I find it funny that so many “racers” try to train all winter in the base mode. They tend to insist on doing this on the road. So when it’s freakin’ 25 F in the am, they are stacking on clothes to ride their road bike for 4 or 5 hours. Dumb. Most of them don’t even get into the aerobic zone. They spend most of their time freezing their butts off doing a 4 to 5 hour active recovery from a ride they never did.
I prefer to hit the trail. It’s much warmer due to the slower speeds, but the pace is generally at the top end of the aerobic zone just below the ventilatory threshold. Every now and then you’ll have to gasp for air up a steep climb, but rarely do you fry yourself.
Yesterday was a beauty. 4:30 ride time, 4 miles of pavement. No loops or repeats on any trails. Ate about 2000 kcal when I got home. A bit more sun on the face but I remembered to wear sunscreen this time.