Dietary Nitrate Supplementation and Exercise-Related Performance

Preworkout dietary nitrate magnifies training-induced benefits to physical function in late postmenopausal women: a randomized pilot study

To inform end points for future work, we explored the utility of preworkout (i.e., an acute dose before training) beetroot juice (BRJ) combined with exercise (BRJ + EX) to augment indices of physical function in postmenopausal women compared with exercise only (EX). A two-arm pilot study was used to compare 24 postmenopausal women following an 8-wk, circuit-based exercise intervention. Participants were randomized to BRJ + EX (n = 12) or EX (n = 12). BRJ + EX participants consumed 140 mL of BRJ 120-180 min (only) before training for 7 wk, then discontinued during the final week to mitigate carryover effects. Physical function indices were 6-min walk test (6MWT), estimated V̇o2peak, heart rate recovery (HRR), and maximal knee extensor power (Pmax). A treadmill task was used to measure V̇o2 on-kinetics wherein mean response time (MRT) coincided with the duration to reach 63% of steady-state V̇o2. Results showed greater changes (Δ) among BRJ + EX participants for 6MWT distance (40 ± 23 m vs. 8 ± 25 m; P = 0.003, d = 1.35), ΔV̇o2peak (1.5 ± 0.9 mL·kg-1·min-1 vs. 0.3 ± 1.0 mL·kg-1·min-1; P = 0.008, d = 1.20), and ΔHRR (-10 ± 6 beats/min vs. -1 ± 9 beats/min; P = 0.017, d = 1.05). Large and medium effect sizes favoring BRJ + EX were detected for ΔPmax (P = 0.07, d = 0.83) and ΔMRT (P = 0.257, d = 0.50), respectively. In postmenopausal women, BRJ + EX appears to magnify some adaptive benefits to physical function including aerobic capacity and recovery beyond that of training without BRJ. Investigation into contributing mechanisms is needed.NEW & NOTEWORTHY Though exercise training represents the principal strategy to combat age-related decline, the attendant effects of menopause weaken aspects of exercise adaptation compared with premenopausal women and age-matched men. Here we provide important initial evidence that preworkout (i.e., an acute dose before training) beetroot juice coupled with an 8-wk, circuit-based exercise training intervention may uniquely benefit late postmenopausal women by enhancing indices of physical function including aerobic capacity and recovery.

Oxidative stress and aging: synergies for age related diseases

Aging is characterized by a progressive decline in physiological function and underlies several disabilities, including the increased sensitivity of cells and tissues to undergo pathological oxidative stress. In recent years, efforts have been made to better understand the relationship between age and oxidative stress and further develop therapeutic strategies to minimize the impact of both events on age-related diseases. In this work, we review the impact of the oxidant and antioxidant systems during aging and disease development and discuss the crosstalk of oxidative stress and other aging processes, with a focus on studies conducted in elderly populations.

Exploring the Impact of Alternative Sources of Dietary Nitrate Supplementation on Exercise Performance

An increase in the level of nitric oxide (NO) plays a key role in regulating the human cardiovascular system (lowering blood pressure, improving blood flow), glycemic control in type 2 diabetes, and may help enhance exercise capacity in healthy individuals (including athletes). This molecule is formed by endogenous enzymatic synthesis and the intake of inorganic nitrate (NO3-) from dietary sources. Although one of the most well-known natural sources of NO3- in the daily diet is beetroot (Beta vulgaris), this review also explores other plant sources of NO3- with comparable concentrations that could serve as ergogenic aids, supporting exercise performance or recovery in healthy individuals. The results of the analysis demonstrate that red spinach (Amaranthus spp.) and green spinach (Spinacia oleracea) are alternative natural sources rich in dietary NO3-. The outcomes of the collected studies showed that consumption of selected alternative sources of inorganic NO3- could support physical condition. Red spinach and green spinach have been shown to improve exercise performance or accelerate recovery after physical exertion in healthy subjects (including athletes).

Regulatory effects of curcumin on nitric oxide signaling in the cardiovascular system

The continuously rising prevalence of cardiovascular disease (CVD) globally substantially impacts the economic growth of developing countries. Indeed, one of the leading causes of death worldwide is unfavorable cardiovascular events. Reduced nitric oxide (NO) generation is the pathogenic foundation of endothelial dysfunction, which is regarded as the first stage in the development of a number of CVDs. Nitric oxide exerts an array of biological effects, including vasodilation, the suppression of vascular smooth muscle cell proliferation and the functional control of cardiac cells. Numerous treatment strategies aim to increase NO synthesis or upregulate downstream NO signaling pathways. The major component of Curcuma longa, curcumin, has long been utilized in traditional medicine to treat various illnesses, especially CVDs. Curcumin improves CV function as well as having important pleiotropic effects, such as anti-inflammatory and antioxidant, through its ability to increase the bioavailability of NO and to positively impact NO-related signaling pathways. In this review, we discuss the scientific literature relating to curcumin's positive effects on NO signaling and vascular endothelial function.

A review on nitrates' health benefits and disease prevention

Dietary nitrates (NO3-) are naturally occurring compounds in various vegetables, especially beetroot, which is mainly supplemented in the form of BRJ. Dietary nitrates (NO3-) play a crucial function in human physiology. On consumption, nitrates (NO3-) undergo a conversion process, producing nitric oxide (NO) via a complex metabolic pathway. Nitric oxide (NO) is associated with many physiological processes, entailing immune modulation, neurotransmission, and vasodilation, enabling blood vessel dilation and relaxation, which boosts blood flow and oxygen delivery to tissues, positively influencing cardiovascular health, exercise performance, and cognitive function. There are various analytical processes to determine the level of nitrate (NO3-) present in dietary sources. The impact of dietary nitrates (NO3-) can differ among individuals. Thus, the review revisits the dietary source of nitrates (NO3-), its metabolism, absorption, excretion, analytical techniques to assess nitrates (NO3-) content in various dietary sources, and discusses health effects.

Effects of dietary supplements on athletic performance in elite soccer players: a systematic review

Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support yohimbine supplementation or the use of Resurgex Plus® to improve athletic performance in elite soccer players. Still, more well-designed research with elite soccer players is needed to improve support and advice regarding the use of dietary supplements for athletic performance enhancement.

Hesperidin Functions as an Ergogenic Aid by Increasing Endothelial Function and Decreasing Exercise-Induced Oxidative Stress and Inflammation, Thereby Contributing to Improved Exercise Performance

The regulation of blood flow to peripheral muscles is crucial for proper skeletal muscle functioning and exercise performance. During exercise, increased mitochondrial oxidative phosphorylation leads to increased electron leakage and consequently induces an increase in ROS formation, contributing to DNA, lipid, and protein damage. Moreover, exercise may increase blood- and intramuscular inflammatory factors leading to a deterioration in endurance performance. The aim of this review is to investigate the potential mechanisms through which the polyphenol hesperidin could lead to enhanced exercise performance, namely improved endothelial function, reduced exercise-induced oxidative stress, and inflammation. We selected in vivo RCTs, animal studies, and in vitro studies in which hesperidin, its aglycone form hesperetin, hesperetin-metabolites, or orange juice are supplemented at any dosage and where the parameters related to endothelial function, oxidative stress, and/or inflammation have been measured. The results collected in this review show that hesperidin improves endothelial function (via increased NO availability), inhibits ROS production, decreases production and plasma levels of pro-inflammatory markers, and improves anaerobic exercise outcomes (e.g., power, speed, energy). For elite and recreational athletes, hesperidin could be used as an ergogenic aid to enhance muscle recovery between training sessions, optimize oxygen and nutrient supplies to the muscles, and improve anaerobic performance.