Caffeine consumption habits do not influence the exercise blood pressure response following caffeine ingestion

The purpose of this study was to determine if the BP response during walking following caffeine ingestion differed between those who regularly consume caffeine and those who do not.

A double-blind cross-over experimental design was used. Data were collected in a research laboratory with a clinical exercise testing room. Eight regular caffeine users and eight men who did not habitually consume caffeine were studied. Each subject consumed of a beverage once with and once without 4.5 mg caffeine/kg fat-free mass added to the drink. Following consumption each subject walked at three intensities of exercise (30, 50, and 70% of VO2peak). Measures of BP were obtained by the auscultatory technique.

Caffeine consumption resulted in significant increases in both systolic BP and diastolic BP at rest and during exercise. The elevation during exercise was 7-8 mmHg at all three exercise intensities for systolic BP; however, for diastolic BP there was only a significant elevation (4 mmHg) at the highest exercise intensity. No differences were noted between those men who regularly consume and those who regularly abstain from caffeine. There was a wide range in the resting BP response to caffeine (combined SBP and DBP ranged from 10-39 mmHg) suggesting that there are marked differences in sensitivity to caffeine, irrespective of individuals' consumption habits.

Consideration should be given to caffeine intake prior to exercise in patients for whom an additional increase in BP during exercise would not be desirable.