The effect of age on cerebral blood flow responses during repeated and sustained stand to sit transitions

Aging is associated with impaired cerebrovascular blood flow and function, attributed to reduced vasodilatory capacity of the cerebrovascular network. Older adults may also have an impaired relationship between changes in blood pressure and cerebral blood flow; however, previous reports conflict. This study aimed to compare the blood pressure and cerebral blood flow responses to both repeated and sustained stand-to-sit transitions in young and older adults, and to assess the relationship with cerebrovascular reactivity.In 20 young (age: 24\ua0±\ua04\ua0years) and 20 older (age: 71\ua0±\ua07\ua0years) adults we compared middle cerebral artery flow velocity (MCAv), end-tidal partial pressure of carbon dioxide (P CO ), and blood pressure (mean arterial blood pressure [MAP]) during repeated stand-to-sit (10\ua0s standing and 10\ua0s sitting) and sustained stand-to-sit (3\ua0min standing followed by 2\ua0min sitting) transitions. Cerebrovascular reactivity to changes in carbon dioxide levels was assessed using a repeated breath-hold test.The % change in MCAv per % change in MAP (%∆MCAv/%∆MAP) was higher in the older adults than in the young adults during repeated stand-to-sit transitions. During the sustained protocol the %∆MCAv/%∆MAP response was similar in both age groups. A high %∆MCAv/%∆MAP response during the repeated stand-to-sit protocol was associated with low cerebrovascular reactivity to CO (r\ua0=\ua0-.39; p\ua

Short Bouts of Intensive Exercise During the Workday Have a Positive Effect on Neuro-cognitive Performance

Beside its positive impact on physical health, exercise is indicated to positively affect cognitive performance based on a relocation of cortical activity. This study examined the influence of different types of breaks on cognitive performance and related cortical activity in office-based employees. Breaks were filled with exercise, resting or a usual break and a control condition where employees continued working without any break. Cognitive performance was assessed using the d2-R test and two commercially available cognitive tasks. Brain cortical activity was recorded using electroencephalography before and after breaks. Individual's mood was analysed using a profile of mood state. Results indicate a positive effect of a 3-min boxing intervention on cognitive performance, mirrored by a decrease in prefrontal cortex activity. Although perceived psychological state was increased after the usual break, this is reflected in neither cortical activity nor cognitive performance. With respect to the fact that also bike activity resulted an increase in prefrontal alpha-2 activity, a positive effect of exercise on neuro-cognitive performance can be stated. Health and economic benefits may result from brief physical activity breaks and help to maintain workplace performance and job satisfaction. © 2015 John Wiley & Sons, Ltd

Rating of perceived exertion – a valid method for monitoring light to vigorous exercise intensity in individuals with subjective and mild cognitive impairment?

In rehabilitation settings, exercise intensity is often monitored with Borg's rating of perceived exertion (RPE). However, previous studies showed that severe cognitive impairment may limit the usability of the RPE. The aim of this study was to assess the relationship between RPE and heart rate (HR), and to establish whether a target RPE can be used to achieve exercise intensity based on an individual's HR-RPE in people with early cognitive impairment. 97 participants (74.7 ± 6 years) with early cognitive impairment completed an incremental exercise test. Of these, 54 were tested during a single, RPE guided exercise session. RPE and HR were monitored throughout. Correlations between HR and RPE were assessed using Spearman's correlation. Mean differences between measured HR and target HR were calculated and compared using a two-way ANOVA with factors cognition and exercise mode. Bland-Altman plots were constructed to analyse the agreement between target and measured HR. HR and RPE correlated moderately with each other (

Neurocognitive performance is enhanced during short periods of microgravity-Part 2

Previous studies showed a decrease in reaction time during the weightlessness phase of a parabolic flight. This effect was found to be stronger with increasing task complexity and was independent of previous experience of weightlessness as well as anti-nausea medication. Analysis of event related potentials showed a decreased amplitude of the N100-P200 complex in weightlessness but was not able to distinguish a possible effect of task complexity. The present study aimed to extend this previous work, by comparing behavioral (reaction time) and neurological (event related potentials analysis) performance to a simple (oddball) and a complex (mental arithmetic + oddball) task during weightlessness. 28 participants participated in two experiments. 11 participants performed a simple oddball experiment in the 1G and 0G phases of a parabolic flight. 17 participants were presented a complex arithmetic task in combination with an oddball task during the 1G and 0G phases of a parabolic flight. Reaction time as well as event related potentials (ERP) were assessed. Results revealed a reduced reaction time (p < .05) for the complex task during 0G. No gravity effects on reaction time were found for the simple task. In both experiments a reduction of typical ERP amplitudes was noticeable in weightlessness. It is assumed that the weightlessness induced fluid shift to the brain is positively affecting neuro-behavioral performance