Been having the same problem, all the years of skating and skiing finally catching up to me a little. I do get some knee inflammation and discomfort after long days on the hill, some days are worse than others but overall nothing too crazy, just enough to know I am aging. Aside from working out 2-3 days a week, eating somewhat healthy, here are a few things I have found helpful.
- Just to reiterate, not that it isn't painfully obvious, but weight training and some cardio help a lot in keeping the muscles strong, I feel as tho this helps with impact specifically in the sense that your muscles can take more of the load than your joints and ultimately offers more support.
- After a day on the hill, I like to stretch and also ice my knees for about 30 minutes to bring down that inflammation, also just feels great if I'm totally honest.
- Pop a couple Advil prior to shredding or after, either way just helps with inflammation. If you struggle with some knee discomfort even when you aren't skiing, Advil can help alleviate some of that while you ski. For me I noticed that helped a lot when training for soccer while I was in school after not doing shit for the summer, just helped prevent the soreness.
- Epsom Salt Baths, this one is a bit of a grey area, I've done them a few times, but basically your body absorbs magnesium which is supposed to help with inflammation. Although I've read that there really isn't much evidence to support this.
- Cold plunge, there is a quite a bit of research on this, but I have heard that cold plunges can have drastic effects on the brain and body including an increase in dopamine that lasts about 6 hours, improved alterness, and better circulation, which is supposed to help reduce inflammation.
- Good sleep, this is probably the most important. After a good day of shredding, and just in general, you need to get proper sleep on a consistent basis. There is a guy named Matt Walker who studies sleep, and I do not think I have heard someone present scientific facts on a topic as well as this guy has. Not only will you get better at skiing, you also reduce the risk of injury by 60%. I'd recommend the joe rogan podcast with him, it's mind blowing. The reason I say you will get better, is because when you go into deep sleep, your brain is replaying what you did that day some 3 times as fast as it does when you're awake, essentially it is a shortcut to muscle memory. If you think this is cap, listen for yourself.
Some of these things are kind of up for your own interpretation in terms of how effective they would be for you, but that said, I think it's all worth trying. I think the main key in all of it is consistency; working out, getting good sleep, and eating healthy on a regular basis is going to improve joint pain and just make you a better athlete all together.
Putting this into practice takes some effort and discipline, much easier said than done, but that's the name of the game.
