Do running surfaces really matter?

I have had years of achilles / calf problems. I've lost about 18 months of running to them over the last 5 years. Every time I come back from injury, there is a ~2 month period where I can do most anything on soft surfaces (including grass), but I can barely run a couple miles on hard surfaces without a flair-up. And, later in recovery, when I can run on hard surfaces, concrete is distinctly worse than asphalt. Even the type of asphalt matters. (The kind where you can see the grains and he asphalt looks porous is the best to run on.)

Uneven grass is worse than clay or dirt early on, though, but still better than crushed limestone, and way better than asphalt.

Where has The Concrete Runner gone? Would love to see him chime in on this thread.

All of those saying that softer surfaces are better for keeping you healthy obviously have not done any research on the subject. Just because what "seems" right is not necessarily the truth. The surface type you run on does not change the amount of force that goes into your body. The force you generate has to go somewhere, it doesn't just disappear because you are running on grass. If it did disappear then you wouldn't be going anywhere.

notafatty wrote:

http://www.slowtwitch.com/Training/Running/Concrete_or_Asphalt__4793.html

These data corroborate my own experience that asphalt is softer to run on when it's warm out but feels like concrete in the winter. Run enough miles and you get a feeling for how hard the surface is. Fresh asphalt on a hot day feels almost like running on a rubber mat although the smell isn't worth it.

As most people seem to agree on here, dirt trails and dirt roads the best running surface. IMO grass is pretty good too but with the downside that doing laps of a field complex and gets boring fast.

At least from experience, I can say that surface DEFINITELY makes a difference.

When I was running in Flagstaff for part of the summer this past year, I was amazed at the amount of volume I could get in in a week's time without feeling the usual fatigue on my legs. I hit two consecutive weeks of 90 miles (something I had never done before) and the only time my legs were ever sore was after my 18-mile long runs. I would say about 95% of my weekly miles were conducted on dirt roads or grass.

However - the altitude is what made everything difficult. When I was back at sea level and without the same access to soft surfaces, my legs immediately felt the miles and that volume became a lot more difficult to hit.

With respect to concrete versus asphalt hardness is one variable, but surface texture variations affect the pressure distribution across the bottom of the foot during each step. If there is more variation to the surface then there should be less fatigue because the stresses to the foot are constantly changing even though the surface support is consistent (unlike a grass surface which is highly variable).

Asphalt generally has a porosity component to the surface that allows the air that is being compressed during the foot strike to distribute much faster versus a completely flat surface that may be found on most concrete.

Smack your palm on a table top and notice the feeling. Then put a thin cloth on the top of the table and smack your hand on the cloth and with the same force you will notice less discomfort. A thin cloth isn't adding cushioning, but it changes the surface texture.

3hr-marathoner wrote:

notafatty wrote:

http://www.slowtwitch.com/Training/Running/Concrete_or_Asphalt__4793.html

These data corroborate my own experience that asphalt is softer to run on when it's warm out but feels like concrete in the winter. Run enough miles and you get a feeling for how hard the surface is. Fresh asphalt on a hot day feels almost like running on a rubber mat although the smell isn't worth it.

Dude, did you not even read your own article?

"So I might as well let you know up front that the hardness difference between concrete and asphalt is insignificant when running in shoes, because the cushioning afforded by shoes far exceeds any cushioning provided by those surfaces."

That is because asphalt, unlike concrete, is a highly viscous liquid. It changes consistency with temperature. It flexes. That is why it is used for roads. Concrete is inflexible, so expansion/contraction because of temperature changes causes it to crack.

3hr-marathoner wrote:

notafatty wrote:

http://www.slowtwitch.com/Training/Running/Concrete_or_Asphalt__4793.html

These data corroborate my own experience that asphalt is softer to run on when it's warm out but feels like concrete in the winter. Run enough miles and you get a feeling for how hard the surface is. Fresh asphalt on a hot day feels almost like running on a rubber mat although the smell isn't worth it.

As most people seem to agree on here, dirt trails and dirt roads the best running surface. IMO grass is pretty good too but with the downside that doing laps of a field complex and gets boring fast.

That study is incorrect! When air temperature is over 80 degrees, I can visibly push my thumb into asphalt. Obviously, cement doesn't move. When I have had little option but train on cement sidewalks, injuries. I can feel it too. No one is going to tell me the difference between asphalt and cement is in my head.

Stopme99 wrote:

I was talking to our sports doctor over the weekend and she was told me that running on asphalt or crushed limestone is actually the best running surface. She said that in most instances running on grass can lead to more stress fractures than on a hard smooth surface.

She explained that almost all grass surfaces are uneven in some way and lead to over usage or compensation. This causes a lot more strain in the calf area and eventually leads to stress fractures.

She also said you should train on the surface you will be racing on and in the spring running on the roads is encouraged.

What are your thoughts?

I will admit that my calves are always tighter after running miles on the grass.

Honestly it's whatever your body is used to. What your doctor said about putting more strain on your calf is true, however exercising those muscles will also strengthen them and make you stronger down the road (no pun intended).

As long as you're consistent in your training and listen to your body, the surfaces you're running on are the last of your worries. This is coming from a guy who spent high school and college running 85-120 miles per week, then a few years later running 60-70 miles per week with an extra 20 lbs and developing no stress fractures.

Stopme99 wrote:

I was talking to our sports doctor over the weekend and she was told me that running on asphalt or crushed limestone is actually the best running surface. She said that in most instances running on grass can lead to more stress fractures than on a hard smooth surface.

She explained that almost all grass surfaces are uneven in some way and lead to over usage or compensation. This causes a lot more strain in the calf area and eventually leads to stress fractures.

She also said you should train on the surface you will be racing on and in the spring running on the roads is encouraged.

What are your thoughts?

I will admit that my calves are always tighter after running miles on the grass.

I would like to see her evidence to back up the claim.

I have over 40 years of running under my belt. I have a bit of osteoarthritis in one knee. I can tell the difference between a 5 mile run on the concrete path and the 5 mile dirt path or trail run the following day so I am going with yes based on my experience.

Now, running on a trail (something with rocks, roots, etc as opposed to a path that has none of them---just my differentiation) might increase the risk of rolling an ankle or tripping.

A lot of these responses are along the lines of "this one time I did A, B, and C, and the outcome was D, therefore B = D!" Unfortunately just because you had an experience one time does not make it science. This is the same type of thinking that started the static stretching fad. A bunch of people who felt like it helped them and came to the conclusion that they must be on to something. That is called a fad, not science.

Your body stiffens up when you run on softer surfaces and relaxes on harder surfaces. There are a few good articles out there on that. The impact point is not what causes injuries! I highly recommend looking at some of Jay Dicharry's research on injuries. It has much more to do with the ground contact time combined with force. A lot of people here are confusing force with pressure. They are two different things but easy to get confused because pressure is easier to feel and notice than force. Pressure can be the cause of some injuries (stone bruise), but for the most part force is the usual culprit.

If you take an athlete and have them run 6 min pace on grass and 6 minute pace on road, the force that is going back into the athlete from the ground will be the same on both surfaces. If the force going back into the athlete was not the same then the athlete would not be running the same speed on both surfaces.

With that in mind here is a common scenario:

Runner A runs on soft surfaces. Because the surfaces are softer they don't run as fast as they would with the same effort on a hard surface. Because they are running slower the amount of force that goes into their body is lower. They then attribute their lack of injuries to their running surface. But really the lack of injuries come from the fact that they are running slower and therefore less force in going back into their body than it would be running at faster speeds.

Hardloper wrote:

3hr-marathoner wrote:

These data corroborate my own experience that asphalt is softer to run on when it's warm out but feels like concrete in the winter. Run enough miles and you get a feeling for how hard the surface is. Fresh asphalt on a hot day feels almost like running on a rubber mat although the smell isn't worth it.

Dude, did you not even read your own article?

"So I might as well let you know up front that the hardness difference between concrete and asphalt is insignificant when running in shoes, because the cushioning afforded by shoes far exceeds any cushioning provided by those surfaces."

Oh, there's an article there? I was just looking at the Young's modulus table which says that asphalt is as hard as concrete when it's cold but over 10 times softer in warm weather. ... Just looked at the article. It's bogus. It's not exactly contentious among runners that concrete feels harder when you run on it than asphalt. You usually make sense Hardloper. I don't know why you are on the other side of this.

they do for me. am a 73 year old runner who has run about 35 marathons maybe over 100k miles but never kept a good log. best marathon 2:32:12. for the last 25 years i have been running on fairly rugged trails( some rocks, roots, in a hilly woods). a big advantage is that you stretching all the time and building very strong ankles and distributing the effort all over your entire leg frame . very few injuries (plantar twice and piriformis syndrome three times). the piriformis shows itself in the winter when the roads and trails are harder. from plantar i learned to stay off walking trails in the winter as the foot undulations freeze and result in serrated ridges. never ever run on a lot of pine cones as they are like rough pencils underneath. best for me is running on a golf course (i have a golf course out my back yard that i ran on all summer but they kicked me off due to rules). i find i can recover on soft relatively smooth grass much faster at my age due to leg recovery.

i avoid concrete like the plague. stone dust is ok but dirt or grass is best for me. i avoid asphalt primarily because i don't want to push my luck and get too mad at driver. trails are harder due to increased friction but you get anaerobic workout even on a rest day if it is hilly.

Hardloper wrote:

Dude, did you not even read your own article?

"So I might as well let you know up front that the hardness difference between concrete and asphalt is insignificant when running in shoes, because the cushioning afforded by shoes far exceeds any cushioning provided by those surfaces."

Here's why that the analysis in that article is trash. In round numbers, they list the following for the Youngs moduli:

concrete = asphalt in cold weather = 20 GPa

asphalt in warm weather = 2 GPa

crushed gravel = 0.2 GPa

rubber = 0.002 GPa

Amazingly they don't mention the Young's modulus of the material that we really care about when it comes to stress fractures, bone! Guess what, the Young's modulus of bone is also about 20 GPa (

). So running on 20GPa concrete, whatever shock isn't absorbed by your shoes will be equally shared by the ground and your bones (not really because the geometry is very different but for an order-of-magnitude estimate this is a start). Switch to running on 2 GPa concrete and suddenly an order of magnitude more of the shock gets absorbed by the ground.

But the ground doesn't absorb force! Read my last post. If it absorbed any force you wouldn't go anywhere. That breaks the basic laws of physics. If you are running at a specific speed the same amount of force goes back into your legs no matter what surface you are running on.

running on a surface that is varied in grade/composition (think a trail with rocks/roots/uneven footing) is ideal in the long run because each step has slightly different forces going through your leg, which overtime will strengthen the leg to withstand varied forces instead of the same force repeated through each step (like when running on the roads).

However, uneven terrained trails do pose a higher risk of acute injuries such as twisted ankles, etc.

You're wrong, it DOES absorb the force..not all of it, which is why you are able to move off it, but a good portion of it is taken up by the "give" in the ground. As proof of this ask anyone about the EFFORT it takes to run a the same pace on asphalt vs grass..its a lot harder to do it on a softer surface.

another runner wrote:

But the ground doesn't absorb force! .

another runner wrote:

All of those saying that softer surfaces are better for keeping you healthy obviously have not done any research on the subject. Just because what "seems" right is not necessarily the truth. The surface type you run on does not change the amount of force that goes into your body. The force you generate has to go somewhere, it doesn't just disappear because you are running on grass. If it did disappear then you wouldn't be going anywhere.

Bad logic. Go and run on loose sand or a shortish cable bridge. Even though you are moving forward the same distance, the amount of give (which can be construed as surface softness, though these are extreme cases) definitely changes the effort and muscles used, and anybody that has run on grass versus asphalt regularly will tell you their form changes between each (I run more forefoot on grass). I'm not sure of their impact on injury rates, but surface type obviously has some sort of consequence.