Nitric Oxide in Exercise Physiology

Abstract

Nitric oxide is an endogenous reactive nitrogen species found throughout the human body. Its role in human physiology at rest and during exercise has proven to be essential in maintaining human health and enhancing exercise performance. The bioavailability of nitric oxide can be enhanced via nitrate supplementation. Chapter 1 presents a detailed and critical review of the function of nitric oxide in skeletal muscle, mitochondria and redox state followed by a discussion of the literature investigating its effect of nitrate supplementation in endurance and resistance exercise. Final comments point to the need for a broader look into nitrate supplementation and its effect in resistance exercise in older adults. Chapter 2 explores the effect of chronic nitrate supplementation and resistance training on markers of skeletal muscle mitochondria, redox state and resistance exercise performance in older adults. The results suggest that nitrate supplementation does not provide any additional benefit to the mitochondrial or redox response to resistance training or enhance improvements in leg extensor exercises; however, our results confirmed findings that resistance training can alter the status of mitochondria in skeletal muscle via increases in mitochondrial content and alterations to mitochondrial remodeling in older adults. Therefore, we highlight the need for further investigation into the mitochondrial adaptations occurring with chronic resistance training in older adults.