Department of Nutrition Sciences, The University of Alabama at Birmingham, Birmingham, AL, USA.
Department of Pathology and Center for Free Radical Biology, The University of Alabama at Birmingham, Birmingham, AL, USA.
Physiol Rep. 2020 Oct;8(19):e14574. doi: 10.14814/phy2.14574.
Exercise training improves health outcomes in individuals with obesity (IO); however, it remains challenging for IO to adhere to exercise. Thus, it is critical to identify novel strategies that improve exercise tolerance (ET) and adherence in IO. Beetroot juice (BRJ), high in inorganic dietary nitrate, consistently improves exercise performance in athletes, individuals with cardiopulmonary diseases, and nonobese lean individuals. These improvements may be explained by reduced oxygen uptake (VO ) during exercise, enhanced blood flow, and greater mitochondrial efficiency. To date, we are aware of no studies that have compared the effects of BRJ, sodium nitrate (NaNO3), and nitrate-depleted BRJ (PLA) for improving ET and cardiometabolic health in IO.
Determine if BRJ improves ET, exercise efficiency (EE), and cardiometabolic health in IO and identify possible mechanisms of action.
Vascular hemodynamic, submaximal- and maximal-exercise VO , and time to exhaustion (TTE) were assessed in 16 participants 2.5 hr following consumption of: 1) BRJ, 2) NaNO , 3) PLA, or 4) CON.
A significant treatment effect was observed for submaximal exercise VO (p = .003), and TTE (p < .001). Post hoc analyses revealed lower VO during submaximal exercise in BRJ compared to PLA (p = .009) NaNO3 (p = .042) and CON (0.009), equating to an average improvement of ~ 7% with BRJ. TTE was greater for BRJ compared to other treatment arms, PLA (p = .008), NaNO3 (p = .038), and CON (p=<0.001), equating to ~ 15% improvement with BRJ. No significant changes were observed for other outcomes.
Consumption of BRJ improved EE during submaximal exercise by 7%, and TTE by 15% compared to other conditions. These results suggest that BRJ may improve EE and exercise tolerance in IO.
运动训练可改善肥胖人群（IO）的健康状况；然而，IO 坚持运动仍然具有挑战性。因此，寻找提高 IO 的运动耐量（ET）和依从性的新策略至关重要。甜菜根汁（BRJ）富含无机膳食硝酸盐，可提高运动员、心肺疾病患者和非肥胖瘦人群体的运动表现。这些改善可能是由于运动期间减少了氧气摄取量（VO ）、增强了血液流量和提高了线粒体效率。迄今为止，我们还没有发现比较 BRJ、硝酸钠（NaNO3）和脱硝酸盐 BRJ（PLA）改善 IO 中 ET 和心脏代谢健康的研究。
确定 BRJ 是否可提高 IO 中的 ET、运动效率（EE）和心脏代谢健康，并确定其可能的作用机制。
在 16 名参与者中，在摄入以下内容 2.5 小时后评估血管血流动力学、亚最大和最大运动 VO 以及疲劳时间（TTE）：1）BRJ，2）NaNO3，3）PLA，或 4）CON。
亚最大运动 VO （p=0.003）和 TTE（p<0.001）观察到显著的治疗效果。事后分析显示，BRJ 组亚最大运动时 VO 较低（p=0.009）与 PLA（p=0.042）和 CON（0.009）相比，BRJ 组 TTE 大于其他治疗组，与 PLA（p=0.008）、NaNO3（p=0.038）和 CON（p<0.001）相比，BRJ 组 TTE 提高了约 15%。其他结果没有明显变化。
与其他条件相比，BRJ 可使亚最大运动时的 EE 提高 7%，TTE 提高 15%。这些结果表明，BRJ 可能改善 IO 中的 EE 和运动耐量。
