By Dirk Smith, MSc, SDL (He/Him).
Cardiovascular exercise has been getting quite a bad reputation lately, it is indeed strenuous and can be long and boring. It is often overlooked in favor of more trendy fitness programs including HIIT and Crossfit. People are quick to ditch a long cardio session for a something better or straight up lose motivation to do anything at all, but is cardio really all that bad?
Cardiovascular exercise has been apart of the human experience for thousands of years, both long endurance and shorter, high intensity cardio. From messengers running miles and miles between ancient cities, hunters chasing after animals and people crossing oceans with nothing but ores and the wind. Even today in many parts of the world, endurance running is a part of everyday life and it’s not just for athletes.
Cardiovascular endurance, as defined by the American College of Sports Medicine (ACSM) as "any activity that uses large muscle groups, can be maintained continuously, and is rhythmic in nature." Most common types of cardio include walking, running, swimming, cycling, and rowing.
What exactly does that mean? Well the body utilizes 3 systems to Creatine Phosphate system which is designed for extremely short burst of high intensity exercise (think of Usain Bolt running the 100m). It only lasts for 10-20 seconds before switching over to Anaerobic glycolysis which can maintain moderate-high intensity exercise for 30 seconds up to 2-3 minutes. Finally, the Citric Acid Cycle kicks in, using fat as the primary fuel source, you can sustain moderate amounts of exercises consistently for an extended period of time. The Citric Acid Cycle takes place within the mitochondria of the cells, which makes it the “powerhouse of the cell.”
Within the ACSM definition of cardio, which includes maintaining activity continuously the predominant system used during cardiovascular exercise is Aerobic glycolysis
By Dirk Smith
David "Dirk" Smith M.Sc, SDL, CSCS, (He/Him) is a sport psychology expert, strength & conditioning coach, swimming coach, sports diversity leader, published research scientist, teacher, writer, journalist, and athlete. He brings over 12 years of experience, education, and training to empower athletes to build self efficacy, strength, confidence, and express themselves through sport.