Skiers need endurance to last the full day but they also need that explosive leg strength, core strength and upper body strength. Adding strength training routines two to three times a week will work a combination of upper body, lower body, and core, will increase performance, add to endurance and help to avoid injury on the slopes.
One of my favorite quick and easy weight workouts is the picnic bench workout. A picnic bench can serve as a great piece of exercise equipment if you want a 15-20 minute “bodyweight” workout without having to go inside and be in a gym. Note that though we aren’t doing any specific ab exercises, challenging one’s balance as with the lunges and step-ups, is directly working one’s core. Focus on proper technique and intensity with each exercise.