Os efeitos da beta-alanina em idosos praticantes de atividade física

Abstract

Introduction: Sarcopenia is associated with significant loss of muscle mass and function, impairing the physical capabilities of the elderly population. These losses also corroborate to the early onset of muscle acidosis, making it difficult to perform activities of daily living. The supplementation of β-alanine can delay the onset of fatigue, providing benefits to physical exercise and functional capacity, preventing parameters related to sarcopenia. This review aimed to study the effects of β-alanine supplementation for the delay in the beginning of muscle fatigue and for the improvement of muscle function in elderly people practitioners of physical activity. Methodology: A bibliographic review was carried out targeting articles published between January 2000 and September 2020 in databases such as Scielo (Scientific Electronic Library Online), PubMed (National Library of Medicine) and Google Scholar using terms indexed in the “Descritores em Ciências da Saúde” (DeCS) for concepts related to the elderly, beta-alanine and exercise. The inclusion criteria included clinical trial-type studies, carried out in middle-aged or elderly individuals and only in humans, as exclusion criteria, studies that associated the use of beta-alanine with different ergogenic resources and studies in trained elderly people. Discussion: Increases in the content of muscle carnosine may result in an improvement in the buffering capacity of hydrogen ions (H +), resulting in prolonged exercise time. In the elderly, these additions become relevant to support normal muscle functions and prevent losses from sarcopenia. The main finding of this study is related to a significant positive effect on physical resistance in most studies (75%; 3 of 4 studies). Four double-blind, randomized, placebo-controlled publications (N = 4) were included in the review. The studies were conducted in healthy, independent and physically inactive individuals, involving a total of 83 participants aged between 51 and 92 years, with 44 participating in the β-alanine intervention group and 39 using placebo. The doses administered differed from 2.4g to 3.2g per day and were followed for a variable period from 28 to 90 days. The parameters evaluated were diverse and comprised tests related to physical capacity, activities of daily living, muscle function, executive function and muscle carnosine content. The tests of physical resistance capacity demonstrated significantly better values (P ≤ 0,05) for physical work capacity at the fatigue threshold, time to exhaustion and time until the tolerance limit. Conclusion: β-alanine supplementation demonstrates that it is able to promote an ergogenic effect of muscle resistance in elderly people practitioners of physical activity. However, the use of β-alanine in resistance training protocols does not aim to be efficient to improve localized muscle resistance of elderly people practitioners of physical activity.