DOES ACUTE STRENGTH TRAINING AFFECT MOTOR AND COGNITIVE FUNCTION INTERACTION IN OLD ADULTS?
Margarita Drozdova-Statkevičienė, Vida Janina Česnaitienė, Nerijus Masiulis
Lithuanian Sports University, Kaunas
Relevance of the research. Balance stability becomes increasingly critical with aging. Age effect on balance stability is attributed primarily to sensorimotor dysfunctions (Boisgontier et al., 2014), muscle weakness (Morse et al., 2004), and structural changes in brain grey and white matter (Boisgontier et al., 2008). Evidence from other studies suggests that, despite the above mentioned neural deficits, older adults may recruit additional neural resources to reach sufficient level of sensorimotor control by increasing attention to the task in head (Heuninckx et al., 2008). Since availability of attentional resources and the ability to allocate attention efficiently is declining with aging (Heuninckx et al., 2008), allocation of attentional resources toward a secondary cognitive task is expected to have a larger interference effect on balance in older adults than in young adults (Ruffieux et al., 2015).
Ageing affect and cognitive functions. About 20 % of adults above the age of 65 diagnosed with mild cognitive impairment (Kirova et al., 2015). Most aspects of cognitive function become less effective, the most noticeable working memory, inhibition and long-term memory impairment (Di et al., 2014). Neuropsychological assessments suggest that physical exercise attenuates cognitive declines accompanying aging (Kimura et al., 2010). Many studies give priority to aerobic exercise, but some studies found positive effect of resistance exercise on cognition (Chang et al., 2014). Resistance exercise also could be effective to posture control, because increases knee isokinetic, 1 RM, strength of older men (Wolfson et al., 1996). But we didnʼt found any study, where the direct effect of strength exercise on postural control would be considered. Therefore we decide to assess acute strength training effect on postural control and cognitive function in dual tasking. The object of the research is the effect of strength training on interaction of motor and cognitive function in old adults. The aim is to assess the effect of acute strength training on postural control and cognitive function during dual tasking.
Research methods and organization. The sample included 30 participants, they were random divided into 2 groups: control (67.5 ± 5.3 years) and experiment (67.3 ± 5.0 years). In both groups was measured posturography with a single piezoelectric force plate (KISTLER, Switzerland, Slimline System 9286). Recordings were made under these conditions: (i) single task (ST) of posturography in 3 positions (double stance eyes open/closed; Romberg stance eyes open) and cognitive task separately, (ii) dual task (DT) – posturography in 3 positions while performing a Mathematical Counting task. In the experiment group were performed squats with a barbell using Smith Weightlifting Machine (3 x 90 % 1 RM; 3 x 95 % 1 RM; 3 x 100 % 1 RM) meanwhile control group had rest break. Related samples we calculate with Wilcoxon signed rank test, independent samples – with Mann Whitney U test. Significance level was set to p < .05.
Results and discussion. No significant differences were observed in postural control and cognitive task between groups at baseline measurements during ST and DT in all positions (p > .05). We found, that posture control declined performing DT in REO position (p < .05) in experimental and control groups, but cognitive task performance declined only in experimental group (p = .02). Postural control improved in REO position in both groups (p = .02) performing DT after intervention. Therefore, cognitive task results did not differ in both groups performing DT after intervention.
Conclusions. Acute strength training had no effect on interaction of motor and cognitive function in old adult men. We found only tendencies that strength-training intervention might improve cognitive performance, but this needs further studies.