Estudio de la mitofagia en respuesta a un programa de entrenamiento de fuerza en personas mayores

• Autor(a) principal: Moreira, Osvaldo Costa
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: spa
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://locus.ufv.br//handle/123456789/30188
• topic: Ciências da Saúde; Educação Física; Fisiología; Antropología física; Fisiología del ejercicio; Fisiología del músculo; Mitofagía; Entrenamiento

Introduction: Aging causes physiological, morphological, and functional changes in the body that result in the decreased physical capacity and losses in physiological functions. Strength training (ST), in turn, is a strategy widely used to try to curb the deleterious effects of aging, especially on morphology and functional capacity; however, the body of evidence does not make it clear whether a ST program is able to promote changes in the mitophagic capacity of elderly people, which became the main research question of this dissertation. Objective: To analyze the effects of an ST program on the different muscle strength manifestations, functional fitness indicators, body composition, and mitophagy signaling proteins in the elderly people. Methods: 48 volunteers aged between 70 and 77 years, were divided into two groups, control (CG: without ST) and strength (STG: with ST). They were evaluated by means of maximal strength tests (dynamic, isometric, and power), functional capacity body composition, and blood extraction for analysis of mitophagy proteins, before and after the completion of an ST program. The training was composed by 8 exercises, for the main muscle groups, performed with 3 sets of 8–12 repetitions, and intensity of 5–8 on the OMNI-RES scale. Intragroup comparison was done using the Wilcoxon test and intergroup comparison, using the Mann–Whitney test. Cohen’s D test was used to verify the effect size. Results: As main results revealed, the participants of the STG improved the upper and lower limbs strength, the lower limbs power and the functional capacity after the 8 weeks of training. In addition, significant improvements were observed in PGC-1α, BNIP3, and NIX proteins in the STG, in comparison with the CG. Conclusions: The ST program carried out by elderly people produced increases in the muscle strength, muscle power, and functional capacity in addition to producing positive changes in the macroautophagy, mitochondrial biogenesys and mitophagy proteins, especially in those related to NIX/Bnip3 mitophagy pathway. Key words: Aging, strength training, muscle strength, muscle power, functional capacity, body composition, autophagy mitophagy.