Exercise Physiology Laboratory, University of Castilla-La Mancha, Toledo, Spain.
Int J Sport Nutr Exerc Metab. 2015 Feb;25(1):46-53. doi: 10.1123/ijsnem.2014-0037. Epub 2014 Jun 5.
Caffeine is an ergogenic aid widely used before and during prolonged exercise. Due to its prolonged biological half-life caffeine effects could remain after exercise. We aimed to investigate the metabolic, respiratory, and cardiovascular postexercise responses to preexercise graded caffeine ingestion. Twelve aerobically trained subjects (mean VO₂max = 54 ± 7 ml · min⁻¹ · kg⁻¹) cycled for 60-min at 75% VO₂max after ingesting placebo (0 mg of caffeine per kg of body weight) or 0.5, 1.5, 3.0 and 4.5 mg · kg⁻¹ on five occasions. During the 3 hr postexercise, heart rate, blood pressure, glucose, lactate, and fatty acids were analyzed. None of these variables were statistically affected by preexercise caffeine ingestion between 0.5 and 4.5 mg · kg⁻¹. However, ingestion of 4.5 mg · kg⁻¹ of caffeine raised postexercise energy expenditure 15% above placebo (233 ± 58 vs. 202 ± 49 kcal/3 hr; p < .05). Ventilation and tidal volume were elevated after the 4.5 mg · kg⁻¹ caffeine dose above placebo (9.2 ± 2.5 L · min⁻¹ and 0.67 ± 0.29 L · breath⁻¹ vs. 7.8 ± 1.5 L · min⁻¹ and 0.56 ± 0.20 L · breath⁻¹, respectively; p < .05). Ventilation correlated with tidal volume (r = .45; p < .05) and energy expenditure (r = .72; p < .05). In summary, preexercise ingestion of ergogenic caffeine doses do not alter postexercise cardiovascular responses. However, ingestion of 4.5 mg · kg⁻¹ of caffeine raises 3-hr postexercise energy expenditure (i.e., 31 kcal) likely through increased energy cost of ventilation.
咖啡因是一种广泛用于长时间运动前和运动期间的运动增强剂。由于其较长的生物学半衰期，咖啡因的作用可能会在运动后持续存在。我们旨在研究运动前分级咖啡因摄入对运动后代谢、呼吸和心血管的反应。12 名有氧训练的受试者（平均 VO₂max = 54 ± 7 ml·min⁻¹·kg⁻¹）在摄入安慰剂（每公斤体重 0 毫克咖啡因）或 0.5、1.5、3.0 和 4.5 mg·kg⁻¹ 后，以 75% VO₂max 连续骑行 60 分钟。在运动后 3 小时内，分析心率、血压、血糖、乳酸和脂肪酸。在 0.5 至 4.5 mg·kg⁻¹ 之间，这些变量都没有受到运动前咖啡因摄入的统计学影响。然而，摄入 4.5 mg·kg⁻¹ 的咖啡因使运动后能量消耗比安慰剂高出 15%（233 ± 58 比 202 ± 49 kcal/3 小时；p <.05）。与安慰剂相比，4.5 mg·kg⁻¹ 的咖啡因剂量后通气量和潮气容积升高（9.2 ± 2.5 L·min⁻¹ 和 0.67 ± 0.29 L·breath⁻¹ 比 7.8 ± 1.5 L·min⁻¹ 和 0.56 ± 0.20 L·breath⁻¹，分别；p <.05）。通气量与潮气容积（r =.45；p <.05）和能量消耗（r =.72；p <.05）相关。总之，运动前摄入运动增强咖啡因剂量不会改变运动后的心血管反应。然而，摄入 4.5 mg·kg⁻¹ 的咖啡因会增加 3 小时运动后的能量消耗（即 31 kcal），可能是通过增加通气的能量消耗。
