The Seduction of Soft

Like you, I love to run on trails.

Well, actually, I love to run on trails that aren't too rocky. (I still have memories -- and scars -- from hard, injurious falls on otherwise very nice trails). I love to run on trails, unless, that is, they are so narrow that a group has to go single-file for miles on end, and even a solitary runner is constantly ducking low branches. I enjoy the ups and downs of trails, except the steep embankments where one needs to use all fours to ascend and a parachute or rope ladder to descend.

I like dirt trails, but if a trail has too much mud, I might choose to run on the roads instead. And of course, for many months of the year when trails are covered with snow, or worse, ice, I don't even consider them an option. If I had to hazard a guess, I would say that I do roughly 80% of my annual running mileage on roads, 10% on a track and 10% on trails or grass.

I ponder these things after reading an article in the NY Times this morning questioning the common wisdom that running on trails is better than running on other surfaces. The folks at LetsRun.com dismiss the article outright, calling it "Bad Training Advice." You can read the article yourself, at the following link.

For Runners, Soft Ground Can Be Hard on the Body

I don't think the article is especially insightful, but it does raise an interesting question: what is the benefit of running on trails compared to a harder, more even surface? Have we all just accepted as gospel that running on soft trails is superior to road or track?

Coincidentally, a few days ago I received an email one of my Concord Academy runners. This runner is convinced that she will get injured if she runs on roads, and wants to run as much as possible on grass or trails. I find this to be a surprisingly common feeling among high school runners. In my response, I agreed that trails were very nice, but I also said that I didn't consider running on soft surfaces to be a fail-safe strategy for avoiding injuries. Specifically, I didn't think that the SOFTNESS of the surface was the most important factor. Instead, I mentioned the need for gradual adaptation to mileage, the need to strengthen the muscles of the foot and lower leg to be able to stabilize the body effectively at impact, the role of proprioception, and so on...

And I suggested that it was the UNEVEN nature of trails (not necessarily whether they were harder or softer) that made them different than roads. I thought that the uneven surface would give more variety to one's footstrike, hence, a better workout for the feet and less risk of overuse in the muscles, ligaments, and tendons of the knee and hip. (And by this same logic, runners will sometimes consider a rolling course to be slightly less stressful than a pancake flat course... but I digress.)

Of course, I couldn't prove any of this.

The other reasons to run on trails might be even more compelling. To enjoy the outdoors in a more agreeable environment, to avoid cars and exhaust, to take in the scenery, to introduce variety into one's running. These are perfectly good reasons to run on trails, even if the training effect is elusive.

And then there's the specificity of training. If one is preparing to race on soft surfaces for cross-country, it only makes sense to practice running on those surfaces. But for road runners, perhaps trails are not so necessary.

It's interesting how, when we think about running, we think that "soft" is automatically better than "hard." I remember a time when running shoes were being touted as "pillows for your feet." The impact forces of running are pretty severe; shouldn't your shoes be soft to cushion the blow? Nowadays, the trend is toward less shoe and letting the natural mechanics of the unshod foot handle the stress of landing, but it wasn't always that way.

In the end, isn't the whole question a little fatuous? We run where we like because that's where we like to run. Sometimes it's easier on the mind and body to run on trails (like now, in the summer) and sometimes it's a bear (like one winter trail run where I nearly ended my running career by spraining an already tender ankle). It's great to be able to do long runs off-road and I really enjoy the variety, but in January I get by on a restricted diet of runs on Comm Ave, I don't fall apart. There are no magic shoes to solve all our running problems or make hard training easy, and, sadly, you can still get hurt even if you run all your miles down a garden path strewn with rose petals.