Recently, there have been several studies that have examined the acute effects of aerobic exercise on cognitive function. Importantly, one precise indicator of cognitive function is response time (RT), which has two main components; premotor time (PMT) and motor time (MT). PMT is the time for perception, decision making and response preparation, while MT is executing the response. Using fractionated response time (FRT) instead of RT provides a more precise estimate of the location of the effect of aerobic exercise on cognitive or motor components of the response. There is emerging evidence that shows an acute bout of exercise may improve FRT. Therefore, the purpose of this systematic review and meta-analysis was to explore the acute effect of aerobic exercise on FRT by considering the effects of various cognitive function tests. Fourteen studies were included investigating FRT during and/or after aerobic exercise. The results indicated that during exercise, PMT increased in simple reaction time and decreased in flanker task; MT decreased in choice reaction time; interestingly, RT decreased when it was assessed by choice reaction time and flanker task, almost similar to PMT and MT. After exercise, PMT decreased specifically in flanker and go/no-go tasks. However, MT and RT did not change significantly. In conclusion, as changes in RT are affected by both PMT and MT, FRT provides a more precise estimate of the locus of the effects of aerobic exercise on response time.
Alibazi, RJ, Pearce, AJ, Rostami, M, Frazer, AK, Brownstein, C, and Kidgell, DJ. Determining the intracortical responses after a single session of aerobic exercise in young healthy individuals: a systematic review and best evidence synthesis. J Strength Cond Res 35(2): 562–575, 2021—A single bout of aerobic exercise (AE) may induce changes in the excitability of the intracortical circuits of the primary motor cortex (M1). Similar to noninvasive brain stimulation techniques, such as transcranial direct current stimulation, AE could be used as a priming technique to facilitate motor learning. This review examined the effect of AE on modulating intracortical excitability and inhibition in human subjects. A systematic review, according to PRISMA guidelines, identified studies by database searching, hand searching, and citation tracking between inception and the last week of February 2020. Methodological quality of included studies was determined using the Downs and Black quality index and Cochrane Collaboration of risk of bias tool. Data were synthesized and analyzed using best-evidence synthesis. There was strong evidence for AE not to change corticospinal excitability and conflicting evidence for increasing intracortical facilitation and reducing silent period and long-interval cortical inhibition. Aerobic exercise did reduce short-interval cortical inhibition, which suggests AE modulates the excitability of the short-latency inhibitory circuits within the M1; however, given the small number of included studies, it remains unclear how AE affects all circuits. In light of the above, AE may have important implications during periods of rehabilitation, whereby priming AE could be used to facilitate motor learning.
Muscle fatigue is considered to be one cause of shoulder pain, and subjects with generalized joint hypermobility (GJH) are affected more by shoulder pain. The purpose of this study was to examine the effects of muscle fatigue on acromiohumeral distance (AHD) and scapular dyskinesis in women with GJH. Thirty-six asymptomatic participants were assigned to either a GJH (n = 20) or control group (n = 16) using the Beighton scale. Before and after elevation fatigue trials, AHD was measured with ultrasonography at rest and when the arm was in 90° active elevation. A scapular dyskinesis test was used to visually observe alterations in scapular movement. Our results showed that in both groups, the fatigue reduced AHD in the 90° elevation position and increased the presence of scapular dyskinesis; however, no differences were found between the two groups. Although GJH has been identified as a factor for developing musculoskeletal disorders, generalized joint hypermobility did not result in changes to scapular dyskinesis or AHD, even after an elevation fatigue task. More studies are needed to evaluate the effects of muscle fatigue in subjects with GJH and a history of shoulder instability.
The corticospinal-responses to high-intensity and low-intensity strength-training of the upper-limb are modulated in an intensity-dependent manner. Whether an intensity-dependent threshold occurs following acute strengthtraining of the knee extensors (KE) remains unclear. We assessed the corticospinal-responses to an acute bout of either high-intensity (85% of maximal strength) or low-intensity (30% of maximal strength) KE strength-training with measures taken during an isometric KE task at baseline, post 5, 30 and 60 minutes. Twenty-eight healthy volunteers (23 ± 3 years) were randomized to high-intensity (n = 11), low-intensity (n = 10) or to a control group (n = 7). Corticospinal-responses were evoked with transcranial magnetic stimulation (TMS) at intracortical and corticospinal levels. An acute bout of high-or low-intensity KE strength-training had no effect on maximum voluntary contraction (MVC) force post-exercise (P > 0.05). High-intensity training increased corticospinal excitability (range 130% to 180%) from 5-60 minutes post-exercise compared to low-intensity training (17-30% increase). Large effect sizes (ES) showed that short-interval cortical inhibition (SICI) was reduced only for the highintensity training group from 5-60 minutes post-exercise (24-44% decrease), compared to low-intensity (ES ranges 1-1.3). These findings show a training-intensity threshold is required to adjust CSE and SICI following strength training in the lower-limb.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.