Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans
Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans
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DOI：
10.1152/japplphysiol.00046.2010
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发表时间：
2010-07-01
影响因子：
3.3
通讯作者：
Jones, Andrew M.
中科院分区：
文献类型：
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作者：
Bailey, Stephen J.;Fulford, Jonathan;Jones, Andrew M.
Bailey SJ，Fulford J，Vanhatalo A，Winyard PG，Blackwell Jr，DiMenna FJ，Wilkerson DP，Benjamin N，Jones AM在人类伸膝运动中，饮食补充硝酸盐可提高肌肉收缩效率。应用生理学杂志109：135-148,2010。2010年5月13日首次出版；DOI：10.1152/japplPhysiol.00046.2010。-这项研究的目的是阐明报道的在短期膳食硝酸盐(NO3-)补充后运动的氧耗降低的机制基础。在一项随机、双盲、交叉研究中，7名男性(年龄19-38岁)连续6天每天摄入500毫升富含硝酸盐的甜菜根汁(BR，5.1 mmolNO3-/天)或安慰剂(PL，硝酸盐含量可忽略不计)，并在最后3天完成一系列低强度和高强度“台阶”运动测试，以确定肌肉代谢(使用P-31-MRS)和肺摄氧量(V)对运动(2)的反应。在第4-6天，BR导致血浆[亚硝酸盐]显著升高(Mean+/-SE，PL 231+/-76 vs.Br547+/-55 nM；P<；0.05)。在低强度运动中，BR减弱了肌肉磷酸肌酸浓度的降低([PCR]；PL 8.1+/-1.2 vs.BR 5.2+/-0.8 mM；P<；0.05)和(V)的增加(PL 484+/-41 vs.BR 362+/-30ml/min；P<；0.05)。在高强度运动中，BR降低了[PCr](PL3.9+/-1.1vs.BR1.6+/-0.7 mm；P<；0.05)和(V)比Doto(2)(PL209+/-30vs.BR100+/-26ml/min；P<；0.05)慢波成分的波幅，并缩短了疲劳时间(PL586+/-80vs.BR734+/-109 S；P<；0.01)。据估计，低强度(PL296+/-58 vs.BR192+/-38亩M/S；P<；0.05)和高强度(PL607+/-65 vs.BR436+/-43亩M/S；P<；0.05)运动的总ATP周转率都较低。因此，在饮食补充N3之后，运动的O2成本降低似乎是由于肌肉产生的ATP成本降低。补充硝酸盐减少了肌肉代谢的干扰，使得高强度运动可以耐受更长的时间。
Bailey SJ, Fulford J, Vanhatalo A, Winyard PG, Blackwell JR, DiMenna FJ, Wilkerson DP, Benjamin N, Jones AM. Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. J Appl Physiol 109: 135-148, 2010. First published May 13, 2010; doi:10.1152/japplphysiol.00046.2010.-The purpose of this study was to elucidate the mechanistic bases for the reported reduction in the O-2 cost of exercise following short-term dietary nitrate (NO3-) supplementation. In a randomized, double-blind, crossover study, seven men (aged 19-38 yr) consumed 500 ml/day of either nitrate-rich beetroot juice (BR, 5.1 mmol of NO3-/day) or placebo (PL, with negligible nitrate content) for 6 consecutive days, and completed a series of low-intensity and high-intensity "step" exercise tests on the last 3 days for the determination of the muscle metabolic (using P-31-MRS) and pulmonary oxygen uptake ((V) over dotO(2)) responses to exercise. On days 4-6, BR resulted in a significant increase in plasma [ nitrite] (mean +/- SE, PL 231 +/- 76 vs. BR 547 +/- 55 nM; P < 0.05). During low-intensity exercise, BR attenuated the reduction in muscle phosphocreatine concentration ([PCr]; PL 8.1 +/- 1.2 vs. BR 5.2 +/- 0.8 mM; P < 0.05) and the increase in (V) over dotO(2) (PL 484 +/- 41 vs. BR 362 +/- 30 ml/min; P < 0.05). During high-intensity exercise, BR reduced the amplitudes of the [ PCr] (PL 3.9 +/- 1.1 vs. BR 1.6 +/- 0.7 mM; P < 0.05) and (V) over dotO(2) (PL 209 +/- 30 vs. BR 100 +/- 26 ml/min; P < 0.05) slow components and improved time to exhaustion (PL 586 +/- 80 vs. BR 734 +/- 109 s; P < 0.01). The total ATP turnover rate was estimated to be less for both low-intensity (PL 296 +/- 58 vs. BR 192 +/- 38 mu M/s; P < 0.05) and high-intensity (PL 607 +/- 65 vs. BR 436 +/- 43 mu M/s; P < 0.05) exercise. Thus the reduced O-2 cost of exercise following dietary NO3- supplementation appears to be due to a reduced ATP cost of muscle force production. The reduced muscle metabolic perturbation with NO3- supplementation allowed high-intensity exercise to be tolerated for a greater period of time.