Tuesday night, I skied my favorite trail in the Carleton Arb, a nice route along the Cannon River. As you might recall from a facetious race report, the mostly-flat trail does go up and down a substantial but by no means brutal hill, making it hella fun to doublepole. I usually do two out-and-backs, which sums up to 13.7 kilometers or about 8.3 miles. Depending on intensity, trail conditions, snow cover, and other factors, this usually takes me less than an hour - a good solid workout.
On Tuesday, the trail was entirely ice except for a few patches of dry drift snow. In other words, it was fast. I did one leg of the out-and-back - the leg that goes up the big hill, not down it - in a flat 14 minutes, about two minutes faster than I'd ever done it before. Without even really trying, I zoomed up the hill in 3:15, a full forty-five seconds quicker than I usually climb it going pretty hard. I had to take a little detour onto another trail to get a full hour in. Doing the math later, I found that, over the 1:00.16 workout, I had averaged a pace of 4:11 per kilometer. According to my heart-rate monitor, my average HR was just 133, and I had burned 600-some calories (a dubious metric, given the vagaries of calorie counting). More subjectively, I just didn't feel very taxed by the workout and concluded immediately that I'd do the same workout on Wednesday night.
Not quite "famous last words," but perhaps "obscure and bad advice to self." Tonight, the trail was in utterly opposite shape: the ice was now concealed by a couple inches of dry, very cold snow that had fallen during the day. Dry, cold snow is very, very slow snow, which I realized when my first pole plants advanced me maybe two feet down the trail. "No problem!" I said to myself (out loud, which you can do when you're alone in the woods): "This'll be a good long workout." And was it: I did exactly the same route right down to the detour, frequently felt like I was really really and/or too hard, got hellaciously hungry at about 45 minutes, and finished in 1:16.52 - more than 15 minutes slower than the night before. My monitor showed an average HR of 140 and that 900-calorie burn. My average pace was 5:20/km - well over a minute slower per k.
Just for giggles, I used my tired arms to calculate the speed per kilometer of Jørgen Aukland, who won the Vasaloppet on Sunday. Over 90 kilometers (not a misprint!), he averaged 2:49 per kilometer. In slow snow. On a flat course with a couple decent climbs.
I think this summer's workout regime just changed.