Dr. Naomi Parrella, M.D., and Mike Giardina discuss the impact of disrupted circadian rhythms on metabolic flexibility at the 2022 CrossFit Games.
Dr. Parrella starts by explaining how important metabolic flexibility is for physical performance, recovery, and avoiding disease. Each one of these activities requires energy, she explains, and metabolic flexibility allows the body to create energy from different fuel sources, depending on energy needs and what fuels are available.
Metabolic flexibility is dependent on healthy mitochondria, microscopic organelles that produce most of the energy required to power cells. Usually, we focus on exercise and nutrition to improve mitochondrial function and, therefore, increase metabolic flexibility. This is because exercise and nutrition have a large impact on mitochondrial health — but so do circadian rhythms, adds Dr. Parrella.
Circadian rhythms are naturally occurring cycles in the human body. These cycles can be understood on a daily, monthly, or seasonal basis. In our current state, with steady levels of stress, constant distractions, and shift work, our circadian rhythms can be disrupted. Maybe this sounds like you: You work out hard five to six days a week, you eat pretty well, but you work a stressful job, your sleep quality is questionable, and you have no way to manage stress. Though you’re working out hard, your waistline is increasing, labs are going the wrong way, and you feel like you have no energy. Irregular sleeping patterns and the inability to manage stress disrupt the body’s natural cycles, keeping it guessing and unsure how to perform. This dysregulation can lead to mitochondrial damage, resulting in a higher risk of chronic disease.
According to Dr. Parrella, you need to de-escalate before adding more to your plate. Though exercise and nutrition have a large impact on your health, it is also very important to focus on other lifestyle factors such as sleep and stress management. In this case, it might be more important to slow down a bit, focus on rest, find ways to manage stress, and let your body regain homeostasis before incrementally ramping it back up.
Dr. Naomi Parrella: Circadian Rhythms and Metabolic Flexibility