Emory的core value-rigor

请问Emory的校友或在学生, 对Emory的价值来说，rigor的确切中文意思是什么?

我本来认为是一种”严谨严厉的态度”

但我看学校网站上介绍rigor如下

Rigor instills excellence. At Goizueta, we seek challenges that place us outside our comfort zone. High expectations and goals are the standards that we choose for each other and ourselves.
                

好像是追求挑战
                卓越的意思…

跟字典里的意思不大一样
                不是吗??

麻烦解惑一下~~
谢谢!!