Qin L, Wong S H, Sun F-H, Huang Y, Sheridan S, Sit C H P
Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
Physiol Behav. 2017 May 15;174:170-177. doi: 10.1016/j.physbeh.2017.02.035. Epub 2017 Feb 28.
This study examined the effect of carbohydrate (CHO) and protein (PRO) co-ingestion on energy substrate metabolism, sense of effort, and affective responses during prolonged strenuous endurance exercise. In a four-stage randomized cross-over design, 10 male endurance runners (age: 27.3±1.4yrs; height: 172.9±1.1cm, weight: 63.5±1.6kg; body fat: 9.0±1.4%; V̇O: 62.9±1.8ml/kg/min) ran on a treadmill at 70% of their individual V̇O for 90min. There were two CHO and PRO treatments (CA: CHO+alpha-lactalbumin and CW: CHO+whey PRO isolate), one CHO treatment (CC: CHO+CHO), and a placebo control (CON). On each occasion, subjects consumed 5ml/kg according to their body weight (kg) immediately before and 2ml/kg every 15min during exercise. Blood samples were collected at 0min, 30min, 60min and 90min of exercise to measure glucose, lactate, insulin, and cortisol levels. The extent of physical sensation (abdominal discomfort, leg muscle pain), the sense of effort (rating of perceive exertion, RPE), and affective responses (pleasure-displeasure, arousal) were evaluated by numeric scales before, during, and immediately after exercise. Blood glucose and insulin concentrations in the CA, CW, and CC treatments were higher than in the CON at 90min (P<0.05). Muscle pain (evaluated by a single item, 0 to 10 pain intensity scale from "no pain at all" to "extremely unbearable") was lower following CA ingestion than CON and CW ingestion, at 75min (vs. CON and CW, 1.95±0.61 vs. 3.70±1.00 and 3.60±1.02, P<0.05) and 90min (vs.
CON & CW: 2.40±0.76 vs. 4.20±0.99 and 4.05±1.1, P<0.05). RPE (evaluated by a 15-point, 6 to 20 rating scale ranging from "very, very light" to "very, very hard") following treatment with CA was lower than with CON and CW at 90min (vs. CON and CW: 11.30±1.14 vs. 14.20±1.30 and 13.30±1.24, P<0.05). Compared with CON and CW, CA enhanced the feeling of pleasure (evaluated by feeling scale from -5, "very bad" to +5, "very good") at 90min (vs. CON and CW, 2.20±0.67 vs. -0.30±0.94 and 0.20±0.91, P<0.05). Co-ingestion of CHO and alpha-lactalbumin protein attenuates muscle pain, and therefore alleviates the sense of effort and enhances affective responses during 90min of strenuous running at 70% V̇O
本研究考察了碳水化合物（CHO）与蛋白质（PRO）共同摄入对长时间剧烈耐力运动期间能量底物代谢、用力感觉和情感反应的影响。在一项四阶段随机交叉设计中，10名男性耐力跑者（年龄：27.3±1.4岁；身高：172.9±1.1厘米，体重：63.5±1.6千克；体脂：9.0±1.4%；最大摄氧量：62.9±1.8毫升/千克/分钟）在跑步机上以其个人最大摄氧量的70%跑步90分钟。有两种CHO与PRO处理方式（CA：CHO+α-乳白蛋白和CW：CHO+乳清蛋白分离物）、一种CHO处理方式（CC：CHO+CHO）以及一个安慰剂对照（CON）。每次实验时，受试者在运动前即刻按体重（千克）摄入5毫升/千克，运动期间每15分钟摄入2毫升/千克。在运动的0分钟、30分钟、60分钟和90分钟采集血样以测量葡萄糖、乳酸、胰岛素和皮质醇水平。通过数字量表在运动前、运动期间和运动后即刻评估身体感觉程度（腹部不适、腿部肌肉疼痛）、用力感觉（主观用力感觉等级，RPE）以及情感反应（愉悦-不愉悦、唤醒）。在90分钟时，CA、CW和CC处理组的血糖和胰岛素浓度高于CON组（P<0.05）。在75分钟（与CON和CW相比，1.95±0.61 vs. 3.70±1.00和3.60±1.02，P<0.05）和90分钟（与CON和CW相比：2.40±0.76 vs. 4.20±0.99和4.05±1.1，P<0.05）时，摄入CA后肌肉疼痛（通过单项评估，疼痛强度从“毫无疼痛”到“极其难以忍受”的0至10级量表）低于CON和CW组。在90分钟时，CA处理后的RPE（通过15分、6至20级量表评估，范围从“非常非常轻松”到“非常非常艰难”）低于CON和CW组（与CON和CW相比：11.30±1.14 vs. 14.20±1.30和13.30±1.24，P<0.05）。与CON和CW相比，在90分钟时CA增强了愉悦感（通过从-5“非常糟糕”到+5“非常好”的感觉量表评估）（与CON和CW相比，2.20±0.67 vs. -0.30±0.94和0.20±0.91，P<0.05）。CHO与α-乳白蛋白共同摄入可减轻肌肉疼痛，从而在以70%最大摄氧量进行90分钟剧烈跑步期间减轻用力感觉并增强情感反应。
