Lying and misleading headlines: "Researchers find face masks don't hinder breathing during exercise:" Science past and present - and common sense:
Usually citing one superficial study of just 14 persons and which simply tested blood and muscle oxygen levels after a short workout, we see headlines as below:
www.sciencedaily.com › releases › 2020/11 ...Face masks don't hinder breathing during exercise, study finds
Nov 5, 2020 — A new study has found that exercise performance and blood and muscle oxygen levels are not affected for healthy individuals wearing a face ... The study evaluated use of a three-layer cloth face mask... involving 14 physically active and healthy men and women..required to do a brief warm-up on a stationary bike. The exercise test involved a progressive increase in the intensity on the bike while they maintained a required pedal rate. Once they could not sustain the pedal rate the test was over. “Usually a participant reaches exhaustion on this test in six to twelve minutes depending on their fitness level,”
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However, even if the above is true,
the trumpeted "face masks don`t hinder breathing" headlines
that abound (see further below) are lies at face value, since even a
Kleenex hinders breathing, while otherwise they are misleading, for
even if oxygen levels do not decrease with the use of masks, past
studies find it takes more work for the body to deal with the
impairment of breathing fresh air.
Thus any mask does indeed "hinder" breathing, especially the breathing of fresh air and oxygen, even if (as the test at issue claims) not necessarily changing the amount of O2 or CO2 in the blood during the period of testing.
And, among other issues, N95 masks
are also found to have a detrimental effect on nasal resistance after
removal.
Note that I am not saying that masks are not effective in reducing viral transmission and the need for such among the ages and unfit and unhealthy inside, which is common sense, but I oppose the extremes this has led to, from required masking whenever outside to even advocating two or three masks.
People should get outside more, and healthy and fit persons should be able to work and play together (if the get Covid-19, such almost always recover and then have a lasting effective immune repose to reinfection), while the lack of fitness and health (42% Americans obese, 73% overall are overweight, 45% age 18 and older estimated to have high blood pressure) is actually the real cause behind so many Covid-assigned deaths (it is not the extra load in a car that usually causes its failure but it underlying problems). And which pandemic - and the extreme response to it - is a judgment upon a nation that has increasingly forsaken God and hearkened unto lies (see ARE YOU SAVED OR LOST? ).
Evaluation of N95 Respirator Use with a Surgical Mask Cover ... academic.oup.com › annweh › article by EJ Sinkule · 2013 · Cited by 47 — breathing resistance, effects from using N95 respirators, extending N95 ... dizziness, perspiration, and short-term memory loss have been reported (Sayers et al
The differences in inhaled gas concentrations in FFR+SM and FFR-only were significant, especially at lower levels of energy expenditure. The orientation of the SM on the FFR may have a significant effect on the inhaled breathing quality and breathing resistance, although the measurable inhalation and exhalation pressures caused by SM [surgical mask cover ] over FFR [ N95 filtering facepiece respirators] for healthcare users probably will be imperceptible at lower activity levels.
Previous studies have reported elevated concentrations of inhaled carbon dioxide (CO2) and decreased concentrations of inhaled oxygen (O2) associated with wearing FFRs (Sinkule et al., 2003). ..
The increased inhaled CO2 concentrations and decreased inhaled O2 concentrations within the breathing zone of negative-pressure air-purifying respirators, including FFRs, are directly related to dead space.
The effects of wearing FFRs and other types of respiratory protection have been widely studied using a variety of measurement methods (Li et al., 2005; Radonovich et al., 2009; Roberge et al., 2010). Some of these investigations have been quantitative (e.g., levels of inhaled CO2), qualitative (e.g., levels of fatigue), or can reflect characteristics that range from inconvenient (e.g., decreased levels of comfort) to potentially hazardous (e.g., decreased inhaled levels of O2). The physiological effects of breathing elevated inhaled CO2 may include changes in visual performance (Yang et al., 1997), modified exercise endurance (Raven et al., 1979), headaches and dyspnea (Raven et al., 1979). The psychological effects include decreased reasoning and alertness, and increased irritability (Sayers et al., 1987); with CO2 at 7–7.5%, severe dyspnea, headache, dizziness, perspiration, and short-term memory loss have been reported (Sayers et al., 1987; Compressed Gas Association, 1999).
Subjects performing physical activity while breathing decreased O2 concentrations (17%) produced higher levels of lactic acid accumulation at lower levels of energy expenditure as compared with normal O2 concentrations (21%), in addition to achieving lower levels of peak exercise performance (Hogan et al., 1983). Increased breathing resistance with respirators has been identified as the cause of respiratory fatigue and impaired physical work capacity, a shift to anaerobic metabolism from an increased rate of O2 debt; and, early exhaustion at lighter workloads....
In a field study, smaller healthcare workers (e.g. women) were more probable to experience intolerance for wearing FFRs before the end of the shift (Radonovich et al., 2009)...
. Other NIOSH research has indicated significant elevated inhaled CO2 associated with various respirators. Sinkule et al. (2003) ..
Using the same six levels of energy expenditure as the present investigation, FFRs (type was not stratified) produced the highest levels of average inhaled CO2 concentrations and lowest average inhaled O2 concentrations for all levels of energy expenditure as compared with all other respiratory protective devices examined...
At levels of energy expenditure of 1.5 l·min−1 or lower, most average inhaled CO2 concentrations appeared above 2.0% for all FFRs and more so at the lowest level of energy expenditure (rest). The recognizable effect of inhaled CO2 is the stimulating action upon respiration, i.e. respiratory removal of CO2 occurs through the increase in ventilation rate. Respiratory rate, tidal volume, and alveolar CO2 become elevated with inhaled CO2 concentrations above ambient (Schneider and Truesdale, 1922; Consolazio et al., 1947; Patterson et al., 1955). These physiological responses occur to compensate for abnormal diffusion of CO2 from the blood, due to a decrease in the ratio of alveolar to capillary CO2 (Schulte, 1964).
In addition to the increased rate and depth of breathing, cardiac output will increase to compensate for the additional CO2 (Schulte, 1964). While inhaling 1–2% CO2 for 17–32min, slight increases have been reported in systolic and diastolic blood pressures (Schneider and Truesdale, 1922). Exposures of increased inhaled CO2 between 2 and 3% have been known to produce sweating, headache, and dyspnea for some subjects at rest after several hours (Schneider and Truesdale, 1922). If inhaled CO2 concentrations are between 4 and 5%, dyspnea can occur within several minutes and increased blood pressure, dizziness, and headache can occur within 15–32min (Schneider and Truesdale, 1922; Patterson et al., 1955; Schulte, 1964).
If inhaled CO2 exposures are at 5%, mental depression may occur within several hours (Consolazio et al., 1947; Schulte, 1964). As noted in several of these studies, headaches have been reported at inhaled CO2 concentrations similar to those found in this investigation. This is consistent with one study which found that 37% of healthcare workers surveyed reported headaches following FFR use (Lim et al., 2006).
A striking unanticipated finding among the horizontal flat-fold FFRs was a reduction in the average inhaled CO2 concentration when an SM was applied as an additional layer of protection at graphic of 1.0 and 1.5 l·min−1 (Table 3)...
Like the unanticipated change that occurred among the horizontal flat-fold FFRs, where a reduction in the average inhaled CO2 concentration was observed when an SM was applied as an additional layer of protection at graphic of 1.0 l·min−1 and 1.5 l·min−1, an increase in the average inhaled O2 concentration also occurred for this select subset of FFRs....
The average inhaled CO2 concentrations were lower (P < 0.05) among horizontal flat-fold FFRs with SM as compared with horizontal flat-fold FFRs alone at V.O2 of 1.0 l·min−1 and 1.5 l·min−1
[Now note the summary conclusion:]
Results: Generally, concentrations of average inhaled CO2 decreased and average inhaled O2 increased with increasing O2 consumption for FFR+SM and FFR-only. For most work rates, peak inhalation and exhalation pressures were statistically higher in FFR+SM as compared with FFR-only. The type of FFR and the presence of exhalation valves (EVs) had significant effects on average inhaled CO2, average inhaled O2, and breathing pressures. The evidence suggests that placement of an SM on one type of FFR improved inhaled breathing gas concentrations over the FFR without SM; the placement of an SM over an FFR+EV probably will prevent the EV from opening, regardless of activity intensity; and, at lower levels of energy expenditure, EVs in FFR do not open either with or without an SM. (https://academic.oup.com/annweh/article/57/3/384/230992)
[Basically what this is saying it the more restrictive masking one wears - and the flatter it is, reducing dead space, then the less inhaled CO2 [carbon dioxide] occurs and increasing O2 [oxygen] consumption. This is despite the study showing that average inhaled CO2 concentrations increased with the use of FFRs, and common sense tells us that a mask restricts inhalation of oxygen and increases inhalation of carbon dioxide then. Though a flat mask would be better than a cup type.
The only way then that concentrations of average inhaled CO2 can decrease and average inhaled O2increase is a result of the body working harder, as the study says, "respiratory removal of CO2 occurs through the increase in ventilation rate...In addition to the increased rate and depth of breathing, cardiac output will increase to compensate for the additional CO2 " and with slight increases in systolic and diastolic blood pressures.
And that "At levels of energy expenditure of 1.5 l·min−1 or lower, most average inhaled CO2 concentrations appeared above 2.0% for all FFRs and more so at the lowest level of energy expenditure (rest)... Exposures of increased inhaled CO2 between 2 and 3% have been known to produce sweating, headache, and dyspnea for some subjects at rest after several hours." "one study which found that 37% of healthcare workers surveyed reported headaches following FFR use."
More trumpeted "face masks don`t hinder breathing" headlines below, with excerpts of other research cited in response.
Researchers find face masks don`t hinder breathing during . .. A new University of Saskatchewan (USask) study has found that exercise performance and blood and muscle oxygen levels are not affected for healthy individuals wearing a face mask during strenuous workouts... the study, published Nov. 3 in the research journal International Journal of Environmental Research and Public Health...indicate that people can wear face masks during intense exercise with no detrimental effects on performance and minimal impact on blood and muscle oxygenation..
Researchers find face masks don't hinder breathing during ...
Face Masks Don't Hinder Breathing During Exercise, USask ... new University of Saskatchewan (USask) study has found that exercise performance and blood and muscle oxygen levels are not affected for healthy individuals wearing a face mask during strenuous workouts.
Wearing Face Masks During Exercise Don't Hinder Breathing . ..
There are two basic principles relevant to respirator use:
Protective masks and clothing generally shorten the time that a particular activity level can be sustained...
1. Work cannot usually be performed as long or as hard while wearing a respirator compared to when respirators are not worn. Wearing protective clothing plus respirators makes this situation even worse. Either more time must be allowed for a particular task or more workers must be assigned to the same task.
There is a great deal of wearer variability. Some wearers can tolerate respirator high inspiratory or expiratory resistance or pressure levels, while others cannot. Some wearers are much more anxious about wearing respirators than others. Some wearers can tolerate hot, humid conditions inside respirators, whereas others cannot. Because of this variability, each wearer must be treated as an individual...
Buffering the blood against lactic acid formation during anaerobic respiration produces extra carbon dioxide that can be exhaled. This extra carbon dioxide acts as a respiratory stimulant that leads to hyperventilation, or harder and deeper breathing.
All these processes proceed each time a person moves actively. They are much more efficient for younger people than for older people. Maximum oxygen uptake for 20 year olds is about 2.5 l per minute, but declines nearly linearly to about 1.7 l per minute at age 65 [17]. Well-trained individuals can have maximum oxygen uptakes up to twice these values. In addition, the maximum oxygen debt that can be incurred by an individual declines with age and is also affected by training [12].
Metabolic responses during exercise, and especially during emergencies, are modified by the release of the adrenal hormones adrenalin (epinephrine) and cortisol. These hormones increase metabolic rate, increase the rate and force of heart contractions, enhance the availability of blood glucose, reroute blood from the gut to the muscles, and mobilize the nervous system. The combined actions of these hormones can affect physical, emotional, and cognitive functions.
Muscular strength declines with age, making task performance less efficient when more muscles must be recruited to perform a task. Muscular power can be restored relatively rapidly with strength training. Drugs and medicines can also affect body metabolism, as can illness. Products of cigarette smoking and caffeine also affect metabolic rate [65]...
Inhaled air is oxygen rich and carbon dioxide poor. Exhaled air is oxygen poor and carbon dioxide rich. Because air flow in the airways is bidirectional, the first air that reaches the alveoli is the same as the last air that was exhaled during the previous exhalation. This is an indication of the dead volume of the lung, or that volume that stores carbon dioxide from the previous breath. Dead volume for average adults is about 180 ml, but dead volume of respirators can add to the effective dead volume of the respiratory system and affect performance [52].
Inhaled air is oxygen rich and carbon dioxide poor. Exhaled air is oxygen poor and carbon dioxide rich. Because air flow in the airways is bidirectional, the first air that reaches the alveoli is the same as the last air that was exhaled during the previous exhalation. This is an indication of the dead volume of the lung, or that volume that stores carbon dioxide from the previous breath. Dead volume for average adults is about 180 ml, but dead volume of respirators can add to the effective dead volume of the respiratory system and affect performance [52].
Carbon dioxide is a very powerful respiratory stimulant. Increasing the concentration of inhaled carbon dioxide increases lung ventilation much more than does oxygen deficiency. Metabolically-produced carbon dioxide is even more effective than inhaled carbon dioxide at stimulating respiration. This is critical for additions of external dead volume, which transforms exhaled metabolic carbon dioxide into carbon dioxide inhaled during the next breath. Once the anaerobic threshold is reached, blood buffering makes it appear that metabolic carbon dioxide increases, and respiration is stimulated so much that lung ventilation increases dramatically as work rate intensifies... (Fig. 3).
Respiration does not usually limit work performances of healthy individuals, but respiration can limit work time when respirators are worn [44, 51]. The most important function of the respiratory system is the removal of carbon dioxide from the body. Adjustments during exercise increase depth and rate of breathing in order to expel this gaseous end-product of aerobic metabolism. Exercise exhalation becomes actively supported by the abdominal muscles, spewing carbon dioxide at faster rates as exercise intensifies. At some point, the rate at which air can be exhaled becomes limited by the distensible airways in the respiratory system. Any further increase in abdominal pressure cannot increase expiratory flow rate.
Thus, for normal individuals, there is a limitation when exhalation time decreases to one-half second or so [22, 24]. Carbon dioxide cannot be expelled any faster than this minimum exhalation time allows. Additionally, some people suffer from respiratory impairments that limit maximum pressures that can be generated by the respiratory muscles when they breathe through external resistances or against external pressures [59]. Respiratory-limited work usually lasts 5–20 min.
Respirator effects...
Extra inspiratory resistance [38] promotes hypoventilation [2–4, 6, 16, 39, 50, 60] of the wearer (lower volumes of air breathed and smaller amounts of oxygen used). This can result in an earlier transition from aerobic (using oxygen) to anaerobic (no oxygen needed) respiration [10, 32], and faster progress toward the maximum tolerance for exercise (maximum oxygen debt).
Facepiece dead volume accumulates exhaled carbon dioxide in the voids between the respirator and the face and returns it to the respiratory system during the next inspiration. This carbon dioxide then acts as a respiratory stimulant. Because carbon dioxide is a psychoactive gas, dead volume may also produce discomfort and a performance decrement at low-intensity work. A typical value for full-facepiece APR [Air-purifying respirators] respirator dead volume is 350 mL. Such a dead volume is expected to reduce performance time by 19 % at a work rate of 80 to 85 % of maximum oxygen uptake [52].
Intense exercise above the anaerobic threshold uses more air than does moderate exercise, and because very intense exercise metabolism has a higher anaerobic component than does moderate exercise, the air that is used is not consumed as efficiently as it is at lower intensity [43]. The net result is that SCBA tank air depletes much more rapidly at high work rates than at moderate work rates...
Use of respirators in hot conditions leads to several difficulties. Discomfort has been related to facial temperatures inside the facepiece. Facial skin temperatures are more important for comfort than skin temperatures in other parts of the body...
There can be a considerable amount of discomfort associated with wearing respirators, gloves, boots, and protective suits. Those individuals prone to anxious feelings may have their anxieties made worse during periods of inactivity. Anxieties are the most important threat to protective equipment wear, and extremely anxious people should not be asked to wear respirators, if possible.
Studies have shown that anxiety level is a very reliable indicator of difficulty encountered while wearing a respirator. Extremely anxious individuals do not perform for as long or at the same work rate as low-anxiety wearers [28, 61].
For those who can tolerate the discomfort and claustrophobic feelings when wearing respirators, there will nonetheless be physical effects of prolonged wear [54, 57]...
Physiological limits to long term exercise deal with limitations on blood glucose levels and muscle glycogen stores. Dehydration or electrolyte depletion may occur [17]. These are difficult to quantify for any individual, but frequent eating and drinking can deter them from happening [30]. Psychological effects are also important. Feelings of fatigue are common, as are feelings of anxiety and discontent [54, 57]...
Rest times are also dependent on the intensity of the task and the maximum oxygen uptake of the individual [17]. In general, the more intense the work, the longer will be the recovery time, but the relationship is nonlinear. A task that can be performed for an hour requires at least a 10 min rest period. More intense tasks (with shorter performance times) require longer rest times.
Face Masks Do Not Impair Breathing for People with COPD ...
Wait, kids & people with breathing problems should NOT wear ... www.sfgate.com › california-wildfires › article › n95-m... Nov 16, 2018
Paul Chinn/The Chronicle.. People with breathing problems (ironically) are discouraged from wearing a mask without getting a doctor's recommendation. In one statement, CA Dept. of Public Health writes, "Wearing a mask may actually be harmful to some people with heart or lung disease because it can make the lungs work harder to breathe." A doctor will look at the patient's condition, ability to draw in air, and guide them on how to make it fit right if recommended.
Small children should not wear masks. California's Dept. of Public Health points out, "Children should not wear these masks – they do not fit properly and can impede breathing. If the air quality is poor enough that a child requires a mask, the child should remain indoors, in a safe place, and evacuation should be considered."
Recordings of 429 infants were included (median (IQR) gestational age of 28+6 (27+1-30+4) weeks). In 368/429 (86%) infants breathing was observed before application of the face mask and 197/368 (54%) of these infants stopped breathing following application of the face mask. Apnoea occurred at a median of 5 (3–17) seconds after application of the face mask with a duration of 28 (22–34) seconds of the first minute. In a logistic regression model, the occurrence of apnoea after face mask application was inversely associated with gestational age (OR = 1.424 (1.281–1.583), p < 0.001). Infants who stopped breathing had a significantly lower heart rate 82 (66–123) vs 134 (97–151) bpm, p < 0.001) and oxygen saturation (49% (33–59) vs 66% (50–82), p < 0.001) over the first minute after face mask application, compared to infants who continued breathing.
Wearing Face Masks During Exercise Won't Hinder Breathing ... The Saskatchewan study , published Nov. 3, 2020, in the research journal International Journal of Environmental Research and Public Health, evaluated the use of a three-layer cloth mask.
Despite the protective function, the effects of mask wearing on respiratory microclimate, respiratory functions and individual sensations are important as well. It was reported that facemask caused less subjective discomfort feeling, lower perception of humidity, heat and breathe resistance than N95 respirator. 10 Wearing masks could affect the wearer’s whole body thermal sensation. 11
Long- duration wearing of N95 respirator may induce physiological stress on the wearer, making regular tasks more challenging, and causes headaches among healthcare providers. 12 These effects might be due to the respiratory microclimate change surrounding the masks. For example, wearing surgical facemask and N95 respirator was found to induce different temperatures and humidification on outer and inner mask surfaces 10. These differences are attributed to different material properties of the masks, such as lower air permeability and water vapor permeability in N95 respirator. 13 While the N95 respirator would physically increase the nasal resistance more than 100% compared to the condition without respirator, 14 the presence of exhaled moisture or concurrent wearing of surgical facemask has limited effect on breathing resistance.... 15,16
Conclusion In conclusion, there is an increase of nasal resistance upon removal of N95 respirator and surgical facemask after 3hours wearing which potentially due to nasal physiological changes, instead of the size of nasal airways. The nasal resistance was not recovered even after 1.5hours removal of respirator/facemask. In addition, the N95 respirator caused higher post-wearing nasal resistance than surgical facemask with different recovery routines.
Working Out With a Face Mask Doesn't Hinder Breathing ...Researchers measured oxygen levels in the blood and muscles of 14 physically active and healthy participants during an aerobic fitness test...The data showed no evidence that breathing was hindered during the workout.
Face Masks Don't Inhibit Breathing or Performance During ...
Our study revealed a decrease in the oxygen saturation of arterial pulsations (SpO2) and a slight increase in pulse rates compared to preoperative values in all surgeon groups. The decrease was more prominent in the surgeons aged over 35.. Considering our findings, pulse rates of the surgeon's increase and SpO2 decrease after the first hour. This early change in SpO2 may be either due to the facial mask or the operational stress. Since a very small decrease in saturation at this level, reflects a large decrease in PaO2, our findings may have a clinical value for the health workers and the surgeons.
