〜ようにする vs 〜ようと思う


I'm wondering about the difference between 〜ようにする vs 〜ようと思う, which both
express intention. Here's an example sentence from A Dictionary of Basic
Japanese Grammar (pg 562).

> 私は毎日運動するようにする。
>
> I'll make sure that I do exercises everyday.

Changing this to the volitional form 〜ようと思う, and my best translation:

> 私は毎日運動しようと思う。
>
> I think I will exercise everyday.

Do the English translations capture the nuance in both sentences (the former
seems to express a higher level of intention)? If not, what is the difference?




I think the key difference between two versions is that the former is passive
and somewhat more apologetic and the latter is more proactive.

For example, if a doctor tells you to exercise regularly, you'd tell him
`毎日運動するようにします`. If a mother scolds you that your report card was horrible,
you'd say `毎日勉強するようにするから`

`私は毎日運動しようと思う` has a feel that you planned it, and you are initiating that
change. It feels more positive.

In both cases, I think your translation is spot on.

