Effects Of Aerobic Exercise Intensity Research Articles

Soluble RAGE and skeletal muscle tissue RAGE expression profiles in lean and obese young adults across differential aerobic exercise intensities.

Nearly 40% of Americans have obesity and are at increased risk for developing type 2 diabetes. Skeletal muscle is responsible for >80% of insulin-stimulated glucose uptake that is attenuated by the inflammatory milieu of obesity and augmented by aerobic exercise. The receptor for advanced glycation endproducts (RAGE) is an inflammatory receptor directly linking metabolic dysfunction with inflammation. Circulating soluble isoforms of RAGE (sRAGE) formed either by proteolytic cleavage (cRAGE) or alternative splicing (esRAGE) act as decoys for RAGE ligands, thereby counteracting RAGE-mediated inflammation. We aimed to determine if RAGE expression or alternative splicing of RAGE is altered by obesity in muscle, and whether acute aerobic exercise (AE) modifies RAGE and sRAGE. Young (20-34 yr) participants without [n = 17; body mass index (BMI): 22.6 ± 2.6 kg/m2] and with obesity (n = 7; BMI: 32.8 ± 2.9 kg/m2) performed acute aerobic exercise (AE) at 40%, 65%, or 80% of maximal aerobic capacity (V̇o2max; mL/kg/min) on separate visits. Blood was taken before and 30 min after each AE bout. Muscle biopsy samples were taken before, 30 min, and 3 h after the 80% V̇o2max AE bout. Individuals with obesity had higher total RAGE and esRAGE mRNA and RAGE protein (P < 0.0001). In addition, RAGE and esRAGE transcripts correlated to transcripts of the NF-κB subunit P65 (P < 0.05). There was no effect of AE on total RAGE or esRAGE transcripts, or RAGE protein (P > 0.05), and AE tended to decrease circulating sRAGE in particular at lower intensities of exercise. RAGE expression is exacerbated in skeletal muscle with obesity, which may contribute to muscle inflammation via NF-κB. Future work should investigate the consequences of increased skeletal muscle RAGE on the development of obesity-related metabolic dysfunction and potential mitigating strategies.NEW & NOTEWORTHY This study is the first to investigate the effects of aerobic exercise intensity on circulating sRAGE isoforms, muscle RAGE protein, and muscle RAGE splicing. sRAGE isoforms tended to diminish with exercise, although this effect was attenuated with increasing exercise intensity. Muscle RAGE protein and gene expression were unaffected by exercise. However, individuals with obesity displayed nearly twofold higher muscle RAGE protein and gene expression, which positively correlated with expression of the P65 subunit of NF-κB.

Investigating the effect of exercise on the expression of genes related to cardiac physiological hypertrophy.

Physiological hypertrophy of the heart is associated with an increase in the normal function of the heart, and it directly relates to regular exercise, especially among elite athletes. Researches about special signaling pathways that create physiological hypertrophy have recently received more attention. As a result, the present study was conducted to investigate the effect of aerobic exercise intensity on the expression of genes involved in heart physiological hypertrophy. For this purpose, 30 male Wistar rats were prepared and randomly divided into three groups: control, intense intermittent training, and submaximal continuous training. The intensive intermittent training protocol included 30 minutes of intermittent running, each interval including 4 minutes of running with an intensity of 85-90% VO2max and 2 minutes of active recovery with an intensity of 50-60% VO2max three days a week for 8 weeks. Also, the submaximal continuous exercise group had activity intensity equal to 50-55% of the maximum oxygen consumption. The expression of genes related to cardiac hypertrophy such as MMP-I, TGF-ß1, and TIMP was evaluated through real-time PCR technique. The results showed that the expression of studied genes in the three groups had significant differences (p<0.05). Both training methods led to a significant increase in TGF-ß1 and TIMP gene expression in the heart of rats. But the changes in MMP-I in the intermittent group were not significant compared to the control group. In general, it seems that exercise leads to the improvement of the factors involved in the physiological hypertrophy of the heart. Therefore, the findings of the current research are expressed with caution and more research is needed in the future.

Effects of Aerobic Exercise Intensity on Post-exercise Blood Pressure and Cardiovascular Function in Prehypertensive Men in Their 30s

PURPOSE Blood pressure (BP) in hypertensive individuals is reduced by the accumulation of post-exercise hypotension (PEH) induced by a long period of training. This study aimed to investigate the effects of intensity of two different aerobic exercises with identical energy expenditure on post-exercise blood pressure and cardiovascular function in prehypertensive men.METHODS Eleven prehypertensive men in their 30s participated in two trials repeatedly. In the first trial, the exercise was moderate in intensity and continuous (MICE) with 70% of VO&lt;sub&gt;2&lt;/sub&gt;max, and the exercise in the second trial was high-intensity interval exercise (HIIE) with 50% and 90% of VO&lt;sub&gt;2&lt;/sub&gt;max. Each exercise was performed for 30 min, and the variables related to BP and cardiovascular function were measured at certain times for 1 hr during the recovery phase.RESULTS Our main findings are as follows: (1) Systolic blood pressure was significantly lower at 30 and 45 min of recovery time than the baseline in the HIIE trial, and systolic blood pressure was significantly lower in the HIIE trial than the MICE trial at 10, 15, and 30 min of recovery time. (2) The rate pressure product was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (3) The heart rate was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (4) Stroke volume was significantly lower in the HIIE trial than the MICE trial at 30 min of recovery time. (5) Cardiac output was significantly higher in the HIIE trial than the MICE trial at 15 min of recovery phase. (6) Total vascular conductance was significantly higher in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. (7) Total peripheral resistance was significantly lower in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase.CONCLUSIONS The HIIE shows a higher cardiovascular stress than MICE; however, HIIE contributes to the augmentation of PEH and improvement of cardiovascular function. Therefore, HIIE rather than MICE should be suggested in BP control and enhancement of cardiovascular function in prehypertensive males.

Effect of aerobic exercise intensity on health-related quality of life in severe obesity: a randomized controlled trial

BackgroundAerobic exercise is an important part of obesity treatment and may improve health-related quality of life (HRQOL). The objective of this study was to compare the effect of two different exercise programs on health-related quality of life in patients with severe obesity.MethodsThis was a single-center, open-label, randomized, parallel-group study comparing the effects of a 24-week moderate-intensity continuous training (MICT) program and a combined high-intensity interval training program with MICT (HIIT/MICT). The primary objective (specified secondary outcome) was to assess HRQOL by using the general health dimension of the Short Form Health Survey (SF-36). The secondary objectives were to assess other dimensional SF-36 scores, the impact of weight on the physical and psychosocial aspects of quality of life (IWQOL-Lite), and the burden of obesity-specific weight symptoms (WRSM).Results73 patients were enrolled and reported patient reported outcome measures, with 71 patients (55% females) allocated to either MICT (n = 34) or HIIT/MICT (n = 37). In the intention-to-treat analysis, general health scores increased between baseline and 24-week follow-up in both the HIIT/MICT group and the MICT group, with a mean change of 13 (95% CI 6–21) points and 11 (95% CI 5–17) points, respectively, with no difference between the groups. The effect sizes of these changes were moderate. The vitality and social functioning scores of SF-36, and the physical function and self-esteem scores of IWQOL-Lite increased moderately in both groups, with no difference between groups. The tiredness, back pain, and physical stamina scores based on WRSM showed moderate to strong changes in both the groups.ConclusionsPatients who had completed a combined HIIT/MICT program did not experience larger improvements in general health compared with those completing a clean 24-week MICT program. Exercise may confer general health benefits independent of intensity.Trials registrationRegional Committees for Medical and Health Research Ethics south east, Norway, October 23, 2013 (identifier: 2013/1849) and ClinicalTrials.gov December 8, 2014 (identifier: NCT02311738).

Effect of Aerobic Exercise Intensity on Energy Expenditure and Weight Loss in Severe Obesity-A Randomized Controlled Trial.

ObjectiveThis study aimed to compare the effects of two aerobic exercise programs of different intensities on energy expenditure.MethodsThis was a single‐center randomized controlled trial of patients with severe obesity allocated to a 24‐week moderate‐intensity continuous training (MICT) program or a combined MICT with high‐intensity interval training (HIIT/MICT) program. The primary outcome was energy expenditure during exercise (EEDE). Secondary outcomes included resting metabolic rate, cardiorespiratory fitness, and body composition.ResultsA total of 82 (56% females) patients were screened, and 71 (55% females) patients were allocated to HIIT/MICT (n = 37) or MICT (n = 34). Per‐protocol analysis showed that EEDE increased by 10% (95% CI: 3%‐17%) in the HIIT/MICT group (n = 16) and 7.5% (95% CI: 4%‐10%) in the MICT group (n = 24), with no differences between groups. In the 8‐ to 16‐ week per‐protocol analysis, the HIIT/MICT group had a significantly larger increase in EEDE compared with the MICT group. Resting metabolic rate remained unchanged in both groups. HIIT/MICT and MICT were associated with significant weight loss of 5 kg and 2 kg, respectively.ConclusionsPatients completing a 24‐week combined HIIT/MICT program did not achieve a higher EEDE compared with those who completed a 24‐week MICT program. The HIIT/MICT group experienced, on average, a 3‐kg‐larger weight loss than the MICT group.

The effects of Aerobic exercise intensity participation training on body composition, health related fitness and quality of life in elderly women

Purpose The purpose of this study was to investigate the effects of aerobic exercise intensity on body composition, health related fitness, and quality of life in elderly women. Methods 48 elderly women over 65 years of age without physical and mental problems were assigned to four groups: control group, low intensity, moderate intensity, and high intensity aerobic training group. The aerobic exercise group applied a heart rate reserve (HRR) to low-intensity group (HRR 40-55%), moderate intensity group (HRR 55-70%), high intensity group (HRR&gt; 70%) for 12 weeks, 3 times a week for 20 minutes a day. Subjects of the control group were to maintain their usual lifestyles during the same intervention period. Body composition, health related fitness, and quality of life were measured and analyzed using repeated two-way ANOVA. Results The main results obtained in this study are as follows. 1) There was a significant decrease in sitting forward bending in the low intensity group and a significant increase in EQ-VAS. 2) There was a significant decrease in body weight, BMI, and 6 minutes walking in the moderate intensity group, and a significant increase in grip strength and EQ-VAS. 3) The high intensity group showed a significant decrease in weight, BMI, waist circumference, sitting forward bending, and 6 minutes walking, and a significant increase in grip strength, sit and stand, functional reach, and VO2max. On the other hand, there was no significant change in all variables in the control group. Conclusions In conclusion, aerobic training was found to be effective for body composition, health related fitness and quality of life in elderly women. In particular, it can be concluded that high intensity aerobic training is effective for health related fitness, and low and moderate intensity aerobic exercise is effective for improving quality of life.

The effects of aerobic exercise intensity on memory in older adults.

Aerobic exercise may enhance memory in older adults. However, the optimal intensity and underlying mechanism are unclear. This community-based study examined the effect of aerobic exercise intensity on memory and general cognitive abilities. Brain-derived neurotrophic factor (BDNF) was examined as a potential mechanism. Sixty-four sedentary older adults participated in 1 of 3 groups: (i) high-intensity interval training (HIIT); (ii) moderate continuous training (MCT); or (iii) stretching control (CON). Prior to and following the intervention, high-interference memory was assessed using a Mnemonic Similarity task and executive functions were assessed using Go Nogo and Flanker tasks. HIIT led to the greatest memory performance compared with MCT and CON (F[2,55] = 6.04, p = 0.004) and greater improvements in memory correlated with greater increases in fitness (rs (46) = 0.27, p = 0.03). Exercise intensity seemed to matter less for executive functioning, as positive trends were observed for both HIIT and MCT. No significant differences in BDNF were found between groups. Overall, these results suggest that aerobic exercise may enhance memory in older adults, with the potential for higher intensity exercise to yield the greatest benefit. While our findings suggest that BDNF does not regulate these adaptations, the mechanisms remain to be determined. Novelty High-intensity interval training results in the greatest memory performance in inactive older adults compared with moderate continuous training or stretching. Improvement in fitness correlates with improvement in memory performance.

Effects of Aerobic Exercise Intensity on Clinical & Neural Outcomes in Depressed Youth

Effects of Aerobic Exercise Intensity on Clinical & Neural Outcomes in Depressed Youth

Healthy body composition as a means to prevent disease: the importance of exercise intensity

Background: Senescence-related changes in body composition are implicated in the progression of chronic disease. Aerobic exercise can induce favourable body composition changes (increased muscle and reduced fat). However, whether greater exercise intensity results in superior adaptations is contentious, with mixed reports in previous literature depending on baseline body composition and health status. This, large-scale, extended-duration randomised controlled trial (RCT), investigates the dose-response effect of aerobic exercise intensity on body composition in healthy older adults.

유산소운동 강도가 비만 유·무에 따른 주관적 식욕인식과 에너지보상에 미치는 영향

The study was conducted to identify the effects of aerobic exercise intensity on subjective appetite recognition and energy compensation due to obesity.Obesity group consisted of 10 persons with body fat percentage of 25% or more and non-obesity group consisted of 10 persons with body fat percentage of 10% or less. The results of the repeated measure ANOVA were as follows. Both non-obese men and obese men showed an increase in AgRP, NPY after high intensity exercise, but for non-obese men, PYY were also shown to have increased. In addition, for non-obese men, PYY were shown to increase after one hour of meal after high-intensity aerobic exercise. However, the obese men found PYY to be low even after one hour of meals after high-intensity aerobic exercise. In the case of subjective appetite, the non-obese men had a very low perception of hunger immediately before the meal, just after aerobic exercise, and the caloric intake actually was lower when exercise was not performed. However, in the obese men, hunger perception was very low immediately after the high intensity exercise, but before the meal, the hunger was higher than when the exercise was not performed, and the calorie intake actually was higher than when the exercise was not performed. These results suggest that exercise with high intensity in obese men compared with non-obese men induces subjective hunger perception right before eating, unlike the level of appetite suppressing hormone immediately after exercise, and energy intake is higher than energy consumption.

Kinetics of Reactive Oxygen Species and Total Antioxidant Capacity during Moderate Treadmill Running after 8 Weeks of Endurance Training

The purpose of this study is to investigate the effect of aerobic exercise intensity on the kinetics of reactive oxygen species and total antioxidant capacity during the moderate intensity of treadmill running. Twelve healthy collegiate male students participated and were randomly divided into two groups. Each group of subjects trained at 80% and 50% HRmax respectively for 30 min per session, 3 times per week for 8 weeks. After 48 hours of the training session, treadmill running task was imposed on each group at 70% of VO2max for 90 minutes. Metabolic data were monitored using a gas analysis system. Blood samples were taken from the finger before exercise and after 30 minutes, 60 minutes, and 90 minutes of exercise for measuring the blood lactate, derivatives of Reactive Oxygen Metabolites (d‐ROM), and biological antioxidant potential (BAP). All data were analyzed by two‐way ANOVA of SPSS 18.0. The differences between pre and post training were significant in d‐ROM and BAP (p&lt;.05). The changes of d‐ROM were significantly increased by aerobic training, and there were significant differences among exercise durations (p&lt;.05). The changes of BAP were not significantly different between training intensity groups, and there were significant differences among exercise durations (p&lt;.05). As shown above, the occurrence of d‐ROM and BAP were altered by training intensity and exercise duration. In other words, the occurrence of reactive oxygen by high intensive training was abundant and there were significant changes in 30 minutes of exercise based on exercise duration. On the other hand, there were significant changes in total antioxidant capacity in 60 minutes of exercise based on exercise duration. In conclusion, low‐intensity training and within 60 minutes of exercise might be suitable in the point of defending the cellular damage caused by exercise.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Moderate-Intensity Exercise Induces Neurogenesis and Improves Cognition in Old Mice by Upregulating Hippocampal Hippocalcin, Otub1, and Spectrin-α.

Exercise increases the levels of neurogenic factors and enhances neurogenesis, memory, and learning. However, the molecular link between exercise and neurogenesis is not clear. The purpose of this study was to examine the effects of exercise intensity on cognitive function and protein expression in the hippocampus of old mice. To compare the effects of aerobic exercise intensity on cognition in old mice, we exposed 18-month-old mice to low- and moderate-intensity treadmill exercise for 4weeks. Moderate-intensity exercise improved cognitive function in the old mice, while low-intensity exercise did not. To investigate the underlying mechanisms, two-dimensional electrophoresis was used to examine protein expression. Using peptide fingerprinting mass spectrometry, we identified 19 proteins that were upregulated in the hippocampus following exercise training, and seven of these proteins were normalized by the control value. Among them, the levels of 14-3-3 zeta and heat shock protein 70, which have been shown to be induced by exercise training and related to neurogenesis, were dramatically increased by moderate exercise. Hippocalcin, α-spectrin, ovarian tumor domain-containing ubiquitin aldehyde-binding protein 1 (otub1), mu-crystallin, serine racemase, and rho GDP dissociation inhibitor 1, which are related to neurogenesis, neuroprotection, and synaptic strength, were upregulated in the hippocampus by moderate exercise. In addition, we confirmed that neurogenic markers, including doublecortin and the neuronal nuclei antigen, and hippocalcin, otub1, and spectrin-α are potential molecular links between hippocampal neurogenesis and exercise in the elderly. Thus, these results showed that steady moderate-intensity exercise delayed the declines in cognitive function in the elderly through the activation of multiple factors.

Effect of Exercise Intensity on Neurotrophic Factors and Blood-Brain Barrier Permeability Induced by Oxidative-Nitrosative Stress in Male College Students.

We investigated the effects of aerobic exercise intensity on oxidative-nitrosative stress, neurotrophic factor expression, and blood-brain barrier (BBB) permeability. Fifteen healthy men performed treadmill running under low-intensity (LI), moderate-intensity (MI), and high-intensity (HI) conditions. Blood samples were collected immediately before exercise (IBE), immediately after exercise (IAE), and 60 min after exercise (60MAE) to examine oxidative-nitrosative stress (reactive oxygen species [ROS]; nitric oxide [NO]), neurotrophic factors (brain-derived neurotrophic factor [BDNF]; nerve growth factor [NGF]), and blood-brain barrier (BBB) permeability (S-100β; neuron-specific enolase). ROS concentration significantly increased IAE and following HI (4.9 ± 1.7 mM) compared with that after LI (2.8 ± 1.4 mM) exercise (p < .05). At 60MAE, ROS concentration was higher following HI (2.5 ± 1.2 mM) than after LI (1.5 ± 0.5 mM) and MI (1.4 ± 0.3 mM) conditions (p < .05). Plasma NO IAE increased significantly after MI and HI exercise (p < .05). Serum BDNF, NGF, and S-100b levels were significantly higher IAE following MI and HI exercise (p < .05). BDNF and S-100b were higher IAE following MI (29.6 ± 3.4 ng/mL and 87.1 ± 22.8 ng/L, respectively) and HI (31.4 ± 3.8 ng/mL and 100.6 ± 21.2 ng/L, respectively) than following LI (26.5 ± 3.0 ng/mL and 64.8 ± 19.2 ng/L, respectively) exercise (p < .05). 60MAE, S-100b was higher following HI (71.1 ± 14.5 ng/L) than LI (56.2 ± 14.7 ng/L) exercise (p < .05). NSE levels were not significantly different among all intensity conditions and time points (p > .05). Moderate- and/or high-intensity exercise may induce higher oxidative-nitrosative stress than may low-intensity exercise, which can increase peripheral neurotrophic factor levels by increasing BBB permeability.

Acute effects of aerobic exercise intensity on arterial stiffness after glucose ingestion in young men.

Arterial stiffness increases after glucose ingestion. Acute low- and moderate-intensity aerobic exercise decreases arterial stiffness. However, the acute effects of 30min of cycling at low- and moderate-intensity [25% (LE trial) and 65% (ME trial) peak oxygen uptake, respectively] on arterial stiffness at 30, 60 and 120min of a postexercise glucose ingestion. Ten healthy young men (age, 22·4±0·5years) performed LE and ME trials on separate days in a randomized controlled crossover fashion. Carotid-femoral (aortic) pulse wave velocity (PWV), femoral-ankle (leg) PWV, carotid augmentation index (AIx) and carotid blood pressure (BP) (applanation tonometry), brachial and ankle BP (oscillometric device), heart rate (HR) (electrocardiography), blood glucose (UV-hexokinase method) and blood insulin (CLEIA method) levels were measured at before (baseline) and at 30, 60 and 120min after the 75-g OGTT. Leg PWV, ankle pulse pressure and BG levels significantly increased from baseline after the 75-g OGTT in the LE trial (P<0·05), but not in the ME trial. Insulin levels and HR significantly increased from baseline after the 75-g OGTT in both trials (P<0·05). Aortic PWV, carotid AIx, brachial BP and carotid BP did not change from baseline after the 75-g OGTT in both trials. The present findings indicate that aerobic exercise at moderate intensity before glucose ingestion suppresses increases leg arterial stiffness after glucose ingestion.

Effects of aerobic exercise intensity on ambulatory blood pressure and vascular responses in resistant hypertension: a crossover trial.

Resistant hypertension often exposes patients to poor blood pressure (BP) control, resulting in clinical vulnerability, possible need for device-based procedures (denervation) and increased therapy costs. Regular exercise markedly benefits patients with hypertension, including resistant patients. However, little is known about short-term exercise effects in resistant hypertension. To evaluate acute hemodynamic effects of exercise in resistant hypertension. After maximal exercise testing, 20 patients (54.0 ± 5.7 years, 30.2 ± 4.9 kg/m) with resistant hypertension participated in three crossover interventions, in random order, and on separate days: control (45' of rest), and light intensity and moderate intensity (45' of aerobic exercise at 50 and 75% of maximum heart rate, respectively). Ambulatory BP, forearm blood flow (with subsequent calculation of vascular resistance), and reactive hyperemia were measured before and after interventions trough venous occlusion plethysmography. Compared with control, both exercise intensities reduced ambulatory systolic pressure over 5 h (light: -7.7 ± 2.4 mmHg and moderate: -9.4 ± 2.8 mmHg, P < 0.01), whereas only light intensity reduced diastolic pressure (-5.7 ± 2.2 mmHg, P < 0.01). Light intensity also lowered systolic and diastolic pressures over 10-h daytime (-3.8 ± 1.3 and -4.0 ± 1.3 mmHg, respectively, P < 0.02), night-time (-6.0 ± 2.4 and -6.1 ± 1.6 mmHg, respectively, P < 0.05), and diastolic pressure over 19 h (-4.8 ± 1.2 mmHg, P < 0.01). Forearm blood flow changed (decreased) compared with baseline only at 50 min after light intensity (P < 0.05). After the control and light intensity sessions, vascular resistance increased at the end of 1 h, and after moderate intensity, it decreased only at the moment (∼2 min) immediately after intervention (P < 0.05). A single session of light or moderate aerobic exercise acutely reduces ambulatory BP in resistant hypertension, although benefits persist longer following light intensity.

Effect of aerobic exercise intensity on glycemic control in type 2 diabetes: a meta-analysis of head-to-head randomized trials.

To conduct a meta-analysis of head-to-head trials comparing aerobic exercise training of different intensities on glycemic control in type 2 diabetes. Databases, including MEDLINE and EMBASE, were searched up to January 2016. Randomized trials of at least 12weeks in duration that compared two exercise interventions of different intensities were identified. Two reviewers independently extracted data from eligible trials. Using fixed effect model, weighted mean differences (WMD) between different exercise intensities were calculated for changes in glycated hemoglobin (HbA1c) and secondary outcomes, such as fasting glucose and fasting insulin. Eight studies with a total of 235 participants were eligible. The exercise interventions lasted from 12weeks to 6months. The prescribed exercise intensities varied among studies. Four studies utilized vigorous exercise intensities for short durations by performing interval training. Overall, higher-intensity exercise resulted in a greater reduction in HbA1c compared to lower-intensity exercise (WMD=-0.22%; 95% confidence interval [-0.38, -0.06]; or -2.4mmol/mol [-4.15, -0.66], I (2)=0). Adherence to exercise and proportion of dropouts did not differ within trials. No adverse events were reported in these small trials with selected inclusion criteria. Although our meta-analysis had a limited sample size, increasing exercise intensity safely accentuated reductions in HbA1c in some people with type 2 diabetes. Different approaches have been used to increase exercise intensity (i.e., some used interval training, whereas others used higher-intensity continuous exercise). However, at this time, it is unclear which form, if any, leads to the most favorable results.

Abstract TP143: Effects of Aerobic Exercise Intensity on Novel Blood Biomarkers of Neuroplasticity After Stroke

Introduction: Aerobic exercise (AEX) may facilitate neurologic stroke recovery. Among healthy adults, intense AEX is known to upregulate brain-derived neurotrophic factor (BDNF), a critical facilitator of neuroplasticity, motor learning and cognition. Increased blood lactate during AEX appears to be a key mechanism underlying this effect. Intense AEX also increases blood ionized calcium (Ca++). In animal studies, some of this increased Ca++ has been shown to be transported to the brain and enhance synthesis of monoamine neurotransmitters (e.g. dopamine) that are associated with neuroplasticity and motor learning. Thus, increased blood lactate and Ca++ during AEX represent potentially important biomarkers of central neurologic benefits, but neither has been previously studied in persons with stroke. Hypothesis: High intensity AEX will elicit significantly larger lactate and Ca++ responses than moderate intensity in chronic stroke. Methods: Using a crossover design, eight subjects (mean ± SD age, 57 ± 8 years; years post stroke, 8.7 ± 2.7) performed one 20 minute session each of moderate and high intensity treadmill AEX in random order. Blood lactate and Ca++ were measured at baseline and multiple time points during and after AEX. Mixed effects models were used to examine changes within and between protocols using an alpha of 0.05. Results: Blood lactate response was significantly greater for high vs moderate intensity AEX (p&lt;0.0001). While moderate intensity showed no significant changes with time (p=0.60), high intensity showed significant increases during and immediately after AEX (all p&lt;0.0001). Blood Ca++ showed no significant protocol by time interaction (p=0.08) but did show a significant time effect (p&lt;0.0001) with increases during (p&lt;0.0001) and immediately after (p=0.01) AEX. Conclusions: Unlike moderate intensity AEX, high intensity elicited a robust lactate response. This has promising implications for the effects of high-intensity AEX on BDNF post-stroke. Both protocols combined showed an increase in Ca++, which has promising implications for the effects of AEX on monoamine neurotransmitter synthesis after stroke.

Abstract 17258: Effects of Aerobic Exercise Intensity on Ambulatory Blood Pressure Monitoring and Vascular Responses in Resistant Hypertension: A Cross-over Trial

Introduction: Patients with resistant hypertension are usually exposed to poor blood pressure (BP) control, resulting in clinical vulnerability, possibility of device-based procedures (denervation), and cumulative costs with drug therapy. Regular aerobic exercise promotes marked benefits in hypertension, including the subset of resistant patients. However, little is known about acute effects of exercise on patients with resistant hypertension. Hypothesis: We hypothesized that a single aerobic session would reduce BP and improve vascular variables. Thus, we compared ambulatory BP and vascular parameters in response to two intensities of aerobic sessions and a non-exercise control session in patients with resistant hypertension. Methods: After a maximal exercise test, 18 patients (54±6 years, 30.2±4.9 kg/m2) participated in three interventions in random order, crossover design, and on separate days: control session (45’ of rest), light intensity (LI) and moderate intensity (MI) sessions (45’ of aerobic exercise at 50% and 75% of HRmax, respectively). Ambulatory BP monitoring (Space Labs, 90702) comprised a 19h period after each session. Vascular variables were measured at the non-dominant forearm by venous occlusion plethysmography (Hokanson Inc) before and up to 1h after all sessions. Results: Compared with control session, both exercise sessions reduced ambulatory systolic BP in a 5h period (LI: -7.7±2.4mm Hg and MI: -9.4±2.8mm Hg, p&lt;0.01), whereas only LI session reduced diastolic BP (-5.7±2.2mm Hg, p&lt;0.01). In addition, LI induced lower values in systolic and diastolic BP during 10h-daytime (-3.8±1.3mm Hg and -4.0±1.3mm Hg, respectively, p&lt;0.02), nighttime (-6.0±2.4 mm Hg and -6.1±1.6mm Hg, respectively, p&lt;0.05) and in diastolic BP during 19h (-4.8±1.2mm Hg, p&lt;0.01). Forearm blood flow decreased only at minute 50 after LI (p&lt;0.05), with no other changes. In control and LI sessions, forearm vascular resistance increased at the end of 1h recovery period and in MI session, it decreased immediately after the intervention (p&lt;0.05). Conclusions: A single aerobic exercise session in light or moderate intensities induces beneficial changes in ambulatory BP in resistant hypertension, with advantages in effect length for lighter intensities.

Effects of aerobic exercise intensity on 24-h ambulatory blood pressure in individuals with type 2 diabetes and prehypertension.

[Purpose] To verify the effects of different intensities of aerobic exercise on 24-hour ambulatory blood pressure (BP) responses in individuals with type 2 diabetes mellitus (T2D) and prehypertension. [Subjects and Methods] Ten individuals with T2D and prehypertension (55.8 ± 7.7 years old; blood glucose 133.0 ± 36.7 mg·dL−1 and awake BP 130.6 ± 1.6/ 80.5 ± 1.8 mmHg) completed three randomly assigned experiments: non-exercise control (CON) and exercise at moderate (MOD) and maximal (MAX) intensities. Heart rate (HR), BP, blood lactate concentrations ([Lac]), oxygen uptake (VO2), and rate of perceived exertion (RPE) were measured at rest, during the experimental sessions, and during the 60 min recovery period. After this period, ambulatory blood pressure was monitored for 24 h. [Results] The results indicate that [Lac] (MAX: 6.7±2.0 vs. MOD: 3.8±1.2 mM), RPE (MAX: 19±1.3 vs. MOD: 11±2.3) and VO2peak (MAX: 20.2±4.1 vs. MOD: 14.0±3.0 mL·kg−1·min−1) were highest following the MAX session. Compared with CON, only MAX elicited post-exercise BP reduction that lasted for 8 h after exercise and during sleep. [Conclusion] A single session of aerobic exercise resulted in 24 h BP reductions in individuals with T2D, especially while sleeping, and this reduction seems to be dependent on the intensity of the exercise performed.

Effect of Aerobic Exercise Intensity on Memory Retention in Female Collegiate Students

Effect of Aerobic Exercise Intensity on Memory Retention in Female Collegiate Students