There is no question that if you train long enough as a runner or walker, you will almost certainly develop some sort of overuse injury in your lower body. Whether it is an IT band injury as you describe or plantar fasciitis, Achilles problems, or maybe piriformis syndrome, our legs take a lot of pounding and we are not always the best at learning to listen to our bodies when we get little warning signs that an injury may be coming. When an overuse injury does occur it can be quite painful, debilitating, and frustrating. One of the most frustrating parts of being injured is realizing the fitness you worked so hard to obtain may decrease or completely vanish if you do not do something to maintain your aerobic base. Indeed, the fear of losing fitness can be such a motivator to train again that runners and walkers are often unwilling to take time off or are tempted into resuming training too soon. When this happens, almost always the result is an injury that lasts much longer than it should or gets even worse.
Perhaps the best way to steer clear of overuse injuries is to build some cross training into your weekly routine, every week. Not just when you feel an injury coming on. If an injury still does occur you will already have a few “go to” activities you are proficient at, and will be able to maintain much, if not all, of your aerobic fitness.
Clearly, there is no better option than running/walking, when it comes to building and maintaining running/walking fitness. But there are some great alternatives that come relatively close, and the best alternatives are those that are most similar to the motion of running/walking. Aerobic activities like swimming and rowing will help to maintain your aerobic fitness, but they are so unlike running in their movements as they are upper body dominant sports, not lower body dominant like running/walking. Below are some of my favorite choices for training through an injury:
Pool running/walking is the most common alternative, and many professional runners practice pool running exclusively when injured. There are two types of pool running/walking: deep water, where the feet do not make contact with the bottom of the pool (thus no impact), and shallow water (usually waist high), where the feet do make contact with the bottom of the pool. When deep water pool running/walking an individual will frequently wear a floatation vest that allows them to stay upright in the water in a more natural running position. I believe shallow-water running/walking is preferable because it enables the runner to better maintain the adaptations to the repetitive impact of normal running (but significantly lower impact than being outside or using a treadmill), thus reducing the risk that new injuries occur after the runner returns to normal outdoor running/walking. However, because shallow pool running/walking is a low impact (versus a non impact) activity, it may not be possible to be pain free for all types of overuse injuries, particularly plantar fasciitis and Achilles problems.
Steep Uphill Walking
A number of research articles published in the last decade have clearly demonstrated that the brain uses precisely the same motor pattern to run or walk briskly on steep gradients. So the way to think about this is that when you are walking on a very steep incline (at least 12%) from a motor nerve and muscle firing pattern perspective running is the same as walking, and walking the same as running. Therefore, walking on a steep incline is a highly specific way to maintain running fitness. However, the impact force is greatly reduced compared with running, so steep uphill walking is possible with most injuries.
For some runners, it may seem that walking on a treadmill will decrease their fitness because they aren't maintaining their normal pace. However, if you put the grade at 12% set the speed for a brisk walk, and watch your heart rate monitor. You will soon find yourself in zone 2, just like your Saturday workout zone that is necessary for fitness adaptations, and your impact will be very low.
The only limitation of steep uphill running is that like shallow water pool running, while it is a low impact activity, it is not a non-impact activity. Thus it may not be done pain free with all injuries. For example, I would not advise someone with Achilles problems to engage in steep uphill walking.
The idea behind the many and varied elliptical trainers that now populate all fitness centers is that their motion mimics that of running with almost no impact whatsoever. Therefore you are able to maintain running fitness and the running motion effectively.
Cycling may seem less running specific than the other running/walking alternatives I have mentioned but there is no question it offers an alternative that is completely no impact and provides a break from the pounding of daily running. A number of high profile professional runners have incorporated cycling successfully into their training programs when injured, or simply as an effective way to cross train once per week. In 2004, while training for the New York City marathon, Meb Keflezighi relied a great deal on bike training to build and maintain fitness because of injury troubles. In that race he still finished second.
Best wishes for your continued training success.