HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana.
Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
J Strength Cond Res. 2018 Aug;32(8):2243-2249. doi: 10.1519/JSC.0000000000002226.
Shei, R-J, Paris, HL, Beck, CP, Chapman, RF, and Mickleborough, TD. Repeated high-intensity cycling performance is unaffected by timing of carbohydrate ingestion. J Strength Cond Res 32(8): 2243-2249, 2018-To determine whether carbohydrate (CHO) feeding taken immediately before, early, or late in a series of high-intensity cycling exercises affected cycling performance. A total of 16 trained, male cyclists (>6 hours postprandial) performed 3-, 4-km cycling time trials (TT1, TT2, and TT3) separated by 15 minutes of active recovery on 4 separate occasions. Carbohydrate feeding (80 g) was given either before TT1 (PRE1), before TT2 (PRE2), before TT3 (PRE3), or not at all (control, CTL). Treatment order was randomized. Sweet placebo was given before the other TTs. Blood glucose (BG) concentration was measured before each trial. Mean power output (Pmean) and time to completion (TTC) were recorded. Pmean was higher in TT1 compared with TT2 (p = 0.001) and TT3 (p = 0.004) in all conditions, but no differences were observed between treatments. Time to completion was lower in TT1 compared with TT2 (p = 0.01), but no other differences in TTC (within or between treatments) were observed. Within CTL and PRE1, BG did not differ between TT1, TT2, and TT3. In PRE2, BG was significantly higher in TT2 compared with TT1 (p = 0.006), in TT3 compared with TT1 (p = 0.001), and in TT3 compared with TT2 (p = 0.01). In PRE3, BG was significantly higher in TT3 compared with TT1 and TT2 (p = 0.001 for both). Given that performance was not influenced by the timing of CHO ingestion, athletes engaging in repeated, high-intensity cycling exercise do not need to ingest CHO before- or between-exercise bouts; furthermore, athletes should refrain from ingesting CHO between bouts if they wish to avoid a rise in BG.
谁，R-J，巴黎，HL，贝克，CP，查普曼，RF 和米克尔伯勒，TD。重复高强度的自行车运动表现不受碳水化合物摄入时间的影响。J 力量与调节研究 32（8）：2243-2249，2018-为了确定碳水化合物（CHO）喂养是否在一系列高强度自行车运动前、早或晚摄入会影响自行车运动表现。共有 16 名受过训练的男性自行车手（餐后 6 小时以上）在 4 个不同的场合，分别进行了 3、4 公里的自行车计时赛（TT1、TT2 和 TT3），每次间隔 15 分钟的主动恢复。CHO 喂养（80 克）分别在 TT1 之前（PRE1）、TT2 之前（PRE2）、TT3 之前（PRE3）或根本不给予（对照，CTL）。治疗顺序是随机的。在其他 TT 之前给予甜安慰剂。在每次试验前测量血糖（BG）浓度。记录平均功率输出（Pmean）和完成时间（TTC）。在所有条件下，TT1 的 Pmean 均高于 TT2（p=0.001）和 TT3（p=0.004），但治疗之间无差异。与 TT2 相比，TT1 的完成时间更短（p=0.01），但在 TTC 内（在治疗之间）没有观察到其他差异。在 CTL 和 PRE1 中，BG 在 TT1、TT2 和 TT3 之间没有差异。在 PRE2 中，与 TT1 相比，TT2 的 BG 显著升高（p=0.006），与 TT1 相比，TT3 的 BG 显著升高（p=0.001），与 TT2 相比，TT3 的 BG 显著升高（p=0.01）。在 PRE3 中，与 TT1 和 TT2 相比，TT3 的 BG 显著升高（两者均为 p=0.001）。鉴于运动表现不受 CHO 摄入时间的影响，进行重复高强度自行车运动的运动员不需要在运动前或运动之间摄入 CHO；此外，如果运动员希望避免 BG 升高，他们应该避免在运动之间摄入 CHO。
