I'll write about barefoot training and my college career. I'm a few years out of college now and planning on getting back into shape, but my college training makes a nice, compact case study.
Note: The barefoot/shod dichotomy is mixed up with hard/soft surfaces one in my training history. I once ran just two miles barefoot on the roads. Shortly after that I learned I had a metatarsal stress fracture. I don't know for sure that that one run caused it, but it scared me enough that I refused to run barefoot on anything harder than dirt. I would run barefoot whenever I was running on something soft, then put on shoes when I ran on something hard. Because of this, I can't say that barefoot is the key factor in what I'm about to describe, as compared to simply soft surfaces in general.
First a short back story, then barefoot vs. shoes.
I ran in DIII, so I was a competitive runner, but not at a high level. I mostly trained around 60 - 70 miles per week when things were going well. I improved consistently; my 5000m times were
- Frosh: DNR (4:32 1500m)
- Soph: ~16:20 or so
- Junior: 15:46
- Senior: 15:28
- 5th year: 15:21
I improved, but I was also consistently injured. I had to take between two weeks and three months off over and over again. I'd cross train in the swimming pool or on the bike, then return to training and competition when I was mostly-healed. I spent at least a third of my time injured.
Searching for a possible cure, I started running barefoot in the summer after my freshman year, motivated by reading online message boards (this was well before Born to Run) and talking with my running mentor. I began with short barefoot jogs on grass at a nearby park. The main thing I noticed at first was that my calves were consistently sore after barefoot runs. However, each week I could run a little further, and within three months I could do full, ten-mile runs barefoot without any soreness.
From that point on, I alternated between barefoot and shod running. I preferred barefoot running because I liked the feel of the contact with the ground and the lightness of my feet. I also came to believe that it was better for me in terms of injuries, so I tried to run barefoot when I could. Since my school was very small and much more academically-focused than athletically-focused, our team was fairly loosely-organized, and the coaches gave me a lot of liberty to train the way I wanted.
However, my teammates and friends only occasionally wanted to run laps around the field with me, and I did not want to run barefoot any other way. So, in order to run with my friends and train with my team, I would eventually decide that running in shoes was fine, then lace them up and go off running on the roads. Then I would get hurt.
A litany of my injuries includes achilles tendinitis, groin strain, ITB syndrome, metatarsal stress fracture, tibial stress fracture, unexplained foot pain, and maybe some minor ones I'm forgetting. It was actually a pretty consistent pattern - each major injury I suffered came after a period where I started doing more running on roads in shoes. I came to associate all hard surfaces with imminent danger.
However, when I say it was a consistent pattern, it would be more accurate to phrase it like this:
I believed strongly that running on soft surfaces was much better for
me. This belief was mostly built on personal anecdote, personal
observation, and considerable bias based on the prevailing attitude
among my running friends and reading articles and message boards
online. Because of this belief, I have a strong bias when examining
my own training logs. Yes, I can see a pattern when I look at my
training logs. And yes, despite acknowledging my own bias, I still
believe I am correct - running on roads and other hard surfaces is
much worse for me than running on trails or grass fields. But since I
mixed both forms of running day in and day out, and because injuries
form over long periods of time, I cannot unambiguously extricate the
two forms' separate influence on me. I do not know that running barefoot on
soft surfaces is better, but nonetheless I will swear it. While I
acknowledge the irrationality of this position, it is simply how I feel.
I made no attempt to run slowly while going barefoot. I ran lots of barefoot striders across the fields, sometimes sprinting all out. In fact it is a common practice among high school and college cross country runners to run their normal daily run in shoes, then finish with barefoot striders across a field; I've seen people doing it all across the country.
When I was my fittest, in my fifth year, I would run most days barefoot, going at a comfortable speed, then wrapping up the pace to something fast in the last couple miles of the run as long as I felt good. I would run up to about 90 minutes this way. To be specific, "a comfortable speed" back then meant about 7:00/mi on the slow side and 6:20/mi on the fast side. "Wrapping up the pace" over the last bit meant I might run that last two miles in 11:00 or 10:30 for a long run. So I had no qualms about running fairly fast while barefoot.
Then one or two days a week I would run harder workouts in shoes on the track or on a 1.5 mile trail nearby. That, with a little gym work, was the entirety of my training. There were no hills, no plyos, etc. I don't deny those things are useful training tools, but with just barefoot aerobic running and some straightforward speedwork, I got very fit compared to the rest of my college career, in which I employed more diverse training. (Despite this fitness, I raced only a few seconds faster that year than I did when still on the team, which is part of why I want to get back into that kind of shape and hit some good times again.)
I think the difference was that I stayed healthy for about eight straight months that fifth year, which was rare for me. Consistent training beats intense training, and I came to believe that running the majority of my miles barefoot on the grass protected me from the pounding my body would otherwise have taken on the roads.
Now, several years later, I am working on getting back into shape. I run on soft surfaces, sometimes in light shoes and sometimes barefoot depending on the venue. So there's my barefoot story.
I do have two more anecdotes, though.
First:
Two years ago I was living in Berkeley, so I went to see a big track meet the school was hosting. Afterwards, I went to the baseball field behind the track to do some barefoot jogging. A guy came out and started setting up hurdles for drills. When I got close, I realized it was Olympian Bolota Asmerom. I helped him set up the hurdles to have a chance to talk to him for a couple minutes. He commented on me running barefoot and said, "Hey, have you checked out those new shoes? The Vibrams? They're pretty sweet." So there's one endorsement for you.
Second:
While I was an undergrad, there were two grad students who would occasionally come run with us. They were brothers and both good athletes. One had been a highly-successful prep runner and gone on to compete in DI as a collegian. The other converted to running from college baseball after graduation. They were hardcore into barefoot running, and would happily run barefoot anywhere. One year on Thanksgiving they ran a 30-some mile route to the beach barefoot through the streets and sidewalks of Los Angeles. They were both big guys, too, maybe 180 pounds each. They told me that if you just look where you're going you probably won't step on much glass. I guess some people can pull off any sort of barefoot. They never converted me to barefoot running on the roads, even though they frequently offered to take me.
They started marathon training sometime around the beginning of my senior year. These guys were both pretty big jokers, a bit on the crazy side, although perhaps not as extreme as the young couple in Born to Run. (One of them did go on about the barefoot chapter in that book for half an hour during a barefoot run around the infield of the track.) I didn't think they were taking their marathon training too seriously; they were both grad students and therefore had little free time. Neither of them were on teams any more. They were just a couple of laid-back guys who loved being a bit eccentric and enjoying life. Sure, when I saw them run, they were still running real workouts and all, but I figured they probably weren't putting in the same time and energy they used to.
One day, having not run into them for a few weeks, someone linked me to a news story online. It was from the local paper where their marathon was. It featured a picture of the older brother, six-foot-two with a giant golden afro, hammering down main street through this town. Both barefoot, they had gone 1-2 in the marathon.