I don't think weightlifting to an extreme level is necessary, but I think a good benchmark is if you can do multiple squat sets with the equivalent of your bodyweight on the bar. That's not going to make you massive, but it's a good level of strength. Doing squats will also improve your RoM. Every pro racer I see is basically a beast, they do a lot of plyo/agility stuff, but you can bet they do a lot of heavy lifts as well.
It is perhaps interesting to note that racers need to blast for a couple minutes, they are more like a 100m sprinter on land. We (most of us) need endurance, to have fun for a full day. More like a marathon runner.
But yes, squats with moderate, and I would say, low weight but many repetitions is an amazing exercise: core strength, length strength, you name it. Very complete. I do it with dumbells.
Definitely not "dry land" training But last summer I did a lot of stand up paddle boarding which was an excellent core builder.!
Funny that you said that! A few weeks ago, a "ski bum" (tending tables at the Stein Eriksen Lodge) suggested the same to me, for the same reasons! Wow. I was really surprised. I thought it was a lazy way to move around the lake. Good to know, and lucky you guys who live close to both mountains and lakes!
I go to a friggin' gym