How to Build a Superhuman Athlete

Muscle Endurance

Former professional cyclist Lance Armstrong is no stranger to the medal podium, having won the Tour de France -- the world's largest cycling tournament -- a record seven times before retiring in 2005. The race is not for the faint of heart -- it takes place over 23 days and 21 stages, generally crisscrossing more than 1,864 miles through France and neighboring countries, and requires an almost inhuman amount of endurance.

Whether it's for running, cycling, swimming, or myriad other sports, scientists have boiled human stamina down to three main factors: maximal oxygen consumption, the lactate threshold (the intensity at which lactic acid starts accumulating in the blood stream), and efficiency (i.e., the amount of oxygen one needs to do the task -- in Armstrong's case, pedal his bike). A researcher tailed Armstrong for 13 years to figure out which of these three components was the most important for him.

Even after having undergone chemotherapy and surgery for testicular cancer, Armstrong still had an elite athlete's body: his maximal heart rate topped out at 200 beats per minute, pumping huge quantities of blood and oxygen to his legs; and his maximal blood lactate concentration was "remarkably low" in the trained state. However, the notable improvement made over that decades-plus period was Armstrong's muscular efficiency and a reduced body fat. Considering the Tour de France involves much uphill biking, these two changes contributed to an 18 percent improvement in his power-to-body-weight ratio, and that efficiency is thought to be what pushed Armstrong ahead of his competitors.

So what can we mortals do to realistically improve our muscle endurance?

Train these three areas, says Cutti: aerobic conditioning, power and speed, and competition-specific challenges. "If you're looking to build endurance, the focus is not to go as hard as you can for 30 seconds," he says. Instead, you can view your training from the "triangle approach": switch up between a lot of low-intensity exercises and a few high-intensity exercises. In other words, as the time spent working out decreases, the intensity of your exercising should increase. Vary your workouts -- athletes build up their endurance by targeting their weaknesses (and maintaining their strengths) from all angles. "You never want to just focus on one level," Cutti adds.