Upper Body
Cross-country skiers swing their arms and use ski poles to push off of the snow. This swinging motion helps a skier to gain momentum and rhythm in their stride. The triceps brachii is the large muscle on the back of the upper arm, connecting at the elbow. The biceps brachii forms the prominent muscle on the front of the upper arm. The triceps and biceps work together to aid in the diagonal cross country ski stride. When a skier uses the double poling technique (planting both poles at once to push off), they will mostly use the biceps. When using the skate ski technique, they will mostly use their triceps. The pectoralis major muscles, which are over the chest and deltoids (on the shoulders), are used in the pole planting technique.
Core
Having a strong core is an integral part of the cross-country skier's body, and if you don't already have sculpted abs, this is a great way to get them. The abdominal muscles, of which there are six extending from the ribs to the pelvis, are used quite a bit in cross country skiing, especially in the double pole plant technique. The gluteus maximus, the largest of the muscles on a skier's buttocks, is used extensively in the skate skiing technique and a little bit in all cross-country skiing. The latissimus dorsi muscles (lats), which are the two large mid-back muscles on either side of the spinal column, are also used, especially in double pole planting.
Lower Body
Cross country skiers have strong legs, as they are constantly pushing off with them to gain keep or gain forward movement. The gastrocnemius muscle, also known commonly as the calf muscle at the back of the leg below the knee, is used most vigorously in diagonal cross-country skiing. The sartorius muscle is a slender muscle that runs diagonally from the top outside of the thigh to the lower inside of the thigh and is used in the diagonal as well as skate skiing techniques. The rectus femoris runs from the knee cap up to the top (over the femur bone) of the thigh and is one of the four muscles that create the quadriceps--it is also used in the diagonal and skate ski methods.
