Return to training in the COVID-19 era: The physiological effects of face masks during exercise

Effect of facemask use on cognitive function during a maximal running aerobic fitness test

Background: The aim of the present randomized, crossover study was to determine the physiological and cognitive function responses while wearing a facemask during a maximal running aerobic fitness test.

Methods: Fourteen healthy, nonsmoking physical education students (age = 17.5 years, height = 1.72 m, body mass = 70.4 kg) volunteered to participate in this study. They carried out a 20 m multistage fitness test (MSFT) while wearing or not a cloth facemask on two separate occasions performed in random order. The “Rating of Perceived Exertion” (RPE) and the d2 test for visual attention were administered and assessed before and immediately after the MSFT for both conditions (with or without a facemask).

Results: When wearing the facemask, the participants exhibited lower maximal aerobic speed (p = 0.039), VO_2max (p = 0.039), distance covered during the MSFT (p = 0.057), and concentration performance (p < 0.001), when compared with the control situation (without facemask). Moreover, they made more errors compared with the control condition (p = 0.021). The use of a cloth facemask during maximal endurance running tests (such as the MSFT) reduced VO_2max, and measures of cognitive performance as assessed by the test of focused visual attention (the d2 test). This data suggests avoiding using a cloth facemask during maximal aerobic fitness tests, and before any tasks that require a high level of visual attention.

Inhaled CO2 Concentration While Wearing Face Masks: A Pilot Study Using Capnography

Background

Face masks are recommended based on the assumption that they protect against SARS-CoV-2 transmission, however studies on their potential side effects are still lacking. We aimed to evaluate the inhaled air carbon dioxide (CO2) concentration, when wearing masks.

Methods

We measured end-tidal CO2 using professional side-stream capnography, with water-removing tubing, (1) without masks, (2) wearing a surgical mask, and (3) wearing a FFP2 respirator (for 5 minutes each while seated after 10 minutes of rest), in 146 healthy volunteers aged 10 to 90 years, from the general population of Ferrara, Italy. The inhaled air CO2 concentration was computed as: ([mask volume × end-tidal CO2] + [tidal volume - mask volume] × ambient air CO2)/tidal volume.

Results

With surgical masks, the mean CO2 concentration was 7091 ± 2491 ppm in children, 4835 ± 869 in adults, and 4379 ± 978 in the elderly. With FFP2 respirators, this concentration was 13 665 ± 3655 in children, 8502 ± 1859 in adults, and 9027 ± 1882 in the elderly. The proportion showing a CO2 concentration higher than the 5000 ppm (8-hour average) acceptable threshold for workers was 41.1% with surgical masks, and 99.3% with FFP2 respirators. Adjusting for age, gender, BMI, and smoking, the inhaled air CO2 concentration significantly increased with increasing respiratory rate (mean 10 837 ±3712 ppm among participants ⩾18 breaths/minute, with FFP2 respirators), and among the minors.

Conclusion

If these results are confirmed, the current guidelines on mask-wearing should be reevaluated.

The Physiological Effects of Face Masks During Exercise Worn Due to COVID-19: A Systematic Review

CONTEXT

Use of face masks in sport has been a particularly complex issue during the COVID-19 pandemic.

OBJECTIVES

A systematic review to examine the physiological effects the different types of masks have on healthy adults when doing physical exercise.

DATA SOURCES

PubMed, SPORTDiscus, Scopus, and Litcovid were searched up to March 20, 2021, following the PRISMA model. Articles published in the last 5 years with healthy adults.

STUDY SELECTION

A total of 633 studies related to the use of masks during physical exercise were found, of which 8 articles met the criteria to be included.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 2.

DATA EXTRACTION

The search process and the review of the articles were carried out by independent expert researchers. The risk of bias and the methodological quality of the different studies included in the systematic review were calculated following the Cochrane criteria using an adaptation for random cross-studies. Once the information was properly structured, the results were extracted, and the findings of the study analyzed.

RESULTS

There were significant changes in the following physiological variables when engaging in physical exercise using masks: 25% in the heart rate and dyspnea, 37.5% in the rating of perceived exertion, 50% in the pulmonary variables, and 37.5% in discomfort. The oxygen saturation, blood pressure, systolic blood pressure, diastolic blood pressure, and the concentration of blood lactate did not present any significant effect in this study.

CONCLUSION

The usage of masks by a healthy adult population during the performance of physical exercise has shown minimal effects with regard to physiological, cardiorespiratory, and perceived responses. Some symptoms can be dyspnea, effort perceived, or discomfort, among others. These findings indicate that the use of masks is not harmful to individuals' health. It does not present any significant detrimental effect on physical performance or risk to their well-being. However, further experiments are required to corroborate the findings of this review.

Pulmonary function testing during SARS-CoV-2: An ANZSRS/TSANZ position statement

The Thoracic Society of Australia and New Zealand (TSANZ) and the Australian and New Zealand Society of Respiratory Science (ANZSRS) commissioned a joint position paper on pulmonary function testing during coronavirus disease 2019 (COVID-19) in July 2021. A working group was formed via an expression of interest to members of both organizations and commenced work in September 2021. A rapid review of the literature was undertaken, with a 'best evidence synthesis' approach taken to answer the research questions formed. This allowed the working group to accept findings of prior relevant reviews or societal document where appropriate. The advice provided is for providers of pulmonary function tests across all settings. The advice is intended to supplement local infection prevention and state, territory or national directives. The working group's key messages reflect a precautionary approach to protect the safety of both healthcare workers (HCWs) and patients in a rapidly changing environment. The decision on strategies employed may vary depending on local transmission and practice environment. The advice is likely to require review as evidence grows and the COVID-19 pandemic evolves. While this position statement was contextualized specifically to the COVID-19 pandemic, the working group strongly advocates that any changes to clinical/laboratory practice, made in the interest of optimizing the safety and well-being of HCWs and patients involved in pulmonary function testing, are carefully considered in light of their potential for ongoing use to reduce transmission of other droplet and/or aerosol borne diseases.

Effects of surgical and FFP2 masks on cardiopulmonary exercise capacity in patients with heart failure

Aims

Surgical and FFP2 masks are recommended to reduce transmission of SARS-CoV-2. The cardiopulmonary effects of facemasks in patients with chronic heart failure are unknown. This prospective, cross-over study quantified the effects of wearing no mask (nm), surgical mask (sm), and FFP2 mask (ffpm) in patients with stable heart failure.

Methods

12 patients with clinically stable chronic heart failure (HF) (age 63.8±12 years, left ventricular ejection fraction (LVEF) 43.8±11%, NTProBNP 573±567 pg/ml) underwent spiroergometry with and without masks in a randomized sequence. Comfort/discomfort was assessed using a standardized questionnaire.

Results

Maximum power was reduced with both types of masks (nm: 108.3 W vs. sm: 101.2 W vs. ffpm: 95.6 W, p<0.01). Maximum respiratory oxygen uptake (1499ml/min vs. 1481 ml/min vs. 1300 ml/min, p = 0.95 and <0.01), peak ventilation (62.1 l/min vs. 56.4 l/min vs. 50.3 l/min, p = 0.15 and p<0.05) and O2-pulse (11.6 ml/beat vs. 11.8 ml/beat vs. 10.6 ml/beat, p = 0.87 and p<0.01) were significantly changed with ffpm but not sm. Discomfort was moderately but significantly increased (nm: 1.6 vs. sm: 3.4 vs. ffpm: 4.4, p<0.05).

Conclusion

Both surgical and FFP masks reduce exercise capacity in heart failure patients, while FFP2 masks reduce oxygen uptake and peak ventilation. This reduction in cardiopulmonary performance should be considered in heart failure patients whose daily life activities are often just as challenging as exercise is for healthy adults.

Acute Effects of Facial Coverings on Anaerobic Exercise Performance in College-Aged Adults

The use of facial coverings has been amplified during the COVID-19 pandemic as a means to minimize the spread of disease. However, facial coverings may impede ventilation during high-intensity activity, leading to a reduction in cardiopulmonary exercise capacity. Thus, the purpose of this study was to determine the acute impact of different facial coverings on exercise performance in college-aged individuals during a 300-yard shuttle. It was hypothesized that the lowest heart rate (HR), completion time (CT), and rate of perceived exertion (RPE) would occur with no mask. Furthermore, it was hypothesized the SHEMA97 mask would have lower HR, CT, and RPE compared to surgical and fabric masks. Results showed the use of the fabric mask resulted in significantly higher HR compared to no mask (p = 0.006). The SHEMA97 mask resulted in faster CT and lower RPE compared to both the fabric and surgical masks (p < 0.001). All mask conditions yielded significantly higher levels of perceived discomfort than wearing no mask (p < 0.05). While the use of facial coverings can help prevent the spread of disease, their use during exercise may pose limitations to performance; however, the ability of the SHEMA97 to provide minimal changes to CT and RPE provides a promising option.

Mask Use for Athletes: A Systematic Review of Safety and Performance Outcomes

CONTEXT

With the current Centers for Disease Control and Prevention recommendations for mask use to minimize transmission of coronavirus 2019 (COVID-19) coupled with concern for future pandemics that would require mask wearing, providing data-driven guidance with respect to athletic performance is essential.

OBJECTIVE

The purpose of this study was to perform a systematic review of existing literature on the use of face masks while exercising to assess the physiologic effects of face masks worn during athletic activities.

DATA SOURCES

A systematic review was conducted of studies on face mask use during exercise according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Potential studies were identified through searches of MEDLINE, Embase, Cochrane CENTRAL and CINAHL databases.

STUDY SELECTION

Screening was completed independently by 2 coauthors who sought to identify studies that described the effects of oronasal mask use, if any, on sports/exercise/physical activity, for any age, gender, or level of sport. Articles describing mask effects without exercise, articles published before 1980, and non-English language studies were excluded.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Data extraction focused on physiologic parameters measured during physical activity performed while wearing a face mask.

RESULTS

Twenty-two articles met all inclusion criteria. Study analysis revealed that the use of masks in healthy volunteers during exercise had no significant effect on physiologic parameters measured including heart rate (HR), respiratory rate (RR), oxygen saturation, and perceived exertion. Of the studies that investigated N95 masks in the healthy adult population, 2 reported modest changes in RR and maximum power output indicative of decreased athletic performance when subjects were exercising at maximum effort. Similar findings were seen in studies of subpopulations including children and pregnant women.

CONCLUSION

Available data suggest that healthy individuals can perform moderate-to-vigorous exercise while wearing a face mask without experiencing changes in HR, RR, and oxygen saturation that would compromise individual safety or athletic performance. In the specific situation in which an N95 mask is worn, maximum power generated may be impaired.

WHAT IS KNOWN ABOUT THE SUBJECT

To date, there has been no systematic review of the existing literature to provide a clear consensus on whether face mask use significantly impacts athletic performance. Mask use has been demonstrated safe in the workplace; however, the use of face masks during exercise has not been examined on a large scale, particularly with respect to physiologic parameters.

WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE

This analysis highlights that available data suggest that healthy individuals can perform heavy exercise in face masks with minimal physiologic changes. This is the first systematic review of studies analyzing exercise use wearing masks. With the evidence presented here commonly cited concerns about both safety and performance decrements with mask use during physical activities may be allayed.

Effect of N95 Respirator on Oxygen and Carbon Dioxide Physiologic Response: A Systematic Review and Meta-Analysis

During the COVID-19 pandemic, N95 respirators were commonly used in many situations. Respiratory problems from prolonged use of respirators were discussed in many studies, which show varied results. From the inconclusive results, the current systematic review and meta-analysis discerned the effects of the N95 respirator by assessing the oxygen and carbon dioxide changes in both high- and low-to-moderate-intensity physical activities in a healthy population. Thirteen studies were identified for inclusion in the study. In high-intensity physical activities, our meta-analysis showed borderline lower oxygen saturation and higher carbon dioxide partial pressure, but oxygen saturation did not change in low-to-moderate physical activity. The use of N95 respirators could statistically affect the physiologic changes of carbon dioxide and oxygen in high-intensity physical activity among healthy participants, but this may not be clinically significant. Some users who have certain health conditions, such as respiratory problems, should be informed of the clinical symptoms related to hypercarbia and hypoxia for the early detection of adverse effects of N95 respirators.

Prevention of droplet dispersal with 'e-mask': A new daily use endoscopic mask during bronchoscopy

BACKGROUND AND OBJECTIVE

Bronchoscopy is an airborne particle-generating procedure. However, few methods for safe bronchoscopy have been developed. To reduce airborne particles during bronchoscopy, we created an 'e-mask', which is a simple, disposable mask for patients. Our objective was to evaluate the e-mask's protective ability against airborne particles and to assess respiratory adverse events and complications.

METHODS

Patients with stage 2-4 chronic obstructive pulmonary disease were excluded. We performed visualization and quantifying experiments on airborne particles with and without the e-mask. We prospectively evaluated whether wearing the e-mask during bronchoscopy was associated with the incidence of patients requiring >5 L/min oxygen to maintain >90% oxygen saturation, and patients with >45 mm Hg end-tidal carbon dioxide (EtCO₂ ) elevation, in addition to complications, compared to historical controls.

RESULTS

In the visualization experiment, more than ten thousand times of airborne particles were generated without the e-mask than with the e-mask. The volume of airborne particles was significantly reduced with the e-mask, compared to that without the e-mask (p = 0.011). Multivariate logistic regression analysis revealed that wearing the e-mask had no significant effect on the incidence of patients requiring >5 L/min oxygen to maintain >90% oxygen saturation, (p = 0.959); however, wearing the e-mask was a significant factor in >45 mm Hg EtCO₂ elevation (p = 0.026). No significant differences in complications were observed between the e-mask and control groups (5.8% vs. 2.5%, p = 0.395).

CONCLUSION

Wearing the e-mask during bronchoscopy significantly reduced the generation of airborne particles during bronchoscopy without increasing complications.

Aerobic Performance Detriments while Wearing a Face Mask Diverge Among Males and Females

The current study examined the impact of wearing a face mask (FM) at rest and while exercising on cardiorespiratory variables and aerobic performance between males and females. Nine males (21.4 ± 0.5 yr) and 9 females (21.8 ± 3.6 yr) performed a pulmonary function test and a graded maximal exercise test (GXT) on a treadmill with an FM and without an FM in random order. During the GXT, cardiorespiratory variables were measured at different exercise intensities (rest, 40%, 55%, 70%, 80%, 100% of VO₂max) and during recovery. Regardless of sex, both males and females significantly (p = .01) reduced their resting pulmonary functions, including forced vital capacity (18.7% and 19.6%, respectively), forced expiratory volume in one second (43.9% and 45.7%, respectively), and peak expiratory flow (85.2% and 87.5%, respectively) with an FM. During the GXT, both VO₂ and ventilation (VE) in males were significantly (p < .01) lower with an FM only at 100% of VO₂max, while females showed a significantly (p < .01) lower VO₂, VE, and tidal volume (V_t) with an FM throughout the entire GXT. The partial pressure of exhaled CO₂ was significantly (p = .02) higher at 100% of VO₂max with an FM only in males. Although wearing an FM reduced resting pulmonary functions and the maximal aerobic performance for both males and females, there was a clear sex-specific response during the GXT, indicating that females were less capable to adapt to the pulmonary obstruction induced by wearing an FM.

Acute Effects of Wearing Different Surgical Face Masks during High-Intensity, Short-Rest Resistance Exercise on Cardiorespiratory and Pulmonary Function and Perceptual Responses in Weightlifters

This study investigated the effect of wearing a typical surgical mask (SM) or a three-dimensional (3D) SM (3DSM) during whole-body, high-intensity, short-rest resistance exercise on cardiorespiratory, respiratory, and perceptual comfort responses in weightlifters. Twenty elite weightlifters (6 women and 14 men; age = 24.1 ± 4.9 years; height: 167.45 ± 7.60 cm; body mass = 76.48 ± 19.86 kg) who participated in this study performed 3 resistance exercise sessions in a randomized order: (1) without a mask (NM), (2) while wearing a typical SM, and (3) while wearing a 3DSM. Resistance exercise consisted of a descending pyramid scheme starting at 10 repetitions, with a decrease of one repetition per set for the back squat, bench press, and deadlift, as fast as possible at 75% of the one-repetition maximum. Cardiorespiratory and pulmonary function and comfort were measured. Across all conditions, effective postexercise hypotension (PEH) was noted in terms of decreased systolic blood pressure (−4.64%), diastolic BP (−5.36%), mean arterial pressure (−5.02%), and ankle–brachial index (−6.84%). However, the heart rate (40.34%) and rate of pressure product (33.60%) increased, and no effects on pulmonary function were observed in the three conditions. The participants reported higher breathing resistance and tightness when wearing a typical SM than when wearing a 3DSM or no mask. Therefore, both wearing and not wearing a face mask during whole-body, high-intensity, short-rest resistance exercise promoted PEH and exerted no detrimental effect on pulmonary function. Coaches, trainers, and athletes should consider wearing a 3DSM during resistance exercise.

Effect of Cloth Masks and N95 Respirators on Maximal Exercise Performance in Collegiate Athletes

This study compared exercise performance and comfort while wearing an N95 filtering facepiece respirator (N95), cloth mask, or no intervention control for source control during a maximal graded treadmill exercise test (GXT). Twelve Division 1 athletes (50% female, age = 20.1 ± 1.2, BMI = 23.5 ± 1.6) completed GXTs under three randomized conditions (N95, cloth mask, control). GXT duration, heart rate (HR), respiration rate (RR), transcutaneous oxygen saturation (SpO2), transcutaneous carbon dioxide (TcPCO2), rating of perceived exertion (RPE), and perceived comfort were measured. Participants ran significantly longer in control (26.06 min) versus N95 (24.20 min, p = 0.03) or cloth masks (24.06 min, p = 0.04). No differences occurred in the slope of HR or SpO2 across conditions (p > 0.05). TcPCO2 decreased faster in control (B = −0.89) versus N95 (B = 0.14, p = 0.02) or cloth masks (B = −0.26, p = 0.03). RR increased faster in control (B = 8.32) versus cloth masks (B = 6.20, p = 0.04). RPE increased faster in the N95 (B = 1.91) and cloth masks (B = 1.79) versus control (B = 1.59, p < 0.001 and p = 0.05, respectively). Facial irritation/itching/pinching was higher in the N95 versus cloth masks, but sweat/moisture buildup was lower (p < 0.05 for all). Wearing cloth masks or N95s for source control may impact exercise performance, especially at higher intensities. Significant physiological differences were observed between cloth masks and N95s compared to control, while no physiological differences were found between cloth masks and N95s; however, comfort my differ.

Effect of Surgical Mask use on Peak Physical Performance During Exercise Treadmill Testing-A Real World, Crossover Study

Background: Mask wearing is an essential strategy to combat the spread of SARS-CoV-2. Some individuals may wear masks during physical activity to reduce disease transmission. This study aimed to investigate the real-world effect of wearing a surgical face mask on physiological parameters at peak exercise in healthy individuals.

Methods: In this crossover design study, participants underwent maximal treadmill electrocardiogram exercise tests using the Bruce protocol on two separate occasions, once with a standard 3-ply surgical face mask and once without. Heart rate, oxygen saturation, blood pressure, rate pressure product, metabolic equivalents (METS) and total exercise time were measured. Subjective rate of perceived exertion was also assessed using the modified Borg Scale.

Results: 50 adults (mean age = 31.7 ± 6.5 years; 27 males) completed both treadmill tests. Mask wearing resulted in a significant reduction in peak METS by 1.5 units, maximum speed by 0.5 km/h, exercise time by 68.4 s with a significantly lower peak heart rate by 4.4 bpm, and lower percentage of age-predicted maximum heart rate by 2.5% (p < 0.001 for all parameters). During each corresponding stage of the Bruce protocol, the average modified Borg score was found to be significantly higher in subjects exercising with mask after adjusting for age, gender and body mass index (p < 0.03).

Conclusion: In a cohort of healthy individuals, wearing of a surgical face mask during maximal treadmill exercise lead to reduced physical performance and increased rate of perceived exertion. Individuals exercising with surgical masks need to be mindful of these limitations while undergoing physical training in order to differentiate these physiological responses from symptoms of early respiratory illness.

Blood gas levels, cardiovascular strain and cognitive performance during surgical mask and filtering face piece application

Mask induced airway resistance and carbon dioxide rebreathing is discussed to impact gas exchange and to induce discomfort and impairments in cognitive performance. N = 23 healthy humans (13 females, 10 males; 23.5 ± 2.1 years) participated in this randomized crossover trial (3 arms, 48-h washout periods). During interventions participants wore either a surgical face mask (SM), a filtering face piece (FFP2) or no mask (NM). Interventions included a 20-min siting period and 20 min steady state cycling on an ergometer at 77% of the maximal heart rate (HR). Hemodynamic data (HR, blood pressure), metabolic outcomes (pulse derived oxygen saturation, capillary carbon dioxide (pCO₂), and oxygen partial pressure (pO₂), lactate, pH, base excess), subjective response (ability to concentrate, arousal, perceived exertion) and cognitive performance (Stroop Test) were assessed. Compared to NM, both masks increased pCO₂ (NM 31.9 ± 3.3 mmHg, SM = 35.2 ± 4.0 mmHg, FFP2 = 34.5 ± 3.8 mmHg, F = 12.670, p < 0.001) and decreased pH (NM = 7.42 ± 0.03, SM = 7.39 ± 0.03, FFP2 = 7.39 ± 0.04, F = 11.4, p < 0.001) during exercise. The FFP2 increased blood pressure during exercise (NM = 158 ± 15 mmHg, SM = 159 ± 16 mmHg, FFP2 = 162 ± 17 mmHg, F = 3.21, p = 0.050), the SM increased HR during sitting (NM = 70 ± 8 bpm, SM = 74 ± 8 bpm, FFP2 = 73 ± 8 bpm, F = 4.70, p = 0.014). No mask showed any comparative effect on other hemodynamic, metabolic, subjective, or cognitive outcomes. Mask wearing leads to slightly increased cardiovascular stress and elevated carbon dioxide levels during exercise but did not affect cognitive performance or wellbeing.

Exercise Training Programs Improve Cardiorespiratory and Functional Fitness in Adults With Asthma: A SYSTEMATIC REVIEW AND META-ANALYSIS

PURPOSE

This systematic review aimed to identify the characteristics and determine the effects of exercise interventions on improving health-related physical fitness in adults with asthma.

REVIEW METHODS

A systematic search was completed in MEDLINE, CINAHL, Embase, and SPORTDiscus for peer-reviewed publications of experimental studies that investigated the effects of an exercise training intervention on performance-based health-related physical fitness outcomes in adults with asthma. Two reviewers independently screened studies for inclusion according to predetermined criteria and performed data extraction and quality assessment of included studies.

SUMMARY

Forty-five articles were included, in which results for 39 unique studies were reported. Subjects (n = 2135) were aged 22 ± 4 to 71 ± 11 yr with mild-severe asthma. Most exercise programs used aerobic exercise, either alone or in combination with resistance or breathing/stretching exercises. The most common exercise program characteristics were supervised moderate-to-vigorous intensity aerobic exercise performed for 30-45 min 3 d/wk. Meta-analyses revealed significant improvements in cardiorespiratory fitness (V˙o2peak: unstandardized mean difference [MD] 3.1 mL/kg/min, 95% CI, 1.9-4.3), functional fitness (walking distance: MD 41 m, 95% CI, 27-54), and overall health-related physical fitness (standardized mean difference [SMD] 0.67, 95% CI, 0.46-0.89) in favor of groups who underwent experimental exercise training interventions. Aerobic exercise elicited superior improvements in health-related physical fitness compared with breathing/stretching exercise (SMD 0.47, 95% CI, 0.14-0.81).Supervised exercise training programs, particularly those aerobic in nature, are effective in eliciting clinically meaningful improvements in cardiorespiratory and functional fitness in adults with asthma.PROSPERO registration ID number = CRD42018092828.

The Effects of Face Coverings on Perceived Exertion and Attention Allocation during a Stepping Task

The COVID-19 pandemic has impacted the entire world from lockdowns to various recommended restrictions including social distancing and wearing face coverings. In a safe environment, cardiovascular exercise is important for both physical health and mental health. The current study examined the effects of face coverings on rating of perceived exertion and attention allocation during an exertive stepping task. Participants completed a stepping task with a weighted vest at 20% of their bodyweight until volitional fatigue with a face covering (n = 23) or without a face covering (n = 31). Results revealed a non-significant difference (p = 0.25) in the duration of the stepping task (in seconds) between the no face covering (M = 455.81, SD = 289.77) and face covering (M = 547.83, SD = 285.93) conditions. Results indicated increases in perceived exertion (p < 0.001) and heart rate (p < 0.001) as time progressed across the four time points (i.e., 30 s, 1/3 time to exhaustion, 2/3 time to exhaustion, and exhaustion) in both conditions. No significant differences were found between the conditions for RPE (p = 0.09) and heart rate (p = 0.50). Participants wearing a face covering were more internally focused across the duration of the stepping task (p = 0.05). This study has relevance for applied practitioners implementing physical activity interventions that require face coverings.

Physiological Effects of Wearing N95 Respirator on Medical Staff During Prolong Work Hours in Covid-19 Departments

OBJECTIVE

The objective of the current study was to determine gas exchange abnormalities and physiological changes among healthcare workers during a 4-hour emergency department (ED) shift while wearing the N95 respirator.

METHODS

Single-center prospective observational study. Comparisons of paired measurements were performed using a non-parametric Wilcoxon matched-pairs signed-rank test. Results: Forty-one subjects were included. Prolonged N95 respirator use was associated with a significant decline in plasma pH (7.35 mmHg vs 7.34 mmHg, P = 0.02), PvO 2 (23.2 mmHg vs 18.6 mmHg, P < 0.001) and a concurrent increase in EtCO 2 (32.5 mmHg vs 38.5 mmHg, P < 0.0001). PvCO 2 and bicarbonate levels did not differ. No significant change was observed for heart rate or oxygen saturation.

CONCLUSION

Using an N95 respirator for prolonged periods by healthcare professionals may provoke changes in gas exchange. The clinical significance of these changes remains to be determined.

Safety and Comfort of Wearing Medical Masks in Adult Surgical Patients After General Anesthesia During the COVID-19 Epidemic: A Retrospective, Observational Cohort Study

OBJECTIVE

This study assessed oxygen saturation variation and comfort in adult surgical patients wearing masks in PACU during the COVID-19 epidemic.

DESIGN

Retrospective observation was applied in this study.

METHODS

One hundred thirty-seven patients wearing no medical masks (Group A, aged from 20 to 87) and 136 patients wearing medical masks (Group B, aged from 18 to 91) were selected in this retrospective study after extubation in PACU. After extubation their pulse oxygen saturation, noninvasive mean blood pressure and heart rate were recorded at two different time points (treated with 40% O₂ oxygen therapy for 10 minutes and breathing room air for 10 minutes). The comfort, arterial blood gas data, complications and duration of patients were also reviewed in PACU.

FINDINGS

There were no significant differences in the pulse oxygen saturation between the two groups after inhaling 40% O₂ or air. Compared with Group A, patients in Group B have lower comfort (6 [4-7] vs 7 [6-8]; P < .001), with shortened duration after extubation in PACU (50 [45-55] vs 56 [48-60]; P < .001). No significant differences were found in heart rate, noninvasive mean blood pressure, arterial blood gas data and complications. And no hypoxemia and respiratory adverse events happened in two groups.

CONCLUSIONS

Wearing medical masks does not reduce oxygen saturation in adult surgical patients during recovery from general anesthesia. The discomfort caused by masks is the concern in PACU.

Effects of Face Masks on Physiological Parameters and Voice Production during Cycling Activity

This study investigates the effects of face masks on physiological and voice parameters, focusing on cyclists that perform incremental sports activity. Three healthy male subjects were monitored in a climatic chamber wearing three types of masks with different acoustic properties, breathing resistance, and air filtration performance. Masks A and B were surgical masks made of hydrophobic fabric and three layers of non-woven fabric of 100% polypropylene, respectively. Mask S was a multilayer cloth mask designed for sports activity. Mask B and Mask S behave similarly and show lower sound attenuation and sound transmission loss and lower breathing resistance than Mask A, although Mask A exhibits slightly higher filtration efficiency. Similar cheek temperatures were observed for Masks A and B, while a significantly higher temperature was measured with Mask S at incremental physical activity. No differences were found between the masks and the no-mask condition for voice monitoring. Overall, Mask B and Mask S are suitable for sports activities without adverse effects on voice production while ensuring good breathing resistance and filtration efficiency. These outcomes support choosing appropriate masks for sports activities, showing the best trade-off between breathing resistance and filtration efficiency, sound attenuation, and sound transmission loss.

The impacts of surgical mask in young healthy subjects on cardiopulmonary function and muscle performance: a randomized crossover trial

Objective

To explore the impacts of surgical mask in normal subjects on cardiopulmonary function and muscle performance under different motor load and gender differences.

Design

Randomized crossover trial.

Setting

The Fifth Affiliated Hospital of Guangzhou Medical University, June 16th to December 30th, 2020.

Participants

Thirty-one college students (age: male 21.27 ± 1.22 years; female 21.31 ± 0.79 years) were recruited and randomly allocated in two groups.

Interventions

Group 1 first received CPET in the mask-on condition followed by 48 h of washout, and then received CPET in the mask-off condition. Group 2 first received CPET in the mask-off condition followed by 48 h of washout, then received CPET in the mask-on condition. The sEMG data were simultaneously collected.

Main outcome measures

The primary outcome was maximum oxygen uptake (VO₂ max) from CPET, which was performed on a cycle ergometer—this is the most important parameter associated with an individual’s physical conditioning. The secondary parameters included parameters reflecting exercise tolerance and heart function (oxygen uptake, anaerobic valve, maximum oxygen pulse, heart rate reserve), parameters reflecting ventilation function (respiration reserve, ventilation volume, tidal volume, breathing frequency), parameters reflecting gas exchange (end-tidal oxygen and carbon dioxide partial pressure, oxygen equivalent, carbon dioxide equivalent, and the relationship between dead space and tidal volume) and parameters reflecting skeletal muscle function [oxygen uptake, anaerobic valve, work efficiency, and EMG parameters including root mean square (RMS)].

Results

Comparing the mask-on and mask-off condition, wearing surgical mask had some negative effects on VO₂/kg (peak) and ventilation (peak) in both male and female health subjects [VO₂/kg (peak): 28.65 ± 3.53 vs 33.22 ± 4.31 (P = 0.001) and 22.54 ± 3.87 vs 26.61 ± 4.03 (P < 0.001) ml/min/kg in male and female respectively; ventilation (peak): 71.59 ± 16.83 vs 82.02 ± 17.01 (P = 0.015) and 42.46 ± 10.09 vs 53.95 ± 10.33 (P < 0.001) liter in male and female respectively], although, based on self-rated scales, there was no difference in subjective feelings when comparing the mask-off and mask-on condition. Wearing surgical masks showed greater lower limb muscle activity just in male subjects [mean RMS of vastus medialis (load): 65.36 ± 15.15 vs 76.46 ± 19.04 μV, P = 0.031]. Moreover, wearing surgical masks produced a greater decrease in △tidal volume (VTpeak) during intensive exercises phase in male subjects than in female [male − 0.80 ± 0.15 vs female − 0.62 ± 0.11 l P = 0.001].

Conclusions

Wearing medical/surgical mask showed a negative impact on the ventilation function in young healthy subjects during CPET, especially in high-intensity phase. Moreover, some negative effects were found both in ventilation and lower limb muscle actives in male young subjects during mask-on condition. Future studies should focus on the subjects with cardiopulmonary diseases to explore the effect of wearing mask.

Trial registration

Chinese Clinical Trial Registry (ChiCTR2000033449).

Perceived Exertion during Moderate and Vigorous Physical Activity While Mask Wearing: A Quantitative and Qualitative Pilot Study

There is limited research examining the perception of exertion during exercise while wearing a facemask. The current study examined if mask usage during moderate or vigorous physical activity (MVPA) changed the self-reported perception of exertion. Seventy-two adults (18 years and older) who were physically active before the COVID-19 pandemic completed a questionnaire that assessed exercise habits and perceptions of mask wearing during MVPA. Participants reported their ratings of perceived exertion (RPE, on a scale of 1−10) while exercising. Wearing a mask resulted in higher RPE vs. no mask during both vigorous (8.4 ± 0.2 vs. 7.4 ± 0.1; p < 0.001) and moderate PA (6.6 ± 0.2 vs. 5.6 ± 0.2; p < 0.001). Qualitative analysis revealed mostly negative perceptions of exercising while wearing a mask, including respiratory issues, detriments to cardiovascular endurance, and general discomfort. A total of 40% of participants reported that they stopped exercising in an indoor/public setting because of a mask mandate in their region. Participants reported participating in less vigorous PA (4.7 ± 0.4 vs. 4.0 ± 0.4 h/week; p = 0.046), but not less moderate PA (3.3 ± 0.3 vs. 3.0 ± 0.3 h/week; p = 0.443) pre vs. during the pandemic. Our study suggests that facemask usage during MVPA causes an increase in RPE and may be one reason for a decrease in vigorous PA during the COVID-19 pandemic.

The Cardiopulmonary Effects of Medical Masks and Filtering Facepiece Respirators on Healthy Health Care Workers in the Emergency Department: A Prospective Cohort Study

Background

International COVID-19 guidelines recommend that health care workers (HCWs) wear filtering facepiece (FFP) respirators to reduce exposure risk. However, there are concerns about FFP respirators causing hypercapnia via rebreathing carbon dioxide (CO₂). Most previous studies measured the physiological effects of FFP respirators on treadmills or while resting, and such measurements may not reflect the physiological changes of HCWs working in the emergency department (ED).

Objective

Our aim was to evaluate the physiological and clinical impacts of FFP type II (FFP2) respirators on HCWs during 2 h of their day shift in the ED.

Methods

We included emergency HCWs in this prospective cohort study. We measured end-tidal CO₂ (ETCO₂), mean arterial pressure (MAP), respiratory rate (RR), and heart rate values and dyspnea scores of subjects at two time points. The first measurements were carried out with medical masks while resting. Subjects then began their day shift in the ED with medical mask plus FFP2 respirator. We called subjects after 2 h for the second measurement.

Results

The median age of 153 healthy volunteers was 24.0 years (interquartile range 24.0–25.0 years). Subjects’ MAP, RR, and ETCO₂ values and dyspnea scores were significantly higher after 2 h. Median ETCO₂ values increased from 36.4 to 38.8 mm Hg. None of the subjects had hypercapnia symptoms, hypoxia, or other adverse effects.

Conclusion

We did not observe any clinical reflection of these changes in physiological values. Thus, we evaluated these changes to be clinically insignificant. We found that it is safe for healthy HCWs to wear medical masks plus FFP2 respirators during a 2-h working shift in the ED.

Handball Training and Competition With Facemasks in Galicia: The FISICOVID-DXTGALEGO Protocols Experience

Objective

COVID-19 caused a complete stop in non-professional sports. The use of face masks for team sports is not a widely used measure in non-professional sports. The study aimed to evaluate the perception about using the mask and the adaptation difficulties related to training and competition in team sports following the FISICOVID-DXTGALEGO protocol.

Methods

Seven hundred eighty-seven handball players from the Galician Handball Federation were followed during their return to participation after months of confinement through an electronic questionnaire of perception and experience on the use of a mask.

Results

There is an excellent adaptation to the mask in training and competition with medium and high correlations. The 86,41% of players reported an adaptation to the mask in 3 weeks with a three times a week training frequency. The negative opinion on the mask was drastically reduced (-66.86%) after use. The 80,44% of players considered the use of a mask as an essential measure to resume competitions.

Conclusions

It is very feasible to adapt to training and compete with a mask (hygienic or surgical) in a short period. The use of a mask following these protocols changed previous opinions on the disadvantages of the mask during training and competition.

Bayesian network meta-analysis of face masks' impact on human physiology

Several concerns regarding the safety of face masks use have been propounded in public opinion. The objective of this review is to examine if these concerns find support in the literature by providing a comprehensive overview of physiological responses to the use of face masks. We have performed a systematic review, pairwise and network meta-analyses to investigate physiological responses to the use of face masks. The study has been registered with PROSPERO (C RD42020224791). Obtained results were screened using our exclusion and inclusion criteria. Meta-analyses were performed using the GeMTC and meta R packages. We have identified 26 studies meeting our inclusion and exclusion criteria, encompassing 751 participants. The use of face masks was not associated with significant changes in pulsoxymetrically measured oxygen saturation, even during maximal-effort exercises. The only significant physiological responses to the use of face masks during low-intensity activities were a slight increase in heart rate, mildly elevated partial pressure of carbon dioxide (not meeting criteria for hypercarbia), increased temperature of facial skin covered by the mask, and subsequent increase of the score in the rating of heat perception, with N95 filtering facepiece respirators having a greater effect than surgical masks. In high-intensity conditions, the use of face masks was associated with decreased oxygen uptake, ventilation, and RR. Face masks are safe to use and do not cause significant alterations in human physiology. The increase in heart rate stems most likely from increased respiratory work required to overcome breathing resistance. The increase in carbon dioxide is too small to be clinically relevant. An increased rating of heat perception when using face masks results from higher temperature of facial skin covered by the mask.

Effect of wearing different types of face masks during dynamic and isometric resistance training on intraocular pressure

CLINICAL RELEVANCE

The use of face masks has demonstrated to be an effective strategy to prevent transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Wearing face masks, mainly Filtering Face Piece 2 (FFP2) masks, during exercise practice has demonstrated to affect several physiological measures.

BACKGROUND

This study was aimed at assessing the intraocular pressure (IOP) behaviour during the execution of the dynamic and isometric biceps-curl exercise with a surgical and FFP2 face mask.

METHODS

Twenty two physically active young adults performed sets of 10 repetitions against the 10-RM (repetition maximum) load and 1-minute isometric effort against a load 15% lower than the 10-RM load with the FFP2 and surgical mask and without any mask. A total of six exercise sets (3 experimental conditions [FFP2, surgical and control] × 2 exercise modalities) were performed. A rebound tonometer was used to measure IOP before, during (10 measurements), and after (30-seconds of passive recovery) each training set.

RESULTS

At rest, there were not statistically significant IOP differences (p = 0.222). During dynamic exercise, there was a progressive IOP rise (p < 0.001), and a higher IOP response with the FFP2 than without the mask (corrected p-value = 0.003). For the isometric exercise, there was a greater IOP response as a function of accumulated effort (p < 0.001), which was dependent of the face mask used (FFP2> surgical>control; corrected p-values< 0.01).

CONCLUSIONS

The FFP2 masks cause a heightened IOP response during the execution of dynamic and isometric biceps-curl exercise, suggesting that, when possible, glaucoma patients should limit the use of FFP2 masks during resistance training.

Effects of a taped filter mask on peak power, perceived breathlessness, heart rate, blood lactate and oxygen saturation during a graded exercise test in young healthy adults: a randomized controlled trial

BACKGROUND

Face masks are an effective, non-pharmacological strategy to reduce the transmission of Severe Acute Respiratory Syndrome Coronavirus-2 and other pathogens. However, it is a challenge to keep masks sealed during exercise, as ventilation can increase from 5 to 10 L/min at rest to up to 200 L/min so that masks may be blown away from the face. To reduce leakage e.g. during exercise, a face mask was developed that is taped onto the face. The aim of this study was to investigate during a graded exercise test the effect of a taped filter mask on the perception of breathlessness, heart rate, blood lactate concentration, and oxygen saturation when compared to a surgical mask and no mask.

METHODS

Eight healthy trained participants (4 females), aged 24.5 ± 3.3 years performed graded exercise test until volitional exhaustion under three conditions: (1) No mask/control, (2) surgical mask or (3) taped filter mask. During these tests, we measured perception of breathlessness, heart rate, blood lactate concentration and peripheral oxygen saturation and analysed the resultant data with one or two-way repeated measures ANOVAs. We also used a questionnaire to evaluate mask comfort and analysed the data with paired t-tests.

RESULTS

When compared to wearing no mask, maximal workload was significantly reduced with a taped filter face mask by 12 ± 6% (p < 0.001) and with a surgical mask by 3 ± 6% (p > 0.05). Moreover, subjects perceive the sensation of "severe breathlessness" at a 12 ± 9% lower workload (p = 0.012) with a taped face mask, and 7 ± 13% lower workload with a surgical mask (p > 0.05) when compared to wearing no mask. Oxygen saturation at 65% of the maximal workload is 1.5% lower (p = 0.018) with a taped mask than no mask. Heart rate and blood lactate concentration are not significantly different in-between no mask, surgical mask and taped mask at any workload. When compared to wearing a surgical mask, wearing a taped filter face mask has a significantly better wearing comfort (p = 0.038), feels better on the skin (p = 0.004), there is a lower sensation of moisture (p = 0.026) and wearers perceive that less heat is generated (p = 0.021). We found no sex/gender differences for any of the measured parameters.

CONCLUSIONS

A taped mask is well tolerated during light and moderate exercise intensity but reduces maximal exercise capacity.

Physiological Effects of Surgical and N95 Masks During Exercise in the Covid-19 Era

Background

During the COVID-19 pandemic, studies of the physiological effects of masking during exercise have been rare.

Methods

Twelve healthcare workers performed a cardiopulmonary exercise test while wearing a surgical mask, an N95 mask, or no mask. Variables were collected at rest, warm-up, anaerobic threshold, and maximal exercise.

Results

From rest to maximal exercise, both the surgical and N95 masks decreased inspiratory flow, minute ventilation, and prolonged inspiratory time compared to the no mask condition. Oxygen uptake (VO₂) and oxygen pulse (VO₂/HR) decreased at rest, warm-up, and maximal exercise in both the surgical and N95 mask conditions (vs. no mask). At the anaerobic threshold, the surgical mask also led to a reduction of oxygen uptake and oxygen pulse compared to no mask. The maximal oxygen uptake (VO₂% predicted) also decreased in both the surgical and N95 mask conditions. In addition, the severity of dyspnea increased, and exercise time decreased for both surgical and N95 masks. Compared to no mask, wearing an N95 mask led to lower breathing frequency and lower ventilation efficacy (assessed by VE/VCO₂ and VE/VO₂) from rest to maximal exercise (all p < 0.05 for trend). Wearing an N95 also led to retention of carbon dioxide (p < 0.05 for trend).

Conclusions

Wearing a surgical mask leads to a somewhat negative impact on cardiopulmonary function, and this effect is more serious with an N95 mask. Attention should be paid to exercise while wearing surgical or N95 masks.

The effect of the protective face mask on cardiorespiratory response during aerobic exercise

Protective face mask (PFM) has been widely used for safety purposes and, after the advent of the COVID-19 pandemic, its use is growing steadily, not only among healthcare personnel but also the general population. While PFM is important to preserve the wearer from contaminating agents present in the airflow, they are well known to increase the subjective perception of breathing difficulty. Although some studies demonstrated that PFM use worsens exercise tolerance, there are several studies stating that there is no such limitation with the use of PFM. Moreover, no serious adverse effects during physical exercise have been found in the literature. Physical exercise represents a significant challenge to the human body through a series of integrated changes in function that involve most of its physiologic systems. In this respect, cardiovascular and respiratory systems provide the capacity to sustain physical tasks over extended periods. Within this scenario, both convective oxygen (O₂ ) transport (product of arterial O₂ content x blood flow) to the working locomotor muscles and O₂ diffusive transport from muscle capillaries to mitochondria are of paramount importance to endurance performance. Interestingly, the effects of PFM on cardiorespiratory response during aerobic exercise depends on the type of mask and exercise (i.e., walking, running, or cycling), including decrease in ventilatory demands, arterial oxygen levels, maximal oxygen consumption, and endurance performance. The purpose of this review was to elucidate the effect of protective face mask-wearing on 1) cardiorespiratory responses during aerobic exercise and 2) endurance performance.

Smart facemask for wireless CO2 monitoring

The use of facemasks by the general population is recommended worldwide to prevent the spread of SARS-CoV-2. Despite the evidence in favour of facemasks to reduce community transmission, there is also agreement on the potential adverse effects of their prolonged usage, mainly caused by CO2 rebreathing. Herein we report the development of a sensing platform for gaseous CO2 real-time determination inside FFP2 facemasks. The system consists of an opto-chemical sensor combined with a flexible, battery-less, near-field-enabled tag with resolution and limit of detection of 103 and 140 ppm respectively, and sensor lifetime of 8 h, which is comparable with recommended FFP2 facemask usage times. We include a custom smartphone application for wireless powering, data processing, alert management, results displaying and sharing. Through performance tests during daily activity and exercise monitoring, we demonstrate its utility for non-invasive, wearable health assessment and its potential applicability for preclinical research and diagnostics.

Effects of wearing different facial masks on respiratory symptoms, oxygen saturation, and functional capacity during six-minute walk test in healthy subjects

BACKGROUND

During the current COVID-19 pandemic and increased air pollution levels, wearing a facial mask has been recommended. This study aimed to compare the impact of wearing different masks when performing a submaximal functional activity (six-minute walk test; 6MWT) on respiratory symptoms, oxygen saturation, and functional capacity.

METHODS

Twenty-nine subjects (10 men, 19 women; age 22 ± 1 yr.; FEV₁/FVC 0.90 ± 0.01) performed four rounds of 6MWT wearing different masks (surgical (Medima SK, Thailand), handmade cloth, and N95 (3M AuraTM 1870⁺, USA)) and while not wearing a mask. Respiratory symptoms (dyspnea and breathing effort), oxygen saturation, and other physiological parameters were assessed before and after each walking trial.

RESULTS

Six-minute walking distances were comparable between walking trials (P = 0.59). At the end of minute 6, a significant difference between groups was found on dyspnea (P = 0.02) and breathing effort (P < 0.001). Post hoc tests showed that wearing a cloth mask significantly increased dyspnea (P = 0.004) compared to wearing a surgical mask. Wearing a cloth mask also significantly increased breathing effort compared to wearing a surgical mask (P < 0.001) and not wearing a mask (P < 0.001). Likewise, while wearing an N95 mask, breathing effort significantly increased compared to wearing a surgical mask (P = 0.007) and not wearing a mask (P = 0.002).

CONCLUSIONS

Wearing different masks while performing submaximal functional activity results in no differences in functional performance, oxygen saturation, heart rate, or blood pressure. However, wearing cloth masks and N95 masks results in higher respiratory symptoms.

Inhaled CO2 Concentration While Wearing Face Masks: A Pilot Study Using Capnography

BACKGROUND

Face masks are recommended based on the assumption that they protect against SARS-CoV-2 transmission, however studies on their potential side effects are still lacking. We aimed to evaluate the inhaled air carbon dioxide (CO₂) concentration, when wearing masks.

METHODS

We measured end-tidal CO₂ using professional side-stream capnography, with water-removing tubing, (1) without masks, (2) wearing a surgical mask, and (3) wearing a FFP2 respirator (for 5 minutes each while seated after 10 minutes of rest), in 146 healthy volunteers aged 10 to 90 years, from the general population of Ferrara, Italy. The inhaled air CO₂ concentration was computed as: ([mask volume × end-tidal CO₂] + [tidal volume - mask volume] × ambient air CO₂)/tidal volume.

RESULTS

With surgical masks, the mean CO₂ concentration was 7091 ± 2491 ppm in children, 4835 ± 869 in adults, and 4379 ± 978 in the elderly. With FFP2 respirators, this concentration was 13 665 ± 3655 in children, 8502 ± 1859 in adults, and 9027 ± 1882 in the elderly. The proportion showing a CO₂ concentration higher than the 5000 ppm (8-hour average) acceptable threshold for workers was 41.1% with surgical masks, and 99.3% with FFP2 respirators. Adjusting for age, gender, BMI, and smoking, the inhaled air CO₂ concentration significantly increased with increasing respiratory rate (mean 10 837 ±3712 ppm among participants ⩾18 breaths/minute, with FFP2 respirators), and among the minors.

CONCLUSION

If these results are confirmed, the current guidelines on mask-wearing should be reevaluated.

Effects of wearing a cloth face mask on performance, physiological and perceptual responses during a graded treadmill running exercise test

OBJECTIVES

To (1) determine if wearing a cloth face mask significantly affected exercise performance and associated physiological responses, and (2) describe perceptual measures of effort and participants' experiences while wearing a face mask during a maximal treadmill test.

METHODS

Randomised controlled trial of healthy adults aged 18-29 years. Participants completed two (with and without a cloth face mask) maximal cardiopulmonary exercise tests (CPETs) on a treadmill following the Bruce protocol. Blood pressure, heart rate, oxygen saturation, exertion and shortness of breath were measured. Descriptive data and physical activity history were collected pretrial; perceptions of wearing face masks and experiential data were gathered immediately following the masked trial.

RESULTS

The final sample included 31 adults (age=23.2±3.1 years; 14 women/17 men). Data indicated that wearing a cloth face mask led to a significant reduction in exercise time (-01:39±01:19 min/sec, p<0.001), maximal oxygen consumption (VO2max) (-818±552 mL/min, p<0.001), minute ventilation (-45.2±20.3 L/min), maximal heart rate (-8.4±17.0 beats per minute, p<0.01) and increased dyspnoea (1.7±2.9, p<0.001). Our data also suggest that differences in SpO2 and rating of perceived exertion existed between the different stages of the CPET as participant's exercise intensity increased. No significant differences were found between conditions after the 7-minute recovery period.

CONCLUSION

Cloth face masks led to a 14% reduction in exercise time and 29% decrease in VO2max, attributed to perceived discomfort associated with mask-wearing. Compared with no mask, participants reported feeling increasingly short of breath and claustrophobic at higher exercise intensities while wearing a cloth face mask. Coaches, trainers and athletes should consider modifying the frequency, intensity, time and type of exercise when wearing a cloth face mask.

ACL injury prevention: Where have we come from and where are we going?

Anterior cruciate ligament (ACL) injuries are one of the most common and severe knee injuries across sports. As such, ACL injury prevention has been a focus of research and sports medicine practice for the past three-plus decades. Examining the current research and identifying both clinical strategies and research gaps, the aim of this review is to empower clinicians and researchers with knowledge of where the ACL injury prevention literature is currently and where it is going in the future. This paper examines the mechanism of ACL injury prevention, screening, implementation, compliance, adherence, coronavirus, and areas of future research. Clinical significance: The time lag between research and practical implementation in general healthcare settings can be as long as 17 years; however, athletes playing sports today are unable to wait that long. With effective programs already established, implementation and adherence to these programs is essential. Strategies such as coaching education, increasing awareness of free programs, identifying barriers, and overcoming implementation obstacles through creative collaboration are just a few ways that could help improve both ACL injury prevention implementation and adherence.

N95 vs Half-face Respirator Wear in Surgical Trainees: Physiologic and Psychological Effects of Prolonged Use

Objectives

As specialists of the upper airway, otolaryngologists are at high risk for COVID-19 transmission. N95 and half-face respirator (HFR) masks are commonly worn, each with advantages in functionality and comfort. In this study, physiologic and psychological parameters of prolonged N95 vs HFR wear were compared.

Study Design

Prospective crossover cohort study.

Setting

Single academic tertiary care hospital.

Methods

A prospective crossover cohort study was performed. Healthy otolaryngology trainees and medical students (N = 23) participated and wore N95 and HFR masks continuously for 3 hours each on separate days. Various measures were analyzed: vitals, spirometry variables, scores on the State-Trait Anxiety Inventory and HIT-6 (Headache Impact Test-6), distress, and "difficulty being understood."

Results

The average age was 26.3 years (SD, 3.42). There were no significant differences in vital signs and spirometry variables between N95 and HFR wear. N95 wear was associated with decreases in oxygen saturation of approximately 1.09% more than with HFRs (95% CI, 0.105-2.077). State-Trait Anxiety Inventory scores increased more with HFR wear when compared with mean changes with N95 wear (95% CI, 1.350-8.741). There were no significant differences in HIT-6 scores or distress levels between masks. The proportions of participants reporting difficulty being understood was significantly higher with HFRs.

Conclusions

Oxygen saturation decreases with prolonged N95 wear, but anxiety and difficulty being understood are greater with HFR wear. Although HFRs have less resistance to gas exchange, N95 respirators may produce less anxiety and distress in clinical situations. Further studies are warranted to evaluate the clinical significance of these differences.

Level of Evidence

2.

Facemasks during aerobic exercise: Implications for cardiac rehabilitation programs during the Covid-19 pandemic

Introduction and objectives

During the COVID-19 pandemic, among the safety measures adopted, use of facemasks during exercise training sessions in cardiac rehabilitation programs raised concerns regarding possible detrimental effects on exercise capacity. Our study examined the cardiorespiratory impact of wearing two types of the most common facemasks during treadmill aerobic training.

Methods

Twelve healthy health professionals completed three trials of a symptom-limited Bruce treadmill protocol: Without a mask, with a surgical mask and with a respirator. Perceived exertion and dyspnea were evaluated with the Borg Scale of Perceived Exertion and the Borg Dyspnea Scale, respectively. Blood pressure, heart rate and arterial oxygen saturation (SpO2) were measured at each 3-minute stage.

Results

Using a surgical mask or a respirator resulted in a shorter duration of exercise testing. At peak capacity, using a respirator resulted in higher levels of dyspnea and perceived exertion compared to not wearing a facemask. A significant drop in SpO2 was present at the end of exercise testing only when using a respirator. There were no differences in either chronotropic or blood pressure responses between testing conditions.

Conclusions

Professionals involved in cardiac rehabilitation should be aware of the cardiorespiratory impact of facemasks. Future studies should assess whether exposure to these conditions may impact on the overall results of contemporary cardiac rehabilitation programs.

Effect of Wearing Surgical Face Masks During Exercise: Does Intensity Matter?

Face masks are widely recommended as means of controlling the coronavirus disease outbreak. This study aimed to examine the physiological and perceptual responses of wearing surgical face masks while exercising at different intensities. Thirteen healthy young adults (mean age, 21.9 ± 1.4 years) conducted randomized crossover trials with or without a surgical face mask. In each trial, participants completed an incremental treadmill protocol, with three 6-min stages (light, moderate, and vigorous at 25, 50, and 75% maximal oxygen uptake, respectively). Physiological outcomes (heart rate, blood lactate, and oxygen saturation level), perceived exertion and discomfort feeling were assessed. No significant differences were observed in physiological outcomes with or without masks at different exercise intensities (p > 0.05). However, the rating of perceived exertion (RPE) was significantly higher when exercising vigorously (mask: 15.5 ± 1.5 vs. no-mask: 14.2 ± 2.1, p < 0.05). Participants wearing masks reported marked discomfort, such as feeling hot, humid, and breathing resistance. Although face mask-wearing during exercise may not have detrimental effects on major physiological parameters, it can increase perceived exertion level and discomfort when the exercise intensity exceeds a certain threshold. Therefore, healthcare professionals should cautiously evaluate each person’s ability to exercise while wearing a mask and tailor their prescription accordingly.

The Impact of Ubiquitous Face Masks and Filtering Face Piece Application During Rest, Work and Exercise on Gas Exchange, Pulmonary Function and Physical Performance: A Systematic Review with Meta-analysis

BACKGROUND

Protection against airborne infection is currently, due to the COVID-19-associated restrictions, ubiquitously applied during public transport use, work and leisure time. Increased carbon dioxide re-inhalation and breathing resistance may result thereof and, in turn, may negatively impact metabolism and performance.

OBJECTIVES

To deduce the impact of the surgical mask and filtering face piece type 2 (FFP2) or N95 respirator application on gas exchange (pulse-derived oxygen saturation (SpO₂), carbon dioxide partial pressure (PCO₂), carbon dioxide exhalation (VCO₂) and oxygen uptake (VO₂)), pulmonary function (respiratory rate and ventilation) and physical performance (heart rate HR, peak power output W_peak).

METHODS

Systematic review with meta-analysis. Literature available in Medline/Pubmed, the Cochrane Library and the Web of Knowledge with the last search on the 6^th of May 2021. Eligibility criteria: Randomised controlled parallel group or crossover trials (RCT), full-text availability, comparison of the acute effects of ≥ 1 intervention (surgical mask or FFP2/N95 application) to a control/comparator condition (i.e. no mask wearing). Participants were required to be healthy humans and > 16 years of age without conditions or illnesses influencing pulmonary function or metabolism. Risk of bias was rated using the crossover extension of the Cochrane risk of bias assessment tool II. Standardised mean differences (SMD, Hedges' g) with 95% confidence intervals (CI) were calculated, overall and for subgroups based on mask and exercise type, as pooled effect size estimators in our random-effects meta-analysis.

RESULTS

Of the 1499 records retrieved, 14 RCTs (all crossover trials, high risk of bias) with 25 independent intervention arms (effect sizes per outcome) on 246 participants were included. Masks led to a decrease in SpO₂ during vigorous intensity exercise (6 effect sizes; SMD = - 0.40 [95% CI: - 0.70, - 0.09], mostly attributed to FFP2/N95) and to a SpO₂-increase during rest (5 effect sizes; SMD = 0.34 [95% CI: 0.04, 0.64]); no general effect of mask wearing on SpO₂ occurred (21 effect sizes, SMD = 0.34 [95% CI: 0.04, 0.64]). Wearing a mask led to a general oxygen uptake decrease (5 effect sizes, SMD = - 0.44 [95% CI: - 0.75, - 0.14]), to slower respiratory rates (15 effect sizes, SMD = - 0.25 [95% CI: - 0.44, - 0.06]) and to a decreased ventilation (11 effect sizes, SMD = - 0.43 [95% CI: - 0.74, - 0.12]). Heart rate (25 effect sizes; SMD = 0.05 [95% CI: - 0.09, 0.19]), W_peak (9 effect sizes; SMD = - 0.12 [95% CI: - 0.39, 0.15]), PCO₂ (11 effect sizes; SMD = 0.07 [95% CI: - 0.14, 0.29]) and VCO₂ (4 effect sizes, SMD = - 0.30 [95% CI: - 0.71, 0.10]) were not different to the control, either in total or dependent on mask type or physical activity status.

CONCLUSION

The number of crossover-RCT studies was low and the designs displayed a high risk of bias. The within-mask- and -intensity-homogeneous effects on gas exchange kinetics indicated larger detrimental effects during exhausting physical activities. Pulse-derived oxygen saturation was increased during rest when a mask was applied, whereas wearing a mask during exhausting exercise led to decreased oxygen saturation. Breathing frequency and ventilation adaptations were not related to exercise intensity. FFP2/N95 and, to a lesser extent, surgical mask application negatively impacted the capacity for gas exchange and pulmonary function but not the peak physical performance. Registration: Prospero registration number: CRD42021244634.

Does wearing a facemask decrease arterial blood oxygenation and impair exercise tolerance?

INTRODUCTION

Concerns have been raised that COVID-19 face coverings compromise lung function and pulmonary gas exchange to the extent that they produce arterial hypoxemia and hypercapnia during high intensity exercise resulting in exercise intolerance in recreational exercisers. This study therefore aimed to investigate the effects of a surgical, flannel or vertical-fold N95 masks on cardiorespiratory responses to incremental exercise.

METHODS

This investigation studied 11 adult males and females at rest and while performing progressive cycle exercise to exhaustion. We tested the hypotheses that wearing a surgical (S), flannel (F) or horizontal-fold N95 mask compared to no mask (control) would not promote arterial deoxygenation or exercise intolerance nor alter primary cardiovascular variables during submaximal or maximal exercise.

RESULTS

Despite the masks significantly increasing end-expired peri-oral %CO₂ and reducing %O_2, each ∼0.8-2% during exercise (P < 0.05), our results supported the hypotheses. Specifically, none of these masks reduced sub-maximal or maximal exercise arterial O₂ saturation (P = 0.744), but ratings of dyspnea were significantly increased (P = 0.007). Moreover, maximal exercise capacity was not compromised nor were there any significant alterations of primary cardiovascular responses (mean arterial pressure, stroke volume, cardiac output) found during sub-maximal exercise.

CONCLUSION

Whereas these results are for young healthy recreational male and female exercisers and cannot be applied directly to elite athletes, older or patient populations, they do support that arterial hypoxemia and exercise intolerance are not the obligatory consequences of COVID-19-indicated mask-wearing at least for cycling exercise.

What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues

Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.

Effects of surgical masks on the responses to constant work-rate cycling performed at different intensity domains

We aimed at examining the impact of wearing surgical face masks on exercise performance. Thirty-two healthy adults (16 males and 16 females) completed a graded exercise test to measure peak oxygen uptake (VO_2peak ) and the ventilatory threshold (VT). Then, on separate days, all participants performed resting and standardized protocols (moderate intensity: 25% infra-VT; severe intensity: 25% supra-VT) on two different conditions (with and without a surgical mask). The use of masks reduced both VO₂ and minute ventilation during moderate and severe exercise (p < 0.0001), and this effect was particularly pronounced during severe exercise. Time to exhaustion was also shortened by ~10% on the face mask condition (p = 0.014). In contrast, neither heart rate nor the respiratory exchange ratio was affected by masking. The submaximal VO₂ was similar between the two epochs of analysis obtained during moderate cycling (i.e. 3-6 min vs. 7-10 min) and this occurred similarly between conditions. In conclusion, the impact of the surgical masks on exercise capacity is particularly pronounced during severe exercise performed at constant work rate. Ultimately, this may implicate a considerable impairment of structured or even unstructured strenuous physical activity. Clinical Trials registration number: NCT04963049.

Safety of surgical masks during phisical activity evaluated with graded cycle ergometry test

AIMS

At the time of the coronavirus disease 2019 (COVID-19) pandemic wearing surgical mask (SM) is recommended for the prevention of contracting or exposing others to airborne transmission of COVID-19. It is somewhat controversial whether wearing SM during exercise affects performance and health status and/or may influence the results. In order to give an answer we planned a prospective, randomized, crossover study to evaluate the effects of wearing a SM or no-SM in 33 (17 male) physically active helthy subjects during a graded exercise cycle ergometry test.

METHODS

The two tests were performed in random order in the same subjects. The participants were all tested the same day, after a recovery time of at least of one hour, in order to avoid interferences on physical performances. Arterial oxygen saturation, heart rate and arterial blood pressure were assessed throughout the exercise tests every step of two minutes, at the end of exercise, performed at the same time with and without mask.

RESULTS AND CONCLUSIONS

Wearing SM had no effect on performance, since the duration of cycle ergometry test with SM and without SM median, respectively, was 14.2, [lower-upper quartile 13.9-14.8] versus 14.3 [13.9-15.5] minutes, p=0.094, and median peak power was 150 W [150-180] versus 150 W [120-180] p=0.754. When expressed relative to peak exercise performance, no differences were found between wearing or not wearing SM regarding arterial oxygen saturation, or heart rate at any time during the exercise tests. Wearing SM during vigorous exercise had no detrimental effect on cardiovascular parameters, as well as on exercise metrics in all participants. No ventricular repolarization abnormalities and no arrhythmias were reported on the electrocardiograms.

Wearing a Surgical Face Mask Has Minimal Effect on Performance and Physiological Measures during High-Intensity Exercise in Youth Ice-Hockey Players: A Randomized Cross-Over Trial

COVID-19 transmission is prevalent during ice-hockey; however, it is unknown whether wearing face masks as a mitigation strategy affects hockey players’ performance. We used a randomized cross-over study to compare wearing a surgical mask to a sham mask (control) in youth hockey players (21 males, 5 females, 11.7 ± 1.6 y) during a simulated hockey period (cycle ergometry; six shifts of 20 s of “easy” pedaling (40% peak power), 10 s of “hard” pedaling (95% peak power), 20 s of “easy” pedaling, with shifts separated by 5 min rests). A seventh shift involved two 20 s Wingate tests separated by 40 s rest. Heart rate, arterial oxygen saturation and vastus lateralis tissue oxygenation index (hemoglobin saturation/desaturation) was assessed each shift. On-ice testing was conducted with the maximal Yo-Yo intermittent recovery test. No differences between mask and control conditions for performance were found (Wingate average power: 245 ± 93 vs. 237 ± 93 W, Peak power: 314 ± 116 vs. 304 ± 115 W, on-ice distance: 274 ± 116 vs. 274 ± 110 m) and for heart rate or arterial oxygen saturation during simulated hockey shifts. Tissue oxygenation index was lower from shifts one to six for males (p < 0.05) and shift seven for females (p < 0.01) while wearing a mask. Wearing a face mask had no effect on performance in hockey players with only minor effects on muscle oxygenation. ClinicalTrials.gov (NCT04874766) (accessed on 6 May 2021).