Dear Osa community,
Although we’ve had some cold and wet days recently, I’m finding the earlier sunrise and morning birdsong energizing, and I’m excited to continue our conversation about exercise this week. I hope you enjoy!
Last week we briefly discussed a 2009 study by Kokkinos et al., in which aerobic capacity was found to be protective against death from any cause and even compensated for the additional mortality risk associated with factors such as diabetes and dyslipidemia. A group composed of some of the same researchers recently published a more comprehensive study on the very same topic in which they utilized data from a much larger population (750,302 vs. 4,631 from the 2009 study) which included both men and women as well as more racial groups. This study reached the same conclusion as the first but is applicable to a much more diverse group of people: in summary, greater cardiorespiratory fitness decreases mortality risk from any cause, for pretty much everyone. A particularly striking finding is that cardiorespiratory fitness mattered even more so than age, which we typically consider the greatest risk factor for mortality¹.
Given these dramatic findings, I wanted to discuss with you a bit more about what we mean when we talk about cardiorespiratory fitness and how nutrition factors in.
Cardiorespiratory fitness may be measured by a couple of different methods in the research setting, including “metabolic equivalents” (METs) and VO₂ max, but what each of these describes is the efficiency with which someone can use oxygen and fuel (carbohydrates, fats, or proteins) to generate energy. The translation of fuel and oxygen into usable energy is what is known in biochemical terms as oxidative phosphorylation and is also called the aerobic energy system. This is the system that can produce energy for long periods of time and so is the primary system relied upon for all exercise which is performed at an intensity that can be sustained for more than a couple of minutes. (Sprinting and other very high intensity exercises rely on anaerobic energy systems, which is a topic for another time). So, every time you take a brisk walk, jog, run, bike, swim, row, etc., you are primarily using your aerobic energy system. How well this system works determines your cardiorespiratory fitness, and this is affected by both how you train and how you eat. This week we’ll take a bite out of the big topic of nutrition, and next week we’ll discuss some training research and tips.
The topic of fueling for exercise is multi-faceted. Today we’re going to touch on micronutrients needed to run your aerobic system. The pathways of oxidative phosphorylation require a number of micronutrients to function. These micronutrients are needed for the action of enzymes which power the reactions that convert energy-containing molecules (i.e., the carbohydrates, fats, and proteins from your meal) into the body’s energy currency molecule, ATP (adenosine triphosphate). To do this, we need a variety of B-vitamins, several minerals–namely, magnesium, zinc, and selenium–and a couple of accessory nutrients which our bodies can make but which may be depleted under various conditions, and these are coenzyme Q10, alpha-lipoic acid, and carnitine. The richest source of B-vitamins is liver, but we also get these from other animal products including meat, seafood, and milk; and from legumes, leafy greens, and seeds. It is important to know that plants contain a lower density of B-vitamins and are lacking in vitamin B12, so those following vegan diets need supplementation, such as through fortified foods (nutritional yeast, e.g.) or supplements, to sustain healthy levels. Minerals are found in foods grown in soil, such as greens and root vegetables, whole grains, beans, nuts and seeds; and they are also found in… (you guessed it!) organ meats. Recall from a couple of weeks ago when we talked about declining mineral content of soil due to modern agricultural practices. This means we need to be extra mindful of our consumption of these foods and consider supplementation when we have evidence of deficiency*. If you would like to learn more about these micronutrients, here² is a narrative review which was written to inform the treatment of critical illness but is applicable to everyone concerned with optimal function of their energy pathways and contains a chart and graphics which I find helpful.
If you are having a hard time finding the energy to exercise as you would like to, considering the micronutrient sufficiency of your diet is one starting place. I hope this conversation is inspiring you to fuel your cells and move to your heart’s content! Please share it around and reach out with any questions or suggested topics for future newsletters.
Wishing you a beautiful week,
*Please know that this newsletter does not constitute clinical advice and is for educational purposes only. Please consult your healthcare provider about any nutritional and supplemental changes.
References
- Kokkinos, P., Faselis, C., Samuel, I. B. H., Pittaras, A., Doumas, M., Murphy, R., Heimall, M. S., Sui, X., Zhang, J., & Myers, J. (2022). Cardiorespiratory Fitness and Mortality Risk Across the Spectra of Age, Race, and Sex. Journal of the American College of Cardiology, 80(6), 598–609. https://doi.org/10.1016/j.jacc.2022.05.031https://pubmed.ncbi.nlm.nih.gov/35926933/
- Wesselink, E., Koekkoek, W. A. C., Grefte, S., Witkamp, R. F., & van Zanten, A. R. H. (2019). Feeding mitochondria: Potential role of nutritional components to improve critical illness convalescence. Clinical nutrition (Edinburgh, Scotland), 38(3), 982–995. https://doi.org/10.1016/j.clnu.2018.08.032 https://pubmed.ncbi.nlm.nih.gov/30201141/