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An inaugural workshop supported by “The Leo and Anne Albert Charitable Trust,” was held October 4–7, 2019 in Scottsdale, Arizona, to focus on the effects of exercise on the brain and to discuss how physical activity may prevent or delay the onset of aging-related neurodegenerative conditions. The Scientific Program Committee (led by Dr. Jeff Burns) assembled translational, clinical, and basic scientists who research various aspects of the effects of exercise on the body and brain, with the overall goal of gaining a better understanding as to how to delay or prevent neurodegenerative diseases. In particular, research topics included the links between cardiorespiratory fitness, the cerebrovasculature, energy metabolism, peripheral organs, and cognitive function, which are all highly relevant to understanding the effects of acute and chronic exercise on the brain. The Albert Trust workshop participants addressed these and related topics, as well as how other lifestyle interventions, such as diet, affect age-related cognitive decline associated with Alzheimer’s and other neurodegenerative diseases. This report provides a synopsis of the presentations and discussions by the participants, and a delineation of the next steps towards advancing our understanding of the effects of exercise on the aging brain.

Over the course of aging, there is an early degradation of cerebrovascular health, which may be attenuated with aerobic exercise training. Yet, the acute cerebrovascular response to a single bout of exercise remains elusive, particularly within key brain regions most affected by age-related disease processes. We investigated the acute global and region-specific cerebral blood flow (CBF) response to 15 minutes of moderate-intensity aerobic exercise in older adults (≥65 years; n = 60) using arterial spin labeling magnetic resonance imaging. Within 0–6 min post-exercise, CBF decreased across all regions, an effect that was attenuated in the hippocampus. The exercise-induced CBF drop was followed by a rebound effect over the 24-minute postexercise assessment period, an effect that was most robust in the hippocampus. Individuals with low baseline perfusion demonstrated the greatest hippocampal-specific CBF effect post-exercise, showing no immediate drop and a rapid increase in CBF that exceeded baseline levels within 6–12 minutes postexercise. Gains in domain-specific cognitive performance postexercise were not associated with changes in regional CBF, suggesting dissociable effects of exercise on acute neural and vascular plasticity. Together, the present findings support a precision-medicine framework for the use of exercise to target brain health that carefully considers age-related changes in the cerebrovascular system.

During aerobic exercise, central hemodynamics and CO2 partial pressure are central to middle cerebral artery blood velocity (MCAv) response. Still, the extent of their contribution is unknown. The purpose of this study was to characterize and utilize statistical modeling to determine the contribution of heart rate (HR), mean arterial pressure (MAP), and end-tidal CO2(PETCO2) dynamics to MCAv dynamics. Three randomized exercise bouts were completed on a recumbent stepper at 30-40% (Low), 45-55% (Mod1), and 60-70% (Mod2) of estimated HRmax. A 90-s resting period was followed by 6-min of continuous exercise within the estimated HR ranges. HR, MAP, PETCO2, and MCAv exercise dynamics were modeled with a monoexponential curve. From this modeling, the baseline (BL), time delay (TD), time constant (τ), and steady-state (SS) responses were determined. Backward AIC linear regression models determined contributing dynamics. Seventeen healthy adults completed all exercise bouts (28 ± 6 yrs, 8 females). The time from initiation of exercise to an exponential increase in HR (HRTD) was significantly longer for Low than Mod2 (p=0.047). The time constant for the rise in HR (HRτ) was significantly shorter for Low than Mod1 and Mod2 (p=0.01). The absolute change in HR from baseline to steady-state (HRSS) was significantly lower for Low than Mod1 and Mod2 (pSSwas significantly lower for Low than Mod1 (p=0.01) and Mod2 (pTD, and MAPTDaccounted for 17% of variation for MCAvTD(p=0.01). HRTD, PETCO2TD, and MCAvTDaccounted for 21% of variation MCAvτ (pSS, and PETCO2SSaccounted for 60% of variation for MCAvSS(p2do not account for most MCAv response until the steady-state phase. Thus, other physiological factors should be considered with assessing cerebrovascular function during aerobic exercise.

There is a positive association between cardiorespiratory fitness and cognitive health, but the interaction between cardiorespiratory fitness and aging on cerebral hemodynamics is unclear. These potential interactions are further influenced by sex differences. The purpose of this study was to determine the sex-specific relationships between cardiorespiratory fitness, age, and cerebral hemodynamics in humans. Measurements of unilateral middle cerebral artery blood velocity (MCAv) and cerebral pulsatility index obtained using transcranial Doppler ultrasound and cardiorespiratory fitness [maximal oxygen consumption (V̇o(2max))] obtained from maximal incremental exercise tests were retrieved from study records at three institutions. A total of 153 healthy participants were included in the analysis (age = 42 ± 20 yr, range = 18–83 yr). There was no association between V̇o(2max) and MCAv in all participants (P = 0.20). The association between V̇o(2max) and MCAv was positive in women, but no longer significant after age adjustment (univariate: P = 0.01; age-adjusted: P = 0.45). In addition, there was no association between V̇o(2max) and MCAv in men (univariate: P = 0.25, age-adjusted: P = 0.57). For V̇o(2max) and cerebral pulsatility index, there were significant negative associations in all participants (P < 0.001), in men (P < 0.001) and women (P < 0.001). This association remained significant when adjusting for age in women only (P = 0.03). In summary, higher cardiorespiratory fitness was associated with a lower cerebral pulsatility index in all participants, and the significance remained only in women when adjusting for age. Future studies are needed to determine the sex-specific impact of cardiorespiratory fitness improvements on cerebrovascular health. NEW & NOTEWORTHY We present data pooled from three institutions to study the impact of age, sex, and cardiorespiratory fitness on cerebral hemodynamics. Cardiorespiratory fitness was positively associated with middle cerebral artery blood velocity in women, but not in men. Furthermore, cardiorespiratory fitness was inversely associated with cerebral pulsatility index in both men and women, which remained significant in women when adjusting for age. These data suggest a sex-specific impact of cardiorespiratory fitness on resting cerebral hemodynamics.

PURPOSE: Physical activity within the hospital post-stroke is recommended for cardiovascular and musculoskeletal health, but no studies have examined cerebrovascular health. We hypothesized individuals who walked farther distances (FARhigh) during the acute phase of stroke recovery in a hospital setting would have a higher resting middle cerebral artery blood velocity (MCAv) and a greater cerebrovascular response (CVR) to moderate-intensity exercise at 3-months post-stroke, compared to individuals who walked shorter distances (FARlow). METHODS: At 3-month post-stroke, we recorded 90-seconds of resting baseline (BL) MCAv followed by 6-minutes of moderate-intensity exercise. We calculated CVR as the change in MCAv from BL to steady-state exercise. We retrospectively collected farthest distance walked within the hospital post-stroke from the electronic medical record. Participants were classified as FARhigh or FARlow based on average farthest walking distance. RESULTS: Twenty participants completed the study, age 63 (15) years. BL MCAv was not different between groups (p = 0.07). In comparison to FARlow, we report a higher CVR in FARhigh’s ipsilesional ([Formula: see text] = 7.38 (5.42) vs [Formula: see text] = 2.19 (3.53), p = 0.02) and contralesional hemisphere ([Formula: see text] = 8.15 (6.37) vs [Formula: see text] = 2.06 (4.76), p = 0.04). CONCLUSIONS: Physical activity during the hospital stay post-stroke may support cerebrovascular health after discharge. Prospective studies are needed to support this finding.

The main aim of this study was to investigate the effects of circuit resistance training (CRT) on post-exercise appetite and energy intake in chronic hemiparetic stroke patients. A secondary aim was to evaluate the reproducibility of these effects.Seven participants met the eligibility criteria and, in a randomized order, participated in a non-exercise control session (CTL) and two bouts of CRT. The CRT involved 10 exercises with 3 sets of 15-repetition maximum per exercise, performed using a vertical loading approach, with each set interspersed with 45s of walking. Expired gases were carried out to calculate the net energy cost of the exercise and the relative energy intake post-CTL/CRT. Hunger, fullness, desire to eat, and energy intake were assessed at baseline and for 12 h after CTL and CRT.Compared to CTL, hunger, desire to eat (A bout of CRT elicited decreased post-exercise appetite and relative energy intake in chronic hemiparetic stroke patients. Decreased appetite perceptions lasted for around 9 h and were reproducible.

BackgroundLocomotor high-intensity interval training (HIIT) has been shown to improve walking capacity more than moderate-intensity aerobic training (MAT) after stroke, but it is unclear which training parameter(s) should be prioritized (e.g. speed, heart rate, blood lactate, step count) and to what extent walking capacity gains are the result of neuromotor versus cardiorespiratory adaptations.ObjectiveAssess which training parameters and longitudinal adaptations most strongly mediate 6-minute walk distance (6MWD) gains from post-stroke HIIT.MethodsThe HIT-Stroke Trial randomized 55 persons with chronic stroke and persistent walking limitations to HIIT or MAT and collected detailed training data. Blinded outcomes included 6MWD, plus measures of neuromotor gait function (e.g. fastest 10-meter gait speed) and aerobic capacity (e.g. ventilatory threshold). This ancillary analysis used structural equation models to compare mediating effects of different training parameters and longitudinal adaptations on 6MWD.ResultsNet gains in 6MWD from HIIT versus MAT were primarily mediated by faster training speeds and longitudinal adaptations in neuromotor gait function. Training step count was also positively associated with 6MWD gains, but was lower with HIIT versus MAT, which decreased the net 6MWD gain. HIIT generated higher training heart rate and lactate than MAT, but aerobic capacity gains were similar between groups, and 6MWD changes were not associated with training heart rate, training lactate, or aerobic adaptations.ConclusionsTo increase walking capacity with post-stroke HIIT, training speed and step count appear to be the most important parameters to prioritize.

BackgroundHigh-intensity interval exercise (HIIT) is currently being implemented in stroke rehabilitation to improve walking function. HIIT alternates between high-intensity and recovery bouts, which causes rapid increases and decreases in blood pressure, which may impact cerebrovascular function in people post-stroke. To date, there is no information on the acute cerebrovascular response in people post-stroke. To address this gap in knowledge, we tested whether the cerebrovascular response was reduced when compared to sedentary age- and sex-matched adults (CON) at the following timepoints: 1) baseline (BL), 2) during a single 10-minute bout of low-volume HIIT, 3) immediately following HIIT, and 4) 30 minutes after HIIT.MethodsMiddle cerebral artery blood velocity (MCAv), mean arterial pressure (MAP), heart rate (HR), and end tidal carbon dioxide (PETCO2) were recorded at all timepoints. A submaximal exercise test was used to determine the estimated maximal workload. The low-volume HIIT bout was performed on a recumbent stepper and consisted of 1-minute high-intensity bouts (70% estimated maximal watts) separated by 1-minute active recovery (10% estimated maximal watts). Statistical analysis used linear mixed models and ANCOVA.ResultsIndividuals post-stroke demonstrated a reduced MCAv response during HIIT compared to CON (p = 0.03) and MCAv remained lower immediately following HIIT and 30-minutes after HIIT. MCAv decreased below BL immediately following HIIT in both groups (p ≤ 0.04) and returned to BL at 30-minutes after HIIT. No between differences were found for MAP, HR, and PETCO2.ConclusionsThe key finding from this study suggests a reduced MCAv response during low-volume HIIT in individuals post-stroke compared to age and sex-matched sedentary adults and these differences remained up to 30 minutes following HIIT. Future work is needed to better understand the reduced MCAv response during HIIT despite increased metabolic demand.Clinicaltrials.gov#NCT04673994.

Background and purpose Neurologic physical therapy (PT) can assist people with neurologic conditions and injuries to optimize their health and well-being by addressing barriers at the individual, relationship, community, and societal levels. The purpose of this special interest article is to provide consensus-driven strategies to address barriers to implementing health promotion and wellness (HPW)-related neurologic PT practice. Summary of key points Environmental scan, literature review, and expert input were used to determine barriers and develop strategies. Barriers include lack of time; low knowledge, self-efficacy, and awareness; client complexity; and lack of HPW resources; as well as concerns regarding payment and scope of practice. Four key strategies emerged: (1) develop and disseminate a consensus-based scope of practice for HPW in neurologic PT; (2) increase knowledge of resources related to HPW; (3) promote delivery models for HPW-related neurologic PT; and (4) encourage advocacy, community building and partnership along the continuum of care. Recommendations for clinical practice Clinicians should practice to their full scope of HPW-related PT practice. This includes optimizing movement, including physical activity and fitness, as well as reinforcing the importance of healthy sleep, nutrition, stress, and smoking cessation. These activities address primary, secondary, and tertiary prevention. Clinicians are encouraged to report their experiences with HPW-focused delivery models and outcomes. Additional research is needed to understand the full impact of HPW on PT practice (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A364).

BackgroundAerobic exercise elicits striking effects on neuroplasticity and cognitive executive function but is poorly understood after stroke.ObjectiveWe tested the effect of 4 weeks of aerobic exercise training on inhibitory and facilitatory elements of cognitive executive function and electroencephalography (EEG) markers of cortical inhibition and facilitation. We investigated relationships between stimulus-evoked cortical responses, blood lactate levels during training, and aerobic fitness post-intervention.MethodsTwelve individuals with chronic (>6mo) stroke completed an intensive aerobic exercise intervention (40-mins, 3x/week). Electroencephalography and motor response times were assessed during congruent (response facilitation) and incongruent (response inhibition) stimuli of a Flanker task. Aerobic fitness capacity was assessed as VO2-peak during a treadmill test pre- and post-intervention. Blood lactate was assessed acutely (ResultsFollowing exercise training, the response inhibition speed increased while response facilitation remained unchanged. A relationship between earlier cortical N2 response and faster response inhibition emerged post-intervention. Individuals who produced higher lactate during exercise training achieved faster response inhibition and tended to show earlier cortical N2 responses post-intervention. There were no associations between VO2-peak and metrics of behavioral or neurophysiologic function.ConclusionsThese findings provide novel evidence for selective benefits of aerobic exercise on inhibitory control during the initial 4-week period after initiation of exercise training, and implicate a potential therapeutic effect of lactate on post-stroke cortical inhibitory function.Trial RegistrationClinicalTrials.govIdentifier:NCT03760016. First posted: November 30, 2018.https://clinicaltrials.gov/ct2/show/NCT03760016

Sex as a biological variable appears to contribute to the multifactorial etiology of Alzheimer’s disease. We tested sex-based interactions between cerebrovascular function and APOE4 genotype on resistance and resilience to brain pathology and cognitive executive dysfunction in cognitively-normal older adults. Female APOE4 carriers had higher amyloid-β deposition yet achieved similar cognitive performance to males and female noncarriers. Further, female APOE4 carriers with robust cerebrovascular responses to exercise possessed lower amyloid-β. These results suggest a unique cognitive resilience and identify cerebrovascular function as a key mechanism for resistance to age-related brain pathology in females with high genetic vulnerability to Alzheimer’s disease.

IntroductionNovel implementation of a force sensor during a sit-to-stand measure of dynamic cerebral autoregulation (dCA) has been shown to measure the exact moment an individual stands up from a chair, called arise-and-off (AO). Traditional measures estimate time delay (TD) before the onset of the dCA response from the verbal command to stand. We hypothesized that using a force sensor to measure AO would significantly improve the accuracy of the TD measure compared to estimating from verbal command.MethodsMiddle cerebral artery blood velocity (MCAv) and mean arterial pressure (MAP) were measured simultaneously during three sit-to-stand measures of dCA. Participants were seated for 60 seconds, then performed a sit-to-stand and the force sensor detected AO. TD was calculated as the time from AO until an increase in cerebrovascular conductance (CVC = MCAv/MAP). TD was also calculated from verbal command to stand.ResultsSixty-five participants completed the study: twenty-five young adults (age 25±2 years), twenty older adults (age 61±13 years), and twenty individuals with stroke (age 60±13 years). There was a significant difference in TD when using AO compared to estimating (F-value=49.9, pDiscussionThe addition of a force sensor to detect AO during a sit-to-stand procedure showed a significant difference in the TD dCA measurement. Our data support the implementation of a force sensor during sit-to-stand dCA measures in healthy adults across all ages and after stroke.

PURPOSE: It is plausible that statins could improve cerebral blood flow through pleiotropic mechanisms. The purpose of this investigation was to assess the contribution of statins to cerebrovascular variables in older adults with dyslipidemia and familial history of dementia. Furthermore, we explored the interaction between statin use and sex due to prevalent bias in statin trials. METHODS: Middle cerebral artery blood flow velocity (MCAv) was measured using transcranial Doppler ultrasound. Continuous supine rest recordings lasted 8 min. Participants included in analyses were statin (n = 100) or non-statin users (n = 112). RESULTS: MCAv and cerebrovascular conductance were significantly higher in statin users (p = 0.047; p = 0.04), and pulsatility index (PI) was significantly lower in statin users (p < 0.01). An interaction effect between statin use and sex was present for PI (p = 0.02); female statin users had significantly lower cerebrovascular resistance than the other three groups. CONCLUSION: In this cross-sectional analysis, statin use was positively associated with cerebrovascular variables in older adults at risk for dementia. Female statin users had significantly higher resting MCAv and cerebrovascular conductance than female non-statin users. The greatest contribution of statin use was the association with reduced cerebrovascular resistance. Given that cerebrovascular dysregulation is one of the earliest changes in Alzheimer’s disease and related dementia pathology, targeting the cerebrovasculature with statins may be a promising prevention strategy.

IntroductionFor walking rehabilitation after stroke, training intensity and duration are critical dosing parameters that lack optimization. This trial aimed to determine the optimal training intensity (vigorous vs moderate) and minimum training duration (4, 8 or 12 weeks) needed to maximize immediate improvement in walking capacity in chronic stroke.MethodsPersons with chronic post-stroke gait dysfunction at three centers were randomized to high-intensity interval training (HIT) or moderate intensity aerobic training (MAT), each involving 45 minutes of treadmill and overground walking exercise with a physical therapist, 3 times per week for 12 weeks. The HIT protocol used repeated 30 second bursts of walking at maximum safe speed, alternated with 30-60 second recovery periods, targeting an average aerobic intensity above 60% heart rate reserve (HRR). The MAT protocol used continuous walking with speed adjusted to maintain an initial target of 40 ± 5% HRR, progressing by 5% HRR every 2 weeks, up to 60% HRR as tolerated. Blinded assessment at baseline and after 4, 8 and 12 weeks of training included the 6-minute walk test (6MWT) as the primary measure of walking capacity.ResultsRandomized participants (N=55) attended 1,675 (85%) of 1,980 planned treatment sessions and 197 (90%) of 220 planned testing sessions. No serious adverse events related to study procedures occurred. Compared with MAT, HIT involved significantly higher training speeds (161% vs 96% baseline fastest 10-meter speed, pDiscussionThese findings show proof of concept that vigorous training intensity is a critical dosing parameter for walking rehabilitation. In chronic stroke, vigorous walking exercise can produce significant and meaningful gains in walking capacity with only 4 weeks of training, but at least 12 weeks are needed to maximize immediate gains.

ImportanceFor walking rehabilitation after stroke, training intensity and duration are critical dosing parameters that lack optimization.ObjectiveTo assess the optimal training intensity (vigorous vs moderate) and minimum training duration (4, 8, or 12 weeks) needed to maximize immediate improvement in walking capacity in patients with chronic stroke.Design, Setting, and ParticipantsThis multicenter randomized clinical trial using an intent-to-treat analysis was conducted from January 2019 to April 2022 at rehabilitation and exercise research laboratories. Survivors of a single stroke who were aged 40 to 80 years and had persistent walking limitations 6 months or more after the stroke were enrolled.InterventionsParticipants were randomized 1:1 to high-intensity interval training (HIIT) or moderate-intensity aerobic training (MAT), each involving 45 minutes of walking practice 3 times per week for 12 weeks. The HIIT protocol used repeated 30-second bursts of walking at maximum safe speed, alternated with 30- to 60-second rest periods, targeting a mean aerobic intensity above 60% of the heart rate reserve (HRR). The MAT protocol used continuous walking with speed adjusted to maintain an initial target of 40% of the HRR, progressing up to 60% of the HRR as tolerated.Main Outcomes and MeasuresThe main outcome was 6-minute walk test distance. Outcomes were assessed by blinded raters after 4, 8, and 12 weeks of training.ResultsOf 55 participants (mean [SD] age, 63 [10] years; 36 male [65.5%]), 27 were randomized to HIIT and 28 to MAT. The mean (SD) time since stroke was 2.5 (1.3) years, and mean (SD) 6-minute walk test distance at baseline was 239 (132) m. Participants attended 1675 of 1980 planned treatment visits (84.6%) and 197 of 220 planned testing visits (89.5%). No serious adverse events related to study procedures occurred. Groups had similar 6-minute walk test distance changes after 4 weeks (HIIT, 27 m [95% CI, 6-48 m]; MAT, 12 m [95% CI, −9 to 33 m]; mean difference, 15 m [95% CI, −13 to 42 m]; P = .28), but HIIT elicited greater gains after 8 weeks (58 m [95% CI, 39-76 m] vs 29 m [95% CI, 9-48 m]; mean difference, 29 m [95% CI, 5-54 m]; P = .02) and 12 weeks (71 m [95% CI, 49-94 m] vs 27 m [95% CI, 3-50 m]; mean difference, 44 m [95% CI, 14-74 m]; P = .005) of training; HIIT also showed greater improvements than MAT on some secondary measures of gait speed and fatigue.Conclusions and RelevanceThese findings show proof of concept that vigorous training intensity is a critical dosing parameter for walking rehabilitation. In patients with chronic stroke, vigorous walking exercise produced significant and meaningful gains in walking capacity with only 4 weeks of training, but at least 12 weeks were needed to maximize immediate gains.Trial RegistrationClinicalTrials.gov Identifier: NCT03760016

Cerebrovascular dysfunction likely contributes causally to Alzheimer’s disease (AD). The strongest genetic risk factor for late-onset AD, Apolipoprotein E4 ( APOE4), may act synergistically with vascular risk to cause dementia. Therefore, interventions that improve vascular health, such as exercise, may be particularly beneficial for APOE4 carriers. We assigned cognitively normal adults (65–87 years) to an aerobic exercise intervention or education only. Arterial spin labeling MRI measured hippocampal blood flow (HBF) before and after the 52-week intervention. We selected participants with hypertension at enrollment (n = 44). For APOE4 carriers, change in HBF (ΔHBF) was significantly ( p = 0.006) higher for participants in the exercise intervention (4.09 mL/100g/min) than the control group (−2.08 mL/100g/min). There was no difference in ΔHBF between the control (−0.32 mL/100g/min) and exercise (−0.54 mL/100g/min) groups for non-carriers (p = 0.918). Additionally, a multiple regression showed an interaction between change in systolic blood pressure (ΔSBP) and APOE4 carrier status on ΔHBF ( p = 0.035), with reductions in SBP increasing HBF for APOE4 carriers only. Aerobic exercise improved HBF for hypertensive APOE4 carriers only. Additionally, only APOE4 carriers exhibited an inverse relationship between ΔSBP and ΔHBF. This suggests exercise interventions, particularly those that lower SBP, may be beneficial for individuals at highest genetic risk of AD.ClinicalTrials.gov Identifier: NCT02000583

BackgroundPhysical exercise may support brain health and cognition over the course of typical aging. The goal of this nonrandomized clinical trial was to examine the effect of an acute bout of aerobic exercise on brain blood flow and blood neurotrophic factors associated with exercise response and brain function in older adults with and without possession of the APOE4 allele, a genetic risk factor for developing Alzheimer’s. We hypothesized that older adult APOE4 carriers would have lower cerebral blood flow regulation and would demonstrate blunted neurotrophic response to exercise compared to noncarriers.MethodsSixty-two older adults (73±5 years old, 41 female) consented to this prospectively enrolling clinical trial, utilizing a single arm, single visit, experimental design, with post-hoc assessment of difference in outcomes based on APOE4 carriership. All participants completed a single 15-minute bout of moderate-intensity aerobic exercise. The primary outcome measure was change in cortical gray matter cerebral blood flow in cortical gray matter measured by magnetic resonance imaging (MRI) arterial spin labeling (ASL), defined as the total perfusion (area under the curve, AUC) following exercise. Secondary outcomes were changes in blood neurotrophin concentrations of insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and brain derived neurotrophic factor (BDNF).ResultsGenotyping failed in one individual (n=23 APOE4 carriers and n=38 APOE4 non-carriers) and two participants could not complete primary outcome testing. Cerebral blood flow AUC increased immediately following exercise, regardless of APOE4 carrier status. In an exploratory regional analyses, we found that cerebral blood flow increased in hippocampal brain regions, while showing no change in cerebellar brain regions across both groups. Among high interindividual variability, there were no significant changes in any of the 3 neurotrophic factors for either group immediately following exercise.ConclusionsOur findings show that both APOE4 carriers and non-carriers show similar effects of exercise-induced increases in cerebral blood flow and neurotrophic response to acute aerobic exercise. Our results provide further evidence that acute exercise-induced increases in cerebral blood flow may be regional specific, and that exercise-induced neurotrophin release may show a differential effect in the aging cardiovascular system. Results from this study build upon previous research in younger adults by providing an initial characterization of the acute brain blood flow and neurotrophin responses to a bout of exercise in older adults with and without this known risk allele for cardiovascular disease and Alzheimer’s disease.Trials registrationDementia Risk and Dynamic Response to Exercise (DYNAMIC); Identifier: NCT04009629FundingThis study was funded by grants from the national institutes of health R21 AG061548, P30 AG072973 and P30 AG035982, and the Leo and Anne Albert Charitable Trust. The Hoglund Biomedical Imaging Center is supported by a generous gift from Forrest and Sally Hoglund and funding from the National Institutes of Health including S10 RR29577, and UL1 TR002366.

PURPOSE: The aim of this study was to evaluate the relationship of cardiovascular disease (CVD) on middle cerebral blood flow velocity (MCAv) at rest and during exercise. A secondary aim was to explore the relationship between MCAv and 1) the presence of white matter lesions and 2) cognitive function. METHODS: We recruited individuals who were cognitively normal older adults. CVD risk was assessed by the Pooled Cohort atherosclerotic cardiovascular disease (ASCVD) risk score. Transcranial Doppler ultrasound measured middle cerebral artery at rest and during a bout of moderate intensity exercise. We quantified white matter lesions from MRI and cognitive function outcomes included executive function, language, processing speed, and attention. RESULTS: Seventy-two participants 70.1 ± 4.7 years of age completed the study protocol. ASCVD risk score was significantly associated with resting and exercise MCAv (p0.468). We observed a significant association between resting and exercise MCAv and language processing (p=0.010) but not other cognitive domains. CONCLUSION: In cognitively normal older adults, higher ASCVD risk score was associated with blunted resting and exercise MCAv and with lower language processing performance. These results highlight the need for CVD risk management to maintain optimal brain health.

BACKGROUND AND OBJECTIVES: High-intensity interval training (HIIT) is a promising strategy for improving gait and fitness after stroke, but optimal parameters remain unknown. We tested the effects of short vs long interval type and over-ground vs treadmill mode on training intensity. METHODS: Using a repeated measures design, 10 participants with chronic hemiparetic gait performed 12 HIIT sessions over 4 weeks, alternating between short and long-interval HIIT sessions. Both protocols included 10 minutes of over-ground HIIT, then 20 minutes of treadmill HIIT and another 10 minutes over-ground. Short-interval HIIT involved 30 second bursts at maximum safe speed and 30–60 second rest periods. Long-interval HIIT involved 4-minute bursts at ~90% of peak heart rate (HR(peak)) and 3-minute recovery periods at ~70% HR(peak). RESULTS: Compared with long-interval HIIT, short-interval HIIT had significantly faster mean overground speeds (0.75 vs 0.67 m/s) and treadmill speeds (0.90 vs 0.51 m/s), with similar mean treadmill HR (82.9 vs 81.8 %HR(peak)) and session perceived exertion (16.3 vs 16.3), but lower overground HR (78.4 vs 81.1 %HR(peak)) and session step counts (1481 vs 1672). For short-interval HIIT, training speeds and HR were significantly higher on the treadmill vs. overground. For long-interval HIIT, the treadmill elicited HR similar to overground training at significantly slower speeds. CONCLUSIONS: Both short and long-interval HIIT elicit high intensities but emphasize different dosing parameters. Based on these preliminary findings and previous studies, we hypothesize that overground and treadmill short-interval HIIT could be optimal for improving gait speed and overground long-interval HIIT could be optimal for improving gait endurance.

To prospectively assess cognitive function, anthropomorphic measures, and bone mineral density in men receiving androgen deprivation therapy (ADT) for prostate cancer; explore relationships between cognitive function and central adiposity; and gather preliminary data from a personalized education, exercise, and nutrition intervention.33 participants consented from a randomized controlled intervention trial.Neurocognitive performance and self-report of cognitive function were assessed at baseline and 6 and 12 months. Dual-energy x-ray absorptiometry (DEXA) scans were obtained at baseline and 6 months.No between-group differences in cognitive function were demonstrated. Increased visceral adiposity was not associated with decrements in visuospatial abilities. Significant increases in fat mass without increases in body mass index or waist-hip ratio provided further evidence for DEXA as the preferred central adiposity measure.Well-powered prospective research is needed to fully characterize the effects of ADT on cognitive function and the potential benefits of exercise and nutrition-based interventions.

We are the first, to our knowledge, to characterize the cerebrovascular and hemodynamic response to low-volume high-intensity interval exercise (HIIT, 1-min intervals) in young healthy adults. Middle cerebral artery blood velocity (MCAv) decreased during the HIIT bout and rebounded during active recovery. Women demonstrated a significantly higher resting MCAv than men and the difference remained during HIIT. Here, we report a novel protocol and characterized the MCAv response during an acute bout of low-volume HIIT.