不管你是否相信，我从来没有这样刻苦学习过，甚至七年前准备参加高考也没有这样刻苦过。

Believe it or not, I had never ever been studying so hard before, even including the period when I was preparing for the exam of entrance to university in China seven years ago.

youdao

首先，我训练刻苦——现在每天游泳七英里半，在那以前我也通过适度刻苦训练保持身体健康。

First, I am training hard now swimming seven and a half miles a day. Prior to that time I also kept physically fit by training moderately hard.

youdao

机遇是重要的，但刻苦是关键；自己不刻苦，机遇再多也没用。

The opportunity is important, but assiduous is a key; Oneself isn't assiduous, opportunity again have another also useless.

youdao

like he was the hardest... that I was the hardest worker he had seen in sports in like 10 years.

他是训练最刻苦的……我是他这十年来见过的训练最刻苦的球员。

足球部队长的领导力 - SpeakingMax英语口语达人

but I made up for it by working really hard on the gym and working really hard on the field.

但我通过体育馆和足球场上的刻苦训练弥补了天赋不足。

足球部队长的领导力 - SpeakingMax英语口语达人

I think that, in general, universities here are just looking for people who are intelligent and hard-working,

总的来说，我认为这里的大学希望招收聪明又刻苦的学生，

如果是在考虑留学 - SpeakingMax英语口语达人