TY JOUR TI The fitness industry: transformation of human capital theory, current realities and development prospects in the context of digitalization KW fitness industry KW human capital KW health KW G. Becker’s theory KW digitalization KW mental health KW personalization KW conscious consumption KW segmentation KW market structure JO Theoretical economics AU Vysochina, M.V. AU Margarita, Y.V. PY 2026 IS PB Yaroslavl State Technical University