It's the Terrible Too's More than the Shoes

From The Science of Sport

"Shoes, running technique and so forth are factors in injuries, yes, but the only factor that is KNOWN to cause injury is training too long, too hard, too soon (or combinations of the three)....training is key and any runner who trains at the right level for their history and circumstances (this is where strength, flexibility, stability come into it), will not get injured."

More Support for Non-Linear Periodization

From ScienceDaily.com

To achieve the study's equivalent results by endurance training you'd need to complete over 10 hours of continuous moderate bicycling exercise over a two-week period. The "secret" to why HIT (high-intensity interval training) is so effective is unclear. However, the study by Gibala and co-workers also provides insight into the molecular signals that regulate muscle adaptation to interval training. It appears that HIT stimulates many of the same cellular pathways that are responsible for the beneficial effects we associate with endurance training.

Obey the Signs of Overtraining

From Human Kinetics

No device can measure your recovery status and readiness to train hard any better than your own body can. When your body is poorly recovered from recent hard training, you can always feel it. And when factors outside of your training, such as lack of sleep or job stress, compromise your capacity to perform, you can always feel that. Before you even lace up your shoes, you know that you’re not going to have a good day because of the heaviness, sluggishness, soreness, or low motivation you feel. Your body itself is an exquisitely crafted piece of technology whose primary function is self-preservation....It’s important that you learn to recognize these symptoms and get in the habit of obeying them.

Strike One for Objectivity

The Educated Runner

(Editor: This, from Owen Anderson, is simply the best summary of the barefoot running issue I've seen. As always, click the link above to read the full article.)

...it’s important to remember that most injuries in running are caused by an imbalance between the strain and micro-damage experienced by a muscle or connective tissue during training and the tissue’s ability to recover from such stress. This imbalance can occur when training is conducted shod – or barefooted! A weak or overly tight hamstring muscle which has been undone by excessive mileage won’t care if its owner was running barefooted or wearing shoes – it will still feel the pain.