A systematic review of methods of scoring inhaler technique.

Many inhaler devices are currently used in clinical practice to deliver medication, with each inhaler device offering different benefits to overcome technique issues. Inhaler technique remains poor, contributing to reduced airway drug deposition and consequently poor disease control. Scoring inhaler technique has been used within research as an outcome measure of inhaler technique assessment, and this systematic review collates and evaluates these scoring methods. The review protocol was prospectively registered in PROSPERO (CRD42020218869). A total of 172 articles were screened with 77 included, and the results presented using narrative synthesis due to the heterogeneity of the study design and data. The most frequently used scoring method awarded one point per step in the inhaler technique checklist and was included in 59/77 (77%) of articles; however limited and varied guidance was provided for score interpretation. Other inhaler technique scoring methods included grading the final inhaler technique score, expressing the total score as a percentage/ratio, deducting points from the final score when errors were made, and weighting steps within the checklist depending on how crucial the step was. Vast heterogeneity in the number of steps and content in the inhaler technique checklists was observed across all device types (range 5-19 steps). Only 4/77 (5%) of the inhaler technique measures had undertaken fundamental steps required in the scale development process for use in real world practice. This review demonstrates the demand for a tool that measures inhaler technique and highlights the current unmet need for one that has undergone validation.

Inspiratory muscle fatigue at the swimming tumble turns: its occurrence and effects on kinematic parameters of the turns.

Introduction: The present study had two objectives: 1) to investigate the effects of tumble turns on the development of inspiratory muscle fatigue (IMF) and compare this to whole swimming, and 2) to evaluate the effects of pre-induced IMF on the kinematic parameters of tumble turns. Fourteen young club-level swimmers (13 ± 2 years of ages) completed three swim trials. Methods: The first trial was used to determine the 400-m front crawl swim time at maximal effort (400FC). The other two trials consisted of a series of 15 tumble turns at the 400FC pace. In one of the turn-only trials, IMF was pre-induced (TURNS-IMF), whereas in the other turn-only trial it was not (TURNS-C). Results: Compared with baseline values, the values for maximal inspiratory mouth pressure (PImax) at the end of the swim were significantly lower at all trials. However, the magnitude of inspiratory muscle fatigue was less after TURNS-C (PImax decreased by 12%) than after 400FC (PImax decreased by 28%). The tumble turns were slower during 400FC than during TURNS-C and TURNS-IMF. In addition, compared to TURNS-C, turns in the TURNS-IMF were performed with higher rotation times and shorter apnea and swim-out times. Discussion: The results of the present study suggest that tumble turns put a strain on the inspiratory muscles and directly contribute to the IMF observed during 400FC swimming. Furthermore, pre-induced IMF resulted in significantly shorter apneas and slower rotations during tumble turns. IMF therefore has the potential to negatively affect overall swimming performance, and strategies should be sought to reduce its effects.

Physiological impact of load carriage exercise: Current understanding and future research directions.

Load carriage (LC) refers to the use of personal protective equipment (PPE) and/or load-bearing apparatus that is mostly worn over the thoracic cavity. A commonplace task across various physically demanding occupational groups, the mass being carried during LC duties can approach the wearer's body mass. When compared to unloaded exercise, LC imposes additional physiological stress that negatively impacts the respiratory system by restricting chest wall movement and altering ventilatory mechanics as well as circulatory responses. Consequently, LC activities accelerate the development of fatigue in the respiratory muscles and reduce exercise performance in occupational tasks. Therefore, understanding the implications of LC and the effects specific factors have on physiological capacities during LC activity are important to the implementation of effective mitigation strategies to ameliorate the detrimental effects of thoracic LC. Accordingly, this review highlights the current physiological understanding of LC activities and outlines the knowledge and efficacy of current interventions and research that have attempted to improve LC performance, whilst also highlighting pertinent knowledge gaps that must be explored via future research activities.

Measurement of Vital Signs Using Lifelight Remote Photoplethysmography: Results of the VISION-D and VISION-V Observational Studies.

BACKGROUND: The detection of early changes in vital signs (VSs) enables timely intervention; however, the measurement of VSs requires hands-on technical expertise and is often time-consuming. The contactless measurement of VSs is beneficial to prevent infection, such as during the COVID-19 pandemic. Lifelight is a novel software being developed to measure VSs by remote photoplethysmography based on video captures of the face via the integral camera on mobile phones and tablets. We report two early studies in the development of Lifelight. OBJECTIVE: The objective of the Vital Sign Comparison Between Lifelight and Standard of Care: Development (VISION-D) study (NCT04763746) was to measure respiratory rate (RR), pulse rate (PR), and blood pressure (BP) simultaneously by using the current standard of care manual methods and the Lifelight software to iteratively refine the software algorithms. The objective of the Vital Sign Comparison Between Lifelight and Standard of Care: Validation (VISION-V) study (NCT03998098) was to validate the use of Lifelight software to accurately measure VSs. METHODS: BP, PR, and RR were measured simultaneously using Lifelight, a sphygmomanometer (BP and PR), and the manual counting of RR. Accuracy performance targets for each VS were defined from a systematic literature review of the performance of state-of-the-art VSs technologies. RESULTS: The VISION-D data set (17,233 measurements from 8585 participants) met the accuracy targets for RR (mean error 0.3, SD 3.6 vs target mean error 2.3, SD 5.0; n=7462), PR (mean error 0.3, SD 4.0 vs mean error 2.2, SD 9.2; n=10,214), and diastolic BP (mean error -0.4, SD 8.5 vs mean error 5.5, SD 8.9; n=8951); for systolic BP, the mean error target was met but not the SD (mean error 3.5, SD 16.8 vs mean error 6.7, SD 15.3; n=9233). Fitzpatrick skin type did not affect accuracy. The VISION-V data set (679 measurements from 127 participants) met all the standards: mean error -0.1, SD 3.4 for RR; mean error 1.4, SD 3.8 for PR; mean error 2.8, SD 14.5 for systolic BP; and mean error -0.3, SD 7.0 for diastolic BP. CONCLUSIONS: At this early stage in development, Lifelight demonstrates sufficient accuracy in the measurement of VSs to support certification for a Level 1 Conformité Européenne mark. As the use of Lifelight does not require specific training or equipment, the software is potentially useful for the contactless measurement of VSs by nonclinical staff in residential and home care settings. Work is continuing to enhance data collection and processing to achieve the robustness and accuracy required for routine clinical use. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/14326.

Oxygen uptake kinetics and ventilatory and metabolic parameters do not differ between moderate-intensity front crawl and breaststroke swimming.

Pulmonary oxygen uptake ( V̇O2 ) kinetics have been well studied during land-based exercise. However, less is known about V̇O2 kinetics during swimming exercise and comparisons between strokes is non-existent. We aimed to characterize and compare the V̇O2 kinetics, ventilatory,e and metabolic response to constant velocity moderate-intensity freely breathing front crawl (FC) and breaststroke (BR) swimming in a swimming flume. These two strokes reflect predominantly upper body versus lower body modes of swimming locomotion, respectively. Eight trained swimmers (4 females, 20 ± 1 years, 1.74 ± 0.06 m; 66.8 ± 6.3 kg) attended 5-6 laboratory-based swimming sessions. The first two trials determined FC and BR V̇O2max and the ventilatory threshold (VT), respectively, during progressive intensity swimming to the limit of tolerance. Subsequent trials involved counterbalanced FC and BR transitions from prone floating to constant velocity moderate-intensity swimming at 80% of the velocity at VT (vVT), separated by 30-min recovery. Breath-by-breath changes in pulmonary gas exchange and ventilation were measured continuously using a snorkel and aquatic metabolic cart system. The ventilatory and metabolic responses were similar (p > 0.05) between strokes during maximal velocity swimming, however, vVT and maximal velocity were slower (p < 0.05) during BR . During moderate-intensity swimming, V̇O2 kinetics, ventilatory and metabolic parameters were similar (p > 0.05) between strokes. In conclusion, when breathing ad libitum, V̇O2 kinetics during moderate-intensity constant velocity swimming, and ventilatory and metabolic responses during moderate-intensity and maximal velocity swimming, are similar between FC and BR strokes.

A Study to Investigate the Prevalence of Device-Specific Errors in Inhaler Technique in Adults With Airway Disease (The SCORES Study): Protocol for a Single Visit Prevalence Study.

BACKGROUND: It is a recurring theme in clinical practice that patients using inhaled medications via an inhaler do not use their device to a standard that allows for optimum therapeutic effect, and some studies have shown that up to 90% of people do not use their inhalers properly. Observation and correction of the inhaler technique by health care professionals is advised by both national and international guidelines and should be performed at every opportunity to ensure that the optimum inhaler technique is achieved by the user. This study will provide a greater understanding of the most frequent technique errors made by people using 13 different inhaler types. OBJECTIVE: This study aims to identify and compare inhaler technique errors and their prevalence in adults, using device-specific checklists in accordance with manufacturers' guidelines, for 13 specific inhaler types across all lung conditions and to correlate these errors with possible determinants of poor technique. It also aims to assess the error frequency at each step in the device-specific questionnaires and compare the error rates among device types. METHODS: In a single visit, participants using an inhaler included in the inclusion criteria will have their inhaler technique observed using an identical placebo device, which will be recorded using device-specific checklists, and technique-optimized, or switched to a suitable inhaler. RESULTS: The study is already underway, and it is anticipated that the results will be available by 2022. CONCLUSIONS: The SCORES (Study to Investigate the Prevalence of Device-Specific Errors in Inhaler Technique in Adults With Airway Disease) study will ascertain the prevalence of device-specific inhaler technique errors at each step in the device-specific checklists, compare error rates among 13 device types, and correlate these errors with possible determinants of poor technique. Future work will involve the clarification and classification of these errors into critical and noncritical categories. TRIAL REGISTRATION: ClinicalTrials.gov NCT04262271; https://clinicaltrials.gov/ct2/show/NCT04262271. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/26350.

Wearing body armour and backpack loads increase the likelihood of expiratory flow limitation and respiratory muscle fatigue during marching.

The effect of load carriage on pulmonary function was investigated during a treadmill march of increasing intensity. 24 male infantry soldiers marched on six occasions wearing either: no load, 15 kg, 30 kg, 40 kg or 50 kg. Each loaded configuration included body armour which was worn as battle-fit or loose-fit (40 kg only). FVC and FEV1 were reduced by 6 to 15% with load. Maximal mouth pressures were reduced post load carriage by up to 11% (inspiratory) and 17% (expiratory). Increased ventilatory demands associated with carrying increased mass were met by increases in breathing frequency (from 3 to 26 breaths·min-1) with minimal changes to tidal volume. 72% of participants experienced expiratory flow limitation whilst wearing the heaviest load. Loosening the armour had minimal effects on pulmonary function. It was concluded that as mass and exercise intensity are increased, the degree of expiratory flow limitation also increases. Practitioner Summary: This study investigated the effect of soldier load carriage on pulmonary function, to inform the trade-off between protection and burden. Load carriage caused an inefficient breathing pattern, respiratory muscle fatigue and expiratory flow limitation during marching. These effects were exacerbated by increases in mass carried and march intensity.

Impact of Weekly Swimming Training Distance on the Ergogenicity of Inspiratory Muscle Training in Well-Trained Youth Swimmers.

Lomax, M, Kapus, J, Brown, PI, and Faghy, M. Impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training in well-trained youth swimmers. J Strength Cond Res 33(8): 2185-2193, 2019-The aim of this study was to examine the impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training (IMT). Thirty-three youth swimmers were recruited and separated into a LOW and HIGH group based on weekly training distance (≤31 km·wk and >41 km·wk, respectively). The LOW and HIGH groups were further subdivided into control and IMT groups for a 6-week IMT intervention giving a total of 4 groups: LOWcon, LOWIMT, HIGHcon, and HIGHIMT. Before and after the intervention period, swimmers completed maximal effort 100- and 200-m front crawl swims, with maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) assessed before and after each swim. Inspiratory muscle training increased PImax (but not PEmax) by 36% in LOWIMT and HIGHIMT groups (p ≤ 0.05), but 100- and 200-m swims were faster only in the LOWIMT group (3 and 7% respectively, p ≤ 0.05). Performance benefits only occurred in those training up to 31 km·wk and indicate that the ergogenicity of IMT is affected by weekly training distance. Consequently, training distances are important considerations, among others, when deciding whether or not to supplement swimming training with IMT.

How cold is too cold? Establishing the minimum water temperature limits for marathon swim racing.

OBJECTIVES: To provide a rationale for minimum water temperature rules for elite and subelite marathon swim racing and highlight factors that make individuals vulnerable to excessive cooling during open water swimming. METHODS: 12 lean competitive swimmers swam for up to 2 hours, three times in different water temperatures between 14°C and 20°C, wearing standard swimming costumes and hats. Rectal temperature (Tre), oxygen consumption, perception of cold and performance were measured. RESULTS: In 16°C, half the swimmers did not complete a 2-hour swim; four became (or were predicted to become) hypothermic within 2 hours. In 18°C, three-quarters completed the swim; three became (or were predicted to become) hypothermic. In 20°C, one swimmer was predicted to become hypothermic in under 2 hours. The mean linear rate of fall of Tre was greater in 16°C (-1.57°C/hour) than 18°C (-1.07°C/hour) (p=0.03). There was no change in swimming performance during the swims or between conditions. Most of the cooling rate could be explained by metabolic heat production and morphology for both 16°C (R2=0.94, p<0.01) and 18°C (R2=0.82, p<0.01) conditions. No relationship was observed between Tre and perception of thermal sensation (r=0.25, p=0.13), and there was a weak correlation between Tre and thermal comfort (r=0.32, p=0.04). CONCLUSION: We recommend that 16°C and 18°C water are too cold for elite marathon swim racing. FédérationInternationale de Natation rules were changed in 2017 to make wetsuits compulsory below 18°C and optional below 20°C.

The effect of inspiratory muscle fatigue on acid-base status and performance during race-paced middle-distance swimming.

The aim of this study was to investigate the effect of pre-induced inspiratory muscle fatigue (IMF) on race-paced swimming and acid-base status. Twenty-one collegiate swimmers performed two discontinuous 400-m race-paced swims on separate days, with (IMF trial) and without (control trial) pre-induced IMF. Swimming characteristics, inspiratory and expiratory mouth pressures, and blood parameters were recorded. IMF and expiratory muscle fatigue (P < 0.05) were evident after both trials and swimming time was slower (P < 0.05) from 150-m following IMF inducement. Pre-induced IMF increased pH before the swim (P < 0.01) and reduced bicarbonate (P < 0.05) and the pressure of carbon dioxide (PCO2) (P < 0.05). pH (P < 0.05), bicarbonate (P < 0.01) and PCO2 (P < 0.05) were lower during swimming in the IMF trial. Blood lactate was similar before both trials (P > 0.05) but was higher (P < 0.01) in the IMF trial after swimming. Pre-induced IMF induced respiratory alkalosis, reduced bicarbonate buffering capacity and slowed swimming speed. Pre-induced and propulsion-induced IMF reflected metabolic acidosis arising from dual role breathing and propulsion muscle fatigue.

Practical Considerations for Assessing Pulmonary Gas Exchange and Ventilation During Flume Swimming Using the MetaSwim Metabolic Cart.

Lomax, M, Mayger, B, Saynor, ZL, Vine, C, and Massey, HC. Practical considerations for assessing pulmonary gas exchange and ventilation during flume swimming using the MetaSwim metabolic cart. J Strength Cond Res 33(7): 1941-1953, 2019-The MetaSwim (MS) metabolic cart can assess pulmonary gas exchange and ventilation in aquatic environments. The aims of this study were: (a) to determine the agreement between minute ventilation (VE), pulmonary oxygen uptake (VO2), and carbon dioxide output (VCO2) using the MS and Douglas bag (DB) methods during flume swimming; and (b) to assess the repeatability of these and other MS-derived parameters. Sixteen trained swimmers completed a combined incremental and supramaximal verification cardiopulmonary swimming test to determine maximal VO2, 2 progressive intensity swimming tests during which MS and DB measurements were made (agreement protocol), and 3-4 constant-velocity submaximal swimming tests during which only the MS was used (repeatability protocol). Agreement was determined using limits of agreement (LoA), bias, random error, and 95% confidence intervals with systematic bias assessed using paired samples t-tests. Within-trial and between-trial repeatability were determined using the coefficient of variation (CV) and the repeatability coefficient (CR). Where data were heteroscedastic, LoA and CR were log-transformed, antilogged, and displayed as ratios. MetaSwim underestimated peak VO2 and VCO2 (≤0.39 L·min) and VE (9.08 L·min), whereas submaximal values varied between 2 and 5% for CV and ±1.09-1.22 for ratio CR. The test-retest CV during constant-velocity swimming for VE, tidal volume, breathing frequency, VO2, VCO2, and end-tidal pressures of O2 and CO2 was <9% (ratio CR of ±1.09-1.34). Thus, the MS and DB cannot be used interchangeably. Whether the MS is suitable for evaluating ventilatory and pulmonary responses in swimming will depend on the size of effect required.

Active recovery strategy and lactate clearance in elite swimmers.

BACKGROUND: Swimming requires sustained high performance, with limited recovery between heats, recovery strategies are essential to performance but are often self-regulated and sub-optimal. Accordingly, we investigated a physiologically determined recovery protocol. METHODS: Fifteen (m=9, f=6) international junior age group swimmers participated in this study. The average age of the participants was 15.8±1.5 years. All participants completed a lactate elevation protocol (8 x 50 m sprints), followed by one of three recovery strategies: 1) velocity at lactate threshold (VLT); 2) coach prescribed protocol (COA); and 3) national governing body recommendations (NGB) and thereafter a 200-m time trial. RESULTS: [lac-]B was similar between trials at baseline (pooled data: 1.3±0.4 mmol.l-1, P>0.05) but increased following 8x50 m sprints (pooled data 9.5±3.5 mmol.l-1, P<0.05) and reduced in all conditions (mean reduction 6.4±1.7 mmol.l-1). [lac-]B remained elevated following NGB (5.6±0.8 mmol.l-1, P<0.05) compared with COA (2.3±1.7 mmol.l-1) and VLT (1.7±1.2 mmol.l-1) but was blunted during the 200-m time trial in VLT (6.4±1.7 mmol.l-1, P<0.05). Time trial performance was similar between trials; VLT (2.24±0.12 min), COA (2.23±0.14 min) and NGB (2.22±0.13 min, P>0.05). CONCLUSIONS: Despite similar performance, individually prescribed recovery strategy with a physiological basis will preserve repeated exercise performance performed on the same day.

Scientific rationale for changing lower water temperature limits for triathlon racing to 12°C with wetsuits and 16°C without wetsuits.

OBJECTIVES: To provide a scientific rationale for lower water temperature and wetsuit rules for elite and subelite triathletes. METHODS: 11 lean, competitive triathletes completed a 20 min flume swim, technical transition including bike control and psychomotor testing and a cycle across five different wetsuit and water temperature conditions: with wetsuit: 10°C, 12°C and 14°C; without wetsuit (skins): 14°C and 16°C. Deep body (rectal) temperature (Tre), psychomotor performance and the ability to complete a technical bike course after the swim were measured, as well as swimming and cycling performance. RESULTS: In skins conditions, only 4 out of 11 athletes could complete the condition in 14°C water, with two becoming hypothermic (Tre<35°C) after a 20 min swim. All 11 athletes completed the condition in 16°C. Tre fell further following 14°C (mean 1.12°C) than 16°C (mean 0.59°C) skins swim (p=0.01). In wetsuit conditions, cold shock prevented most athletes (4 out of 7) from completing the swim in 10°C. In 12°C and 14°C almost all athletes completed the condition (17 out of 18). There was no difference in temperature or performance variables between conditions following wetsuit swims at 12°C and 14°C. CONCLUSION: The minimum recommended water temperature for racing is 12°C in wetsuits and 16°C without wetsuits. International Triathlon Union rules for racing were changed accordingly (January 2017).

Inspiratory Muscle Training Effects on Cycling During Acute Hypoxic Exposure.

INTRODUCTION: Hypoxic environments increase the physiological demands of exercise. Inspiratory muscle training can reduce the demands of exhaustive exercise in this environment. This study examined the impact of inspiratory muscle training on moderate intensity hypoxic cycling exercise. METHODS: There were 17 healthy adult men who undertook 4 wk of inspiratory muscle training (N = 8) or 4 wk of sham inspiratory muscle training (N = 9). Subjects completed four fixed intensity (100 W) and duration (10 min) cycle ergometry tests. Two were undertaken breathing normoxic ambient air and two breathing a hypoxic gas mixture (14.6% oxygen, balance nitrogen). One normoxic and hypoxic test occurred before, and one after, inspiratory muscle training. RESULTS: Inspiratory muscle training increased maximal inspiratory mouth pressure by 21 ± 16 cmH2O. Arterial oxygen saturation and its ratio to minute ventilation also increased after inspiratory muscle training during hypoxic exercise from 83 ± 4% to 86 ± 3% (approximately 3%) and 2.95 ± 0.48 to 3.52 ± 0.54% · L · min-1(approximately 21%), respectively. In addition, minute ventilation and carbon dioxide output fell by 12-13% after inspiratory muscle training during hypoxic exercise. DISCUSSION: Inspiratory muscle training reduced the physiological demand of moderate intensity exercise during acute hypoxic, but not normoxic, exercise. It may therefore be of benefit in adults exercising in a hypoxic environment.Lomax M, Massey HC, House JR. Inspiratory muscle training effects on cycling during acute hypoxic exposure. Aerosp Med Hum Perform. 2017; 88(6):544-549.

Airway dysfunction in elite swimmers: prevalence, impact, and challenges.

The prevalence of airway dysfunction in elite swimmers is among the highest in elite athletes. The traditional view that swimmers naturally gravitate toward swimming because of preexisting respiratory disorders has been challenged. There is now sufficient evidence that the higher prevalence of bronchial tone disorders in elite swimmers is not the result of a natural selection bias. Rather, the combined effects of repeated chlorine by-product exposure and chronic endurance training can lead to airway dysfunction and atopy. This review will detail the underpinning causes of airway dysfunction observed in elite swimmers. It will also show that airway dysfunction does not prevent success in elite level swimming. Neither does it inhibit lung growth and might be partially reversible when elite swimmers retire from competition.

The movement of the trunk and breast during front crawl and breaststroke swimming.

Breast displacement has been investigated in various activities to inform bra design, with the goal of minimising movement; however, breast motion during swimming has yet to be considered. The aim was to investigate trunk and breast kinematics whilst wearing varying levels of breast support during two swimming strokes. Six larger-breasted females swam front crawl and breaststroke (in a swimming flume), in three breast support conditions while three video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated. Greater breast displacement occurred mediolaterally in the swimsuit condition (7.8, s = 1.5 cm) during front crawl and superioinferiorly in the bare-breasted condition (3.7, s = 1.6 cm) during breaststroke, with the sports bra significantly reducing breast displacements. During front crawl, the greatest trunk roll occurred in the sports bra condition (43.1, s = 8.3°) and during breaststroke greater trunk extension occurred in the swimsuit condition (55.4, s = 5.0°); however, no differences were found in trunk kinematics between the three breast support conditions. Results suggest that the swimsuit was ineffective as a means of additional support for larger-breasted women during swimming; incorporating design features of sports bras into swimsuits may improve the breast support provided.

Inspiratory muscle fatigue affects latissimus dorsi but not pectoralis major activity during arms only front crawl sprinting.

The purpose of this study was to determine whether inspiratory muscle fatigue (IMF) affects the muscle activity of the latissimus dorsi and pectoralis major during maximal arms only front crawl swimming. Eight collegiate swimmers were recruited to perform 2 maximal 20-second arms only front crawl sprints in a swimming flume. Both sprints were performed on the same day, and IMF was induced 30 minutes after the first (control) sprint. Maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) were measured before and after each sprint. The median frequency (MDF) of the electromyographic signal burst was recorded from the latissimus dorsi and pectoralis major during each 20-second sprint along with stroke rate and breathing frequency. Median frequency was assessed in absolute units (Hz) and then referenced to the start of the control sprint for normalization. After IMF inducement, stroke rate increased from 56 ± 4 to 59 ± 5 cycles per minute, and latissimus dorsi MDF fell from 67 ± 11 Hz at the start of the sprint to 61 ± 9 Hz at the end. No change was observed in the MDF of the latissimus dorsi during the control sprint. Conversely, the MDF of the pectoralis major shifted to lower frequencies during both sprints but was unaffected by IMF. As the latter induced fatigue in the latissimus dorsi, which was not otherwise apparent during maximal arms only control sprinting, the presence of IMF affects the activity of the latissimus dorsi during front crawl sprinting.

Adaptation of endurance training with a reduced breathing frequency.

The purpose of the study was to investigate the influence of training with reduced breathing frequency (RBF) on tidal volume during incremental exercise where breathing frequency was restricted and on ventilatory response during exercise when breathing a 3% CO2 mixture. Twelve male participants were divided into two groups: experimental (Group E) and control (Group C). Both groups participated three cycle ergometry interval training sessions per week for six weeks. Group E performed it with RBF i.e. 10 breaths per minute and group C with spontaneous breathing. After training Group E showed a higher vital capacity (+8 ± 8%; p = 0.02) and lower ventilatory response during exercise when breathing a 3% CO2 mixture (-45 ± 27%; p = 0.03) compared with pre-training. These parameters were unchanged in Group C. Post-training peak power output with RBF (PPORBF) was increased in both groups. The improvement was greater in Group E (+42 ± 11%; p < 0.01) than in Group C (+11 ± 9%; p = 0.03). Tidal volume at PPORBF was higher post-training in Group E (+41 ± 19%; p = 0.01). The results of the present study indicate that RBF training during cycle ergometry exercise increased tidal volume during incremental exercise where breathing frequency was restricted and decreased ventilatory sensitivity during exercise when breathing a 3% CO2 mixture. Key PointsTraining with a reduced breathing frequency during exercise decreased ventilator sensitivity to carbon dioxide. In addition, it increased minute ventilation during exercise with imposed reduced breathing frequency.Training with reduced breathing frequency could not be realized at higher intensity of exercise due to the additional stress caused by such a breathing pattern. Therefore the improvement in aerobic endurance (considering peak oxygen uptake) could not be expected after this kind of training.

The effect of three recovery protocols on blood lactate clearance after race-paced swimming.

The purpose of the present study was to assess the impact of 3 recovery protocols on blood lactate clearance after maximal intensity swimming. Thirty-three regional standard swimmers were tested throughout the course a year and were required to complete a race-paced 200-m swim in their main stroke or individual medley. After the race-paced swim, swimmers were assigned a self-paced continuous steady rate swim of 20 minutes (self-prescribed); a 20-minute coach-administered modified warm-up consisting of various swimming modes, intensities, and rest intervals (coach prescribed); or a 20-minute land-based recovery consisting of light-intensity walking, skipping, and stretching (land based). Blood lactate concentration was measured from the fingertip before and after the race-paced swim and after the recovery activity. The concentration of blood lactate was higher (p < 0.01) after race-paced swimming (range of 10.5-11.0 mmol·L(-1)) compared with baseline (range 1.3-1.4 mmol·L(-1)). However, there were no differences (p > 0.05) between the groups (recovery protocols) at these time points. Conversely, differences were observed between groups after the recovery activities (p < 0.01). Specifically, blood lactate concentration was higher after the land-based activity (3.7 ± 1.8 mmol·L(-1)) than either the self-prescribed (2.0 ± 1.2 mmol·L(-1)) or coach-prescribed (1.8 ± 0.9 mmol·L(-1)) swimming protocols. The results of the present study suggest that it does not matter whether a self-paced continuous steady rate swimming velocity or a swimming recovery consisting of various strokes, intensities, and rest intervals is adopted as a recovery activity. As both swimming recoveries removed more blood lactate than the land-based recovery, swimmers should therefore be advised to undertake a swimming-based recovery rather than a land-based recovery.

Inspiratory muscle fatigue after race-paced swimming is not restricted to the front crawl stroke.

The occurrence of inspiratory muscle fatigue (IMF) has been documented after front crawl (FC) swimming of various distances. Whether IMF occurs after other competitive swimming strokes is not known. The aim of the present study was to assess the impact of all 4 competitive swimming strokes on the occurrence of IMF after race-paced swimming and to determine whether the magnitude of IMF was related to the breathing pattern adopted and hence breathing frequency (f(b)). Eleven, nationally ranked, youth swimmers completed four 200-m swims (one in each competitive stroke) on separate occasions. The order of the swims, which consisted of FC, backstroke (BK), breaststroke (BR), and butterfly (FLY), was randomized. Maximal inspiratory mouth pressure (MIP) was assessed before (after a swimming and inspiratory muscle warm-up) and after each swim with f(b) calculated post swim from recorded data. Inspiratory muscle fatigue was evident after each 200-m swim (p < 0.05) but did not differ between the 4 strokes (range 18-21%). No relationship (p > 0.05) was observed between f(b) and the change in MIP (FC: r = -0.456; BK: r = 0.218; BR: r = 0.218; and FLY: r = 0.312). These results demonstrate that IMF occurs in response to 200-m race-paced swimming in all strokes and that the magnitude of IMF is similar between strokes when breathing is ad libitum occurring no less than 1 breath (inhalation) every third stroke.