Correlation coefficients (standardized regression coefficients) representing the impact of the five personality traits on physical activity, obtained by linear regression comparing VLBW and control subjects (adjusted for sex and age).

Correlation coefficient is equal to a standardized regression coefficient: a 1 standard deviation unit higher score on a personality trait is associated with the correlation coefficient×standard deviation unit physical activity.VLBW = very low birth weight (aMET×hours of physical activity/year (MET = metabolic equivalents; ratio of metabolic rate during exercise and estimated metabolic rate at rest; 1 MET corresponds energy expenditure of approximately 1 kcal/kg×hour).bPcPdP相关系数（correlation coefficient）等同于标准化回归系数（standardized regression coefficient）：某一人格特质（personality trait）的得分每高出1个标准差单位，即与该相关系数乘以1个标准差单位的身体活动水平相关。极低出生体重（very low birth weight, VLBW）：a. 每年体力活动的代谢当量×小时数（MET = 代谢当量（metabolic equivalents），即运动时代谢率与静息代谢率的比值；1 MET约对应每千克体重每小时1千卡的能量消耗）。bPcPdP