The goal: Make your quads burn now so you can get more runs in later. Use a light bar or dumbbells if you’d like, but the point is not to build strength—it’s to get your lower-body muscles used to firing for 30-second to two-minute intervals, just like they’ll have to do on the slopes.
Drop into a squat (glutes back as if you’re sitting in a chair, chest lifted, knees tracking behind your toes) until your thighs are almost parallel to the floor. Lift to a quarter-squat position, and then drop again. Repeat for 30 seconds to two minutes, without coming all the way up to standing until the interval is over. Rest one minute, and repeat.
Take a large step forward with your right foot, and drop into a lunge (right knee over right ankle, torso perpendicular to the floor) until your right thigh is nearly parallel to the floor. Stand up, bringing your left foot forward next to your right foot. Repeat, this time stepping forward with your left foot. Continue lunging forward with alternating feet for 30 seconds to two minutes, turning around if you run out of space.