Translation:I ran for thirty minutes this morning.
This is a short explanation. Definitely look for grammar notes elsewhere. 跑步 is a verb+object construction. These are common in Chinese. 跑 ="run" is the verb 步 = "steps" is the object. So in Chinese, you don't just run, you "run steps." The verb and object are separated because of this particular sentence structure showing the time duration. You can think of the sentence like: 早上 = In the morning 我 = I 跑了=ran 三十分钟的步 = thirty minutes of steps.
I don't understand why 跑 and 步 are separated in the sentence. The tips and notes at the beginning just said that the verb comes before the 了 which is followed by the time spent and then a noun. I don't see that modeled in any of these sentences and am confused by the separation of the verb. Can anyone explain this to me?
That's exactly what you're seeing here. 跑步 is a "verb+object" construction. They are very common in Chinese. Many (though not quite all) words that seem to be 2 character verbs are actually verb+object constructions. These are verbs that require their objects, so you will see them together. But as you see here, you have to know that grammatically they are actually a verb and a noun. 跑 is the verb. 步 is the object (noun). Other examples are 睡觉 (sleep), 唱歌 (sing), and 走路 (walk).
Hey, I know how to explain this!
This case is called "open-ended action verbs with obligatory objects".
So, for example "跑" is the open-ended action verb and "步" is the default object.
Because of the grammar structure of Chinese, the verb is put after the noun phrase, while the default object is put at the end of the phrase.
But when you translate the verb, you have to think of it as "running".
In Chinese "understood words" are dropped more often than in English. While it's true that in both languages "in the morning" and 早上 can be understood to be referring to "THIS morning" OR some other morning understood from the context, in Chinese, unless you really need to specify it, 这个早上 is nearly always shortened to 早上 only.