Cardiorespiratory fitness influences the blood pressure response to experimental weight gain.

OBJECTIVE: We tested the hypothesis that with similar weight gain the increase in blood pressure (BP) would be smaller in men with higher cardiorespiratory fitness (HCRF) than in men with lower cardiorespiratory fitness (LCRF). RESEARCH METHODS AND PROCEDURES: Thirteen men (age = 23 +/- 1, BMI = 24 +/- 1) were overfed by approximately 1000 kcal/d over approximately 8 weeks to achieve a 5-kg weight gain. Resting BP and 24-hour ambulatory BP, body composition, and fat distribution were measured.
RESULTS: Cardiorespiratory fitness (CRF) was higher in the HCRF group compared with the LCRF group (49.9 +/- 1.2 vs. 38.1 +/- 1.4 mL/kg per minute, p < 0.001). At baseline, body weight was similar in the HCRF and LCRF groups, whereas the HCRF group displayed lower levels of total body fat (13.0 +/- 1.7 vs. 16.9 +/- 1.3 kg, p = 0.049) and abdominal visceral fat (49 +/- 6 vs. 80 +/- 14 cm2, p = 0.032). Resting BP and 24-hour ambulatory BP were similar in the two groups at baseline. After weight gain, body weight increased approximately 5 kg (p < 0.05) in both groups; the changes in body composition and regional fat distribution were similar. As hypothesized, the increases in resting systolic (1 +/- 2 vs. 7 +/- 2 mm Hg; p = 0.008) and diastolic (-1 +/- 4 vs. 5 +/- 1 mm Hg; p = 0.005) BP were smaller in the HCRF group. CRF was correlated with the increases in resting systolic (r = -0.64; p = 0.009) and diastolic BP (r = -0.80; p < 0.001). Furthermore, the relationship between CRF and BP remained significant after adjusting for the changes in the proportion of total abdominal fat gained as visceral fat. DISCUSSION: These findings suggest that higher levels of CRF are associated with a smaller increase in BP with weight gain, independently of changes in abdominal visceral fat.