This is the 'Ninja Rabbi' a.k.a Akiva Neuman, an Orthodox Jewish rabbinical student who has competed in several iterations of 'American Ninja Warrior'. He is now auditioning for another season.
What makes his participation notable? That he's a rabbi, of course. There's seemingly a disconnect between being a religious Jew and being physically fit. What do our sources have to say about keeping oneself healthy?
(ט) רַ֡ק הִשָּׁ֣מֶר לְךָ֩ וּשְׁמֹ֨ר נַפְשְׁךָ֜ מְאֹ֗ד פֶּן־תִּשְׁכַּ֨ח אֶת־הַדְּבָרִ֜ים אֲשֶׁר־רָא֣וּ עֵינֶ֗יךָ וּפֶן־יָס֙וּרוּ֙ מִלְּבָ֣בְךָ֔ כֹּ֖ל יְמֵ֣י חַיֶּ֑יךָ וְהוֹדַעְתָּ֥ם לְבָנֶ֖יךָ וְלִבְנֵ֥י בָנֶֽיךָ׃
(9) But take utmost care and watch yourselves scrupulously, so that you do not forget the things that you saw with your own eyes and so that they do not fade from your mind as long as you live. And make them known to your children and to your children’s children:
(א) הוֹאִיל וֶהֱיוֹת הַגּוּף בָּרִיא וְשָׁלֵם מִדַּרְכֵי הַשֵּׁם הוּא. שֶׁהֲרֵי אִי אֶפְשָׁר שֶׁיָּבִין אוֹ יֵדַע דָּבָר מִידִיעַת הַבּוֹרֵא וְהוּא חוֹלֶה. לְפִיכָךְ צָרִיךְ לְהַרְחִיק אָדָם עַצְמוֹ מִדְּבָרִים הַמְאַבְּדִין אֶת הַגּוּף. וּלְהַנְהִיג עַצְמוֹ בִּדְבָרִים הַמַּבְרִין וְהַמַּחֲלִימִים. וְאֵלּוּ הֵן: לְעוֹלָם לֹא יֹאכַל אָדָם אֶלָּא כְּשֶׁהוּא רָעֵב. וְלֹא יִשְׁתֶּה אֶלָּא כְּשֶׁהוּא צָמֵא. וְאַל יַשְׁהֵא נְקָבָיו אֲפִלּוּ רֶגַע אֶחָד. אֶלָּא כָּל זְמַן שֶׁצָּרִיךְ לְהַשְׁתִּין אוֹ לְהָסֵךְ אֶת רַגְלָיו יַעֲמֹד מִיָּד:
(1) Seeing that the maintenance of the body in a healthy and sound condition is a God-chosen way, for, lo, it is impossible that one should understand or know aught of the divine knowledge concerning the Creator when he is sick, it is necessary for man to distance himself from things which destroy the body, and accustom himself in things which are healthful and life-imparting. These are: never shall man partake food save when hungry, nor drink save when thirsty; he shall not defer elimination even one minute, but the moment he feels the need to evacuate urine or feces he must rise immediately.
Rabbi Ḥiyya teaches: One who does not want to come to a situation whereby he contracts intestinal disease should become accustomed to dipping his food in wine or vinegar, both in the summer and in the winter. He also teaches: You should remove your hand, i.e., stop eating, from a meal that you enjoy so that you do not overeat. And do not delay yourself at the time when it is necessary to relieve yourself.
Maimonides discussed three areas of physical activity in his work: philosophy, Halacha, and medicine.
1) In the area of philosophy, he is considered to be the most prominent of philosophers in terms of Judaic philosophy who dealt with matters of health and physical activity. He discussed these two subjects in his two works: Introduction to' Pirkei Avot' (Words of the Fathers), also called the Eight Chapters, and his main book, The Guide for the Perplexed.
2) In the area of Halacha, in his book Mishneh Torah, Maimonides relates in two chapters, written in Halachic language, two ways of preserving and fostering health through nutrition and physical activity.
3)In the area of medicine, he deals both with practical healing and with preventive medicine. These topics are included in two of his medical works: 'Regimen of Health' and sections of the 'Medical Aphorisms of Moses'.
(Sobovitz, PHYSICAL ACTIVITY IN THE TEACHINGS OF MAIMONIDES, 2014, p. 6)
The sole evidence for the existence of gymnasia or athletic festivals in Hellenistic Palestine comes from Jewish sources that appear to be hostile to these sorts of institutions. First and Second Maccabees rail against the construction of a gymnasium in Jerusalem, though they also let slip the ugly secret that the Jerusalem priests frequently attended the wrestling matches and discus throwing that took place in the palaestra.
(Spielman, Playing Roman in Jerusalem, 2012).
This is just scratching the surface, but take a look. From academics to rabbinic sources, there's a lot to cover on the Jewish cultural and religious relationship with fitness.
If you're looking for more, Spielman's article is part of a book on the subject.
Happy hunting!