Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.
Department of Anaesthesia, Western Hospital, Melbourne, VIC, Australia.
Physiol Rep. 2021 Jun;9(11):e14889. doi: 10.14814/phy2.14889.
We investigated whether acute carbohydrate ingestion reduced arterial potassium concentration ([K ]) during and after intense exercise and delayed fatigue.
In a randomized, double-blind crossover design, eight males ingested 300 ml water containing 75 g glucose (CHO) or placebo (CON); rested for 60 min, then performed high-intensity intermittent cycling (HIIC) at 130% , comprising three 45-s exercise bouts (EB), then a fourth EB until fatigue. Radial arterial (a) and antecubital venous (v) blood was sampled at rest, before, during and after HIIC and analyzed for plasma ions and metabolites, with forearm arteriovenous differences (a-v diff) calculated to assess inactive forearm muscle effects.
Glucose ingestion elevated [glucose] and [insulin] above CON (p = .001), being, respectively, ~2- and ~5-fold higher during CHO at 60 min after ingestion (p = .001). Plasma [K ] rose during and declined following each exercise bout in HIIC (p = .001), falling below baseline at 5 min post-exercise (p = .007). Both [K ] and [K ] were lower during CHO (p = .036, p = .001, respectively, treatment main effect). The [K ] across the forearm widened during exercise (p = .001), returned to baseline during recovery, and was greater in CHO than CON during EB1, EB2 (p = .001) and EB3 (p = .005). Time to fatigue did not differ between trials.
Acute oral glucose ingestion, as used in a glucose tolerance test, induced a small, systemic K -lowering effect before, during, and after HIIC, that was detectable in both arterial and venous plasma. This likely reflects insulin-mediated, increased Na ,K -ATPase induced K uptake into non-contracting muscles. However, glucose ingestion did not delay fatigue.
我们研究了急性碳水化合物摄入是否会在剧烈运动期间和之后降低动脉钾浓度([K+])并延迟疲劳。
在一项随机、双盲交叉设计中，8 名男性分别摄入 300ml 含 75g 葡萄糖（CHO）或安慰剂（CON）的水；休息 60 分钟，然后进行高强度间歇循环（HIIC），强度为 130%，包括三个 45 秒的运动回合（EB），然后第四个 EB 直到疲劳。在休息、HIIC 之前、期间和之后采集桡动脉（a）和肘前静脉（v）血液样本，并分析血浆离子和代谢物，通过计算前臂动静脉差（a-v 差）来评估不活动的前臂肌肉的影响。
葡萄糖摄入使[葡萄糖]和[胰岛素]高于 CON（p=0.001），分别在摄入后 60 分钟时高出约 2 倍和 5 倍（p=0.001）。HIIC 期间和每次运动回合后[K+]升高，运动后 5 分钟时降至基线以下（p=0.007）。CHO 期间[K+]和[K]均低于 CON（p=0.036，p=0.001，分别为治疗主要效应）。运动过程中前臂的[K+]变宽（p=0.001），恢复过程中回到基线，在 EB1、EB2（p=0.001）和 EB3（p=0.005）期间 CHO 高于 CON。两次试验的疲劳时间没有差异。
如葡萄糖耐量试验中使用的急性口服葡萄糖摄入会在 HIIC 之前、期间和之后引起小的、全身性的 K 降低效应，在动脉和静脉血浆中都可检测到。这可能反映了胰岛素介导的、增加的 Na+，K+-ATP 酶诱导的非收缩肌肉中 K 的摄取。然而，葡萄糖摄入并没有延迟疲劳。
