Do you believe this? Scientific study: Running on trails isn't any better for your legs/injury prevention than the roads

Not really suprised, but great to get some real data on the aspect of impact forces. I think this falls nicely into evidence that what counts is NOT the softness or hardness below the feet, including surface and cushioning of the shoes. What counts is HOW the foot and leg is able to distribute the impact forces. Another study I have refered to showed that the leg stiffness changed immediately in response to changes of surface hardness, meaning that the leg tried to keep a constant internal load pattern to work optimally as a kind or spring. It has also been shown that runners react to cushioned shoes in that heel striking or sloppy use of the foot is possible due to the very attenuated feel from the surface since it is dampened in the sole, but the impact forces still travel up the leg.

I have a background from running in terrain (outside the trails) and obviously part of the injuries will be ankle or fall related. I guess this shared study looks beyond those obvious injuries and to the impact forces.

Now there is one big difference in running at flat and smoot surfaces compared to uneven and that is the work the foot, ankle and calf, as well as core and balance needs to do. I think it is obvious that the foot and ankle strength (to balance and counteract the changing uneven surface) will be improved by trail running and that is a good thing. That does not mean one cannot be injured if the strength is not enough, so progression is needed.

Now, I have known that soft surface does not necessarily reduce impact for some time and my take on this is that running on trail can give strength and balance benefits and not the least give a more varied load to the leg so that the repetitiveness is less and injuries connected to repetitive and similar movements could be less. Maybe I am right, maybe wrong and this study kindof do not support my view. On the contrary we believe in alternating between shoes when running flat to prevent injury and if this is true, then variation of load is important.

My experience with trail or road running is that if I run trail for let us say a week or two, then I will experience slight DOMS when returning to the road, so definately the profile of the impact forces is different.

I still would recommend running on varied surfaces and both flat and hilly. I think the legs will be stronger, more resilient and the aerobic ability better in more of the muscles, giving a better endurance in the long run

The thing studies like this don't take into account is the time element. They are just measuring forces on their subjects for a (relatively) short period of time. Running is an extremely repetitive movement. Small differences add up over time. They don't manifest themselves over a week or two. Stress fractures are bone fractures that occur when bones are subjected to stress over period of time. Run 100 miles a week on concrete (not asphalt) for a year, then run the same mileage over the same period on dirt and tell me which one feels easier on your legs.

calculass wrote:

They contribute to different injuries.

This. So if you are dealing with overuse injuries from the stress particular to running on roads, the occasional trail run is a godsend.

The study makes sense to me. I don't think a hard-packed trail or dirt path is much more compliant than asphalt. If anything, I would guess that the kind of absorbent foams that road shoes now have make road running easier on the legs. If I compare the compliant Boost, react or Zoomx foams to the standard (and usually very thin) layer of EVA you get on most trail shoes, I know which feels like it's absorbing more force.

But, trail running will help over the long-term to build resilience to injury by using muscles and tendons that you don't use while road running. The uneven trails that I run, help to build ankle strength and the fact that they are not straight lines means you are using ligaments and tendons that are otherwise underused. You could probably get the same result with strength training, but I hate going to the gym. The Ethiopians do most of their training on uneven surfaces so it's got to help.

100% false.

If you're running on soft surfaces (trails, grass) (*and* you don't hit a rock/hole that causes a catastrophic injury) you will 100% be better off staying off of pavement. Speed, recovery, tempos, intervals - all should be done on the softest possible surfaces (grass > trail/dirt > track > pavement). I've had and seen countless injuries by guys that run too hard on pavement day-after-day where a slight niggle turns into a tightness/pull turns into a season-long injury. 9 times out of 10 it can be traced back to a hard workout on pavement or a series of back-to-back days run too hard on pavement.

Fewer people get hit by cars on the trails

hmmmmmmm wrote:

WOW. As I nearly fell out of my chair.

ofa lon teh

My goodness! As I nearly fell out of my chair as I red this. As i think about this post a LOT and a TON as I real smart as I go Princeton as dad send me there

I tell my friend and she agree

My god people are stupid

15 is a tiny sample size. In running your feet are constantly striking a surface. If I punch a concrete sidewalk with my right hand & then a dirt trail with my left hand, I assume my left will feel better. But, admittedly that is an unscientific assumption.

krispy kremlin._._._._. wrote:

100% false.

If you're running on soft surfaces (trails, grass) (*and* you don't hit a rock/hole that causes a catastrophic injury) you will 100% be better off staying off of pavement. Speed, recovery, tempos, intervals - all should be done on the softest possible surfaces (grass > trail/dirt > track > pavement). I've had and seen countless injuries by guys that run too hard on pavement day-after-day where a slight niggle turns into a tightness/pull turns into a season-long injury. 9 times out of 10 it can be traced back to a hard workout on pavement or a series of back-to-back days run too hard on pavement.

It is funny how you just dismiss objective measurements of runners switching surface hardness...When measurements of the leg in action in terms of forces in this study and the measurement of the leg stiffness in another is done, one cannot just dismiss it based on what one believes. Now to explain why and how this change happens is often much harder.

I believed or was taught the same as you claim is true. I was a terrain runner that stayed off any hard surface to prevent injury and these studies suprises me some, but I have to accept them, especially when independent studies points to the same facts. It seems that a soft surface or a cushioned shoe will NOT remove the high impact forces, but they might change them.

On the other side specificity is also important in that you need to run a lot on hard surface to become efficient at hard surfaces. That does not say you should not vary the surfaces, so I agree in your choices of surface, but not the dismissal of objective evidence.

This study made me realize that softer vs harder surfaces makes no difference. So I switched out my punching bag with one made of concrete since it will last longer.

DragonLady wrote:

Get back to me after the “researchers” have run 140 mpw. When you run on dirt after running on concrete during some 140-mile weeks, the difference is extremely noticeable. Virtually every week there’s a “researcher” whose study defies common sense; this one’s no different.

My response will get lost in the pages, but oh well.

When I graduated from college I was pretty competitive, running 13:40's and 28:50's for 5k/10k. That summer I moved to a place that didn't have any soft surface trails, only hard bike paths, instead of the soft surfaces I typically trained in at the University. Within just a couple weeks on the new bike paths running 70-90 mile weeks I got a bad achilles/soleus injury and tried to run through it and strained my soleus. I'm convinced it was because the concrete was less forgiving than the soft surface.

But then again now I do almost 100% of my marathon training on concrete running 100+ mile weeks and I'm perfectly fine. So maybe running on soft surfaces weakens something and when going to concrete exposes those weaknesses. But if a concrete person goes to soft surfaces no change is noticed except they become weaker in some way.

carmine9 wrote:

Fewer people get hit by cars on the trails

Fewer people get eaten by bears on streets.

DragonLady,

Agreed. I know Victoria, BC has a fantastic network of dirt, gravel, chip trails as well as asphalt trails but often with dirt shoulders.

Jon Brown, three-time Olympian, two-time 2:09 marathon runner (BSS, before super shoes ;o)), did 110-plus miles or 170-190-kilometres per week and at least 80 percent off-road, for a reason.

To study recreational runners is fine because the majority of people are recreational, so the audience they are talking to is big, but more serious, age-group fast, sub-elite, elite athletes notice a big difference.

I've never fully bought into the conventional wisdom that running on dirt necessarily makes one less likely to get injured. Here are some questions I have:

1) Running on trails tends to make one run slower. Is it possible than any reduced rate of injury (if one exists), is simply due to trails forcing one to run slower, with less impact per step? Does the load "feel better" simply because you're automatically running slower on that trail?

2) Assuming we evolved running and walking barefoot, it makes sense running on cement (while barefoot) would be unnatural and running on a softer surface like dirt would be more consistent with how our bodies evolved. But since the invention of modern shoes, we're not actually "running on cement." We're running on high tech foam and rubber which simulates a much softer surface. Is it possible that with modern shoes, any injury benefit from running on soft dirt, has been lost due to the fact that we run on soft foam and rubber? Perhaps there's no extra benefit to run on soft foam and rubber and dirt?

3) The last time I ran on a trail, I felt my ankles rolling back and forth and clipped a few tree roots, almost falling. I didn't get injured, but it sure didn't feel the surface was less injury inducing. Running on the beach can feel similarly, with the ankle rolling side to side. Is it possible different surfaces bring different injuries, but that neither is superior, on balance?

Bogus study

This is nothing new. You change the stiffness of your legs to keep impact force the same going from one surface to another. Runners Connect wrote an article on this several years ago with the research. Those with a propensity for certain injuries may personally prefer one surface over another. I recall those with a history of tibial stress fractures should actually stick with firmer shoes and surfaces, not softer, to reduce the strain on the lower legs.

Jon Arne Glomsrud wrote:

It is funny how you just dismiss objective measurements of runners switching surface hardness...When measurements of the leg in action in terms of forces in this study and the measurement of the leg stiffness in another is done, one cannot just dismiss it based on what one believes. Now to explain why and how this change happens is often much harder.

Please. You are treating this "study" like some serious piece of research. But it was just 15 recreational runners (probably meaning people running 10-minute miles for a few miles) with accelerometers (which we are supposed to unquestioningly accept as a reliable instrument for predicting running injuries). We don't know anything about the people who conducted the study - they could be bumbling idiots. But even if they aren't, drawing any general conclusion from such a small study is unjustified.

I'm not even trying to be a proponent of soft surfaces over hard surfaces. I find it unlikely that there is no difference whatsoever regarding the effects of running on one vs. the other. I do think there is an old nugget of conventional wisdom that softer surfaces are automatically "better for you" which is at best overly simplistic. This is sort of like other truisms like "runners need to eat tons of carbs" and "you need to be constantly guzzling water to stay hydrated" - they may be based on some nuggets of truth, but need to be approached with a bit of nuance.

My own lifetime experience of running confirms this FOR ME. I can say that trails and soft surfaces don't really make much of a difference for me when it comes to recovery.

If I run on trails it's because I want different scenery and spend some time hopping over logs, roots, and rocks, not because I think it's easier on my body.

For me personally trails and grass areas increase my chance of injuries. I've had knee pain every time running trails. To the point I couldn't run. So for the last 15 years I've done road running without knee injuries. I'm just not built for the uneven surfaces. But I can find the right shoes that let me pound the pavement without problems. So to keep hobbyjogging I'm strictly a roadrunner. No problems.