Mechanisms of Rapid Local Vasodilation During a Mild‐to‐Moderate Exercise Intensity Transition in Humans: Role for K‐ IR Channel Activation

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Nathaniel B Ketelhut ◽  
Janée D Terwoord ◽  
Christopher M. Hearon ◽  
Jennifer C Richards ◽  
Gary J Luckasen ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Moderate Exercise ◽  
Channel Activation ◽  
Moderate Exercise Intensity

Effects of Face Mask Use on Objective and Subjective Measures of Thermoregulation During Exercise in the Heat

2021 ◽  
pp. 194173812110282
Author(s):  
Ayami Yoshihara ◽  
Erin E. Dierickx ◽  
Gabrielle J. Brewer ◽  
Yasuki Sekiguchi ◽  
Rebecca L. Stearns ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Thermal Sensation ◽  
Face Mask ◽  
Whole Body ◽  
Moderate Exercise ◽  
Physically Active ◽  
Time Points ◽  
The Face ◽  
And Control ◽  
Moderate Exercise Intensity

Background: While increased face mask use has helped reduce COVID-19 transmission, there have been concerns about its influence on thermoregulation during exercise in the heat, but consistent, evidence-based recommendations are lacking. Hypothesis: No physiological differences would exist during low-to-moderate exercise intensity in the heat between trials with and without face masks, but perceptual sensations could vary. Study Design: Crossover study. Level of Evidence: Level 2. Methods: Twelve physically active participants (8 male, 4 female; age = 24 ± 3 years) completed 4 face mask trials and 1 control trial (no mask) in the heat (32.3°C ± 0.04°C; 54.4% ± 0.7% relative humidity [RH]). The protocol was 60 minutes of walking and jogging between 35% and 60% of relative VO2max. Rectal temperature (Trec), heart rate (HR), temperature and humidity inside and outside of the face mask (Tmicro_in, Tmicro_out, RHmicro_in, RHmicro_out) and perceptual variables (rating of perceived exertion (RPE), thermal sensation, thirst sensation, fatigue level, and overall breathing discomfort) were monitored throughout all trials. Results: Mean Trec and HR increased at 30- and 60-minute time points compared with 0-minute time points, but no difference existed between face mask trials and control trials ( P > 0.05). Mean Tmicro_in, RHmicro_in, and humidity difference inside and outside of the face mask (ΔRHmicro) were significantly different between face mask trials ( P < 0.05). There was no significant difference in perceptual variables between face mask trials and control trials ( P > 0.05), except overall breathing discomfort ( P < 0.01). Higher RHmicro_in, RPE, and thermal sensation significantly predicted higher overall breathing discomfort ( r2 = 0.418; P < 0.01). Conclusion: Face mask use during 60 minutes of low-to-moderate exercise intensity in the heat did not significantly affect Trec or HR. Although face mask use may affect overall breathing discomfort due to the changes in the face mask microenvironment, face mask use itself did not cause an increase in whole body thermal stress. Clinical Relevance: Face mask use is feasible and safe during exercise in the heat, at low-to-moderate exercise intensities, for physically active, healthy individuals.

scholarly journals Right ventricular strain rate during exercise accurately identifies male athletes with right ventricular arrhythmias

2019 ◽  
Author(s):  
Mathias Claeys ◽  
Guido Claessen ◽  
Piet Claus ◽  
Ruben De Bosscher ◽  
Christoph Dausin ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Strain Rate ◽  
Exercise Intensity ◽  
Left Ventricular ◽  
Moderate Intensity ◽  
Moderate Exercise ◽  
Deformation Imaging ◽  
Strain And Strain Rate ◽  
Right Ventricular Strain ◽  
Moderate Exercise Intensity

Abstract Aims Athletes with right ventricular (RV) arrhythmias, even in the absence of desmosomal mutations, may have subtle RV abnormalities which can be unmasked by deformation imaging. As exercise places a disproportionate stress on the right ventricle, evaluation of cardiac function and deformation during exercise might improve diagnostic performance. Methods and results We performed bicycle stress echocardiography in 17 apparently healthy endurance athletes (EAs), 12 non-athletic controls (NAs), and 17 athletes with RV arrhythmias without desmosomal mutations (EI-ARVCs) and compared biventricular function at rest and during low (25% of upright peak power) and moderate intensity (60%). At rest, we observed no differences in left ventricular (LV) or RV function between groups. During exercise, however, the increase in RV fractional area change (RVFAC), RV free wall strain (RVFWSL), and strain rate (RVFWSRL) were significantly attenuated in EI-ARVCs as compared to EAs and NAs. At moderate exercise intensity, EI-ARVCs had a lower RVFAC, RVFWSL, and RVFWSRL (all P < 0.01) compared to the control groups. Exercise-related increases in LV ejection fraction, strain, and strain rate were also attenuated in EI-ARVCs (P < 0.05 for interaction). Exercise but not resting parameters identified EI-ARVCs and RVFWSRL with a cut-off value of >−2.35 at moderate exercise intensity had the greatest accuracy to detect EI-ARVCs (area under the curve 0.95). Conclusion Exercise deformation imaging holds promise as a non-invasive diagnostic tool to identify intrinsic RV dysfunction concealed at rest. Strain rate appears to be the most accurate parameter and should be incorporated in future, prospective studies to identify subclinical disease in an early stage.

Effects of moderate exercise intensity on serum nesfatin-1 levels in young females

2021 ◽  
pp. 67-70
Keyword(s):  
Exercise Intensity ◽  
Venous Blood ◽  
Moderate Intensity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Maximal Heart Rate ◽  
Energy Regulation ◽  
Moderate Exercise ◽  
Young Females ◽  
Exercise Induced ◽  
Moderate Exercise Intensity

Purpose: Nesfatin-1 is known as an energy regulatory hormone. Exercise induced increase in nesfatin-1 levels has been considered as powerful mechanism against metabolic disorders. In this study we evaluated the effects of moderate exercise intensity on serum nesfatin-1 levels in young females. Material and Method: Total of 12 females performed a 45 minutes of running exercise at their 70% of maximal heart rate. Venous blood samples were taken before and after exercise. Muscle activity condition were evaluated using serum creatine kinase levels (CK). Nesfatin-1 levels measured using enzyme linked-immunosorbent assay (ELISA) method. CK level was measured using autoanalyser. Paired t-test was used to analyse data for significance. Results: Nesfatin-1 levels increased from baseline value of 159.9±18 ng/mL to 178.2±20 ng/mL to end of exercise (increase of 11%) (p<0.005). In addition, during exercise CK increased significantly from 115.5±20 U/L to 146.7±28 U/L (p<0.05). During exercise, there was no significant correlation between increase of nesfatin-1 and CK levels. There was a positive correlation between nesfatin-1 and fat mass (R=0.66602, P=0.01). Consequently, moderate intensity aerobic exercise induced muscle strain may cause elevate CK levels and stimulate increase in nesfatin-1 levels. Conclusion: Thus, exercise is an important tool that may have additional effects on energy regulation via affecting nesfatin-1 secretion in young females.

scholarly journals Effect of Prescription of Traditional Sports Regimen on Depression of College Students

2021 ◽  
Vol 233 ◽  
pp. 02011
Author(s):  
Yu Ling ◽  
Xia Jun-mei
Keyword(s):  
College Students ◽  
Sleep Quality ◽  
Exercise Intensity ◽  
Control Group ◽  
Moderate Exercise ◽  
Traditional Sports ◽  
Group 2 ◽  
Experimental Group ◽  
Moderate Exercise Intensity ◽  
Group 1

To explore the effect of prescription of traditional sports regimen with different amounts of exercise on improving depression and sleep quality of college students. Depression Screening Scale (PHQ-9) and Zung’s Self-rating Depression Scale (SDS) were used to screen students with mild depression, who were randomly divided into control group, experimental group 1 (moderate exercise intensity, 30min each time, 5 times a week,) and experimental group 2 (moderate exercise intensity, 60min each time, 5 times a week). The exercise prescription intervention with different exercise amount was performed for 16 weeks. Compared with before exercise, the total scores of SDS and PSQI of the two experimental groups decreased significantly after 8 weeks of intervention; after 16 weeks of intervention, the total scores of SDS and PSQI of the experimental groups were obviously different (P < 0.05) compared with 8 weeks of intervention; after 8 weeks of training cessation, the total scores of SDS and PSQI of the experimental groups were increased, but however, significant decrease in the total scores still can be seen compared with those before the experiment(P<0.05). Compared with the control group, after 8 weeks of intervention, 16 weeks of intervention and 8 weeks of training cessation, the total scores of SDS and PSQI of the two experimental groups were significantly reduced and the effect of experimental group 2 on improving PSQI score of college students was significantly better than that of experimental group 1.Traditional sports regimen intervention can improve college students’ depression and improve their sleep quality, and it can still maintain the effect after stopping training for 8 weeks; exercise intervention of 60 minutes each time, 5 times a week, has better effect on improving college students’ sleep quality than that of 30 minutes each time, 5 times a week.

Muscle metaboreflex attenuates spontaneous heart rate baroreflex sensitivity during dynamic exercise

2007 ◽  
Vol 292 (6) ◽  
pp. H2867-H2873 ◽  
Author(s):  
Javier A. Sala-Mercado ◽  
Masashi Ichinose ◽  
Robert L. Hammond ◽  
Tomoko Ichinose ◽  
Marco Pallante ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Intensity ◽  
Baroreflex Sensitivity ◽  
Pressor Response ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Dynamic Exercise ◽  
Moderate Exercise ◽  
Ventricular Systolic Pressure ◽  
Muscle Metaboreflex

Hypoperfusion of active skeletal muscle elicits a reflex pressor response termed the muscle metaboreflex. Dynamic exercise attenuates spontaneous baroreflex sensitivity (SBRS) in the control of heart rate (HR) during rapid, spontaneous changes in blood pressure (BP). Our objective was to determine whether muscle metaboreflex activation (MRA) further diminishes SBRS. Conscious dogs were chronically instrumented for measurement of HR, cardiac output, mean arterial pressure, and left ventricular systolic pressure (LVSP) at rest and during mild (3.2 km/h) or moderate (6.4 km/h at 10% grade) dynamic exercise before and after MRA (via partial reduction of hindlimb blood flow). SBRS was evaluated as the slopes of the linear relations (LRs) between HR and LVSP during spontaneous sequences of at least three consecutive beats when HR changed inversely vs. pressure (expressed as beats·min−1·mmHg−1). During mild exercise, these LRs shifted upward, with a significant decrease in SBRS (−3.0 ± 0.4 vs. −5.2 ± 0.4, P < 0.05 vs. rest). MRA shifted LRs upward and rightward and decreased SBRS (−2.1 ± 0.1, P < 0.05 vs. mild exercise). Moderate exercise shifted LRs upward and rightward and significantly decreased SBRS (−1.2 ± 0.1, P < 0.05 vs. rest). MRA elicited further upward and rightward shifts of the LRs and reductions in SBRS (−0.9 ± 0.1, P < 0.05 vs. moderate exercise). We conclude that dynamic exercise resets the arterial baroreflex to higher BP and HR as exercise intensity increases. In addition, increases in exercise intensity, as well as MRA, attenuate SBRS.

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