体育锻炼

Be good at=do well in在某些方面很长，很熟练。

He is good at sports。

He does well in sports。

他擅长运动。

be good for 对什么有好处

Morning Exercise is good for health.

晨练有益于健康。

be helpful to sb 对某人有帮助

Sound health is helpful to young people who want to achieve success in study or workplace.

良好的健康对想要在学习或工作中取得成功的年轻人很有帮助。

be in good health 身体健康

Morning exercise keeps us in good health.

晨练使我们保持健康。

Young people who have achieved success in study or workplace are always in good health.

在学习或工作中取得成功的年轻人总是身体健康。

总结：

be good at = do well in 在某方面善长, 善于……

be good for 对什么有好处

be helpful to sb 对某人有帮助

be in good health 身体健康