Resistance Training And Executive Functioning Among Senior Women

Abstract

The majority of prospective intervention studies of exercise and cognition to date have focused on aerobic-based exercise training. Few have examined whether other types of exercise training, such as resistance training (RT), may also benefit cognition. PURPOSE: To compare the effect of once-weekly progressive RT (1× RT) and twice-weekly progressive RT (2× RT) to twice-weekly balance and tone exercises (2× BAT) on executive functions among senior women aged 65 to 75 years. METHODS: We conducted a 12-month randomized trial of exercise in 155 senior women. Participants were randomized at baseline to either: 1) 1× RT; 2) 2× RT; or 3) 2× BAT. The protocol for the RT groups was progressive and high-intensity in nature with the aims of increasing muscle strength in the extremities and trunk. Both a Keiser® Pressurized Air system (Keiser Corporation, Fresno, CA, USA) and free weights were used to provide the training stimulus. The BAT program consisted of stretching exercises, general posture education, and toning exercises with body weight. We assessed three key executive functions - set shifting, response inhibition, and working memory - using standard neuropsychological tests at baseline, 6 months, and 12 months. The three key executive functions measured at 6 and 12 months were compared by forced entry multiple linear regression analysis, with baseline scores, baseline global cognitive function, baseline waist circumference, and experimental group included as independent variables in the models. RESULTS: Of the 155 participants assessed and randomized at baseline, 140 returned at 6 months, and 129 returned at 12 months. There were no significant between-group differences in set shifting or working memory at 6 or 12months. There were no significant between-group differences in response inhibition at 6 months. However, there were significant between-group differences in response inhibition at 12 months. Specifically, both the 1XRT and 2XRT groups significant improved compared with the 2X BAT group (P < 0.04). CONCLUSIONS: Executive functions are important to seniors' ability to live independently. Our results suggest that once- or twice-weekly RT may benefit the specific executive process of response inhibition. However, a training duration greater than six months is required to realize this benefit.