Have you ever watched an endurance athlete compete and wondered about the science behind their impressive accomplishments? Maybe you got a chance to see — or participate in — October’s Medtronic Twin Cities Marathon! All human beings require oxygen to function, and in endurance exercise, this fundamental element takes on a particular importance. Read on to learn more about how this works!
Aerobic exercises, also known as “cardio,” are movements like running, walking, biking, and dancing — among others — that get your heart pumping faster and your breathing rate higher. The numerous benefits of aerobic exercise include stronger bones and muscles, better sleep, and improved mental health. Studies have also shown that aerobic exercise can decrease the risk of developing illnesses like heart disease and diabetes.
When aerobic exercise is sustained for a period of time, it’s called “endurance exercise.” There’s no set time or distance to endurance — it’s completely relative to the athlete and their sport. In running, for example, both the mile and the marathon are considered endurance events.
When an athlete breathes in, their lungs expand and fill with oxygen, which is then diffused into the bloodstream. The blood cells that meet this oxygen become oxygen-rich. As the heart keeps pumping, they’re whooshed throughout the body via the arteries, supplying oxygen to the working muscle cells. The muscles take this much-needed delivery in stride — it powers their contractions, thanks to an energy molecule called adenosine triphosphate, or ATP. As the athlete keeps breathing, their blood continues to be oxygenated and their muscles continue to be powered.
The body can also generate energy without oxygen, but this process is a little different. Anaerobic exercises are shorter movements performed at higher intensity bursts. Think weightlifting and sprinting. In anaerobic exercise, the muscles are powered by the breakdown of glucose molecules, or “blood sugar.” During this process, a molecule called lactate is produced. Lactate can appear in endurance athletes when oxygen isn’t delivered quickly enough to their working muscle cells. What results from this buildup is a more acidic cellular environment, which can lead to a burning feeling in the muscles.
Confused? Take a deep breath. As a biology professor recently reminded my class, the fact that our cells and organs are the ones navigating these everyday negotiations — and that they don’t require any of our brain power to perform their jobs — is something to be very thankful for. It’s pretty amazing. Your only job as an athlete? Find what feels good for your body and enjoy the benefits of being in motion.
