I am not faulting Cullen. For starters, I have made the same mistake, more times than I care to remember. Also, the competitive runner who is at all injury prone has to take some risks with aches and sore spots, which crop up frequently in training. If you panicked over each one of them, you would never get into any kind of groove in your training. The best you can do is use your experience to develop the ability to guess right most of the time about whether ignoring a new pain is worth chancing. This ability depends not only on experience but also on your willingness to be honest with yourself. Backing off of training is an emotionally difficult call to make, and it is all too easy to talk yourself into believing that a pain is no big deal when in your heart of hearts you know it probably is. Guard against this tendency. Typically, competitive runners have to learn the hard way to be more cautious in dealing with incipient injuries. The older they get, the less often the gamble pays off. Eventually, they get tired of bearing the consequences of their bad risks and become less brazen. Dathan Ritzenhein suffered frequent foot stress fractures during and immediately after college. They started off as dull aches and, as he persisted in running, eventually became searing agonies that made running impossible. By 2006 he had learned his lesson. When a foot pain emerged during a spring track workout, he immediately ceased all land running and instead trained on an antigravity treadmill (more on this later in the chapter) for several weeks. The pain went away, he maintained his fitness, and his summer racing plans were salvaged. Taking the risk of training through pain is not equally worth doing at all times in the training cycle. Generally, there is less cause for risk-taking early in the training cycle, when you have plenty of time to make up for a brief reduction of training before your important races. Training through pain is most worth the risk during the peak period of training, when you are trying to do some work that must get done if you are to achieve your race goals and time to get that work done is running short. 4. Injuries follow change. The sheer unpredictability of injuries never ceases to amaze me. I always seem to get injured when I least expect it, and I seldom get injured when I do. But there is one general pattern of injury onset that makes injuries a little more predictable, hence avoidable, and it is that injuries tend to follow change. The most common changes that precipitate injuries are increases in running mileage and running intensity, but there are others. For example, I once sailed through most of a marathon training cycle injury free, then moved from one apartment located in a flat area to another located in a very hilly area three weeks before race day. After just a few days of running in my new environment, I developed an Achilles tendon strain that was clearly related to the unaccustomed stress of uphill running.