Eight Weeks of High-Intensity Interval Training Using Elevation Mask May Improve Cardiorespiratory Fitness, Pulmonary Functions, and Hematological Variables in University Athletes

BACKGROUND

In the last two decades, high-altitude training (HAT) and elevation training masks (ETMs) have been widely used among athletes to enhance physical performance. However, few studies have examined the effect of wearing ETMs on physiological and hematological parameters in different sports.

AIMS

The present study aimed to investigate the impact of ETM use in athletes on several hematological and physiological indicators among cyclists, runners, and swimmers.

METHODS

The impact of wearing an ETM on lung function (LF), aerobic capacity (AC), and hematological levels in male university-level athletes (cyclists, runners, and swimmers) was investigated using an experimental approach. The participants (N = 44) were divided into (i) an experimental group wearing ETMs (n = 22; aged 21.24 ± 0.14 years old) and (ii) a control group not wearing ETMs (n = 22; aged 21.35 ± 0.19 years old). Both groups underwent 8 weeks of high-intensity cycle ergometer interval training. Pre- and post-training tests included the above-mentioned physiological and hematological parameters.

RESULTS

Except for FEV₁, FEV₁/FVC, VT1, and MHR in the control group and FEV₁/FVC and HRM in the experimental group, all variables were significantly improved after the 8-week cycle ergometer HIIT program. Significant benefits in favor of the experimental group were noted in terms of changes in FVC, FEV₁, VO₂max, VT1, PO to VT, VT2, and PO to VT2.

CONCLUSIONS

The eight-week ETM-assisted HIIT program improved cardiorespiratory fitness and hematological variables in all participants. Future research would be useful to further investigate the physiological changes resulting from ETM-assisted HIIT programs.

Acute psychophysiological responses during exercise while using resistive respiratory devices: A systematic review

Different studies have observed that respiratory muscle training (RMT) improve the endurance and strength of the respiratory muscles, having a positive impact on performance of endurance sports. Nevertheless, it remains to be clarified how to improve the efficiency of such training. The objective of this systematic review was to evaluate the acute physiological responses produced by training the respiratory muscles during exercise with flow resistive devices because such information may support us improve the efficiency of this type of training. A search in the Medline, Science Direct, Web of Science and Scopus databases was conducted, following the PRISMA guidelines. The methodological quality of the articles was assessed using the PEDro scale. Nineteen studies met the inclusion criteria and a total of 212 subjects were included in the studies. The RMT method used in all studies was flow resistive loading, whereas the constant load exercise was the most common type of exercise among the studies. The results obtained seem to indicate that the use of this type of training during exercise reduces the performance, the lactate (La^-) values and the ventilation, whereas the end - tidal partial pressure of carbon dioxide (P_CO2) is increased.

Omitting Hyperventilation in Electroencephalogram during the COVID-19 Pandemic May Reduce Interictal Epileptiform Discharges in Patients with Juvenile Myoclonic Epilepsy

BACKGROUND

To prevent the spread of coronavirus disease 2019 (COVID-19), hyperventilation (HV) activation has been avoided in electroencephalograms (EEGs) since April 2020. The influence of omitting HV in EEG on epilepsy diagnosis remains uncertain for patients with epilepsies other than child absence epilepsy. We hypothesized that EEGs with HV would show more interictal epileptiform discharges (IEDs) than EEGs without HV in patients with juvenile myoclonic epilepsy (JME).

METHODS

We reviewed the EEGs of seizure-free patients with JME who underwent EEG, both with and without HV, from January 2019 to October 2021, in our institution, and compared IEDs between EEG with and without HV.

RESULTS

This study analyzed 23 JME patients. The IED-positive rate was significantly higher in EEG with HV (65.2%) than in EEG without HV (34.8%, p = 0.016). The mean ± standard deviation number of IEDs per minute was significantly larger during HV (1.61 ± 2.25 × 10^-1) than during non-activation of both first EEG (0.57 ± 0.93 × 10^-1, p = 0.039) and second EEG (0.39 ± 0.76 × 10^-1, p = 0.009).

CONCLUSIONS

In JME patients, performing HV during EEG may increase IEDs and appears to facilitate the accurate diagnosis of epilepsy.

The effects of a respiratory training mask on steady-state oxygen consumption at rest and during exercise

No studies have directly measured ventilatory and metabolic responses while wearing a respiratory training mask (RTM) at rest and during exercise. Eleven aerobically fit adults (age: 21 ± 1 years) completed a randomized cross-over study while wearing an RTM or control mask during cycling at 50% Wmax. An RTM was retrofitted with a gas collection tube and set to the manufacturer's "altitude resistance" setting of 6,000 ft (1,800 m). Metabolic gas analysis, ratings of perceived exertion, and oxygen saturation (SpO2) were measured during rest and cycling exercise. The RTM did not affect metabolic, ventilation, and SpO2 at rest compared to the control mask (all, effect of condition: P > 0.05). During exercise, the RTM blunted respiratory rate and minute ventilation (effect of condition: P < 0.05) compared to control. Similar increases in VO2 and VCO2 were observed in both conditions (both, effect of condition: P > 0.05). However, the RTM led to decreased fractional expired O2 and increased fractional expired CO2 (effect of condition: P < 0.05) compared to the control mask. In addition, the RTM decreased SpO2 and increased RPE (both, effect of condition: P < 0.05) during exercise. Despite limited influence on ventilation and metabolism at rest, the RTM reduces ventilation and disrupts gas concentrations during exercise leading to modest hypoxemia.

Breath Tools: A Synthesis of Evidence-Based Breathing Strategies to Enhance Human Running

Running is among the most popular sporting hobbies and often chosen specifically for intrinsic psychological benefits. However, up to 40% of runners may experience exercise-induced dyspnoea as a result of cascading physiological phenomena, possibly causing negative psychological states or barriers to participation. Breathing techniques such as slow, deep breathing have proven benefits at rest, but it is unclear if they can be used during exercise to address respiratory limitations or improve performance. While direct experimental evidence is limited, diverse findings from exercise physiology and sports science combined with anecdotal knowledge from Yoga, meditation, and breathwork suggest that many aspects of breathing could be improved via purposeful strategies. Hence, we sought to synthesize these disparate sources to create a new theoretical framework called “Breath Tools” proposing breathing strategies for use during running to improve tolerance, performance, and lower barriers to long-term enjoyment.

Warm-Up With Added Respiratory Dead Space Volume Mask Improves the Performance of the Cycling Sprint Interval Exercise: Cross-Over Study

Special breathing exercises performed during warm-up lead to hypercapnia and stimulation of mechanisms leading to increased exercise performance, but the effect of a device that increases the respiratory dead space volume (ARDSv) during warm-up has not been studied. The purpose of this study was to investigate the effect of 10 min warm-up with ARDSv on performance, physiological and biochemical responses during sprint interval cycling exercise (SIE). During four laboratory visits at least 72 h apart, they completed: (1) an incremental exercise test (IET) on a cycloergometer, (2) a familiarization session, and cross-over SIE sessions conducted in random order on visits (3) and (4). During one of them, 1200 mL of ARDSv was used for breathing over a 10-min warm-up. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. Work capacity, cardiopulmonary parameters, body temperature, respiratory muscle strength, blood acid-base balance, lactate concentration, and rating of perceived exertion (RPE) were analyzed. After warm-up with ARDSv, P ET CO2 was 45.0 ± 3.7 vs. 41.6 ± 2.5 (mm Hg) (p < 0.001). Body temperature was 0.6 (°C) higher after this form of warm-up (p < 0.05), bicarbonate concentration increased by 1.8 (mmol⋅L-1) (p < 0.01). As a result, work performed was 2.9% greater (p < 0.01) compared to the control condition. Respiratory muscle strength did not decreased. Warming up with added respiratory dead space volume mask prior to cycling SIE produces an ergogenic effect by increasing body temperature and buffering capacity.

Time to Move Beyond a "One-Size Fits All" Approach to Inspiratory Muscle Training

Inspiratory muscle training (IMT) has been studied as a rehabilitation tool and ergogenic aid in clinical, athletic, and healthy populations. This technique aims to improve respiratory muscle strength and endurance, which has been seen to enhance respiratory pressure generation, respiratory muscle weakness, exercise capacity, and quality of life. However, the effects of IMT have been discrepant between populations, with some studies showing improvements with IMT and others not. This may be due to the use of standardized IMT protocols which are uniformly applied to all study participants without considering individual characteristics and training needs. As such, we suggest that research on IMT veer away from a standardized, one-size-fits-all intervention, and instead utilize specific IMT training protocols. In particular, a more personalized approach to an individual's training prescription based upon goals, needs, and desired outcomes of the patient or athlete. In order for the coach or practitioner to adjust and personalize a given IMT prescription for an individual, factors, such as frequency, duration, and modality will be influenced, thus inevitably affecting overall training load and adaptations for a projected outcome. Therefore, by integrating specific methods based on optimization, periodization, and personalization, further studies may overcome previous discrepancies within IMT research.

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.

Airflow restriction mask induces greater central fatigue after a non-exhaustive high-intensity interval exercise

The airflow restriction mask (ARM) is a practical and inexpensive device for respiratory muscle training. Wearing an ARM has recently been combined with high-intensity interval exercise (HIIE), but its effect on neuromuscular fatigue is unknown. The present study investigated the effects of ARM wearing on neuromuscular fatigue after an HIIE session. Fourteen healthy men performed two HIIE sessions (4x4min at 90% HRmax, 3min recovery at 70% HRmax) with or without an ARM. Neuromuscular fatigue was quantified via pre- to post-HIIE changes in maximal voluntary contraction (MVC), voluntary activation (VA, central fatigue), and potentialized evoked twitch force at 100, 10, and 1 Hz (peripheral fatigue). Blood pH and lactate were measured before and after the HIIE session, while HR, SpO₂ , dyspnea, physical sensation of effort (P-RPE), and Task Effort and Awareness (TEA) were recorded every bout. The exercise-induced decrease in MVC was higher (p<0.05) in the ARM (-28±12%) than in the control condition (-20±11%). The VA decreased (p<0.05) in the ARM (-11±9%) but not in the control condition (-4±5%, p>0.05). Pre- to post-HIIE declines in evoked twitch at 100, 10, and 1 Hz were similar (p>0.05) between ARM and control conditions (ARM: -18±10, -43±11 and -38±12%; Control: -18±14, -43±12 and -37±17%). When compared with the control, the HIIE bout wearing ARM was marked by higher heart rate, plasma lactate concentration, dyspnea, P-RPE and TEA, as well as lower SpO₂ and blood pH. In conclusion, ARM increases perceptual and physiological stress during a HIIE, which may lead to a greater post-exercise central fatigue.

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.

Effects of the Elevation Training Mask® 2.0 on dyspnea and respiratory muscle mechanics, electromyography, and fatigue during exhaustive cycling in healthy humans

OBJECTIVES

Examine the effects of the Elevation Training Mask® 2.0 (ETM) on dyspnea, and respiratory muscle function and fatigue during exercise.

DESIGN

Randomized crossover.

METHODS

10 healthy participants completed 2 time-to-exhaustion (TTE) cycling tests while wearing the ETM or under a sham control condition. During the sham, participants were told they were breathing air equivalent to "9000 ft" (matched to the selected resistance valves on the ETM according to the manufacturer), but they were breathing room air. Dyspnea and leg discomfort were assessed using the modified 0-10 category-ratio Borg scale. Qualitative dyspnea descriptors at peak exercise were selected from a list of 15. Crural diaphragmatic electromyography (EMG_di) and transdiaphragmatic pressure (P_di) were measured via a multipair esophageal electrode balloon catheter. Participants performed maximal respiratory maneuvers before and after exercise to estimate the degree of respiratory muscle fatigue.

RESULTS

Exercise with the ETM resulted in a significant decrease in TTE (p = 0.015), as well as increased dyspnea at baseline (p = 0.032) and during the highest equivalent submaximal exercise time (p = 0.0001). The increase in dyspnea with the ETM was significantly correlated with the decrease in exercise time (r = 0.73, p = 0.020). EMG_di and P_di were significantly increased with the ETM at all time points (all p < 0.05). There was a significant increase in the selection frequency of "my breath does not go in all the way" at peak exercise with the ETM (p = 0.02). The ETM did not induce respiratory muscle fatigue.

CONCLUSIONS

Exercising with the ETM appears to decrease exercise performance, in part, by increasing the sensation of dyspnea.

Effects of Acute High-Intensity Exercise With the Elevation Training Mask or Hypoxicator on Pulmonary Function, Metabolism, and Hormones

ABSTRACT

Ott, T, Joyce, MC, and Hillman, AR. Effects of acute high-intensity exercise with the elevation training mask or hypoxicator on pulmonary function, metabolism, and hormones. J Strength Cond Res 35(9): 2486-2491, 2021-The elevation training mask (ETM) 2.0 is an increasingly popular hands-free respiratory muscle training modality proposing to mimic altitude; however, the degree to which this occurs has been questioned. The purpose of this study was to investigate the efficacy of this modality in comparison with using a hypoxicator (HYP) during acute aerobic exercise. Eight regularly active subjects (age: 25 ± 8 years; height: 166 ± 12 cm; body mass 64 ± 10 kg; and V̇o2max: 46 ± 6 ml·kg-1·min-1) completed 3 trials, each including resting metabolic rate measurement, pulmonary function tests, and 13 sprint intervals at 90% V̇o2max using either the HYP, ETM, or control. There was no significant difference in metabolism or heart rate between conditions. Fraction of expired air in the first second was greater after exercise (p = 0.02), while oxygen saturation was lower during exercise with the HYP (p < 0.001). Human growth hormone increased with exercise, but no differences were found between conditions; however, a trend was observed for higher growth hormone after exercise in HYP vs. ETM (p = 0.08). Elevation training mask does not seem to change acute pulmonary function, metabolism, heart rate, or oxygen saturation, indicating it likely does not create a hypoxic environment or mimic altitude.

Effects of hyperventilation with face mask on brain network in patients with epilepsy

OBJECTIVES

During the ongoing pandemic of COVID-19, wearing face masks was recommended, including patients with epilepsy doing the hyperventilation (HV) test during electroencephalogram (EEG) examination somewhere. However, evidence was still limited about the effect of HV with face mask on cortical excitability of patients with epilepsy. The motivation of this work is to make use of the graph theory of EEG to characterize the cortical excitability of patients with epilepsy when they did HV under the condition wearing a surgical face mask.

METHODS

We recruited 19 patients with epilepsy and 17 normal controls. All of participants completed two HV experiments, including HV with face mask (HV+) and HV without a mask (HV). The interval was 30 min and the sequence was random. Each experiment consisted of three segments: resting EEG, EEG of HV, and EEG of post-HV. EEG were recorded successively during each experiment. Participants were asked to evaluate the discomfort degree using a questionnaire when every HV is completed.

RESULTS

All of the participants felt more uncomfortable after HV + . Moreover, not only HV decreased small-worldness index in patients with epilepsy, but also HV + significantly increased the clustering coefficient in patients with epilepsy. Importantly, the three-way of Mask*HV*Epilepsy showed interaction in the clustering coefficient in the delta band, as well as in the path length and the small-worldness index in the theta band.

CONCLUSIONS

The results of this study indicated that patients with epilepsy showed the increased excitability of brain network during HV + . We should pay more attention to the adverse effect on brain network excitability caused by HV + in patients with epilepsy. In the clinical practice under the COVID-19 pandemic, it is important that the wearing face mask remain cautious for the individuals with epilepsy when they carried out HV behavior such as exercise (e.g., running, etc.).

Hematologic adaptation to mask-wearing among pregnant women and obstetrical outcome during the coronavirus disease 2019 pandemic

OBJECTIVE

To evaluate the effect of the coronavirus disease 2019 (COVID-19) mask-wearing on hematological laboratory components and obstetrical outcomes among women delivering during the COVID-19 pandemic.

METHODS

Laboratory results and obstetrical outcomes of women with singleton gestations, admitted for delivery during the COVID-19 mask-wearing period (April-June 2020) were compared with those of women delivering during the parallel period in 2019 and with a larger cohort derived from nine pre-pandemic years (March 2011-April 2020).

RESULTS

Overall, 1838 women delivered during the COVID-19 pandemic. Compared with the pre-pandemic period, mean hemoglobin and fibrinogen levels were significantly higher during the mask-wearing period (12.15 ± 1.1 vs 11.96 ± 1.2, P < 0.001 and 472 ± 103.6 vs 448 ± 85.1 mg/dl, P < 0.001, respectively). Platelet levels were lower (200 ± 56.0 vs 206 ± 57.5 K/µl, P < 0.001). The rate of delivery at <34 weeks of gestation was lower during the mask-wearing period (1.1% vs 2%, odds ratio [OR] 0.57, 95% confidence intervals [CI] 0.37-0.88, P = 0.01), whereas cesarean delivery and postpartum hemorrhage rates were higher (26.7% vs 24.4%, OR 1.13, 95% CI 1.02-1.25, P = 0.022 and 4.1% vs 2.8%, OR 1.5, 95% CI 1.2-1.8, P = 0.001, respectively).

CONCLUSION

A hard-to-ventilate space created by wearing a mask during the COVID-19 era may be the underlying cause of the observed higher hemoglobin level among pregnant women, possibly affecting obstetrical outcomes.

Effects of Wearing the Elevation Training Mask During Low-intensity Cycling Exercise on Intraocular Pressure

PRCIS

Low-intensity aerobic exercise is recommended to reduce intraocular pressure (IOP) levels. However, this effect depends on several factors. We found that using an elevation training mask (ETM) during low-intensity aerobic exercise causes an IOP rise.

PURPOSE

The aim was to assess the influence of wearing an ETM on IOP during low-intensity endurance training.

METHODS

Sixteen physically active young adults (age=23.9±2.9 y) cycled during 30 minutes at 10% of maximal power production with and without an ETM in 2 different days and randomized order. A rebound tonometer was used to measure IOP at baseline, after a warm-up of 5 minutes, during cycling (6, 12, 18, 24, and 30 min), and recovery (5 and 10 min) by rebound tonometry.

RESULTS

The use of an ETM significantly affects the IOP behaviour during exercise (P<0.001, ηp²=0.66). In the ETM condition, there was an IOP increment during exercise (P<0.001, ηp²=0.28) whereas an IOP-lowering effect was observed in the control condition (P<0.001, ηp²=0.41). Post hoc comparisons showed that there were greater IOP values during exercise in the ETM condition in comparison to the control condition (average IOP difference=3.7±2.2 mm Hg; corrected P<0.01, and the Cohen d's >1.10, in all cases).

CONCLUSION

Low-intensity endurance exercise causes an increment in IOP when it is performed wearing an ETM and a decrease in IOP when the air flow is not restricted (control condition). Therefore, the ETM should be discouraged during low-intensity endurance exercise for individuals who need to reduce IOP levels (eg, glaucoma patients or those at risk). However, the external validity of these results needs to be addressed in future studies with the inclusion of glaucoma patients.

Chronic Effects of a Training Program Using a Nasal Inspiratory Restriction Device on Elite Cyclists

This study compared the response of a 9-week cycling training on ventilatory efficiency under two conditions: (i) Combined with respiratory muscle training (RMT) using a new nasal restriction device (FeelBreathe) (FB group) and (ii) without RMT (Control group). Eighteen healthy elite cyclists were randomly separated into the FB group (n = 10) or Control group (n = 8). Gas exchange was measured breath by breath to measure ventilatory efficiency during an incremental test on a cycloergometer before (Pre) and after (Post) the nine weeks of training. The FB group showed higher peak power (Δ (95%HDI) (0.82 W/kg (0.49, 1.17)), VO₂max (5.27 mL/kg/min (0.69, 10.83)) and VT₁ (29.3 W (1.8, 56.7)) compared to Control at Post_FINAL. The FB group showed lower values from Pre to Post_PRE in minute ventilation (VE) (−21.0 L/min (−29.7, −11.5)), Breathing frequency (BF) (−5.1 breaths/min (−9.4, −0.9)), carbon dioxide output (VCO₂) (−0.5 L/min (−0.7, −0.2)), respiratory equivalents for oxygen (EqO₂) (−0.8 L/min (−2.4, 0.8)), heart rate (HR) (−5.9 beats/min (−9.2, −2.5)), respiratory exchange ratio (RER) (−0.1 (−0.1, −0.0) and a higher value in inspiratory time (Tin) (0.05 s (0.00, 0.10)), expiratory time (Tex) (0.11 s (0.05, 0.17)) and end-tidal partial pressure of CO₂ (PETCO₂) (0.3 mmHg (0.1, 0.6)). In conclusion, RMT using FB seems to be a new and easy alternative ergogenic tool which can be used at the same time as day-to-day training for performance enhancement.

The effect of an airflow restriction mask (ARM) on metabolic, ventilatory, and electromyographic responses to continuous cycling exercise

This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.

Psychophysiological Responses During a Cycling Test to Exhaustion While Wearing the Elevation Training Mask

López-Pérez, ME, Romero-Arenas, S, Colomer-Poveda, D, Keller, M, and Márquez, G. Psychophysiological responses during a cycling test to exhaustion while wearing the elevation training mask. J Strength Cond Res XX(X): 000-000, 2020-The aim of this study was to investigate the psychophysiological effects of wearing the elevation training mask (ETM). Twelve men performed time-to-exhaustion (TTE) tests at 75% of peak power output with and without wearing the ETM. Heart rate (HR), rating of perceived exertion (RPE), breathing discomfort (BD), and oxygen saturation (SpO2) were measured during the TTE. Prefrontal cortex (PFC) and vastus lateralis oxygenated, deoxygenated, and total hemoglobin were monitored using near-infrared spectroscopy. At the end of each test, blood lactate values (La-) were collected, and subjects completed the Beck Anxiety Inventory (BAI). The mask caused a reduction in the TTE (-37.7%; p < 0.001) and in the SpO2 (-2%; p < 0.001). Beck Anxiety Inventory scores were negatively correlated with the changes observed in the TTE (r = -0.77; p < 0.01). La-, HR, and muscle oxygenation displayed similar results across conditions. In conjunction with an increased hemodynamic response in the PFC, subjects reported higher RPE and BD values in the ETM condition (p < 0.01). Finally, BAI scores were negatively correlated with the changes observed in the TTE (r = -0.77; p < 0.01). This study suggests that wearing the ETM induces psychophysiological alterations affecting the exercise tolerance and limiting the performance.

Familiarization With Airflow-Restriction Mask During Resistance Exercise: Effect on Tolerance and Total Volume

Teodoro, CL, Gáspari, AF, Berton, R, Barbieri, JF, Silva, M, Castaño, LAA, Guimarães, P, and Moraes, AC. Familiarization with airflow-restriction mask during resistance exercise: Effect on tolerance and total volume. J Strength Cond Res 33(7): 1762-1765, 2019-This study investigated whether familiarization with the airflow-restriction mask (AIRfr) increases tolerance and avoids negative effects on performance of resistance exercise (RE). Ten resistance-trained male subjects performed a familiarization session (FAM), followed by 2 testing sessions, with the AIRfr and without airflow restriction (SHAM) in a counterbalanced and randomized cross-over design. The FAM was performed with the same number of sets, load, and level of airflow-restriction as the AIRfr experimental session. Each session consisted of 4 sets of the leg press exercise with 70% 1 repetition maximum until voluntary failure and a 90-second rest interval between sets. During the FAM, 4 of the 10 subjects expressed some intolerance to the use of airflow restriction. Total volume was lower in the FAM than in the AIRfr (p = 0.01) and the SHAM (p = 0.02), whereas no differences were observed between the AIRfr and the SHAM (p = 0.90). The first use of the AIRfr may not be well tolerated by all subjects. However, a familiarization session with the AIRfr avoids negative interferences in the total volume during RE.

The elevation training mask induces modest hypoxaemia but does not affect heart rate variability during cycling in healthy adults

This study examined the acute effects of the elevation training mask (ETM) on haemodynamics and heart rate variability (HRV) at rest, during cycling, and during recovery in healthy adults. Fifteen healthy male (N=9) and female (N=6) adults (27.0 ± 1.14 years) completed two trials with the mask (MASK) and without the mask (CON). The 40-minute cycling exercise protocol included 10-minute phases of (1) rest, (2) 50% of VO_2peak cycling, (3) 70% of VO_2peak cycling, and (4) recovery. Blood pressure and pulse oximetry saturation (S_PO₂) were measured at each phase. An Actiwave-Cardio ECG monitor (CamNtech, UK) was used to measure HRV variables including time and frequency domains. A greater response in systolic blood pressure (p=.035) was observed at rest while S_PO₂ (p=.033) was lower during high-intensity cycling (70% of VO_2peak) in the MASK trial. The HRV indices were not different between trials during cycling. However, heart rate (p=.047) was greater while inter-beat interval and sympathovagal balance (the ratio between low-frequency and high-frequency components; ln LF/HF, p=.01) were lower in the MASK than the CON trials during recovery. Wearing an ETM during high-intensity cycling (70% of VO_2peak) induces modest hypoxaemia. Although this device did not affect HRV changes during cycling, it seems to delay the cardiac-autonomic recovery from exercise. Healthy adults may be required to perform high-intensity exercise with an ETM to simulate a hypoxic environment, but future studies are needed to determine whether repeated exposure to this condition provides similar benefits as altitude training.

Restrictive Breathing Mask Reduces Repetitions to Failure During a Session of Lower-Body Resistance Exercise

Andre, TL, Gann, JJ, Hwang, PS, Ziperman, E, Magnussen, MJ, and Willoughby, DS. Restrictive breathing mask reduces repetitions to failure during a session of lower-body resistance exercise. J Strength Cond Res 32(8): 2103-2108, 2018-The purpose of this study was to determine the effect of restrictive breathing mask (RBM) on muscle performance, hemodynamic, and perceived stress variables during a session of lower-body resistance exercise. In a crossover design, 10 participants performed 2 separate testing sessions, RBM and no mask, consisting of squat, leg press, and leg extension. The paired-samples t-test was used for session rating of perceived exertion (S-RPE), perceived stress before and after, heart rate (HR), pulse oximetry, and a 2 × 4 (session [mask, no mask] × time [squat exercise, leg press exercise, leg extension exercise, total resistance exercise session]) factorial analysis of variance with repeated measures (p ≤ 0.05). A significant decrease was found in total repetitions during the RBM condition (p < 0.01). A majority of the decrease in repetitions to failure occurred in the squat (p < 0.05) and in the leg press (p < 0.01), whereas no difference was observed in leg extension (p = 0.214). A significant increase was observed in S-RPE during the RBM session (p < 0.01). A significant increase was found in prestress (p < 0.01) and poststress (p = 0.01) in the RBM session. No significant difference existed for HR between exercise sessions (p = 0.08). A significant decrease existed in pulse oximetry during the RBM session (p < 0.01). The use of an RBM had a negative effect on the number of repetitions completed during an acute session of lower-body resistance training.

Recent Advancements in Our Understanding of the Ergogenic Effect of Respiratory Muscle Training in Healthy Humans: A Systematic Review

Shei, R-J. Recent advancements in our understanding of the ergogenic effect of respiratory muscle training in healthy humans: a systematic review. J Strength Cond Res 32(9): 2674-2685, 2018-Respiratory muscle training (RMT) has been shown to be an effective ergogenic aid for sport performance. Respiratory muscle training has been documented to improve performance in a wide range of exercise modalities including running, cycling, swimming, and rowing. The physiological effects of RMT that may explain the improvements in performance have been proposed to include diaphragm hypertrophy, muscle fiber-type switching, improved neural control of the respiratory muscles, increased respiratory muscle economy, attenuation of the respiratory muscle metaboreflex, and decreases in perceived breathlessness and exertion. This review summarizes recent studies on the ergogenicity and mechanisms of RMT since 2013 when the topic was last systematically reviewed. Recent evidence confirms the ergogenic effects of RMT and explores different loading protocols, such as concurrent exercise and RMT (i.e., "functional" RMT). These studies suggest that adapting new training protocols may have an additive improvement effect, but evidence of the efficacy of such an approach is conflicting thus far. Other recent investigations have furthered our understanding of the mechanisms underpinning RMT-associated improvements in performance. Importantly, changes in ventilatory efficiency, oxygen delivery, cytokine release, motor recruitment patterns, and respiratory muscle fatigue resistance are highlighted as potential mechanistic factors linking RMT with performance improvements. It is suggested that future investigations focus on development of sport-specific RMT loading protocols, and that further work be undertaken to better understand the mechanistic basis of RMT-induced performance improvements.

Acute Effects of the Elevation Training Mask on Strength Performance in Recreational Weight lifters

Jagim, AR, Dominy, TA, Camic, CL, Wright, G, Doberstein, S, Jones, MT, and Oliver, JM. Acute effects of the elevation training mask on strength performance in recreational weightlifters. J Strength Cond Res 32(2): 482-489, 2018-The Elevation Training Mask 2.0 (ETM) is a novel device that purportedly simulates altitude training. The purpose of this study was to investigate the acute effects of the ETM on resistance exercise performance, metabolic stress markers, and ratings of mental fatigue. Twenty male recreational weight lifters completed 2 training sessions of back squat and bench press (6 sets of 10 repetitions at 85% of 5-repetition maximum and seventh set to failure) as well as a maximal effort sprint test (18% body mass) with the mask (ETM) and without the mask (NM). Training evaluation included baseline and postexercise blood lactate and oxygen saturation measures. Performance evaluation included peak and average velocity bar velocity, total volume load, total work, total repetitions completed, and sprint performance. Adverse side effects were reported in 12% (n = 3) of participants, which included feelings of light headedness, anxiety, and discomfort. No differences were found in repetitions or total workload in back squat (p = 0.07) or bench press (p = 0.08) between conditions. A lower peak velocity was identified during the back squat, bench press, and sprint test in the ETM condition (p = 0.04). Blood lactate values were lower after bench press and sprint during the ETM condition (p < 0.001). Significantly lower ratings of alertness and focus for task were found after squat, bench press, and sprint test in the ETM condition compared with the NM condition (p < 0.001). Wearing the ETM during bouts of resistance training did not hinder the ability to achieve desired training volumes during the resistance training session. However, wearing the ETM does seem to attenuate the ability to maintain working velocity during training bouts and negatively influence ratings of alertness and focus for task.