run a marathon

[nnyy]

Back in the day, I would run a marathon a lot.

I made this sentence.
I wonder if this sentence is natural.
Should it be "marathons" because I ran a marathon "a lot"?
Is "would" correct or should it be "used to"?
Thanks for your help.

 

[Cagey]

You are making a general statement; omit the article 'a' and use the plural.

Back in the day, I would run marathons a lot.​

​

(As an aside: I wouldn't use 'a lot' this way. I might say, "I would run a lot of marathons.")

 

[kentix]

(As an aside: I wouldn't use 'a lot' this way. I might say, "I would run a lot of marathons.")

 

[Silver]

Hi,

I asked my friend if he would like a meet up with me for dinner today (I asked him last night) and he said:

I have marathon to run tomorrow.

I wonder if the bold is idiomatic.

 

[grassy]

I have a marathon to run tomorrow.

I'd also get rid of "to run", which is redundant there.

 

[Edinburgher]

I agree with grassy that an article is required, and that it would usually be "a". Depending on the exact circumstances, "the" may be possible too.
However, I would probably not omit "to run", although it wouldn't be wrong to do so.