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Carneiro, MAS, de Oliveira Júnior, GN, de Sousa, JFR, Murta, EFC, Orsatti, CL, Michelin, MA, Cyrino, ES, and Orsatti, FL. Effects of resistance training at different loads on inflammatory biomarkers, muscle mass, muscular strength, and physical performance in postmenopausal women. J Strength Cond Res 36(6): 1582–1590, 2022—It has been suggested that the effect of resistance training (RT) on circulating proinflammatory biomarkers may be dependent on muscle mass gain. A few recent studies have suggested that lower-load RT (LLRT; loads <50% of 1 repetition maximum [1RM] and repetition performed until, or close to, voluntary concentric failure) may be superior to higher-load RT (HLRT; loads >70% of 1RM) in increasing muscle mass. Hence, this study aimed to test whether LLRT is superior to HLRT for increasing muscle mass (total fat-free mass [TFFM] and leg fat-free mass [LFFM]) and improving circulating inflammatory biomarkers (interleukin [IL]-6, IL1-ra, tumor necrosis factor [TNF]-α, and extracellular heat shock protein [eHSP]70) in postmenopausal women (PW) (primary outcome). The secondary outcome was to compare the changes in muscular strength and physical performance (4-meter walking test [4-M], timed-up-and-go [TUG] test, and sit-to-stand [STS] test) between the LLRT and HLRT. The PW were randomized into 2 groups: LLRT (n = 14; loads necessary to perform 30–35 repetitions) and HLRT (n = 15; loads necessary to perform 8–12 repetitions). The greater magnitude of increase in LFFM (p = 0.033) was observed in LLRT when compared with HLRT. Moreover, there was a trend for a greater increase in TFFM in LLRT over HLRT (p = 0.070). However, there were similar improvements in TNF-α and muscular strength (p < 0.001). Furthermore, there was no significant difference between the RT schemes on IL-6, IL-1ra, and eHSP70 levels. Thus, although performing LLRT until, or close to, voluntary concentric failure seems to provide a greater stimulus for an increase in muscle mass than HLRT, it does not seem to affect the responses in circulating inflammatory biomarkers, muscular strength, and physical performance in PW. [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]

Purpose: In postmenopausal women, optimizing muscular strength and physical performance through proper resistance training (RT) is crucial in achieving optimal functional reserve later in life. This study aimed to compare if a higher-load-tolower-load (HL-to-LL) scheme is more effective than a lower-load-to-higher-load (LL-to-HL) scheme on muscular strength and physical performance in postmenopausal women after 12 and 24 wk of RT. Methods: Twenty-four postmenopausal women were randomized into two groups: LL-to-HL (n = 12, 27-31 repetitions maximum (RM) in the first 12 wk, and 8-12RM in the last 12 wk) or HL-to-LL (n = 12, 8-12RM during the first 12 wk, and 27-31RM in the last 12 wk). Muscular dynamic (1RM test) and isometric strength (MIVC) and functional tests (sit-to-stand power, 400-m walking, and 6-min walking) were analyzed at baseline, after 12 and 24 wk. Results: Different load intensity transition schemes resulted in enhancements (P < 0.05) in dynamic (45° leg press: LL-to-HL = 21.98% vs HL-to-LL = 16.07%; leg extension: LL-to-HL = 23.25% vs HL-to-LL = 16.28%; leg curl: LL-to-HL = 23.89% vs HL-to-LL = 13.34%) and isometric strength (LLto-HL = 14.63% vs HL-to-LL = 19.42%), sit-to-stand power (LL-to-HL = 7.32% vs HL-to-LL = 0%), and walking speed (400-m test: LL-to-HL = 3.30%vsHL-to-LL = 5.52%; 6-min test: LL-to-HL = 4.44%vs HL-to-LL = 5.55%) after 24wk of RT, without differences between groups (P > 0.05). However, only the HL increased the dynamic strength in 45° leg press and leg extension and sit-to-stand power. Moreover, walking speed changes were more strongly correlated with the changes in MIVC (P < 0.05). Conclusions: Our results indicate that both load intensity transition schemes produce similar improvements in muscular strength and physical performance in postmenopausal women after 24 wk of RT. However, the HL was more effective in increasing 45° leg press and leg extension strength, as well as power (mainly when performed after the LL), whereas having little effect on leg curl strength, isometric strength, and walking speed. Our findings suggest that although an HL makes a muscle isotonically stronger, it may have limited impact on isometric strength and walking speed in postmenopausal women. [ABSTRACT FROM AUTHOR]