The first hour on two wheels is not for the faint hearted. The lack of space means pedestrians, cyclists and vehicles all vie for pavement.

对于心脏不好的人来说，骑车的第一个小时肯定不怎么好受。行人、骑车人和汽车在车道上分寸必争。

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Don't be faint-hearted when things seem a bit slow or boring.

当事情似乎有点乏味或无聊时，不要胆怯。

《柯林斯英汉双解大词典》

This is no time to be faint-hearted.

现在不是胆怯的时候。

《柯林斯英汉双解大词典》

Resource planning and setting appropriate project deadlines is not for the faint hearted.

FORBES: Are Deadlines Important?

In those eight weeks the administrator will be working 18-hour days so it is not for the faint hearted.

BBC: When football club administration kicks off

Entrepreneurship remains an act of faith, and never for the faint hearted.

FORBES: The Next Silicon Valley? Small Town America.