetone.com/180-formula/). This approch focused on aerobic training, so it does not produce too high amount of muscle cannibalism (in comparison with long term anaerobic training). It is common to use such an approach all season long even though your target competition is "short and fast". For more information see book: The Big Book of Endurance Training and Racing (Philip Maffetone).

If you follow the steps above, you will minimize the negative effects and risks of cardio training.

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