Vera Jesús, Martos-Arregui Antonio, Alix-Fages Carlos, Jiménez-Martínez Pablo, García-Ramos Amador
CLARO (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain.
New England College of Optometry, Boston, MA, USA.
Int J Sport Nutr Exerc Metab. 2024 Dec 28;35(3):206-214. doi: 10.1123/ijsnem.2024-0159. Print 2025 May 1.
This study aimed to determine the impact of caffeine (200 mg), beta-alanine (3 g), and their combination on intraocular pressure (IOP), ocular perfusion pressure (OPP), and mean arterial pressure (MAP) at rest and after resistance training. Twenty young men (age = 23.4 ± 4.5 years) took part in this placebo-controlled, triple-blind, balanced crossover study. Participants visited the lab on four different days, with the only difference of the supplement used (caffeine, beta-alanine, caffeine + beta-alanine, and placebo). IOP and blood pressure were measured at baseline after 30 min from supplement intake, and after completing the resistance training session consisting of four alternating sets of bench press and bench pull exercises using a 20 repetition maximum load without reaching failure. In resting conditions, caffeine and the combination of caffeine + beta-alanine caused an acute IOP rise (p = .009 and .004, respectively), whereas beta-alanine and placebo intake did not affect IOP levels (p = .802 in both cases). OPP levels were not influenced by the ingestion of any supplement (p = .801), whereas MAP exhibited a significant increase after 30 min of ingesting 200 mg of caffeine (p = .012). After resistance training, there was an acute reduction of IOP, OPP, and MAP levels (p < .002 in all cases), but these effects were independent of the supplement consumed (p > .272). These findings show that beta-alanine (3 g) did not alter IOP, OPP, and MAP levels in resting conditions and after resistance training. Therefore, beta-alanine supplementation is a safe alternative when avoiding fluctuations of the ocular and cardiovascular hemodynamics is desirable (i.e., glaucoma patients or hypertensive individuals).
本研究旨在确定咖啡因（200毫克）、β-丙氨酸（3克）及其组合对静息状态下以及抗阻训练后眼压（IOP）、眼灌注压（OPP）和平均动脉压（MAP）的影响。20名年轻男性（年龄=23.4±4.5岁）参与了这项安慰剂对照、三盲、平衡交叉研究。参与者在四个不同的日子前往实验室，唯一的区别在于所服用的补充剂（咖啡因、β-丙氨酸、咖啡因+β-丙氨酸和安慰剂）。在摄入补充剂30分钟后、基线时以及完成由四组交替进行的卧推和卧拉练习组成的抗阻训练课程后（使用20次重复最大负荷且未达到疲劳），测量眼压和血压。在静息状态下，咖啡因以及咖啡因+β-丙氨酸组合导致眼压急性升高（分别为p=0.009和0.004），而摄入β-丙氨酸和安慰剂未影响眼压水平（两种情况均为p=0.802）。任何补充剂的摄入均未影响眼灌注压水平（p=0.801），而摄入200毫克咖啡因30分钟后平均动脉压显著升高（p=0.012）。抗阻训练后，眼压、眼灌注压和平均动脉压水平急性降低（所有情况均为p<0.002），但这些影响与所摄入的补充剂无关（p>0.272）。这些发现表明，β-丙氨酸（3克）在静息状态下和抗阻训练后不会改变眼压、眼灌注压和平均动脉压水平。因此，当需要避免眼和心血管血流动力学波动时（即青光眼患者或高血压个体），补充β-丙氨酸是一种安全的选择。
