Graham-Paulson Terri, Perret Claudio, Goosey-Tolfrey Victoria
1 Loughborough University.
2 Swiss Paraplegic Centre Nottwil.
Int J Sport Nutr Exerc Metab. 2018 May 1;28(3):274-278. doi: 10.1123/ijsnem.2017-0089. Epub 2018 May 3.
Caffeine's (CAF) ability to influence upper-body exercise endurance performance may be related to an individual's training status. This case study therefore aimed to investigate the ergogenic effects of CAF dose on 20-km time trial (TT) performance of an elite male paratriathlete (wheelchair user; age = 46 years, body mass = 76.9 kg, body fat = 25.4%, and handcycling [Formula: see text]). The athlete completed four 20-km handcycling TTs on a Cyclus II ergometer under controlled laboratory conditions following the ingestion of 2, 4, and 6 mg/kg CAF or placebo (PLA). Blood lactate concentration, power output, arousal, and ratings of perceived exertion were recorded. Ingestion of 2, 4, and 6 mg/kg CAF resulted in a 2%, 1.5%, and 2.7% faster TT compared with PLA (37:40 min:s). The participant's blood lactate concentration increased throughout all trials and was greater during CAF compared with PLA. There were no obvious differences in ratings of perceived exertion between trials despite different performance times. Baseline arousal scores differed between PLA and 4 mg/kg CAF (1 = low), and 2 and 6 mg/kg CAF (3 = moderate). Arousal increased at each time point following the ingestion of 4 and 6 mg/kg CAF. The largest CAF dose resulted in a positive pacing strategy, which, when combined with an end spurt, resulted in the fastest TT. CAF improved 20-km TT performance of an elite male paratriathlete, which may be related to greater arousal and an increased power output for a given rating of perceived exertion.
咖啡因(CAF)影响上身运动耐力表现的能力可能与个体的训练状态有关。因此,本案例研究旨在调查CAF剂量对一名精英男性残疾铁人三项运动员(轮椅使用者;年龄 = 46岁,体重 = 76.9千克,体脂 = 25.4%,手摇自行车项目)20公里计时赛(TT)成绩的促力效果。在受控的实验室条件下,该运动员在摄入2、4和6毫克/千克CAF或安慰剂(PLA)后,在赛普拉斯二代测力计上完成了四次20公里的手摇自行车TT。记录血乳酸浓度、功率输出、唤醒水平和主观用力感觉评分。与PLA相比,摄入2、4和6毫克/千克CAF使TT速度分别加快了2%、1.5%和2.7%(37:40分钟:秒)。在所有试验中,参与者的血乳酸浓度均升高,且CAF试验中的血乳酸浓度高于PLA试验。尽管成绩不同,但各试验之间主观用力感觉评分没有明显差异。PLA与4毫克/千克CAF(1 = 低)以及2和6毫克/千克CAF(3 = 中等)之间的基线唤醒分数存在差异。摄入4和6毫克/千克CAF后,每个时间点的唤醒水平均升高。最大剂量的CAF导致了积极的配速策略,再加上最后冲刺,使得TT速度最快。CAF提高了一名精英男性残疾铁人三项运动员的20公里TT成绩,这可能与更高的唤醒水平以及在给定主观用力感觉评分下增加的功率输出有关。