Muscle quality. II. Effects of strength training in 65- to 75-yr-old men and women

Abstract

To determine the effects of strength training (ST) on muscle quality (MQ, strength/muscle volume of the trained muscle group), 12 healthy older men (69 +/- 3 yr, range 65-75 yr) and 11 healthy older women (68 +/- 3 yr, range 65-73 yr) were studied before and after a unilateral leg ST program. After a warm-up set, four sets of heavy-resistance knee extensor ST exercise were performed 3 days/wk for 9 wk on the Keiser K-300 leg extension machine. The men exhibited greater absolute increases in the knee extension one-repetition maximum (1-RM) strength test (75 +/- 2 and 94 +/- 3 kg before and after training, respectively) and in quadriceps muscle volume measured by magnetic resonance imaging (1,753 +/- 44 and 1, 955 +/- 43 cm3) than the women (42 +/- 2 and 55 +/- 3 kg for the 1-RM test and 1,125 +/- 53 vs. 1,261 +/- 65 cm3 for quadriceps muscle volume before and after training, respectively, in women; both P < 0.05). However, percent increases were similar for men and women in the 1-RM test (27 and 29% for men and women, respectively), muscle volume (12% for both), and MQ (14 and 16% for men and women, respectively). Significant increases in MQ were observed in both groups in the trained leg (both P < 0.05) and in the 1-RM test for the untrained leg (both P < 0.05), but no significant differences were observed between groups, suggesting neuromuscular adaptations in both gender groups. Thus, although older men appear to have a greater capacity for absolute strength and muscle mass gains than older women in response to ST, the relative contribution of neuromuscular and hypertrophic factors to the increase in strength appears to be similar between genders.

β-Hydroxy-β-Methylbutyrate Did Not Enhance High Intensity Resistance Training-Induced Improvements in Myofiber Dimensions and Myogenic Capacity in Aged Female Rats

“…Even frail elderly individuals beyond the seventh decade of life have shown increases in muscle protein synthesis and myosin heavy chain content following RT (Fiatarone et al, 1994;Yarasheski et al, 1999). Despite its general effectiveness, the degree of RT-induced muscle hypertrophy varies across different age and gender groups Tracy et al, 1999;Welle et al, 1996). We and others have previously observed a blunted hypertrophic response in older females following long-term RT (Bamman et al, 2003;Ivey et al, 2000;Kosek et al, 2006).…”

Strength, Size, and Muscle Quality in the Upper Arm following Unilateral Training in Younger and Older Males and Females

“…For example, mCSA, has been observed to increase from 5.5% to 62% in older individuals in response to resistance training, depending on the technique used. 11,[16][17][18][19][20][21] Of these different methods of assessing strength changes, muscle quality (MQ), the ratio between muscle strength and size, 19 assists to more accurately indicate the amount of neuromuscular versus hypertrophic contribution that is involved in the loss of strength with aging. 16 For this reason, MQ may be a better indicator of overall muscle function than just strength or size alone.…”

“…11,[16][17][18][19][20][21] Of these different methods of assessing strength changes, muscle quality (MQ), the ratio between muscle strength and size, 19 assists to more accurately indicate the amount of neuromuscular versus hypertrophic contribution that is involved in the loss of strength with aging. 16 For this reason, MQ may be a better indicator of overall muscle function than just strength or size alone. 22 There is some evidence that a larger loss in muscle strength than muscle size occurs with aging [23][24][25] making it reasonable to suggest that the overall quality of muscle is reduced.…”

Força muscular em idosos II — Efeito de um programa complementar de treino na força muscular de idosos de ambos os sexos

“…No entanto, apesar de vários estudos referirem os níveis mais elevados da força muscular absoluta dos homens, comparativamente às mulheres, nenhum estudo por nós consultado refere uma especificidade de adaptação de acordo com o sexo. Por exemplo, apesar de Tracy et al (36) encontrarem valores de pré-treino significativamente maiores nos homens, os ganhos musculares relativos do membro exercitado, após treino específico de força durante 9 semanas, foram semelhantes, tanto nos homens, como nas mulheres. De igual modo, Lexell et al (23) verificaram que, apesar dos níveis iniciais de força entre homens e mulheres serem significativamente diferentes, as respostas ao treino de força foram semelhantes, quer nos extensores do joelho, quer nos flexores do cotovelo.…”

“…O seu uso na marcha lenta e rápida (21), na subida de degraus (27) e no movimento de levantar da cadeira (29) tem sido bem documentado em estudos cinemáticos, de electromiografia e de análise cinética. Numerosos trabalhos têm demonstrado que estímu-los adequados de treino em idosos, independentemente do sexo, retardam a diminuição da força e da massa muscular normalmente associada ao envelhecimento (15,19,20,22,30,36). Assim, programas com intensidade suficiente para aumentar a força e o equilíbrio devem ser implementados como forma de prevenção de quedas e lesões.…”