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Background: To determine the effect of resistance training volume on physical and perceptual outcomes of breast cancer survivors submitted to a combined training program. Design: Randomized single-blinded study. Methods: Nineteen breast cancer survivor women were randomized to a single-set (SS) or a multiple-set (MS) group. Both groups completed an 8-week combined training intervention in which the SS and MS groups performed 1 and 3 sets per resistance exercise, respectively. The following outcomes were assessed preintervention and postintervention: maximal knee extension dynamic strength (1-repetition maximum), quadriceps muscle thickness, peak oxygen uptake, time to exhaustion, cancer-related fatigue, and quality of life. Results: Both interventions increased knee extension 1-repetition maximum (SS: 29.8% [37.5%]; MS: 19.3% [11.8%]), quadriceps muscle thickness (9.4% [4.1%]; 8.9% [5.9%]), and quality of life (4.3% [6.3%]; 7.9% [9.0%]), with no difference between the groups. However, only MS improved cancer-related fatigue (−2.1% [1.7%]) and time to exhaustion (21.3% [14.9%]), whereas peak oxygen uptake remained unchanged in both groups. Conclusions: Cancer-related fatigue and time to exhaustion, improved only in the MS group after the intervention. On the other hand, similar knee extension 1-repetition maximum, quadriceps muscle thickness, and quality of life improvements were observed in breast cancer survivors irrespective of the resistance training volume performed. [ABSTRACT FROM AUTHOR]

(a) Ascertain whether lower muscle mass, strength (1 repetition maximum [1RM]), and power (Pmax) in middle-aged women who are breast cancer survivors (BCS), when compared with women of a similar age never diagnosed with cancer (WNC), are related with lower walking speed (WS). (b) Ascertain whether changes in WS are associated with changes in muscle mass, 1RM, and (or) Pmax after resistance training (RT) in middle-aged BCS. A cross-section study was performed. Twenty WNC and 21 BCS were evaluated for lean mass of legs (LLM), 1RM (knee extension), muscle quality index (MQI = 1RM/LLM), Pmax (maximum muscle power-knee extension), and fast WS (10 and 400-meters). Randomized clinical trial was performed. The BCS were randomly divided into the control group (n = 9) and the RT group (n = 11). Breast cancer survivors exhibited lower 1RM (24.2%, p < 0.001), Pmax (30.6%, p < 0.001), MQI (22.2%, p = 0.001), and WS (10-m = 17.0%, p < 0.001 and 400-m = 10.5%, p = 0.002) than WNC. Resistance training increased 1RM (31.6%, p = 0.001), MP (29.0%, p = 0.012), MQI (28.5%, p = 0.008), and WS (10-m = 9.4%, p = 0.009 and 400-m = 6.2%, p = 0.006) in BCS. The changes in WS were positively associated with 1RM (10-m = 68%, p = 0.001 and 400-m = 37%, p = 0.036) and Pmax (10-m = 56%, p = 0.005 and 400-m = 40%, p = 0.027) and MQI (10-m = 63%, p = 0.043 and 400-m = 37%, p = 0.035). Resistance training-induced gains in muscle strength and power mediate the improvement in WS in middle-aged BCS. Resistance training is an effective strategy to improve WS in middle-aged BCS. [ABSTRACT FROM AUTHOR]

Background: The hyperbolic torque-duration curve depicts critical torque (CT) and W prime (W′), with the curve's asymptote representing CT as the boundary between heavy- and severe-intensity domains. W′, the curvature constant, indicates cumulative work beyond CT. This study investigated age-related reductions in W′, CT, and gait speed, and whether W′ and CT predict gait speed independently of muscle torque. Methods: three groups (adults, middle-aged, older) totaling 131 women were studied. W′ and CT were determined using 60 maximal isometric voluntary contractions of knee extensors. The fast gait speed was calculated in walking tests at 10 m, 400 m, and six minutes (6 MWT). Results: gait speed decreased (p < 0.05) with age, as did W′ and CT. Both W′ and CT correlated positively with gait speed at different distances (10 m, 400 m, 6 MWT). Adjusted for maximum muscle torque, only W′ maintained a positive association (p < 0.05) with all gait speed tests (10 m: β = 0.201, SE = 0.086; 400 m: β = 0.262, SE = 0.085; 6 MWT: β = 0.187, SE = 0.086). Conclusions: aging led to declines in W′, CT, and gait speed. W′, not CT, remained a significant predictor of gait speed, indicating its importance for older women's mobility. [ABSTRACT FROM AUTHOR]

Nascimento de Oliveira Júnior, G, de Freitas Rodrigues de Sousa, J, Augusto da Silva Carneiro, M, Martins, FM, Santagnello, SB, Campos Souza, MV, and Orsatti, FL. Resistance training volume enhances muscle hypertrophy, but not strength in postmenopausal women: a randomized controlled trial. J Strength Cond Res 36(5): 1216–1221, 2022—Among several possible resistance training (RT) variables to be manipulated, the training volume has been considered as a critical variable to maximize RT-induced hypertrophy. Many of the studies that compared one set of RT with 3 sets have failed to show a difference in muscle hypertrophy in older adults. However, it is not clear whether further increases in RT volume (i.e., 6 sets) would result in even greater RT-related hypertrophy than 3 sets in older adults. This study aimed to investigate whether higher-volume RT (HV-RT) maximizes gains in lean body mass and muscle strength (MS) when compared with lower-volume RT (LV-RT) in postmenopausal women (PW). Fifty-eight PW were randomized into 1 of the 3 groups: control group (CT, no exercise), HV-RT (6 sets per exercise), and LV-RT (3 sets per exercise). Volunteers took part in a supervised training program (leg press 45°, leg extension, leg curl and standing calf raises) and were assessed for leg lean mass (LLM; dual X-ray absorptiometry) and lower limb MS (leg press and leg extension; 1 repetition maximum [1RM]) before and after 12 weeks of RT. Both HV-RT and LV-RT groups increased (p < 0.05) LLM and MS when compared with the CT group. Higher increases in LLM gains were observed for the HV-RT group when compared with the LV-RT group (6.1 and 2.3%, p < 0.001). Both HV-RT and LV-RT groups similarly increased 1RM in the leg press and leg extension. Thus, there seems to be a dose-response relationship between RT volume and muscle hypertrophy, but not for MS gains in PW. [ABSTRACT FROM AUTHOR]

Menopause transition may impair muscle function, decreasing exercise tolerance. The torque–duration relationship (hyperbolic curve) forms a practical framework within which exercise tolerance may be explored. In this regard, resistance training (RT) increases the curvature constant of this relationship (W′). Muscle hypertrophy and strength gains have been suggested as possible mediators of RT-induced improvement in W′, however, it is unclear what the main mediator is. Higher-volume RT (HV-RT), beyond that recommended by RT-guidelines (i.e. three sets per exercise), may promote greater hypertrophy, but not higher strength gains. Hence, this study aimed to investigate whether greater hypertrophy in HV-RT maximises W′ gain when compared to LVRT in postmenopausal women (PW). Fifty-eight PW were randomised to the control group (CTRL), HV-RT (six sets per exercise) or LV-RT (three sets per exercise). They underwent a 12-week RT program and were assessed for W′, thigh lean body mass (TLBM) and maximal isometric voluntary contraction (MIVC). The TLBM gain was higher (P < 0.001) in the HV-RT (9.4%) than LV-RT (3.7%). However, both HV-RT and LV-RT similarly increased MIVC (9.7% vs. 16.5%, P = 0.063) and W′ (26.4% vs. 34.6% P = 0.163). Additionally, the changes in W′ were associated with the changes in TLBM (31%, P = 0.003) and MIVC (52%, P= <0.001). However, when the changes in TLBM and MIVC were inserted into the predictive model, only the MIVC (33%, P = 0.002) was a predictor of W′. Thus, although HV-RT promoted greater hypertrophy than LV-RT, HV-RT does not seem to maximise W′ in PW. [ABSTRACT FROM AUTHOR]