Q. I am a mother, working full-time. For health reasons, I need to fit in some exercise and bought a treadmill, hoping to use it every morning. I am finding it difficult to juggle davening and going on the treadmill. Would it be acceptable to daven (up to Shemoneh Esrei) while walking on the treadmill? Thank you for all your time and dedication!

A. On question 1019 in regards for a man to use a gym and a trainer before shacharis, we wrote; “Alei Siach (p. 64) writes that Rav Chaim Kanievsky shlit’a answered to a similar question, that it is not correct to do so. Yosef Daas (p.157) mentions different opinions. Tefila Kehilchosa (p. 114, 23) rules in the name of Rav P. Sheinberg zt’l, that if the intention of the individual is to be healthy and strong to be able to serve Hashem better and not for his own benefit and pleasure, it would be considered an act of Heavenly need and is permitted, if it cannot be done at another time. They warn that one should make sure not to miss Tefila Betzibur and the correct time of reading the shema and Tefilah. Hatefilah Vehilchoseha (4: 10) also quotes Divrei Chachamim (1: 2) in the name of Rav Eliyashuv zt’l, that it is permitted since it considered an activity of partial mitzvah. Piskey Teshuvos (89: ) quotes also similar opinions. Horav Shlomo Miller’s Shlit””a opinion follows Horav Chaim Kanievsky Shlit’a only lechatchila.”
In principle, Shulchan Aruch (O.H. 63: 8, 90: 3) permits fruit collectors engaged in their work to read the shema while on top of the tree but not to continue davening the amida, where they have to descend. However, in regards to other labors he rules that one should halt during the reading of the first parsha of the shema.
Accordingly, Horav Shlomo Miller’s Shlit’a opinion is that in the case of women, when other options are not available, one can walk a treadmill while reciting pesukei dezimra and the brochos of shema. One however, should stop for the first parsha of shema and for the amida.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a