Run Slow to Think Fast

Apparently, in the evolutionary race for survival, humans ditched their fur to become elite endurance runners capable of chasing down prey in the scorching heat of the African savannah. I challenge any of you to test this hypothesis during an Austin summer when every step I take on the trail after 10 a.m. makes me feel like I’m on a one-way trip to the center of the sun.

While most of us no longer need to run for dinner, the debate between High-Intensity Interval Training (HIIT) and Zone 2 cardio is a fire that never stops burning in the fitness world.

Recent research suggests that HIIT offers significant advantages in reducing the risk of cardiovascular events and improving metabolic function. A meta-analysis found that HIIT was more effective than moderate-intensity continuous training in improving cardiorespiratory fitness and markers of cardiometabolic health. Similarly, additional studies concluded that HIIT enhances mitochondrial function and glucose metabolism more effectively than low-intensity exercise.

But let’s not overlook zone 2 cardio. Aside from being popular podcast fodder, it works: a study following 1,098 healthy joggers and 3,950 healthy non-joggers for 12 years revealed that light and moderate joggers had lower mortality rates than sedentary individuals and strenuous joggers. Furthermore, an additional study in 2021 found that adults who engaged in moderate-intensity physical activity had better mental health outcomes, including reduced symptoms of depression and anxiety, compared to those who primarily engaged in vigorous-intensity exercise.

Want to know what I think is the true benefit of running slower? Creating a mental sanctuary. Carving out a mental oasis — a sacred space where I can be alone with my thoughts, like a monk in a mountain monastery. During these runs, I reflect on yesterday’s conversations, letting the ideas marinate in my mind. New insights bubble to the surface, like geysers in Yellowstone. I plan my day, fortifying my mental defenses against the challenges that lie ahead, like a general preparing for battle.

It’s been called “constructive internal reflection,” a process that activates the brain’s default mode network. This network is associated with autobiographical memory, self-referential thought, and future planning.

Our society glorifies busyness, multitasking, and hustle culture. Lower-intensity cardio might let you declutter your mind and find clarity in the chaos. So, the next time you lace up your running shoes, consider slowing down and embracing the science-backed benefits of zone 2 cardio for your physical and mental health.