Shalom U’Vracha, Can you please provide some insight regarding stretching (non-ritual yoga, for example)? Do we know if Chazal took time to stretch their bodies and work on their flexibility? I know we are obligated to guard our physical health - but to what extent? Have any of our Rabbis mentioned their workout routines specifically? Thank you!
Most of the sources are general, although we find that R. Shimon ben Gamliel, while head of the Sanhedrin, in addition to being a master juggler (8 burning torches simultaneously), also did stretching acrobatics in the Simchat Beit HaSho’eva in the Beit haMikdash during Sukkot (Sukkah 53a), as part of the festivities (see Rambam Sukka 8, 14). He would stand with his legs unbent (or maybe sit, see Rambam, Tfila 5, 13-14), and lean over and kiss the ground, or do push-ups on his thumbs! Our rabbis teach that one should not do exercise on Shabbat, inferring that it is part of regular weekday Jewish life, and explain: “extend and bend their arms in front and in back, warming up and sweating” (Shulchan Aruch and Mishna Brura, Or. Ch. 328, 42), or hike and run (ibid, 301, 3). Reish Lakish, who used to be a bandit, continued to swim even after he became a Ba'al Tshuva (Yoma 9b), apparently to stay in shape. The main point of physical health and strength is as a means to enable a long and meaningful life where you are energetic and capable of learning Torah, and understanding and implementing all of your ideals and mitzvot (see Rambam, De’ot, ch. 4, esp. 19), to serve God and Israel, especially, when necessary, going to war to help Israel in time of trouble and protect the Land of Israel. Rav Kook adds: not to rely on miracles for one’s health; the strong are respected and can influence others; to combat evil; in our world we need capable physical utensils to hold the spiritual and Godly. Chazal add that our body was given by God and accordingly should be tended and healthy (Vayikra Rabba 34). If you know Hebrew, you might enjoy an article I published on Rav Kook, Physical Strength and Exercising, to see 10 different reasons why Rav Kook stressed their importance, at: http://asif.co.il/wpfb-file/2-14-pdf/.