Rav Yitchak Berkovitz on Hishtadlus

In an interview with Rav Yitzchak Berkovitz of The Jerusalem Kollel, he is quoted as saying the following about hishtadlus:  The first relates to the difficult question of how to find the correct balance between bitachon, trust, and hishtadlus, effort. As a general guide, Rav Yitzchak Berkovits suggests that the amount of effort that is considered ‘normal’ given one’s situation, is correct. For example, if it is normal for such a person to work eight hours a day, then for him to work extra hours may constitute unnecessary hishtadlus, whilst working less hours may be considered insufficient hishtadlus. However, we have now seen that the appropriate level of bitachon varies according to each person, as well as what is normal in general. Therefore, if a person develops a heightened sense of bitachon, he may, in theory, be able to reduce his work hours, and learn more, instead, based on his clear recognition that one’s livelihood ultimately comes only from God and not from work.

http://www.aish.com/tp/i/gl/133791488.html

This sounds exactly like what we've been learning in Sefer Ben Melech.