Figure 4. Cortical surface area (cm2) at age 45 and rate of decline in VO2Max scores (mL/min/Kg) from age 26 to 45. (A) Surface area. (B) Graph showing the correlation between total surface area (cm2, y-axis) and the rate of decline in VO2Max (average decrease in mL/min/kg between each wave of data collection; x-axis). Study members with VO2Max scores declining at a faster rate over time (i.e., larger slopes) did have slightly smaller total surface area (β = -0.09, 95% CI = -0.17 to -0.004, p=0.04). There were no regionally-specific associations. cm3 = centimeters cubed; VO2Max = volume of maximum oxygen uptake; mL/min/kg = milliliters per minute per kilogram; β = standardized coefficient; CI = confidence interval.