Intensity and workload related dose-response effects of acute resistance exercise on domain-specific cognitive function and affective response – A four-armed randomized controlled crossover trial

Abstract

IntroductionPreliminary evidence indicates beneficial acute effects of resistance exercise on domain-specific cognitive function. Studies on dose response relationships and underlying mechanisms so far failed to deduce the impact of intensity and overall workload. ObjectiveTo analyze the impact of different intensities and workloads on effects of full body resistance training on cognitive attention, executive function performance, and affective response. MethodsTwenty-six volunteers (9 (35%) female, age 25.9 ± 4.0 years) participated in three workload-matched (60%, 75% and 90% one repetition maximum intensity (1RM) resistance exercise interventions (RE)) and one workload reduced but intensity matched (75% 1RM, 50% overall workload) RE. Order was randomized, REs were on separate days with ≥48 h washout in between. Stroop Test performance (Attention: word and color condition; Interference control: word color interference), self-perceived levels of arousal and ability to concentrate were assessed before and after each RE. ResultsWorkload-matched REs induced significant changes in attention and interference control. The workload reduced 75% 1RM RE induced changes in interference control, but no changes in attention performance. 75% 1RM exercise with full and 50% workload induced significant changes in arousal. Only 75% 1RM exercise with full workload significantly increased participants ability to concentrate. The repeated measures ANCOVA (Covariates: sex and fluid intelligence) indicated greater changes of interference control after 60% 1RM compared to 90% 1RM RE and greater changes of attention performance after 90% 1RM compared to 75% 1RM and 50% workload RE. DiscussionHigher cognitive functions such as interference control seem to particularly benefit from moderate intensity RE whereas lower cognitive functions may be stimulated by higher intensity and higher workload RE. Self-perceived subjective factors did not mediate these dose response relationships. Future studies could analyze changes in cortisol levels, oxygenation, blood flow or electrophysiological signals to deduce triggers for increased stimulus-driven brain response and more controlled brain function.