Hello. Looking for any advice or input on the following issue:
A bit of history: This is my 2nd season skiing. I have snowboarded prior to that for about 5 years. This season and last I have skied at least every weekend from Nov-May, sometimes 2-3 times a week and always at least 5-7 hours at a time or more. Always stayed in good skiing shape, and never was sore next day after skiing. All of last season and first half of this season I have spent learning and improving on-piste. I have gotten decently confident on just about any blue and black diamond groomed runs. After the initial period of a couple of month, I have stopped getting sore quads from riding in the back seat. Second half of this season, I wanted to concentrate on exploring more of the mountain and spent majority of my time skiing off piste.
Issue: My last 3 times skiing, towards the end of the day (last hour-hour and a half), my upper quads have been starting to burn. 2 of those 3 days were typical Pacific Northwest powder days, where the powder is wet and very heavy. The 3rd day was a 65F bluebird sunny day, with nice and slushy spring snow. 90% of the time on these 3 days were spent off piste on black diamond and blue runs. The soreness is exclusively on the upper quad, from the pelvis down to about mid quad. Lower quads, glutes, calves, hamstrings are not affected at all. But upper quads are burning when skiing during the last hour, where I have to take 2-3 brakes per run. The following day upper quads stay nice and sore also.
My question is: does off piste skiing, especially in heavy snow, require that much more muscle effort than say carving on piste? Or is it that I get in the back seat on steep off piste runs? My boots and skis have remained unchanged, so that leads me to believe that equipment/alignment is not an issue. (boots have been worked on by a boot fitter when I first got them) When I was first learning to ski, my trigger for being in the back seat was the burn in the lower quads, just above the knees, which settled in fairly quickly (a run or two). This went away after a while, and never came back, even during 3 day-all day ski trip. So is there some technique error that loose snow skiing may bring up, or is it just the extra effort or new stimulus to the muscles as a result of skiing in loose heavy snow? Thanks in advance for the help!