Please look at the following MGmat question:

A new study published by the Journal of the American Medical Association has found that women who exercise regularly and maintained a healthy diet are at low risk of sudden cardiac death during physical exertion that is moderate to vigorous in nature.

A. maintained a healthy diet are at low risk of sudden cardiac death during physical exertion that is moderate to vigorous in nature

B. maintain a healthy diet are at low risk of sudden cardiac death during moderate to vigorous physical exertion

C. maintain a healthy diet will be at low risk of sudden cardiac death during moderate to vigorous physical exertion

D. maintained a healthy diet were at low risk of sudden cardiac death during moderate to vigorous physical exertion

E. maintain a healthy diet are at low risk of sudden cardiac death during physical exertion that is moderate to vigorous in nature

The correct choice is B. However, I think choice E is more appropriate.
Both these options correct this:
The present tense verbs “maintain” and “are” are consistent with the present tense verb “exercise.”

However in choice B, it says:
"are at low risk of sudden cardiac death during moderate to vigorous physical exertion"
As I perceive, word During as an ongoing phase or a time interval. Thus, this one changes the meaning and implies that Risk of cardiac death when changing from moderate to vigorous exertion.

Whereas in Choice E, it is simply stated that: are at low risk of sudden cardiac death during physical exertion.....(during any kind of physical exertion which can vary from moderate to vigorous in nature) ..... that is moderate to vigorous in nature

Kindly, correct me...

nope. nothing in there suggests the change from moderate to vigorous exercise.
that would have to be something like "...during a change from moderate to vigorous...".

you should just memorize this as an idiom: "moderate to vigorous" is a category that spans both "moderate" and "vigorous".

same thing: if i drink 6 to 7 liters of water a day, this is not a change from 6 to 7 liters. it's the range of the amount of water i drink.