When you hear the word "endurance," what comes to mind? Completing a marathon and barely being out of breath? Your ability to do infinite sets of bench presses? Or perhaps just being able to finish a Spinning class without feeling completely wiped out? Clayton Horton, director of Greenpath Yoga Studio in San Francisco and a former triathlete and competitive swimmer, states that endurance is simply "the ability to persevere," whether doing an aerobic or an anaerobic activity. Many athletic endeavors are a combination of both aerobic and anaerobic exercise. Try to think of your body's energy systems in terms of a time continuum, says Robert F. Zoeller, Ph.D., an assistant professor of exercise physiology at Florida Atlantic University. "Purely anaerobic activities last less than a minute, such as sprinting, most types of weight lifting, throwing a baseball, or spiking a volleyball," he says.
"However, as the duration increases beyond several minutes, the contribution of anaerobic metabolism decreases while that of aerobic metabolism increases." Something that requires around four to five minutes to complete, like running the mile or swimming a 400-meter freestyle, relies on both energy systems. Activities that are sustained for more than 20 minutes are generally considered aerobic, although there are exceptions. For example, basketball requires aerobic endurance as well as quick bursts of speed and the ability to jump, which is anaerobic. The greater your aerobic and anaerobic endurance, the better able you are to sustain exercise for a prolonged period of time. Improving your endurance can make your cardiovascular and respiratory systems more efficient and decrease both your resting heart rate and stress levels; it can also increase your metabolism, help you maintain a healthy posture, reduce fatigue, and prevent injuries and back problems.
Yoga can help improve your endurance because it can increase stamina on several different levels—physical, physiological, and mental—depending on your specific needs. For example, one of the keys to endurance is to better utilize your oxygen intake. The body relies on oxygen for producing energy while exercising, and so a person with good endurance has a greater capacity to deliver oxygen to the working muscles that make use of this oxygen during exercise. This is one of the main reasons why an unfit person fatigues much sooner than someone in better shape, and it is also why an athlete can sometimes surpass competition of equal talent.
Dean Karnazes, a regular competitor in ultra-marathons in physically demanding locations such as the South Pole and Death Valley, believes his yoga practice-especially the breathing aspect-allows him to use oxygen more efficiently and ultimately improves his overall performance. "My feeling is that yoga helps you to better utilize your oxygen intake, delivering it or transferring it to all the cells that need it for metabolism," he says.
More specifically, Horton explains that yoga improves the respiratory system by creating more room for it to function. "It is hard to take a good breath when your body won't let you," he explains. Horton likens the body to a container in which we try to make more space. "If your rib cage, diaphragm, or spine is stiff, lung capacity is reduced by your physical constrictions and limitations," he says. "Yoga breathing lengthens our bodies through deep inhalations and exhalations, as if we are making ourselves bigger from the inside out and therefore making more room in the internal container for a better breath.
"Being conscious of the breath allows our body to breathe better," says Horton. "Conscious breath teaches you to pay attention to the quality of your breath, and you learn to observe and perhaps even manipulate your breathing during physical activities." For improving endurance through better breathing, Horton suggests asanas that enhance both range of motion and lung capacity by opening the chest and rib cage. These include Urdhva Dhanurasana (Upward-Facing Bow Pose), Ustrasana (Camel Pose), Urdhva Mukha Svanasana (Upward-Facing Dog Pose), as well as Eka Pada Rajakapotasana (One-Legged Pigeon Pose).
However, endurance is not only about breathing better. Developing the muscles so they are stronger and suppler so that they do not fatigue as quickly is equally as important. When it comes to using yoga to improve muscle endurance, Horton recommends focusing on any asanas that promote a lengthening of muscles in the body, such as Parsvakonasana (Side Angle Pose), as well as stabilizing and strengthening poses that develop core strength, such as Navasana (Boat Pose).
In addition Horton feels that yoga improves one's endurance by helping athletes to relax, preserve energy, and better concentrate—especially in demanding circumstances. "Yoga gives you the mental strength to be still and to concentrate in the midst of a difficult pose or while your muscles are burning," he explains. "With yoga, you learn the ability to observe the patterns of tension in the body that take away from efficiency.
"It is important for athletes not to be distracted. Yoga can help you to sit back and be the witness or to observe and be
a little clearer and make better decisions, like being able to pace yourself during a 10K run or a long workout."
Nancy Coulter-Parker is Group Director of Retail Media and Group Editorial Director at New Hope Natural Media, and a regular contributor to Yoga Journal.