> speed up a bit on the downhills
That is bad for your knees.
[edit] I highly recommend the book Born to Run by Cristopher McDougall.
That is bad for your knees.
[edit] I highly recommend the book Born to Run by Cristopher McDougall.
FWIW, I've read nearly every running book there is including that one. I still have healthy knees at 51 and have run tens of thousands of miles on them over all sorts of terrain.
Repeated stress of right intensity makes bones, joints and tendons stronger. Avoiding all stress is a bad advice I have heard many times in my life I am sick and tired of it. It is the stress that causes the body to need to recover and it is during recovery that it becomes stronger.
The only really important thing to remember is that the right intensity is crucial and that it is very easy to suddenly overload a part of your body you have never even been aware of. Even a slight change in technique caused by something like different shoes or an aching toe can shift forces to places that are not ready yet and cause an injury.
That's why good running technique is crucial -- because it is nothing else as a discipline to put your body through predictable motions in response to predictable loads. If you can do it you can now make sure your loads don't change too much over time and you should be relatively safe from injuries.
Lots of injuries are caused by people running for longer duration but slipping with their technique because, for example, their core muscles get fatigued through the run. And this shifts loads to new places and causes things to get overloaded.
Running injuries come from overload or overuse (or bad health). Both causes can be prevented by being conscious of what causes overload and overuse and then training in a way that will prevent it.
If all you ever do is run flat asphalt and then you suddenly decide to run hills then yes, the downhill can be bad for your knees -- but that's just because you stupidly decided to introduce a new load your joints and tendons are not adapted to.
Same happens whenever you change technique or have some kind of imbalance -- your body will adjust by moving loads from one place to another but your brain may not be smart enough to realise the new place may not have had enough time to adjust to it.
Anybody can write a book, I guess. But don't take any running books as gospel. Nobody really understands everything about running (well... maybe Phil Maffetone does).
I run with severed ACL in one of my knees and so out of necessity I have to be much more knowledgeable to be able to keep running safely and keep my legs in good shape.
[Citation needed]
I wouldn't recommend speeding up on the downhills for beginning runners. But if you're well conditioned, running slightly faster on the downhills in a relaxed way won't hurt your knees. It all depends on the slope of course. On very steep hills, it simply isn't be possible to run fast downhill.
> I highly recommend the book Born to Run by Cristopher McDougall.
It's an entertaining read, but that's about it. The science is to be taken with a large grain of salt. (I've run more than 50000 km since reading it.)
I try to place the insole in a way that avoids vibrations when hitting the surface and the ankle to work at a correct angle.