The Effects of Caffeine and Resistance Exercise on Pulse Wave Reflection in Resistance-Trained Women.

Caffeine, alone or in conjunction with an acute bout of resistance exercise (RE), increases measures of pulse wave reflection (PWR), with most studies focusing on men. Therefore, the purpose of this study was to investigate caffeine's effects on measures of PWR alone and following an acute bout of RE in young, healthy, resistance-trained women. Eleven resistance-trained women completed an acute bout of RE using free-weights with repetitions to failure for squat and bench press with caffeine (4mg/kg) and a placebo. Measures of PWR were measured at Rest, 50 minutes following ingestion (caffeine or placebo), immediately following the acute bout of RE and after 10 minutes of recovery. There were no differences (p > 0.05) between caffeine and placebo conditions for measures of PWR at any time point. Aortic pulse pressure (APP), augmentation pressure (AP), augmentation index (AIx), augmentation index normalized at 75bpm (AIx@75), systolic pressure time index (SPTI), and left ventricular wasted energy (ΔEw) significantly increased (p < 0.01) following the acute bout of RE for up to 10 minutes in both conditions while diastolic pressure time index (DPTI) significantly decreased (p < 0.01). There was no change in aortic systolic blood pressure (ASBP), aortic diastolic blood pressure (ADBP), time of the reflected wave (Tr) and subendocardial viability ratio (SEVR) following the acute bout of RE in either condition (p > 0.05). Collectively, this study suggests that a caffeine dose of 4mg/kg does not alter measures of PWR beyond the individual influence of an acute bout of RE in resistance-trained women.