“…The research papers by Chernenko (2015), Ivashchenko, Iermakov, Khudolii, Yermakova, Cieślicka and Harkusha (2018), Ivashchenko (2017) ascertain that the repetition modes of exercises during motor skills development significantly influence training effectiveness. According to Samuel, Zavdy, Levav, Reuveny, Katz and Dubnov-Raz (2017), Balaban (2018), physical activity can both positively and negatively affect children's cognitive activity and their motor skills development. A regression analysis performed on the basis of a 2 k type full factorial experiment data is an effective method for defining optimal modes of ТМФВ, 2019, том 19, № 1 physical exercises during physical education classes (Ivashchenko, 2016).…”