Effects of Heavy Resistance/Power Training on Maximal Strength, Muscle Morphology, and Hormonal Response Patterns in 60-75-Year-Old Men and Women

Abstract

Eleven women (TRW; 64 +/- 4 yrs) and ten men (TRM; 65 +/- 5 yrs) participated in the strength/power training twice a week for 24 weeks. Basal concentrations of serum total and free testosterone, growth hormone (GH), dehydroepiandrosterone sulfate (DHEAS), cortisol and sex hormone binding globulin (SHBG) as well as acute responses of serum total and free testosterone, growth hormone (GH) were measured. Maximal 1RM strength in the squat, chair rise time and muscle fibre distribution and areas of type I and IIa and IIb of the vastus lateralis were also examined. 1RM squat increased in TRW by 26 (SD10)% (p < .001), and in TRM by 35 (7)% (p < .001) and chair rise time improved in both groups (p < .001). Fibre areas increased in type I, (p < .01), IIa (p < .01) and IIb (p < .01) in TRM and type I (p < .05) and IIa (p < .05) in TRW. The proportion of type IIa increased from 31% to 43% (p < .05) in TRW and that of type IIb decreased from 27% to 17% (p < .05) in TRW and from 25% to 17% (p < .05) in TRM. Individual concentrations of testosterone/cortisol ratios correlated (r = 0.63; p < .05) with the individual increases in 1RM strength in TRW. The exercise sessions resulted in acute increases in serum GH in both groups (p < .05) with a further increase (p < .01) up to 10 minutes post-loading in TRM at post-training.

Anabolic Responses to Resistance Training in Older Men and Women: A Brief Review

“…Lexell and colleagues (1995) reported similar changes in men and women for the biceps brachii, and Bamman and associates (2003) demonstrated substantial increases in men and lesser magnitude changes in women for the vastus lateralis muscle. Hakkinen et al (2002) also reported that relative hypertrophy was twice as high in Types I and IIb fiber CSA for the vastus lateralis muscle in men than in women.…”

“…In young adults, the majority of studies (Abe, DeHoyos, Pollock, & Garzarella, 2000;Cureton, Collins, Hill, & McElhannon, 1988;Hurlbut et al, 2002;Lemmer et al, 2000Lemmer et al, , 2001O'Hagan, Sale, MacDougall, & Garner, 1995;Roth et al, 2001;Staron et al, 1994) indicate that men and women experience similar relative changes in fat-free mass, muscle CSA, and fiber CSA after training, although others (Ivey et al) have reported a greater response in men. In older adults (>60 years), some investigations have demonstrated similar relative strength gains and body-composition changes between men and women after training (Fiatarone et al, 1994;Ivey et al;Lexell, 1995;McCartney, Hicks, Martin, & Webber, 1995;McCartney et al, 1996;Roth et al;Tracy et al, 1999), whereas others indicate the presence of sex differences as determined by singlemuscle-fiber contractile function (Trappe et al, 2001), fiber diameter (Bamman et al, 2003;Hakkinen et al, 2002), and muscle CSA (Hakkinen et al, 1998). It has been suggested that differences in anabolic hormones and the myostatin genotype might contribute to these sex differences (Bamman et al; Ivey et al).…”

The Pleiotropic Effect of Physical Exercise on Mitochondrial Dynamics in Aging Skeletal Muscle

“…CSA [54,114,115] as well as the proportion of type IIa fiber distribution [116]. Increasing muscle protein synthesis and muscle fiber hypertrophy corresponds to an increase in force-generating capacity and an improvement in ADL performance, leading to a significant improvement in quality of life.…”

Adaptações neuromusculares ao treinamento de força e concorrente em homens idosos.

“…O treinamento de força (TF) é uma intervenção efetiva para o aumento na força [1][2][3]6 , potência 6,13,21 , ativação 7,8,10,13,15 e massa muscular 2,6,8,11,16 . Adaptações na função neuromuscular decorrente do treinamento de força nessa população aparenta ser semelhante do que em indivíduos jovens 16 , e essas adaptações resultam em melhora significativa na capacidade funcional dessa população 22 .…”

“…Indivíduos idosos submetidos ao treinamento de força (TF) apresentam aumento significativo na força muscular [1][2][3][4] , potência muscular 5,6 , ativação muscular [7][8][9][10][11] e massa muscular 12,13 . A melhora na força muscular decorrente do treinamento de força nessa população aparenta ser semelhante [14][15][16] do que à observada em indivíduos jovens, o que lhe confere grande treinabilidade, apesar do prejuízo na função neuromuscular decorrente do envelhecimento 9 .…”