Not only protective against trauma, modern helmets are also warm and comfortable. Conditioning programs for skiing should have a few components. Cardiovascular fitness from aerobic exercise is a good starting point. Bicycle exercise is low impact, but builds quadriceps strength and endurance. Leg press machines or squats build strength and power in the lower extremities as well.
Most gyms have machines to strengthen the hip abductors and adductors.
These muscle groups can also be strengthened with theraband or pulley resistance programs. Strong but flexible abdominal and back musculature ties the dynamically active lower extremities ties to the quieter rhythmic motions of the torso and upper extremities. Sit ups, crunches, leg ups and back extensions work together to provide this strength. The arms function primarily in balance and timing of turns. The pole plant initiates a turn.