Caffeine Influence on Blood Pressure Response to Aerobic Exercise in Hypertensive Subjects

Blood pressure reduction (BP) promoted by physical exercise is evident according to the current literature. Neurohumoral mechanisms explain this hypotensive response, in which decrease of the sympathetic activity appears as one of its main mechanisms. However, the ingestion of caffeine-rich food (CA) can suppress this sympathetic attenuation. The objective of this study was to elucidate the impact of CA ingestion in BP after exercise, in hypertensive individuals. Seven hypertensive subjects (52.3 +/-3.3 years), being 5 women, accomplished two walk sessions with 40 minutes of duration, in two days of training, having previously ingested CA (4 mg/kg of body weight) or placebo (PL). BP and heart rate were verified previously to the ingestion, after 15, 30, 45, 60 minutes of the ingestion, at rest and with 10, 20 and 30 minutes after exercise. Data were treated through descriptive statistics and by the non-parametric Wilcoxon test (p<0.05). BP mean increased from 124.9/80.9 mmHg before ingestion to 129.4/84.3 mmHg 60 minutes later (p<0.05). In the recovery period, after 30 minutes of exercise, hypotensive answer was observed in the PL procedure (decrease of 122.6/79.4 mmHg to 115.7/78.6 mmHg), while in the procedure with CA, BP was significantly higher than at rest (increase of 124.9/80.9 mmHg to 136.9/90.9 mmHg, p<0.05). It was concluded that CA not only suppresses the hypotensive response to exercise, but also provokes post-exercise hypertension.