Effects of an external nasal dilator on the work of breathing during exercise

Improvement of the aerobic performance in endurance athletes presenting nasal valve compromise with the application of an internal nasal dilator

PURPOSE

We investigated the effects of an internal nasal dilator on nasal airflow and cardio-respiratory capacity in adult endurance athletes, while performing controlled exhaustive physical exercise.

METHODS

Prospective observational study. Participants were 38 adult endurance athletes, 23 with and 15 without nasal valve compromise. Nasal patency was objectively evaluated with anterior rhinomanometry, acoustic rhinometry and peak nasal inspiratory flow (PNIF). Maximum oxygen uptake (VO2max), maximum pulmonary ventilation, time to exhaustion and total time of nasal respiration were recorded during a submaximal treadmill test. Dyspnea intensity and fatigue perception were evaluated using a labeled visual analog scale. All assessments were performed with and without the application of the internal nasal dilator.

RESULTS

All the parameters related to aerobic capacity were significantly reduced in the group of athletes with nasal valve compromise (p. <0.05 for all variables). The internal nasal dilator improved statistically significantly the nasal patency (p. <0.001), VO2max and aerobic performance and self-rating of dyspnea and fatigue (p. <0.05 for all parameters) only in athletes with nasal obstruction. PNIF correlated significantly with VO2max (rho = 0.4, p. <0.05).

CONCLUSIONS

Internal nasal dilation improves nasal patency and aerobic performance during submaximal exercise in adult endurance athletes with nasal obstruction symptoms due to nasal valve compromise.

Distinguishing science from pseudoscience in commercial respiratory interventions: an evidence-based guide for health and exercise professionals

Respiratory function has become a global health priority. Not only is chronic respiratory disease a leading cause of worldwide morbidity and mortality, but the COVID-19 pandemic has heightened attention on respiratory health and the means of enhancing it. Subsequently, and inevitably, the respiratory system has become a target of the multi-trillion-dollar health and wellness industry. Numerous commercial, respiratory-related interventions are now coupled to therapeutic and/or ergogenic claims that vary in their plausibility: from the reasonable to the absurd. Moreover, legitimate and illegitimate claims are often conflated in a wellness space that lacks regulation. The abundance of interventions, the range of potential therapeutic targets in the respiratory system, and the wealth of research that varies in quality, all confound the ability for health and exercise professionals to make informed risk-to-benefit assessments with their patients and clients. This review focuses on numerous commercial interventions that purport to improve respiratory health, including nasal dilators, nasal breathing, and systematized breathing interventions (such as pursed-lips breathing), respiratory muscle training, canned oxygen, nutritional supplements, and inhaled L-menthol. For each intervention we describe the premise, examine the plausibility, and systematically contrast commercial claims against the published literature. The overarching aim is to assist health and exercise professionals to distinguish science from pseudoscience and make pragmatic and safe risk-to-benefit decisions.

Safety and Efficacy of External Nasal Dilator Strips with N95 Respirator Masks by Emergency Department Personnel

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has prompted increased use of personal protective equipment (PPE) to maintain the health and safety of caregivers. This study was conducted in 2020 to evaluate the safety and efficacy of external nasal dilator strips (ENDS) coupled with N95 respirators in a sample of community hospital emergency department personnel.

METHODS

After obtaining written consent, the authors tested participants' response to exercise (i.e., walking up 10 flights of stairs) while wearing an N95 respirator, both with and without an ENDS. The authors measured participants' heart rate and respiratory effort responses over four minutes following their exercise trial. A convenience sample of these personnel also repeated their respirator fit testing while wearing an ENDS with the N95 style they had previously been fitted for.

RESULTS

A total of N = 50 participants were enrolled. Peak heart rate while wearing an ENDS was 125 beats per minute (BPM) with the ENDS versus 130 BPM without (p = 0.21). The Borg Exertion Score while wearing an ENDS peaked at 13 with the ENDS versus 14 without (p = 0.08). However, when subjects were surveyed before and after the trial upon whether they would consider using an ENDS beneath their N95 using a scale of 1-5, their interest in this significantly increased (p = 0.004). Four of the 13 (31%) participants who completed repeated fit testing while wearing the ENDS beneath their N95 respirator failed the repeat testing.

CONCLUSIONS

These results first suggest that a sizable proportion of ED personnel may fail N95 fit testing while wearing an ENDS beneath the N95 mask for which they had been previously fitted. Although providers' subjective interest in use of ENDS increased, these results also demonstrate that use of an ENDS beneath an N95 respirator may not significantly increase exercise tolerance.

A comparison of methods used to quantify the work of breathing during exercise

The mechanical work of breathing (Wb) is an insightful tool used to assess respiratory mechanics during exercise. There are several different methods used to calculate the Wb, however, each approach having its own distinct advantages/disadvantages. To date, a comprehensive assessment of the differences in the components of Wb between these methods is lacking. We therefore sought to compare the values of Wb during graded exercise as determined via the four most popular methods: 1) pressure-volume integration; 2) the Hedstrand diagram; 3) the Otis diagram; and the 4) modified Campbell diagram. Forty-two participants (30 ± 15 yr; 16 women) performed graded cycling to volitional exhaustion. Esophageal pressure-volume loops were obtained throughout exercise. These data were used to calculate the total Wb and, where possible, its subcomponents of inspiratory and expiratory, resistive and elastic Wb, using each of the four methods. Our results demonstrate that the components of Wb were indeed different between methods across the minute ventilations engendered by graded exercise. Importantly, however, no systematic pattern in these differences could be observed. Our findings indicate that the values of Wb obtained during exercise are uniquely determined by the specific method chosen to compute its value-no two methods yield identical results. Because there is currently no "gold-standard" for measuring the Wb, it is emphasized that future investigators be cognizant of the limitations incurred by their chosen method, such that observations made by others may be interpreted with greater context, and transparency.NEW & NOTEWORTHY The measurement of the work of breathing (Wb) during exercise provides us with deep insights into respiratory (patho)physiology, and sheds light on the putative factors which lead to respiratory muscle fatigue. There are 4 popular methods available to determine the Wb. Our study demonstrates that no two of these methods produce identical values of Wb during exercise. This paper also discusses the practical and theoretical limitations of each method.

Effects of the Turbine™ on Ventilatory and Sensory Responses to Incremental Cycling

INTRODUCTION

The Turbine™ is a nasal dilator marketed to athletes to increase airflow, which may serve to reduce dyspnea and improve exercise performance, presumably via reductions in the work of breathing (WOB). However, the unpublished data supporting these claims were collected in individuals at rest that were exclusively nasal breathing. These data are not indicative of how the device influences breathing during exercise at higher ventilations when a larger proportion of breathing is through the mouth. Accordingly, the purpose of this study was to empirically test the efficacy of the Turbine™ during exercise. We hypothesized that the Turbine™ would modestly reduce the WOB at rest and very low exercise intensities but would have no effect on the WOB at moderate to high exercise intensities.

METHODS

We conducted a randomized crossover study in young, healthy individuals (7M:1F; age = 27 ± 5 yr) with normal lung function. Each participant performed two incremental cycle exercise tests to exhaustion with the Turbine™ device or under a sham control condition. For the sham control condition, participants were told they were breathing a low-density gas to reduce the WOB, but they were actually breathing room air. The WOB was determined through the integration of ensemble averaged esophageal pressure-volume loops. Standard cardiorespiratory measures were recorded using a commercially available metabolic cart. Dyspnea was assessed throughout exercise using the 0-10 Borg scale.

RESULTS

Peak V˙O2 and work rate were not different between conditions (P = 0.70 and P = 0.35, respectively). In addition, there was no interaction or main effect of condition on dyspnea, ventilation, or WOB throughout the exercise (all P > 0.05).

CONCLUSION

These findings suggest that the Turbine™ does not reduce the WOB and has no effect on dyspnea or exercise capacity.

Nasal function and cardio-respiratory capacity of adolescent with external nasal dilator

BACKGROUND

the external nasal dilator (END) has been employed for the purpose of aiding sporting performance. The objective of this study was to evaluate nasal function and cardio-respiratory capacity in healthy adolescent athletes using the END.

METHODS

double-blind, crossover clinical trial in which adolescents were evaluated while using the experimental and placebo END during physical exercise. Values for peak nasal inspiratory flow (PNIF), nasal resistance (NR) and maximal oxygen uptake (VO₂max) were obtained in randomized order. Additionally, the rating of perceived exertion (RPE) after the cardio-respiratory test was assessed.

RESULTS

for the 71 adolescents evaluated, the use of the experimental END, compared to the placebo, produced a significant improvement in values of PNIF (177.4 ± 20.9 L/min and 172.8 ± 20.2 L/min) (p = 0.020), NR (0.24 ± 0.16 and 0.27 ± 0.16) (p = 0.007), VO₂max. (39.5 ± 5.2 mL/kg. min-1 and 37.5 ± 5.2 mL/kg. min-1) (p < 0.001) and RPE (6.0 ± 2.2 and 5.5 ± 2.4) (p < 0.001), respectively.

CONCLUSION

the END reduced NR, increased PNIF and improved VO₂max. In addition, it improved RPE after the maximal cardio-respiratory test. The use of the END can significantly improve nasal function, increase cardio-respiratory capacity and reduce rating of perceived exertion during a maximal test involving adolescent athletes.

Does the external nasal dilator strip help in sports activity? A systematic review and meta-analysis

BACKGROUND

Numerous studies have shown that the external nasal dilator (END) increases the cross sectional area of the nasal valve, thereby reducing nasal resistance, transnasal inspiratory pressure, stabilizing the lateral nasal vestibule, and preventing its collapse during final inhalation.

OBJECTIVES

Our objective was to carry out a systematic review of the literature and meta-analysis on the effects of the END during physical exercise.

METHODS

After selecting articles in the PubMed, Cochrane Library and EMBASE databases, 624 studies were identified. However, after applying the inclusion and exclusion criteria, 19 articles were considered eligible for review.

RESULTS

Those studies included in the meta-analysis, the maximal oxygen uptake (VO₂max.) outcome was assessed in 168 participants in which no statistically significant difference was found, MD (95% CI) = 0.86 [- 0.43, 2.15], p = 0.19, and I² = 0%. The heart rate (HR) outcome was assessed in 138 participants in which no statistically significant difference was found, MD (95% CI) = 0.02 [- 3.19, 3.22], p = 0.99, and I² = 0%. The rating of perceived exertion (RPE) outcome was assessed in 92 participants in which no statistically significant difference was found, MD (95% CI) =  - 0.12 [- 0.52, 0.28], p = 0.56, and I² = 27%.

CONCLUSIONS

The external nasal dilator strip showed no improvement in VO₂max., HR and RPE outcomes in healthy individuals during exercise.

Effects of boil-and-bite and custom-fit mouthguards on cardiorespiratory responses to aerobic exercise

BACKGROUND

The physiological responses to exercise when wearing a mouthguard may depend on the type of mouthguard and the facemask used during exercise testing. This study compared the effects of boil-and-bite (BBMG) and custom-fit (CFMG) protective mouthguards on the metabolic, cardiovascular, and ventilatory responses to exercise when wearing a facemask that allowed mouth only or nose and mouth breathing.

METHODS

Twenty-four male college Lacrosse players (mean = 20±2 years) participated in this study. Each participant performed six submaximal exercise tests while wearing one of two facemasks (mouth only breathing and nose and mouth breathing) and one of three mouthguard conditions (BBMG, CFMG, no mouthguard). Steady-state VO<inf>2</inf>, rate of perceived exertion (RPE), tidal volume (V<inf>T</inf>), respiratory rate (RR), minute ventilation (VE), and heart rate (HR) values were measured at intensities of exercise corresponding to 60% and 80% of VO<inf>2peak</inf>.

RESULTS

There were significant main effects for facemask type (mouth only breathing vs. nose and mouth breathing) for VO<inf>2</inf>, VE, V<inf>T</inf>, and RPE. There were significant main effects for mouthguard (BBMG, CFMG, and no mouthguard) for VO<inf>2</inf>, VE, RR, and HR. There were also multiple significant interactions. All of the differences in VO<inf>2</inf>, HR, VE, V<inf>T</inf>, RR, and RPE, although statistically significant, were negligible and of little practical significance.

CONCLUSIONS

The physiological responses to wearing a BBMG or CFMG are of little practical significance so they can be worn to reduce the likelihood of dental injuries without impeding metabolic, cardiovascular and ventilatory responses.

The Effects of an External Nasal Dilator on Labor

Background

The aim of this study was to assess the effect of an external nasal dilator on several variables characterizing labor in both mother and fetus.

Methods

One hundred and fifty primigravida women in active labor were randomized to wear, throughout labor, either a dilator spring-loaded nasal strip or a placebo device. Data were obtained during labor and compared between the groups. After delivery, the satisfaction rate was assessed.

Results

No differences were found between the study and the control group regarding rate of induction or augmentation of labor as well as Montevideo units reached, frequency of rupture of membranes, duration of the active phase and second stage of labor, usage of epidural analgesia, normal fetal heart pattern, meconium-stained amniotic fluid, and neonatal well being. Length of maternal and neonatal hospitalization also did not differ between the groups. Satisfaction rate was significantly higher in parturient women wearing nasal strips with a dilator spring than in parturient women wearing a placebo spring (P < 0.0001).

Conclusion

Nasal strips do not change the course but ameliorate the quality of labor by improving the ease of breathing. Nasal dilators sustain the respiratory effort associated with the long process of labor and may control the switch from nasal to oronasal breathing during delivery.

Effect of the external nasal dilator on adolescent athleteswith and without allergic rhinitis

OBJECTIVES

The ability to effectively breathe through the nose is an important component of physical exercise. The goal of this study is to evaluate the effect of the external nasal dilator (END) on healthy adolescent athletes and those with allergic rhinitis.

METHODS

Clinical trial, double-blind, crossover, in which we evaluated healthy adolescent athletes with allergic rhinitis, using experimental and placebo ENDs, submitted to a maximum cardio-respiratory test in randomized order. Predicted values for peak nasal inspiratory flow (PNIF%) and nasal resistance (NR) were obtained, and the rating of perceived exertion (RPE) was also assessed after the race test.

RESULTS

65 adolescents participated in the study, 30 of whom had allergic rhinitis. The use of experimental ENDs demonstrated a statistically significant improvement in peak nasal inspiratory flow values (predicted %), nasal resistance, maximal oxygen uptake value (VO₂Max.) and rating of perceived exertion, both in the healthy group and the one with allergic rhinitis.

CONCLUSION

Results suggested that END reduces nasal resistance, improves maximal oxygen uptake and rating of perceived exertion after a maximum cardio-respiratory test on healthy adolescents and those with allergic rhinitis.

Neither internal nor external nasal dilation improves cycling 20-km time trial performance

OBJECTIVES

Research is equivocal regarding endurance performance benefits of external nasal dilators, and currently research focusing on internal nasal dilators is non-existent. Both devices are used within competitive cycling. This study examined the influence of external and internal nasal dilation on cycling economy of motion and 20-km time trial performance.

DESIGN

The study utilized a randomized, counterbalanced cross-over design.

METHODS

Fifteen trained cyclists completed three exercise sessions consisting of a 15min standardized warm up and 20-km cycling time trial while wearing either a Breathe Right^® external nasal dilator, Turbine^® internal nasal dilator or no device (control). During the warm up, heart rate, ratings of perceived exertion and dyspnea and expired gases were collected. During the time trial, heart rate, perceived exertion, and dyspnea were collected at 4-km intervals and mean 20-km power output was recorded.

RESULTS

No differences were observed for mean 20-km power output between the internal (270±45W) or external dilator (271±44W) and control (272±44W). No differences in the economy of motion were observed throughout the 15-min warm up between conditions.

CONCLUSIONS

The Turbine^® and Breathe Right^® nasal dilators are ineffective at enhancing 20-km cycling time trial performance.

External nasal dilators: definition, background, and current uses

Our goal was to revise the literature about external nasal dilators (ENDs) as to their definition, history, and current uses. We reviewed journals in the PubMed and MEDLINE databases. The current uses hereby presented and discussed are physical exercise, nasal congestion and sleep, snoring, pregnancy, cancer, and healthy individuals. Numerous studies have shown that ENDs increase the cross-sectional area of the nasal valve, reducing nasal resistance and transnasal inspiratory pressure and stabilizing the lateral nasal vestibule, avoiding its collapse during final inspiration. These effects also facilitate breathing and are beneficial to patients with nasal obstruction. Furthermore, END use is simple, noninvasive, painless, affordable, and bears minimum risk to the user. Most studies have limited sample size and are mainly focused on physical exercise. In conclusion, ENDs seem useful, so further studies involving potential effects on the performance of physical tests and improvements in sleep quality are necessary, especially in children and teenagers.

Evaluation of the effectiveness of the external nasal dilator strip in adolescent athletes: a randomized trial

OBJECTIVES

Evaluate the cardio-respiratory capacity (VO₂max.) and peak nasal inspiratory flow (PNIF) of healthy adolescent athletes with experimental and placebo external nasal dilator strips (ENDS).

METHODS

48 healthy adolescent athletes between the ages of 11 and 15 were evaluated and submitted to a cardio-respiratory 1000 m race in randomized order. The participants had peak nasal inspiratory flow (PNIF) values measured using the In-check-inspiratory flow meter. Dyspnea intensity was evaluated after a 1000 m test race using a labeled visual analog scale for dyspnea.

RESULTS

In relation to VO2max., when the participants used the experimental ENDS, significantly higher means were noted than when the placebo was used (53.0 ± 4.2 mL/kg min(-1) and 51.2 ± 5.5 mL/kg min(-1), respectively) (p<0.05). In relation to PNIF, there was a statistically significant difference between the experimental and placebo ENDS result, that being, 123 ± 38 L/min and 116 ± 38 L/min, respectively (p<0.05). The dyspnea perceived by the participants was representatively lesser in the experimental ENDS condition compared to the placebo after the cardio-respiratory test (p<0.05).

CONCLUSIONS

The results suggest that the ENDS improve maximal oxygen uptake, nasal patency and respiratory effort in healthy adolescent athletes after submaximal exercise.

Are exhalation valves on N95 filtering facepiece respirators beneficial at low-moderate work rates: an overview

Exhalation valves (EVs) are touted as useful in dissipating humidity, heat, and carbon dioxide from the dead space of N95 filtering facepiece respirators and decreasing exhalation resistance, thereby making the respirator more comfortable and less physiologically demanding. Despite decades of use, there is limited research on the psychophysiological impact of EVs on the wearer at the current, low-moderate work rates of many workers. The available literature indicates that past and current EVs on the market decrease exhalation resistance to a variable degree and may improve dead space heat dissipation and, consequently, the temperature of the skin covered by the respirator. EVs have little substantial effect on dead space humidity, respiratory rate, heart rate, core temperature, speech intelligibility, or dead space oxygen and carbon dioxide levels at the aforementioned work rates. The studies also indicate that EVs may impact comfort and tolerance when N95 filtering facepiece respirators are worn for extended periods or at high work rates. Because comfort and tolerance impact respirator use compliance and, by extension, protection, more research into the psychophysiological impact of EVs on wearers and the development of new EVs tailored for low-moderate work rates are warranted.

The external nasal dilator: style over function?

This study examined the effects of an external nasal dilator (END) on sedentary and aerobically trained women using the blood lactate threshold as a measure of aerobic performance. Three groups of women (sedentary, pre-season, in-season) participated in the study: nine sedentary college students (age 19 +/- 1.0 y), eight pre-season college athletes (age 20 +/- 2.3 y), and six in-season college rowers (age 20 +/- 1.7 y). A two-way repeated-measures design was used with subjects in each group being exposed to both conditions (with END and without END). The first two groups performed two incremental exercise tests in random order on a cycle ergometer, and the third group performed the tests on a rowing ergometer. Participants in each group wore an END strip for only one of the tests. Venous blood was collected at rest, during the final 30 seconds of each stage, and 1 and 3 minutes into the recovery period for the determination of blood lactate concentration and identification of the blood lactate threshold. No significant differences (P = 0.05) were found in blood lactate concentration at the lactate threshold between conditions for either group (sedentary: with END 2.51 +/- 1.18 mmol x L(-1), without END 2.56 +/- 0.84 mmol x L(-1); pre-season: with END 2.93 +/- 0.97 mmol x L(-1), without END 2.81 +/- 1.15 mmol x L(-1); and in-season: with END 3.93 +/- 0.50 mmol x L(-1), without END 3.49 +/- 0.387 mmol x L(-1)). We conclude that (a) the END did not improve the lactate threshold in either sedentary or trained college-age women, and (b) the END did not result in lower blood lactate levels during moderate to high-intensity exercise in the three groups examined in this study.

Effects of an external nasal dilator strip (ENDS) compared to xylometazolin nasal spray

Nasal blockage is a common complaint in Family Practice. Decongestive nosedrops are frequently employed therapeutic measures. Due to a considerable risk of abuse and side effects, alternatives are wanted. The purpose of this study was to elucidate to what extent ENDS might represent an alternative to decongestive nose sprays (DNS). The effects of DNS (xylometazolin) and ENDS (BreatheRight) on subjective and objective nasal blockage were compared in 89 patients. Main outcome measures were recordings of nasal symptom scores on visual analogue scales (VAS), minimal cross-sectional areas (MCA) and nasal cavity volumes (NCV) as measured by acoustic rhinometry (AR), and peak nasal inspiratory flow (PNIF). ENDS significantly increased the MCA and the NCV in the anterior 0.0-3.0 cm of the nose compared to DNS, but had no effect on MCA from 3.0 to 5.4 cm behind the nostrils. In contrast to DNS, ENDS had no effect on the posterior NCV. ENDS and DNS gave comparable increase in nasal inspiratory flow as measured by PNIF, and in the subject's own experience of nasal obstruction. ENDS may represent an alternative to DNS as a measure against nasal blockage.

Inactivity, exercise, and visceral fat. STRRIDE: a randomized, controlled study of exercise intensity and amount

Despite the importance of randomized, dose-response studies for proper evaluation of effective clinical interventions, there have been no dose-response studies on the effects of exercise amount on abdominal obesity, a major risk factor for metabolic syndrome, diabetes, and cardiovascular disease. One hundred seventy-five sedentary, overweight men and women with mild to moderate dyslipidemia were randomly assigned to participate for 6 mo in a control group or for approximately 8 mo in one of three exercise groups: 1) low amount, moderate intensity, equivalent to walking 12 miles/wk (19.2 km) at 40-55% of peak oxygen consumption; 2) low amount, vigorous intensity, equivalent to jogging 12 miles/wk at 65-80% of peak oxygen consumption; or 3) high amount, vigorous intensity, equivalent to jogging 20 miles/wk (32.0 km). Computed tomography scans were analyzed for abdominal fat. Controls gained visceral fat (8.6 +/- 17.2%; P = 0.001). The equivalent of 11 miles of exercise per week, at either intensity, prevented significant accumulation of visceral fat. The highest amount of exercise resulted in decreased visceral (-6.9 +/- 20.8%; P = 0.038) and subcutaneous (-7.0 +/- 10.8%; P < 0.001) abdominal fat. Significant gains in visceral fat over only 6 mo emphasize the high cost of continued inactivity. A modest exercise program, consistent with recommendations from the Centers for Disease Control/American College of Sports Medicine (CDC/ACSM), prevented significant increases in visceral fat. Importantly, a modest increase over the CDC/ACSM exercise recommendations resulted in significant decreases in visceral, subcutaneous, and total abdominal fat without changes in caloric intake.

Effects of an external nasal dilator on athletic performance of male adolescents

This study examined the effect of an external nasal dilator strip (ENDS) on three field tests of maximal performance and monitored the rating of perceived breathing effort (RPBE). Thirty male Chinese students (age 15.2 +/- 1.6 yrs) performed three maximal field tests: (a) short-term anaerobic power (SAnP: 40-m sprint); (b) long-term anaerobic power (LAnP: shuttle sprint); and (c) peak aerobic performance (AeP: multistage 20-m shuttle run) under three conditions: ENDS, placebo, and control. Students were randomly placed into 6 groups using a fully counterbalanced single-blind design. No significant differences were seen between conditions in the anaerobic performances measured by SAnP and LAnP. However, the ENDS produced a significant improvement in peak aerobic performance (p = 0.037) compared to the control condition of 3.2% (95% CI= 6.2-0.2; Cohen effect size = 0.2), and also compared to the placebo condition (p = 0.018) of 2.9% (95% CI = 5.1-0.2; Cohen effect size =0.2). The ENDS condition also significantly reduced RPBE during the AeP and LAnP tests by an average of 5.5% and 3.8%, respectively. Wearing an external nasal dilator can significantly reduce breathing effort and improve peak aerobic performance during field tests involving maximal running.