Sharing of a rant and observation from my perspective.
Every off-season I partake in training with the goal to keep in shape for skiing, prevent injury, and hopefully improve my buoy count. This has been going on now for 15ish years and throughout that time I've had mixed results. It's funny you can really work on something, for example strength through weight training, And it helps to a point but Somewhere along the line you achieve max results that transfer and the rest just makes you better at the training method and no longer helps skiing maybe even hindering. Skiing and sports are complex and most formal exercise is rudimentary. Movements such as squats or deadlifts are imperative to understand and be proficient at but endless cycles only benefit to a point. it's as if the basic motor patterns overdrive the inate reflexes we develop within our sport through practice. Genetically I think we respond differently to the same things so for some weight training is best others cardio and others yoga for example so I think there is no best training program for everyone. For me I respond best to some trail running and a variety of exercises but I think mostly an offseason where I learn something new and identify and challenge a weakness. Skiing is precision, balance and reaction. acquiring a leverage position upon completion of the turn and resisting the forces of the boat for acceleration all the while staying submax in order to stay in control allows you to manage and navigate the course. Essentially we connect the dots get in a good position and hold the force while we make adjustments to set up the next set of events. I realized last year that doing tons of reps and developing lots of power as is the objective for so many other sports isn't conducive for skiing. In response I've been focusing on holds using parallettes as in gymnastics, it made me realize a major weakness in core strength and flexibility. I can deadlift 3x body weight but a 20 second L-sit was very difficult. Additionally I've been spending some time bouldering at a climbing gym, again it's core strength, holds, problem solving and transfer of energy. We'll see what next year has in store.