Maximum dynamic lower-limb strength was maintained during 24 weeks reduced training frequency in previously sedentary older women
There is little study into the effects of reducing strength-training below the recommended twice-weekly frequency, particularly in older women, despite the possibility that individuals will encounter periods of reduced training frequency. The purpose of the present study was to determine the effects of a period of reduced training frequency on maximum strength and muscle mass of the lower limbs in comparison with the recommended training frequency of twice-per-week. After an initial 12-week period where all subjects trained twice-per-week, a reduced strength training group (RST) trained once-per-week while another strength training group (ST) continued to train twice-per-week for 24 weeks. A non-training age-matched control group (CON) was used for comparison. All subjects were tested for leg press one-repetition maximum (1-RM), electromyogram (EMG) amplitude of vastus lateralis and medialis and quadriceps cross-sectional area (CSA) measured by panoramic ultrasound at week 0, 12 and 36. Both ST and RST continued to increase 1-RM during the reduced training frequency period compared to control (∼8% and ∼5% vs. ∼-3%, respectively, P<0.05). Accompanying these changes were significant increases in EMG amplitude in both ST and RST (P<0.05). However, the initial gains in quadriceps CSA made from week 0 to 12 in RST were lost when training once-per-week (RST ∼-5%). Therefore, reduced training frequency in this population does not adversely affect maximum strength or muscle activity but can negatively affect muscle mass, even reversing training-induced gains. Older individuals not training at least twice-per-week may compromise potential increases in muscle mass; important in counteracting effects of aging.