Some people believe that if you lift weights long enough, some type of musculoskeletal injury is inevitable. On the surface, this observation appears to make sense. The underlying cause of these exercise-related injuries is written off to a vague concept of "wear and tear." Simply put, years of consistent training especially that which features the lifting of heavy weights will gradually wear down the internal structure of joints and connective tissue. This results in chronic injury and pain. In truth, such a scenario is not inevitable, although with the passing years joints do become far more vulnerable to injury because of age-related changes in connective tissue integrity. Specifically, as you age connective tissue, which is a "dry" tissue not containing much water (in contrast, muscle tissue is 72% water with a far greater blood supply compared to connective tissue, explaining why muscle injuries tend to heal far more rapidly than joint or connective tissue injuries) becomes even drier with age and it gets worse when you get past age 40 or so. This increased stiffness of connective tissue sets the stage for chronic injuries and pain unless you make some adjustments in the way you stress the connective tissue and joints.
The entire concept of periodized training, where training is divided into periodic phases that feature varying amounts of weight lifted, how many repetitions are done, training volume, frequency, and intensity, is to spare connective tissue from the constant effects of having heavier weights stress this tissue. Muscle can recover far more rapidly than connective tissue, such as that found in joints, tendons, and ligaments, so you have to make some concessions to this biological fact of life. From what I've seen in my over 50 years of training experience, those who insist on training with very heavy weights year-round are usually the people who wind up with chronic injuries. Indeed, two prominent professional bodybuilders, Mike Mentzer and Dorian Yates, both favored a high-intensity style of training that featured using heavy weights and training to complete muscular failure. This system wasn't alternated with phases of lighter training but instead was done all year without a break. While both Mentzer and Yates were highly successful competitors, with Mentzer being the first bodybuilder to win the Mr.Universe contest with a perfect score, and Yates winning the coveted Mr.Olympia contest six consecutive years, both men had to retire from competition because of their cumulative injuries. When Yates announced his retirement he emphasized that it wasn't because of any fears of competition from others, but rather because his injuries prevented him from using the level of training intensity that he believed was necessary to achieve his best condition. As for Mike Mentzer, he confided to me that while he wanted to get back into great shape again, the pain from his chronic injuries, especially his shoulder pain, precluded this dream.
The dilemma about all this is that . . .