The long-standing caffeine habituation paradigm was never investigated in strength endurance and jumping exercise performance through a straightforward methodology. The authors examined if habitual caffeine consumption would influence the caffeine ergogenic effects on strength endurance and jumping performance as well as perceptual responses. Thirty-six strength-trained individuals were mathematically allocated into tertiles according to their habitual caffeine consumption: low (20 ± 11 mg/day), moderate (88 ± 33 mg/day), and high consumers (281 ± 167 mg/day). Then, in a double-blind, crossover, counterbalanced fashion, they performed a countermovement vertical jump test and a strength endurance test either after caffeine (6 mg/kg) and placebo supplementation or after no supplementation (control). Perceptual responses such as ratings of perceived exertion and pain were measured at the termination of the exercises. Acute caffeine supplementation improved countermovement vertical jump performance (p = .001) and total repetitions (p = .004), regardless of caffeine habituation. Accordingly, analysis of absolute change from the control session showed that caffeine promoted a significantly greater improvement in both countermovement vertical jump performance (p = .004) and total repetitions (p = .0001) compared with placebo. Caffeine did not affect the rating of perceived exertion and pain in any exercise tests, irrespective of tertiles (for all comparisons, p > .05 for both measures). Caffeine side effects were similar in low, moderate, and high caffeine consumers. These results show that habitual caffeine consumption does not influence the potential of caffeine as an ergogenic aid in strength endurance and jumping exercise performance, thus challenging recommendations to withdraw from the habitual caffeine consumption before supplementing with caffeine.

长期存在的咖啡因习惯范式从未通过简单的方法在力量耐力和跳跃运动表现中进行研究。作者检查了习惯性咖啡因摄入是否会影响咖啡因对力量耐力和跳跃表现以及感知反应的增效作用。36 名受过力量训练的人根据他们习惯性的咖啡因摄入量在数学上被分成三组：低（20 ± 11 毫克/天）、中等（88 ± 33 毫克/天）和高消费（281 ± 167 毫克/天） . 然后，以双盲、交叉、平衡的方式，他们在咖啡因（6 mg/kg）和安慰剂补充后或不补充（对照）后进行了反向运动垂直跳跃测试和力量耐力测试。在练习结束时测量感知反应，例如感知劳累和疼痛的评级。急性咖啡因补充改善了反向垂直跳跃的表现（p  = .001) 和总重复次数 ( p  = .004)，与咖啡因习惯无关。因此，对对照组绝对变化的分析表明， 与安慰剂相比，咖啡因促进了反向运动垂直跳跃表现 ( p  = .004) 和总重复次数 ( p = .0001) 的显着改善。咖啡因不影响任何运动测试中感知劳累和疼痛的评分，无论三分位数如何（对于所有比较，p > .05 对于这两种措施）。低、中、高咖啡因消费者的咖啡因副作用相似。这些结果表明，习惯性摄入咖啡因不会影响咖啡因作为增强力量耐力和跳跃运动表现的助推剂的潜力，因此对在补充咖啡因之前退出习惯性咖啡因摄入的建议提出了挑战。