Effect of Different Load Intensity Transition Schemes on Muscular Strength and Physical Performance in Postmenopausal Women.

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-to-lower-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 weeks 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 weeks, and 8-12RM in the last 12 weeks) or HL-to-LL (n = 12, 8-12RM during the first 12 weeks, and 27-31 RM in the last 12 weeks). Muscular dynamic (1-RM test) and isometric strength (MIVC) and functional tests (sit-to-stand power, 400-m walking, and 6-minute walking) were analyzed at baseline, after 12 and 24 weeks.

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 (LL-to-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% vs. HL-to-LL = 5.52%; 6-minute test: LL-to-HL = 4.44% vs. HL-to-LL = 5.55%) after 24 weeks 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 weeks 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), while having little effect on leg curl strength, isometric strength, and walking speed. Our findings suggest that while a HL makes a muscle isotonically stronger, it may have limited impact on isometric strength and walking speed in postmenopausal women.