Clifford Tom, Allerton Dean M, Brown Meghan A, Harper Liam, Horsburgh Steven, Keane Karen M, Stevenson Emma J, Howatson Glyn
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
b Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Newcastle NE1 7RU, UK.
Appl Physiol Nutr Metab. 2017 Mar;42(3):263-270. doi: 10.1139/apnm-2016-0525. Epub 2016 Nov 9.
This study examined whether beetroot juice (BTJ) would attenuate inflammation and muscle damage following a marathon. Using a double blind, independent group design, 34 runners (each having completed ca. ∼16 previous marathons) consumed either BTJ or an isocaloric placebo (PLA) for 3 days following a marathon. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), muscle soreness, serum cytokines, leucocytosis, creatine kinase (CK), high sensitivity C-reactive protein (hs-CRP), and aspartate aminotransferase (AST) were measured pre, post, and 2 days after the marathon. CMJ and MIVC were reduced after the marathon (P < 0.05), but no group differences were observed (P > 0.05). Muscle soreness was increased in the day after the marathon (BTJ; 45 ± 48 vs. PLA; 46 ± 39 mm) and had returned to baseline by day 2, irrespective of supplementation (P = 0.694). Cytokines (interleukin-6; IL-6, interleukin-8, tumour necrosis factor-α) were increased immediately post-marathon but apart from IL-6 had returned to baseline values by day 1 post. No interaction effects were evident for IL-6 (P = 0.213). Leucocytes increased 1.7-fold after the race and remained elevated 2 days post, irrespective of supplement (P < 0.0001). CK peaked at 1 day post marathon (BTJ: 965 ± 967, and PLA: 1141 ± 979 IU·L) and like AST and hs-CRP, was still elevated 2 days after the marathon (P < 0.05); however, no group differences were present for these variables. Beetroot juice did not attenuate inflammation or reduce muscle damage following a marathon, possibly because most of these indices were not markedly different from baseline values in the days after the marathon.
本研究考察了甜菜根汁(BTJ)是否会减轻马拉松赛后的炎症和肌肉损伤。采用双盲、独立组设计,34名跑步者(每人之前大约完成过16次马拉松)在马拉松赛后连续3天饮用BTJ或等热量安慰剂(PLA)。在马拉松赛前、赛后以及赛后2天测量最大等长自主收缩(MIVC)、纵跳(CMJ)、肌肉酸痛、血清细胞因子、白细胞增多、肌酸激酶(CK)、高敏C反应蛋白(hs-CRP)和天冬氨酸转氨酶(AST)。马拉松赛后CMJ和MIVC降低(P<0.05),但未观察到组间差异(P>0.05)。马拉松赛后第1天肌肉酸痛增加(BTJ组:45±48与PLA组:46±39毫米),到第2天恢复到基线水平,与补充剂无关(P=0.694)。细胞因子(白细胞介素-6;IL-6、白细胞介素-8、肿瘤坏死因子-α)在马拉松赛后即刻升高,但除IL-6外,在赛后第1天已恢复到基线值。IL-6未观察到交互作用(P=0.213)。赛后白细胞增加1.7倍,赛后2天仍保持升高,与补充剂无关(P<0.0001)。CK在马拉松赛后第1天达到峰值(BTJ组:965±967,PLA组:1141±979 IU·L)且与AST和hs-CRP一样,在马拉松赛后2天仍升高(P<0.05);然而,这些变量在组间没有差异。甜菜根汁并未减轻马拉松赛后的炎症或减少肌肉损伤,可能是因为这些指标中的大多数在马拉松赛后几天与基线值并无明显差异。