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.

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

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.

scholarly journals Surveillance for face mask compliance, Chennai, Tamil Nadu, India, October-December, 2020

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257739
Author(s):  
Jagadeesan M. ◽  
Polani Rubeshkumar ◽  
Mohankumar Raju ◽  
Manikandanesan Sakthivel ◽  
Sharan Murali ◽  
...  
Keyword(s):  
Surveillance System ◽  
Tamil Nadu ◽  
Face Mask ◽  
Mitigation Measures ◽  
Shopping Malls ◽  
Cross Sectional ◽  
Public Places ◽  
Media Campaigns ◽  
Time Points ◽  
The Face

Purpose Government of Tamil Nadu, India, mandated the face mask wearing in public places as one of the mitigation measures of COVID-19. We established a surveillance system for monitoring the face mask usage. This study aimed to estimate the proportion of the population who wear face masks appropriately (covering nose, mouth, and chin) in the slums and non-slums of Chennai at different time points. Methods We conducted cross-sectional surveys among the residents of Chennai at two-time points of October and December 2020. The sample size for outdoor mask compliance for the first and second rounds of the survey was 1800 and 1600, respectively, for each of the two subgroups–slums and non-slums. In the second round, we included 640 individuals each in the slums and non-slums indoor public places and 1650 individuals in eleven shopping malls. We calculated the proportions and 95% confidence interval (95%CI) for the mask compliance outdoors and indoors by age, gender, region, and setting (slum and non-slum). Results We observed 3600 and 3200 individuals in the first and second surveys, respectively, for outdoor mask compliance. In both rounds, the prevalence of appropriate mask use outdoors was significantly lower in the slums (28%-29%) than non-slum areas (36%-35%) of Chennai (p<0.01). Outdoor mask compliance was similar within slum and non-slum subgroups across the two surveys. Lack of mask use was higher in the non-slums in the second round (50%) than in the first round of the survey (43%) (p<0.05). In the indoor settings in the 2nd survey, 10%-11% among 1280 individuals wore masks appropriately. Of the 1650 observed in the malls, 947 (57%) wore masks appropriately. Conclusion Nearly one-third of residents of Chennai, India, correctly wore masks in public places. We recommend periodic surveys, enforcement of mask compliance in public places, and mass media campaigns to promote appropriate mask use.

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.

Effect of Contrast Water Therapy Duration on Recovery of Running Performance

2012 ◽  
Vol 7 (2) ◽  
pp. 130-140 ◽  
Author(s):  
Nathan G. Versey ◽  
Shona L. Halson ◽  
Brian T. Dawson
Keyword(s):  
Dose Response ◽  
High Intensity ◽  
Thermal Sensation ◽  
Water Immersion ◽  
Time Trial ◽  
Whole Body ◽  
Running Performance ◽  
Time Points ◽  
Water Therapy ◽  
Contrast Water Therapy

Purpose:To investigate whether contrast water therapy (CWT) assists acute recovery from high-intensity running and whether a dose-response relationship exists.Methods:Ten trained male runners completed 4 trials, each commencing with a 3000-m time trial, followed by 8 × 400-m intervals with 1 min of recovery. Ten minutes postexercise, participants performed 1 of 4 recovery protocols: CWT, by alternating 1 min hot (38°C) and 1 min cold (15°C) for 6 (CWT6), 12 (CWT12), or 18 min (CWT18), or a seated rest control trial. The 3000-m time trial was repeated 2 h later.Results:3000-m performance slowed from 632 ± 4 to 647 ± 4 s in control, 631 ± 4 to 642 ± 4 s in CWT6, 633 ± 4 to 648 ± 4 s in CWT12, and 631 ± 4 to 647 ± 4 s in CWT18. Following CWT6, performance (smallest worthwhile change of 0.3%) was substantially faster than control (87% probability, 0.8 ± 0.8% mean ± 90% confidence limit), however, there was no effect for CWT12 (34%, 0.0 ± 1.0%) or CWT18 (34%, –0.1 ± 0.8%). There were no substantial differences between conditions in exercise heart rates, or postexercise calf and thigh girths. Algometer thigh pain threshold during CWT12 was higher at all time points compared with control. Subjective measures of thermal sensation and muscle soreness were lower in all CWT conditions at some post-water-immersion time points compared with control; however, there were no consistent differences in whole body fatigue following CWT.Conclusions:Contrast water therapy for 6 min assisted acute recovery from high-intensity running; however, CWT duration did not have a dose-response effect on recovery of running performance.

Moderate exercise at energy balance does not affect 24-h leucine oxidation or nitrogen retention in healthy men

1997 ◽  
Vol 273 (2) ◽  
pp. E394-E407 ◽  
Author(s):  
A. E. el-Khoury ◽  
A. Forslund ◽  
R. Olsson ◽  
S. Branth ◽  
A. Sjodin ◽  
...  
Keyword(s):  
Physical Exercise ◽  
Nitrogen Retention ◽  
Whole Body ◽  
Acid Oxidation ◽  
Moderate Exercise ◽  
Significant Deterioration ◽  
Physically Active ◽  
Leucine Oxidation ◽  
Exercise Regimen ◽  
15N Urea

Short-term metabolic experiments have revealed that physical exercise increases the oxidation of leucine, which has been interpreted to indicate an increased requirement for dietary protein in physically active subjects. Because it may be inaccurate to extrapolate measurements of amino acid oxidation made over a few hours to the entire day, we have carried out a continuous 24-h intravenous [1-13C]leucine/[15N]urea tracer study in eight healthy adult men. Their diet supplied 1 g protein.kg-1.day-1, and exercise (mean maximal O2 consumption 46%) was for 90 min during the 12-h fast and 12-h fed periods of the day. Subjects were adapted to the diet and exercise regimen for 6 days. Then, on day 7, they were dressed in the University of Uppsala energy metabolic unit's direct calorimeter suit, were connected to an open-hood indirect calorimeter, and received the tracers. Exercise increased leucine oxidation by approximately 50 and 30% over preexercise rates for fast and fed periods, respectively. This increase amounted to approximately 4-7% of daily leucine oxidation. Subjects remained in body leucine equilibrium (balance -4.6 +/- 10.5 mg.kg-1.day-1; -3.6 +/- 8.3% of intake; P = not significant from zero balance). Therefore, moderate exercise did not cause a significant deterioration in leucine homeostasis at a protein intake of 1 g.kg-1.day-1. These findings underscore the importance of carrying out precise, continuous, 24-h measurements of whole body leucine kinetics; this model should be of value in studies concerning the quantitative interactions among physical exercise, energy/protein metabolism, and diet in humans.

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