Exercise In Healthy Adults Research Articles

COUNTERPOINT: Pulmonary Vascular Resistance 2.0— Shedding Light or Casting Shadows?

COUNTERPOINT: Pulmonary Vascular Resistance 2.0— Shedding Light or Casting Shadows?

Retracted: Effects of Caffeine Intake on Cardiopulmonary Variables and QT Interval after a Moderate-Intensity Aerobic Exercise in Healthy Adults: A Randomized Controlled Trial.

[This retracts the article DOI: 10.1155/2022/3170947.].

Measurement of thermal sweating at rest and steady-state exercise in healthy adults: Inter-day reliability and relationships with components of partitional calorimetry.

Inter-day reliability of sweat measurements, including the absorbent patch and modified iodine-paper techniques, at rest and exercise were evaluated. We further evaluated the effect of iodine paper size and the method of establishing sweat gland activation (sweat gland counting or surface area covered) on reliability. Furthermore, the relationships between all measurement techniques and metabolic heat production [Ḣprod] and evaporative requirement for heat balance [Ėreq] were determined. Twelve participants were assessed for whole-body sweat loss (WBSL), local sweat rate (LSR; absorbent patch) and sweat gland activation (SGA; iodine-paper) during rest and sub-maximal cycling at ~200, ~250 and ~300 W/m2 Ḣprod in the heat. Variations in iodine paper (1 x 1 cm-9 x 9 cm) were used to quantify SGA by counting sweat glands or surface area covered. The 'optimal' area of SGA was also determined based on the highest density of recruited glands. All measures of the sweating response were positively related with Ḣprod and Ėreq (r = 0.53-0.84), with the 9 x 9 cm and 6 x 6 cm iodine paper sizes being the strongest (r = 0.66-0.84) for SGA. Superior inter-day reliability was found for all measures during exercise (CV% = 6-33.2) compared to rest (CV% = 33.5-77.9). The iodine-paper technique was most reliable at 9 x 9 cm (CV% = 15.9) or when the 1 x 1 cm (CV% = 17.6) and 3 x 3 cm (CV% = 15.5) optimal SGA was determined, particularly when measuring the sweat gland number. WBSL, LSR and SGA measurement techniques are sufficiently reliable to detect changes in thermal sweating typically reported. We recommend 9 x 9 cm paper sizes or 1 x 1 cm-3 x 3 cm optimal areas, using either gland counting or surface area to determine SGA.

A 10-mg dose of amiloride increases time to failure during blood-flow-restricted plantar flexion in healthy adults without influencing blood pressure.

Amiloride has been shown to inhibit acid-sensing ion channels (ASICs), which contribute to ischemia-related muscle pain during exercise. The purpose of this study was to determine if a single oral dose of amiloride would improve exercise tolerance and attenuate blood pressure during blood-flow-restricted (BFR) exercise in healthy adults. Ten subjects (4 females) performed isometric plantar flexion exercise with BFR (30% maximal voluntary contraction) after ingesting either a 10-mg dose of amiloride or a volume-matched placebo (random order). Time to failure, time-tension index (TTI), and perceived pain (visual analog scale) were compared between the amiloride and placebo trials. Mean blood pressure, heart rate, blood pressure index (BPI), and BPI normalized to TTI (BPInorm) were also compared between trials using both time-matched (TM50 and TM100) and effort-matched (T50 and T100) comparisons. Time to failure (+69.4 ± 63.2 s, P < 0.01) and TTI (+1,441 ± 633 kg·s, P = 0.02) were both significantly increased in the amiloride trial compared with placebo, despite no increase in pain (+0.4 ± 1.7 cm, P = 0.46). In contrast, amiloride had no significant influence on the mean blood pressure or heart rate responses, nor were there any significant differences in BPI or BPInorm between trials when matched for time (all P ≥ 0.13). When matched for effort, BPI was significantly greater in the amiloride trial (+5,300 ± 1,798 mmHg·s, P = 0.01), likely owing to an increase in total exercise duration. In conclusion, a 10-mg oral dose of amiloride appears to significantly improve the tolerance to BFR exercise in healthy adults without influencing blood pressure responses.

Adjusting For Exercise Intensity Attenuates Sex Differences In Blood Pressure During Exercise In Healthy Adults

PURPOSE: The exercise pressor reflex, composed of the muscle mechano- and metaboreflex, increases blood pressure (BP). Compared to males, healthy female adults typically exhibit blunted BP responses to exercise. However, recent work suggests that sex differences in BP during isometric handgrip (HG) exercise and post-exercise ischemia (PEI; metaboreflex isolation) are attenuated after adjusting for differences in maximal voluntary contraction (MVC). Therefore, the purpose of this study was to determine whether sex differences in BP responses during HG and PEI would be attenuated after adjustment for submaximal HG squeezing force. METHODS: We analyzed data from 95 participants including 34 females (age: 24±4 years, BMI: 24±4 kg/m2, screening BP: 106±13/64±9 mmHg, Mean ± SD) and 61 males (age: 25±5 years, BMI: 2±3 kg/m2, screening BP: 113±11/66±9 mmHg). All females were tested during days 1-5 of their menstrual cycle. Maximal HG force for each participant was defined as the average of three MVCs. Following a 10-minute baseline period, participants performed static static HG exercise at 40% of their average MVC for two minutes followed by three minutes of PEI via brachial occlusion. We obtained beat-to-beat BP readings via finger photoplethysmography (Finometer). Statistical analyses included t-tests, 2-way ANOVAs (sex x time), and ANCOVAs (average HG force as a covariate). RESULTS: Females exhibited a lower absolute 40% HG force than males (105±30 N v. 169±45 N, p<0.001). There was a significant sex x time interaction for ∆ systolic BP during HG (e.g., minute 2, females: 20±12 mmHg v. 28±18 mmHg in males, p=0.014), but not ∆ diastolic (p=0.106) or ∆ mean BP (p=0.058). After adjusting for absolute HG force, the sex difference for peak ∆ systolic BP during HG was attenuated (p=0.072). During PEI there were sex x time interactions for ∆ systolic, ∆ diastolic, and ∆ mean BP (p<0.05 for all) and adjustment for HG force did not attenuate these differences. Additionally, in a small strength-matched cohort (N=48, 29 females, female HG force mean = 107±23 N, male HG force mean = 118 ± 24 N, p=0.092) there was not a significant sex difference for peak ∆ systolic BP during HG (p=0.667) or PEI (p=0.828). CONCLUSIONS: Our data indicate that the sex difference in BP reactivity is attenuated after adjusting for absolute HG force during exercise.

Prescribing or co-designing exercise in healthy adults? Effects on mental health and interoceptive awareness.

Universal exercise recommendations for adults neglect individual preferences, changing constraints, and their potential impact on associated health benefits. A recent proposal suggests replacing the standardized World Health Organisation (WHO) exercise recommendations for healthy adults by co-designed interventions where individuals participate actively in the decisions about the selected physical activities and the effort regulation. This study contrasts the effects on mental health and interoceptive awareness of a co-designed and co-adapted exercise intervention with an exercise program based on the WHO recommendations for healthy adults. Twenty healthy adults (10 men and 10 women, 40–55 y.o.) participated voluntarily in the research. They were randomly assigned to a co-designed exercise intervention (CoD group) and a prescribed exercise program (WHO group). Supervised online by specialized personal trainers, both programs lasted 9 weeks and were equivalent in volume and intensity. The effects of the exercise intervention were tested through personal interviews, questionnaires (DASS-21 and MAIA) and a cardiorespiratory exercise test. Intragroup differences (pre-post) were assessed using the Mann-Whitney Wilcoxon test and intergroup differences through Student’s t-tests. Effect sizes were calculated through Cohen’s d. Interviews were analyzed through thematic analysis. Eleven participants completed the intervention (CoD = 8, WHO = 5). Both groups improved, but non significantly, their cardiorespiratory testing results, and no differences were found between them post-intervention. Mental health was only enhanced in the CoD group (p < 0.001), and interoceptive awareness improved in seven of the eight scales in the CoD group (p < 0.001) and only in 3 scales in the WHO group (p < 0.01). In conclusion, the co-designed intervention was more effective for developing mental health, interoceptive awareness, autonomy, and exercise self-regulation than the WHO-based exercise program.

The effect of exercise intensity and cardiorespiratory fitness on the kinetic response of middle cerebral artery blood velocity during exercise in healthy adults.

The aim of this study was to compare the kinetic response of middle cerebral artery blood velocity (MCAv) to moderate- and heavy-intensity cycling in adults, and explore the relationship between maximal oxygen uptake (V̇o2max) and MCAv kinetics. Seventeen healthy adults (23.8 ± 2.4 yr, 9 females) completed a ramp incremental test to exhaustion on a cycle ergometer to determine V̇o2max and the gas exchange threshold (GET). Across six separate visits, participants completed three 6-min transitions at a moderate intensity (90% GET) and three at a heavy intensity (40% of the difference between GET and V̇o2max). Bilateral MCAv was measured using transcranial Doppler (TCD) ultrasonography and analyzed using a monoexponential model with a time delay. The time constant (τ) of the MCAv response was not different between moderate- and heavy-intensity cycling (25 ± 10 vs. 26 ± 8 s, P = 0.82), as was the time delay (29 ± 11 vs. 29 ± 10 s, P = 0.95). The amplitude of the exponential increase in MCAv from baseline was greater during heavy-intensity cycling (23.9 ± 10.0 cm·s-1, 34.1 ± 14.4%) compared with moderate-intensity cycling (12.7 ± 4.4 cm·s-1, 18.7 ± 7.5%; P < 0.01). Following the exponential increase, a greater fall in MCAv was observed during heavy-intensity exercise compared with moderate-intensity exercise (9.5 ± 6.9 vs. 2.8 ± 3.8 cm·s-1, P < 0.01). MCAv after 6 min of exercise remained elevated during heavy-intensity exercise compared with moderate-intensity exercise (85.2 ± 9.6 vs. 79.3 ± 7.7 cm·s-1, P ≤ 0.01). V̇o2max was not correlated with MCAv τ or amplitude (r = 0.11-0.26, P > 0.05). These data suggest that the intensity of constant-work rate exercise influences the amplitude, but not time-based, response parameters of MCAv in healthy adults, and found no relationship between cardiorespiratory fitness and MCAv kinetics.NEW & NOTEWORTHY This is the first study to model the MCAv kinetic response to moderate- and heavy-intensity cycling in healthy adults. This study found that the amplitude of the exponential rise in MCAv at exercise onset was greater during heavy-intensity exercise (∼34%) compared with moderate-intensity exercise (∼19%), but the time-based characteristics of the responses were similar between intensities. Higher cardiorespiratory fitness was not associated with a greater or faster MCAv response to moderate- or heavy-intensity exercise.

Noninvasive Assessment Of Cardiovascular Hemodynamics During Exercise Using Systolic Time Intervals

Noninvasive Assessment Of Cardiovascular Hemodynamics During Exercise Using Systolic Time Intervals

Effects of caffeinated energy drinks on cardiovascular responses during exercise in healthy adults: a systematic review and meta-analysis of randomized controlled trials.

The impact of caffeinated energy drinks (CEDs) on the cardiovascular (CV) response to exercise has not been well described. A systematic review and meta-analysis was conducted on the acute effects of CEDs on CV responses during dynamic, aerobic exercise in 296 healthy adult males (224) and females (72) in 21 randomized controlled trials. During exercise, there was an increase in heart rate (HR) (mean difference (MD), 2.86bpm, 95% CI, 2.39-3.34bpm, I2=0%, p<0.00001), and systolic blood pressure (SBP) (MD, 9.02mm Hg, 95% CI, 4.25-13.79mm Hg, I2=0%, p=0.0002) with consumption of CEDs, compared with controls, but diastolic blood pressure was similar. Insufficient data were available to evaluate rate pressure product (HR × SBP) and exercise-induced arrhythmia. Though changes to HR during exercise were modest, the significant increase in exercise SBP highlights the importance of directly assessing CV effects of CEDs with exercise, especially in individuals prone to hypertension. Novelty: Exercise SBP in healthy adults is significantly increased during exercise with the consumption of CEDs compared with controls, despite limited data. The direct assessment of CV effects of CEDs with exercise highlights the particular relevance to individuals prone to hypertension.

Effects of Caffeine Intake on Cardiopulmonary Variables and QT Interval after a Moderate-Intensity Aerobic Exercise in Healthy Adults: A Randomized Controlled Trial.

Caffeine is considered a widely consumed natural and legal psychoactive stimulant with several effects on the body. The present study attempted to investigate the effects of caffeine consumed before and after a physical exercise on cardiovascular and cardiorespiratory functions in healthy adults. 36 healthy adult males were recruited and randomly allocated to one of the three (3) groups: group I (exercise without caffeine consumption), group II (caffeine beverage intake before exercise), and group III (caffeine beverage intake immediately after exercise). The heart rate (HR), QTc interval, blood pressure (BP), respiratory rate (RR), oxygen consumption (VO₂), and carbon dioxide emission (VCO₂) were measured at 0, 5, 10, and 15 min after the exercise. We observed a significant difference in all measured outcomes during the different recovery times in all the groups (p < 0.05). HR, RR, SBP, VO2, and VCO2 gradually decreased with time, DBP contrarily increased with time, and the QTc showed an irregular pattern. We can affirm that ingestion of caffeine before and after moderate aerobic exercise slows down the parasympathetic stimulation, heart rate recovery, and the recovery of HR and QTc with no major effects on BP, RR, VO₂, and VCO₂ in healthy adult men.

Carrots for the donkey: Influence of evaluative conditioning and training on self-paced exercise intensity and delay discounting of exercise in healthy adults.

To choose exercise over alternative behaviours, subjective reward evaluation of the potential choices is a principal step in decision making. However, the selection of exercise intensity might integrate acute visceral responses (i.e. pleasant or unpleasant feelings) and motives related to goals (i.e. enjoyment, competition, health). To understand the factors determining the selection of exercise in its intensity and evaluation as a modality, we conducted a study combining exercise training and evaluative conditioning. Evaluative conditioning was performed by using a novel technique using a primary reinforcer (sweetness) as the unconditioned stimulus and physical strain i.e. heart rate elevation as the conditioned stimulus during interval training, using a randomized control design (N = 58). Pre, post-three weeks interval training w/o conditioning, and after 4 weeks follow-up, participants were tested on self-paced speed selection on treadmill measuring heart rate, subjective pleasantness, and effort levels, as well as delay-discounting of exercise and food rewards. Results revealed that the selection of exercise intensity was significantly increased by adaptation to training and evaluative conditioning, revealing the importance of visceral factors as well as learned expected rewards. Delay discounting rates of self-paced exercise were transiently reduced by training but not affected by evaluative conditioning. In conclusion, exercise decisions are suggested to separate the decision-making process into a modality-specific cognitive evaluation of exercise, and an exercise intensity selection based on acute visceral experience integrating effort, pleasantness, and learned rewards.

Effectiveness Of Blood Flow Restriction Training On Aerobic Performance During Cycling Exercise In Healthy Adults.

Blood flow restriction (BFR) has emerged as an alternate rehabilitation modality, intending to enhance functional outcomes in various populations. However, there is a lack of research evidence on the efficacy of BFR during aerobic exercise. PURPOSE: To compare aerobic capacity following a cycling protocol with BFR at 60% (BFR-60) versus 80% (BFR-80) occlusion. METHODS: Ten healthy participants (26 ± 3.0 years; 6 males; 4 female) were randomly assigned to either: BFR-60 or BFR-80. Aerobic Capacity was measured at baseline, and three weeks during a sub-maximal stationary cycle ergometer protocol connected to a metabolic analyzer for the assessment of peak oxygen consumption (VO2 peak). Aerobic testing consisted of performing the YMCA protocol which consisted of pedaling at 70 rev/min with a load of 25-watts. Heart Rate (HR) was monitored continuously at the end of the first three minutes and used to determine the load increase. Subjects cycled for 15 minutes at which point a 25-watt increase occurred every 3 minutes until the participant reached one or more of the following criteria: 80% of their predicted HR (T80) using the HR reserve formula, an RER >1.0, or a leveling of the oxygen curve. Given the small sample size and the non-normal data distribution for the variable of T80, a Mann-Whitney and Wilcoxon tests were used to evaluate between and within (time) groups differences, respectively. For the between-group comparison, a composite score for T80 based on the pre-post difference was calculated for both groups. Then this calculated difference was used to compare both groups. Peak VO2 was normally distributed, therefore, a 2 x 2 (group by time) ANOVA was used to perform between and within-group comparisons. Statistical significance was at an alpha of 0.05 for all analyses. RESULTS: The between group comparisons of the T80 was not statistically significant. The within group comparison for T80 for the BFR-60 group approached significance (p = 0.08) while the BFR-80 group was not significant (p = 0.89). The within time ANOVA approached significance (p = 0.09) while there were no between group differences (p = 0.99). CONCLUSIONS: Aerobic performance over time was seen to improve primarily in the 60% occlusion BFR group. The small sample size or short intervention duration might have affected the effectiveness of this intervention.

Effect of induced acute metabolic alkalosis on the V̇E/V̇CO2 response to exercise in healthy adults

We tested the hypothesis that increasing the respiratory control systems’ arterial PCO2 equilibrium point via induced acute metabolic alkalosis by ingestion of sodium bicarbonate (NaHCO3, 0.3 g/kg) would decrease the ventilatory equivalent for CO2 (V̇E/V̇CO2) at its lowest point (“nadir”) during constant-load cycle exercise testing performed at 80 % of peak power output in 18 healthy young adults. Compared to the sodium chloride (4 g) control condition, ingestion of NaHCO3: increased arterialized venous pH, HCO3- and PCO2 at rest by 0.05 ± 0.01 units (mean ± SE), 6.4 ± 0.4 mEq/L and 4.3 ± 0.7 mmHg, respectively (all p < 0.0001); and decreased the V̇E/V̇CO2 nadir during exercise by 9.4 % (p < 0.0001) secondary to a 4.7 ± 1.8 L/min decrease in V̇E (p = 0.019). In conclusion, induced acute metabolic alkalosis by ingestion of NaHCO3 decreased the V̇E/V̇CO2 response to strenuous exercise in healthy adults.

Associations of Regional and Network Functional Connectivity With Exercise-Induced Low Back Pain

Musculoskeletal pain is an aversive experience that exists within a variety of conditions and can result in significant impairment for individuals. Gaining greater understanding of the factors related to pain vulnerability and resilience to musculoskeletal pain may help target at-risk individuals for early intervention. This analysis builds on our previous work identifying regions where greater gray matter density was associated with lower pain following standardized, exercise induced musculoskeletal injury. Here we sought to examine the relationship between baseline resting state functional connectivity in a priori regions and networks, and delayed onset muscle soreness (DOMS) pain intensity following a single session of eccentric exercise in healthy adults. Participants completed a baseline functional MRI scan and a high intensity trunk exercise protocol in the erector spinae. Pain intensity ratings were collected 48-hours later. Resting state functional connectivity from four seed regions and 3 networks were separately regressed on pain intensity scores. Results revealed that connectivity between left middle frontal gyrus, the left occipital gyrus and cerebellar network seeds and clusters associated with discriminative, emotional, and cognitive aspects of pain were associated with lower post-DOMS pain. Results suggest resilience to clinically relevant pain is associated with aspects of regional and network neural coherence. Investigations of pain modulatory capacity that integrate multimodal neuroimaging metrics are called for. PerspectiveOur results provide key support for the role of structural and functional coherence in regional and network connectivity in adaptive pain response and represent an important step in clarifying neural mechanisms of resilience to clinically relevant pain.

The Effect of Short Duration Isometric and Dynamic Exercises on Pain Threshold in Healthy Young Females

Abstract Background: Musculoskeletal pain is a common problem encountered in medical practice. Exercise canprovidet empo-rary relief from pain. Hypoalgesia is found to occur during and after single episodes of high intensity aerobic exercise in healthy adults. However, not all individuals are willing or able to engage in high-intensity aerobic exercise. Aim of Study: To examine the character of pain threshold modulation that occurs following short-duration isometric and dynamic exercises. Material and Methods: Eighty healthy female students of College of Applied Medical Sciences, King Saud University, age ranged between 18 and 23 years participated in study. The sample was divided randomly into two equal groups; first group was tested for the effect of isometric exercise on pressure pain threshold and the second group was tested for the effect of dynamic exercise on pain threshold. Results: Results indicated that there were significant effects for both isometric and dynamic exercises on pain threshold which was found to be elevated in both exercised and non-exercise dsides after isometric and dynamic exercises and lasted for ten minutes. Conclusion: It was concluded that short duration non-exhaustive isometric and dynamic exercises was associated with hypoalgesic responses in ipsilateral and contralateral sides in healthy young females.

Reduced post-exercise muscle microvascular perfusion with compression is offset by increased muscle oxygen extraction: Assessment by contrast-enhanced ultrasound.

The microvasculature is important for both health and exercise tolerance in a range of populations. However, methodological limitations have meant changes in microvascular blood flow are rarely assessed in humans during interventions designed to affect skeletal muscle blood flow such as the wearing of compression garments. The aim of this study is, for the first time, to use contrast-enhanced ultrasound to directly measure the effects of compression on muscle microvascular blood flow alongside measures of femoral artery blood flow and muscle oxygenation following intense exercise in healthy adults. It was hypothesized that both muscle microvascular and femoral artery blood flows would be augmented with compression garments as compared with a control condition. Ten recreationally active participants completed two repeated-sprint exercise sessions, with and without lower-limb compression tights. Muscle microvascular blood flow, femoral arterial blood flow (2D and Doppler ultrasound), muscle oxygenation (near-infrared spectroscopy), cycling performance, and venous blood samples were measured/taken throughout exercise and the 1-hour post-exercise recovery period. Compared with control, compression reduced muscle microvascular blood volume and attenuated the exercise-induced increase in microvascular velocity and flow immediately after exercise and 1hour post-exercise. Compression increased femoral artery diameter and augmented the exercise-induced increase in femoral arterial blood flow during exercise. Markers of blood oxygen extraction in muscle were increased with compression during and after exercise. Compression had no effect on blood lactate, glucose, or exercise performance. We provide new evidence that lower-limb compression attenuates the exercise-induced increase in skeletal muscle microvascular blood flow following exercise, despite a divergent increase in femoral artery blood flow. Decreased muscle microvascular perfusion is offset by increased muscle oxygen extraction, a potential mechanism allowing for the maintenance of exercise performance.

Assessment of Cerebrovascular Dynamics and Cognitive Function with Acute Aerobic Exercise in Persons with Multiple Sclerosis.

Cognitive dysfunction in multiple sclerosis (MS) may partially stem from inadequate cerebral blood flow. Cerebral blood flow and cognitive function improve with aerobic exercise in healthy adults. The effect of aerobic exercise on cerebrovascular hemodynamics and cognitive performance in persons with MS is unclear. The acute effect of aerobic exercise versus quiet rest on cerebrovascular hemodynamics and cognitive performance in relapsing-remitting MS was examined. Sixteen adults with relapsing-remitting MS underwent cerebrovascular hemodynamics and cognitive performance testing before, 2 minutes after, and 30 minutes after aerobic exercise (20-minute treadmill walking, 60% peak oxygen consumption) and a time-matched seated control. Brachial blood pressure was obtained via an oscillometric cuff. Right middle cerebral artery (MCA) blood velocity was measured via transcranial Doppler and used to calculate mean velocity, pulsatility index (PI), and conductance. Carotid artery stiffness was measured via ultrasonography and tonometry. Cognitive performance (accuracy, reaction time) was assessed using a modified flanker task. Exercise elicited significant increases in mean pressure and carotid artery stiffness and decreases in MCA conductance at 2 minutes after exercise, which subsided by 30 minutes (P < .05). Exercise did not significantly alter MCA PI. Flanker reaction time decreased during posttesting in both conditions (P < .05). There were no condition × time interactions for cognitive performance. Persons with MS seem resilient to exercise-induced acute changes in MCA PI despite transient carotid stiffening, potentially via reductions in MCA conductance. These data suggest that changes in cognitive performance after acute aerobic exercise are not directly related to transient cerebrovascular responses in persons with MS.

Effect of pedaling cadence on serum levels of brain-derived neurotrophic factor during ergometric exercise in healthy adults

Brain-derived neurotrophic factor (BDNF) is a known essential mediator responsible for the beneficial effects of physical activity on brain health. Exercise-induced lactate is a potential endogenous factor that may increase BDNF expression, and the selection of cadence in exercise prescription is thought to influence lactate concentrations. The aim of this study was to examine the effect of pedaling cadence on circulating BDNF levels through lactate production in healthy adult men. Seventeen healthy adult men participated in three experimental sessions: a 40-min session of cycle-ergometry exercise with a pedaling cadence of 60 rpm at a workload of 40% peak oxygen uptake (Ex.60), a 40-min cycling exercise with a pedaling cadence of 100 rpm at the same workload as the Ex.60 (Ex.100), and a session of complete rest for 40 min (CON). Serum BDNF levels were measured before and after each session, and heart rate (HR) and lactate concentrations were evaluated after each session. Ex.100 significantly increased serum BDNF and lactate levels (p 0.05). The relative change in BDNF levels had a significant strong correlation with relative change in lactate (p 0.05). High-cadence aerobic exercise can increase peripheral BDNF levels through an increase in lactate concentrations, whereas the workload is low to moderate. This study indicates that exercise regimen considering pedaling cadence may have the possibility of inducing better brain health.

Relationship Between the Borg Scale Rating of Perceived Exertion and Leg-Muscle Deoxygenation During Incremental Exercise in Healthy Adults.

The Borg scale rating of perceived exertion is a reliable indicator and widely used to monitor and guide exercise intensity. We aimed to evaluate the relationships between the Borg scale score and oxygenated hemoglobin (O2Hb) and deoxygenated hemoglobin (HHb) concentrations in the leg muscle as measured by near-infrared spectroscopy (NIRS) during cardiopulmonary exercise testing (CPET) in healthy adult men. We also investigated the relationships between the Borg scale score and the work rate (WR), heart rate (HR), oxygen uptake (VO2), and minute ventilation (VE). Participants comprised 12 healthy men. Cardiopulmonary and NIRS parameters were assessed during each minute of CPET and at the end of the test. The Borg scale score was significantly correlated with cardiopulmonary parameters including WR, HR, VO2, and VE during CPET (Rs=0.87-0.95; p<0.05). Furthermore, the Borg scale score was significantly correlated with NIRS parameters including O2Hb and HHb levels during CPET (Rs=-0.48 and 0.45, respectively; p<0.05). The Borg scale score is significantly correlated with cardiopulmonary parameters (WR, HR, VO2, and VE), as well as with leg-muscle oxygenation parameters as assessed by NIRS, during CPET in healthy adults. The correlation coefficients obtained from NIRS parameters were lower than those of cardiopulmonary parameters. The Borg scale score might better reflect cardiopulmonary responses than muscle deoxygenation during exercise. These results can aid in the planning of rehabilitation programs for healthy adults.

Hemodynamic function of the right ventricular-pulmonary vascular-left atrial unit: normal responses to exercise in healthy adults

With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment, which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output. Recent cardiopulmonary exercise hemodynamic studies have enriched the available data from healthy adults, yielded insight into the underlying mechanisms that modify the PV pressure-flow relationship, and better delineated the normal limits of healthy responses to exercise. This review will examine hemodynamic function of the RV-PV-LA unit using the two-element Windkessel model for the pulmonary circulation. It will focus on acute PV and LA responses that accommodate increased RV output during exercise, including PV recruitment and distension and LA reservoir expansion, and the integrated mean pressure-flow response to exercise in healthy adults. Finally, it will consider how these responses may be impacted by age-related remodeling and modified by sex-related cardiopulmonary differences. Studying the determinants and recognizing the normal limits of PV pressure-flow relations during exercise will improve our understanding of cardiopulmonary mechanisms that facilitate or limit exercise.