Takes a long time for something like this to come up, at least for me. How could something that feels so right, natural (not sure how but it does) and beneficial be all that bad for you in the long term? You may go out feeling crappy but when you return often enough you feel better than when you started in mind and body. Even when you have some strains, pains, soft tissue injuries you rehab, heal and get back into it feeling better for continuing.
Not talking about just shorter cruising sessions but long, sessions in high winds, waves, wipeouts, etc. and over many years approaching a decade or more. At the same time, there is nothing to say kiters have to suffer this frequency of impact or trauma either through choice of riding style. I am having trouble thinking of another sport or activity that mirrors the frequency and type of body trauma that a kiter might undergo. Wakeboarding wipeouts, dirt bike, boarder cross snowboarding or skiing wipeouts, rodeo riding and the like. The intensity, type and duration of trauma and related injury varies among these activities.
Still, how much repetitious ACL, rotator cup trauma, rib fracture or ligamentous strains, spinal trauma, disk distention, nerve impingement and more abuse can and should a body put up with and over how many years? There are still more injuries that kiters report not uncommonly. Age and health factors into this in a big way as do the specifics of the injury, rehab and strangely even tolerance to pain. A high pain threshold isn't necessarily a good thing when it allows more extensive trauma. Also, the effects of some of this trauma can be cumulative over time. Screwups far in the past can stay with you and develop years later.
In these other activities people back off or ease off more extreme, impact prone expressions at some point, right? Perhaps prematurely after some particularly acute injury or at some point over time due to long term stresses? So, over the long term is repeated high speed water impacts a bad thing? The answer seems obvious and yet, there's the feeling your more frequently left with along the way that says maybe not that bad.
It would be good to get the views and experiences of guys that have been hitting kiting hard for a long time and had injuries along the way.