Why Being Sore Doesn't Mean You're Getting Stronger
Many people who have become involved in the recent extreme fitness movement's popularity have grown accustomed to being sore all the time. The workouts are often done in a random fashion, which prevents the adaptation that would be necessary to prevent the soreness. But the workouts are perceived as “fun” and productive, because they are done in a group of (usually) friends, and since the workouts make you sore, the soreness comes to be perceived as a positive thing, too -- proof of your commitment, your courage, your membership in The Community, and your willingness to do what it takes to get the job done. Soreness therefore becomes the point itself, the Good at the end of the effort.
It's not. Not at all. Soreness is muscular inflammation, and inflammation has effects beyond just the inflamed tissue itself. DOMS across a large muscle mass is systemic inflammation. Like rheumatoid arthritis, it is a maladaptive stress on all the regulatory mechanisms of the body. It can cause cardiac symptoms, sleep apnea, hypertension, vascular disease, respiratory inflammation and bronchitis, and all kinds of unpleasantness. Occasional soreness is a normal part of training, but chronic systemic inflammation for weeks, months, or years on end is a very bad thing for your health, essentially the same thing as a disease. Our biology is not designed to function under these circumstances, and it cannot adapt to chronic soreness any more than it can adapt to starvation. You may get away with it for a while, especially if you're younger, but it takes a toll.
If you have been operating under the assumption that soreness means progress, re-evaluate your assumptions. Improved performance means progress, and while soreness is an occasional necessary evil, it should never be the objective.