The term “V02 Max” represents the maximum amount of oxygen our lungs can take in in one breath. The suggestion is the greater the V02 Max, the healthier and more efficient we are at circulating oxygen to the body. At higher altitudes, athletes are more efficient at oxygen transport due to the lower oxygen levels resulting in a greater Vo2 Max at sea level.
If this is the case, and considering the high altitudes Santa travels, he has developed amazing lung capacity and efficiency at oxygen transport. In addition, it takes a strong core and amazing flexibility to perform the twists and turns he does to inch down the chimney. Simply put, Santa enjoys a level of fitness reserved for elite athletes.