Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

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.

Indirect Calorimetry in Spontaneously Breathing, Mechanically Ventilated and Extracorporeally Oxygenated Patients: An Engineering Review

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), as well as to the sensors used in commercially available indirect calorimeters. The theoretical and technical aspects of IC in spontaneously breathing subjects and critically ill patients on mechanical ventilation and/or ECMO are covered and a critical review and comparison of the different techniques and sensors is provided. This review also aims to accurately present the physical quantities and mathematical concepts regarding IC to reduce errors and promote consistency in further research. By studying IC on ECMO from an engineering point of view rather than a medical point of view, new problem definitions come into play to further advance these techniques.

Inspiratory Muscle Rehabilitation Training in Pediatrics: What Is the Evidence?

Pulmonary rehabilitation is typically used for reducing respiratory symptoms and improving fitness and quality of life for patients with chronic lung disease. However, it is rarely prescribed and may be underused in pediatric conditions. Pulmonary rehabilitation can include inspiratory muscle training that improves the strength and endurance of the respiratory muscles. The purpose of this narrative review is to summarize the current literature related to inspiratory muscle rehabilitation training (IMRT) in healthy and diseased pediatric populations. This review highlights the different methods of IMRT and their effects on respiratory musculature in children. Available literature demonstrates that IMRT can improve respiratory muscle strength and endurance, perceived dyspnea and exertion, maximum voluntary ventilation, and exercise performance in the pediatric population. These mechanistic changes help explain improvements in symptomology and clinical outcomes with IMRT and highlight our evolving understanding of the role of IMRT in pediatric patients. There remains considerable heterogeneity in the literature related to the type of training utilized, training protocols, duration of the training, use of control versus placebo, and reported outcome measures. There is a need to test and refine different IMRT protocols, conduct larger randomized controlled trials, and include patient-centered clinical outcomes to help improve the evidence base and support the use of IMRT in patient care.

Evaluation of exercise-induced bronchoconstriction and rhinitis in adolescent elite swimmers

OBJECTIVE

Exercise-induced bronchoconstriction (EIB) without asthma and non-allergic rhinitis is frequently reported in athletes who are facing high-risk of airway dysfunctions such as elite swimmers. Therefore, we aimed to evaluate the effect of exercise on nasal and pulmonary functions, additionally to determine the prevalence of EIB and rhinitis in adolescent elite swimmers.

METHODS

The study included 47 adolescent licensed-swimmers (26 males and 21 females) aged between 10 and 17 years old. The prevalence of asthma and allergic disease and the symptom severity scores measured before and after swimming training were assessed through an interview form which includes information related to our study goal. In addition, acoustic rhinometry was utilized to evaluate nasal airway, spirometry was utilized to evaluate EIB in accordance with standard protocols.

RESULTS

Six swimmers had a history of allergic rhinitis (12.8%), while three (6.4%) had asthma. Post-swim mean forced vital capacity (FVC) was significantly higher than pre-swim FVC (p=0.019) and forced expiratory volume 1 (FEV-l)/FVC ratio was significantly lower than pre-swim FEV-l/FVC ratio (p=0.034). In addition, the prevalence of EIB was 8.5%. Moreover, level of nasal discharge statistically increased in post-swim period (p=0.003).

CONCLUSION

We have documented that swimming cause's nasal discharge but do not effect nasal passages. In addition, we observed that the overall prevalence of EIB in swimmers was not different from that of the general population, furthermore swimming exercise significantly increased FVC of swimmers. Therefore, we concluded swimming training can be recommended for children diagnosed with asthma or allergic rhinitis.

Effects of respiratory muscle training in soccer players: a systematic review with a meta-analysis

Respiratory muscle training can improve strength and reduce respiratory muscle fatigue during high-intensity exercise. Little is known about the existing evidence in soccer players. A systematic review with a meta-analysis was performed to analyse the existing evidence on the effects of respiratory muscle training in soccer players. Two independent researchers reviewed 17 databases until July 2019. Inclusion criteria were controlled clinical trials (randomised or not), soccer players (professional or recreational), females and/or males, and respiratory muscle training compared with simulated or regular training groups. The methodological quality and quality of evidence were evaluated with the Cochrane Collaboration Tool and GRADE score, respectively. Statistical analysis was performed using the integral meta-analysis 3.3.070. Nine studies met the eligibility criteria. The meta-analysis was performed for eight variables related to respiratory muscle function, lung function and sports performance. Respiratory muscle training provided a significant improvement compared with simulated or regular training in maximal inspiratory buccal pressure (6 studies, SDM = 0.89; 95 % CI = 0.42, 1.35) and maximum consumption of oxygen (3 studies, SDM = 0.92; 95 % CI = 0.24; 1.61). No significant improvements were observed for other variables. The quality of the evidence was rated as low or very low.

Change in short distance swimming performance following inspiratory muscle fatigue

BACKGROUND

Inspiratory muscle fatigue (IMF) may impair performance in a subsequent exercise. A few studies have reported that IMF decreased swimming performance in sub-maximal intensity or severe intensity domain. However, the impact of IMF on high-intensity short-duration swimming is not clear. The purpose of this study was to clarify the effect of pre-induced IMF on extreme intensity domain swimming.

METHODS

Seven male competitive swimmers swam two 100-m all-out front crawl swimming trials with and without pre-induced IMF. Maximal inspiratory and expiratory mouth pressure (PImax and PEmax, respectively) was used as indicators of inspiratory and expiratory muscle strength before and after swimming, and stroke parameters during swimming were measured. IMF was achieved by having the subjects breathe against an inspiratory pressure threshold load while generating 40% of their predetermined PImax for 10 min.

RESULTS

After the induction of IMF, swimming time (55.94 ± 1.15 s) was significantly slower compared with that in control swimming without IMF (54.09 ± 0.91 s) (p < 0.05). During swimming followed IMF, a significant decrease in stroke rate and a significant increase in stroke length were observed in the latter half of the 100-m swimming trial. In addition, the sense of dyspnea was significantly higher in swimming in the IMF condition than in control condition.

CONCLUSIONS

IMF prior to swimming negatively affects swimming performance in the extreme intensity domain. It is suggested that due to the dual use of respiration and generate propulsion in accessory respiratory muscles, IMF affected swimmers' ability to maintain swimming velocity.

Effect of inspiratory muscle-loaded exercise training on peak oxygen uptake and ventilatory response during incremental exercise under normoxia and hypoxia

Background

Although numerous studies have reported the effect of inspiratory muscle training for improving exercise performance, the outcome of whether exercise performance is improved by inspiratory muscle training is controversial. Therefore, this study investigated the influence of inspiratory muscle-loaded exercise training (IMLET) on peak oxygen uptake (VO_2peak), respiratory responses, and exercise performance under normoxic (N) and hypoxic (H) exercise conditions. We hypothesised that IMLET enhances respiratory muscle strength and improves respiratory response, thereby improving VO_2peak and work capacity under H condition.

Methods

Sixteen university track runners (13 men and 3 women) were randomly assigned to the IMLET (n = 8) or exercise training (ET) group (n = 8). All subjects underwent 4 weeks of 20-min 60% VO_2peak cycling exercise training, thrice per week. IMLET loaded 50% of maximal inspiratory pressure during exercise. At pre- and post-training periods, subjects performed exhaustive incremental cycling under normoxic (N; 20.9 ± 0%) and hypoxic (H; 15.0 ± 0.1%) conditions.

Results

Although maximal inspiratory pressure (PImax) significantly increased after training in both groups, the extent of PImax increase was significantly higher in the IMLET group (from 102 ± 20 to 145 ± 26 cmH₂O in IMLET; from 111 ± 23 to 127 ± 23 cmH₂O in ET; P < 0.05). In both groups, VO_2peak and maximal work load (W_max) similarly increased both under N and H conditions after training (P < 0.05). Further, the extent of W_max decrease under H condition was lower in the IMLET group at post-training test than at pre-training (from − 14.7 ± 2.2% to − 12.5 ± 1.7%; P < 0.05). Maximal minute ventilation in both N and H conditions increased after training than in the pre-training period.

Conclusions

Our IMLET enhanced the respiratory muscle strength, and the decrease in work capacity under hypoxia was reduced regardless of the increase in VO_2peak.

Effect of inspiratory resistive training on diaphragm shear modulus and accessory inspiratory muscle activation

This study aimed to elucidate changes in diaphragm and accessory inspiratory muscle (sternocleidomastoid (SCM) muscle and intercostal muscle (IC)) function after a 6-week training program. Nineteen male elite collegiate swimmers were assigned to either a control group (n = 9) or training group (n = 10). The subjects in the training group performed 30 maximum inspirations at a load resistance of 50% of maximum inspiratory mouth pressure (PImax) using an inspiratory muscle training device. These were conducted twice per day and 6 days per week. At baseline and after 6 weeks, PImax, shear modulus of the diaphragm, and electromyograms (EMG) of the SCM and IC during a maximal inspiratory maneuver were evaluated. Relative change in PImax was greater in the training group than in controls. The shear modulus during a PImax maneuver had increased significantly in both groups after 6 weeks. EMG amplitudes of the SCM increased in the training group after 6 weeks, but not in the control group. EMG amplitudes of the IC did not change after 6 weeks in either group. These results suggest that 6-week inspiratory resistive training significantly improves the activation of the SCM, which could be one of the major mechanisms behind increases in inspiratory muscle strength after resistive training. Novelty Six-week inspiratory resistive training increased diaphragm stiffness during maximal inspiration maneuver. Six-week inspiratory resistive training increased electromyogram amplitudes of the sternocleidomastoid during maximal inspiration maneuver.

The Effect of Respiratory Muscle Training on the Pulmonary Function, Lung Ventilation, and Endurance Performance of Young Soccer Players

This study investigated whether the addition of eight weeks of inspiratory muscle training (IMT) to a regular preseason soccer training program, including incremental endurance training (IET), would change pulmonary function, lung ventilation, and aerobic performance in young soccer players. Sixteen club-level competitive junior soccer players (mean age 17.63 ± 0.48 years, height 182 ± 0.05 cm, body mass 68.88 ± 4.48 kg) participated in the study. Participants were randomly assigned into two groups: experimental (n = 8) and control (n = 8). Both groups performed regular preseason soccer training, including endurance workouts as IET. In addition to this training, the experimental group performed additional IMT for eigght weeks with a commercially available respiratory muscle trainer (Threshold IMT), with a total of 80 inhalations (twice per day, five days per week). Pre- and post-intervention tests of pulmonary function, maximal inspiratory pressure, and the Cooper test were implemented. Eight weeks of IMT had a positive impact on expiratory muscle strength (p = 0.001); however, there was no significant effect on respiratory function parameters. The results also indicate increased efficiency of the inspiratory muscles, contributing to an improvement in aerobic endurance, measured by VO₂max estimated from running distance in the cardiorespiratory Cooper test (p < 0.005).

The effect of inspiratory muscle training on swimming performance, inspiratory muscle strength, lung function, and perceived breathlessness in elite swimmers: a randomized controlled trial

Background:

According to studies performed on terrestrial sports athletes, inspiratory muscle training (IMT) may improve athletes’ performance. However, evidence of its effects in elite swimmers is lacking. Therefore, we aimed to assess the effect of 12-week IMT on swimming performance, inspiratory muscle strength, lung function, and perceived breathlessness in elite swimmers.

Methods:

Elite swimmers from the main FC Porto swimming team (in competitive training for a minimum period of 3 years) were invited to participate and were randomly allocated into intervention or control groups. The intervention group performed 30 inspiratory efforts, twice a day, 5 times a week, against a pressure threshold load equivalent to 50% of maximal inspiratory pressure, whereas the control group performed inspiratory efforts at the same frequency but against a 15% load. Swimming performance was assessed through time trials, converted into points according to International Swimming Federation Points Table. Outcomes were evaluated before and following the 12-week study period.

Results:

A total of 32 participants (22 girls) were included. The median age was 15 and 14 years old for the intervention (n = 17) and control (n = 12) groups, respectively. No differences were found in swimming performance (P = .271), inspiratory muscle strength (P = .914), forced vital capacity (P = .262), forced expiratory volume in 1st second (P = .265), peak expiratory flow (P = .270), and perceived breathlessness (P = .568) between groups after 12 weeks of intervention.

Conclusion:

Twelve weeks of IMT had no effect on swimming performance, lung function, and perceived breathlessness in elite swimmers. These results may be related to swimming-specific factors and/or an applied load insufficient to achieve training overload that could induce further improvements.

Eight Weeks of Inspiratory Muscle Training Improves Pulmonary Function in Disabled Swimmers-A Randomized Trial

BACKGROUND

According to the literature, inspiratory muscle fatigue may increase after swimming training (ST). This study aimed to examine the efficacy of 8-week inspiratory muscular training (IMT) in disabled swimmers, combined with standard sports training, on selected parameters of lung ventilation and the function of respiratory muscles.

METHODS

A total of 16 disabled swimming division athletes from Wroclaw's 'Start' Regional Sports Association qualified for the study. The subjects were randomly divided into two groups (ST and IMT). Both groups participated in swimming training for 8 weeks (8 times a week). The IMT group additionally participated in inspiratory muscle training (8 weeks). In all respondents, a functional lung test and the respiratory muscle strength was measured.

RESULTS

After 8 weeks of training, a significant increase in ventilation parameters and respiratory muscle strength was observed only in the IMT group. In ST group 1, a 20% improvement in the strength of inspiratory muscles was achieved.

CONCLUSIONS

The inclusion of IMT is an important element that complements swimming training, allowing for greater increases in lung ventilation parameters and the strength of respiratory muscles in disabled swimmers.

Critical inspiratory pressure - a new methodology for evaluating and training the inspiratory musculature for recreational cyclists: study protocol for a randomized controlled trial

Background

Inspiratory muscle training (IMT) has brought great benefits in terms of improving physical performance in healthy individuals. However, there is no consensus regarding the best training load, as in most cases the maximal inspiratory pressure (MIP) is used, mainly the intensity of 60% of MIP. Therefore, prescribing an IMT protocol that takes into account inspiratory muscle strength and endurance may bring additional benefits to the commonly used protocols, since respiratory muscles differ from other muscles because of their greater muscular resistance. Thus, IMT using critical inspiratory pressure (PThC) can be an alternative, as the calculation of PThC considers these characteristics. Therefore, the aim of this study is to propose a new IMT protocol to determine the best training load for recreational cyclists.

Methods

Thirty recreational cyclists (between 20 and 40 years old) will be randomized into three groups: sham (SG), PThC (CPG) and 60% of MIP, according to age and aerobic functional capacity. All participants will undergo the following evaluations: pulmonary function test (PFT), respiratory muscle strength test (RMS), cardiopulmonary exercise test (CPET), incremental inspiratory muscle endurance test (iIME) (maximal sustained respiratory pressure for 1 min (PTh_MAX)) and constant load test (CLT) (95%, 100% and 105% of PTh_MÁX) using a linear load inspiratory resistor (PowerBreathe K5). The PThC will be calculated from the inspiratory muscle endurance time (T_LIM) and inspiratory loads of each CLT. The IMT will last 11 weeks (3 times/week and 55 min/session). The session will consist of 5-min warm-up (50% of the training load) and three sets of 15-min breaths (100% of the training load), with a 1-min interval between them. RMS, iIME, CLT and CPET will be performed beforehand, at week 5 and 9 (to adjust the training load) and after training. PFT will be performed before and after training. The data will be analyzed using specific statistical tests (parametric or non-parametric) according to the data distribution and their respective variances. A p value <0.05 will be considered statistically significant.

Discussions

It is expected that the results of this study will enable the training performed with PThC to be used by health professionals as a new tool to evaluate and prescribe IMT.

Trial registration

ClinicalTrials.gov, NCT02984189. Registered on 6 December 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3353-0) contains supplementary material, which is available to authorized users.

Putative Role of Respiratory Muscle Training to Improve Endurance Performance in Hypoxia: A Review

Respiratory/inspiratory muscle training (RMT/IMT) has been proposed to improve the endurance performance of athletes in normoxia. In recent years, due to the increased use of hypoxic training method among athletes, the RMT applicability has also been tested as a method to minimize adverse effects since hyperventilation may cause respiratory muscle fatigue during prolonged exercise in hypoxia. We performed a review in order to determine factors potentially affecting the change in endurance performance in hypoxia after RMT in healthy subjects. A comprehensive search was done in the electronic databases MEDLINE and Google Scholar including keywords: “RMT/IMT,” and/or “endurance performance,” and/or “altitude” and/or “hypoxia.” Seven appropriate studies were found until April 2018. Analysis of the studies showed that two RMT methods were used in the protocols: respiratory muscle endurance (RME) (isocapnic hyperpnea: commonly 10–30′, 3–5 d/week) in three of the seven studies, and respiratory muscle strength (RMS) (Powerbreathe device: commonly 2 × 30 reps at 50% MIP (maximal inspiratory pressure), 5–7 d/week) in the remaining four studies. The duration of the protocols ranged from 4 to 8 weeks, and it was found in synthesis that during exercise in hypoxia, RMT promoted (1) reduced respiratory muscle fatigue, (2) delayed respiratory muscle metaboreflex activation, (3) better maintenance of SaO₂ and blood flow to locomotor muscles. In general, no increases of maximal oxygen uptake (VO_2max) were described. Ventilatory function improvements (maximal inspiratory pressure) achieved by using RMT fostered the capacity to adapt to hypoxia and minimized the impact of respiratory stress during the acclimatization stage in comparison with placebo/sham. In conclusion, RMT was found to elicit general positive effects mainly on respiratory efficiency and breathing patterns, lower dyspneic perceptions and improved physical performance in conditions of hypoxia. Thus, this method is recommended to be used as a pre-exposure tool for strengthening respiratory muscles and minimizing the adverse effects caused by hypoxia related hyperventilation. Future studies will assess these effects in elite athletes.

Effect of high- and low-resistance inspiratory muscle training on physiological response to exercise in cross-country skiers

BACKGROUND

The aim of the study was to evaluate the effect of different kinds of respiratory muscle training (RMT) on work capacity and selected spirometric indices in trained male cross-country skiers.

METHODS

The study involved 13 competitively trained, elite Polish male cross-country skiers. The subjects were randomly divided into two groups who completed 7 weeks of RMT: one with gradually increasing resistance (power RMT) and the other with constant resistance (endurance RMT). Both groups' training programs consisted of 30 inspiratory maneuvers performed twice a day, 6 days a week. The first week of RMT started with a low resistance (29 cmH2O). In the following weeks, resistance in the power RMT group was gradually increased, while in the endurance RMT group, inspiratory resistance was maintained at a constant level of 53 cm H2O (36±8% PImax). Maximal inspiratory pressure (PImax), peak inspiratory flow rate (PIF), and stress test indices were measured before and after RMT. The stress test was conducted on a ski ergometer, with a gradual increase in intensity in all-out effort.

RESULTS

A significant increase in PImax, PIF, and exercise work capacity (test time, work output, and peak power) was noted in both groups. No significant changes were observed in the VO2max or the selected respiratory variables.

CONCLUSIONS

During a short training period (up to 7 weeks), the use of gradual and constant inspiratory resistance during RMT improves exercise and spirometric parameters in a similar way. RMT did not have a considerable impact on breathing efficiency in maximal effort.

Low-Volume High-Intensity Interval Versus Continuous Endurance Training: Effects on Hematological and Cardiorespiratory System Adaptations in Professional Canoe Polo Athletes

Sheykhlouvand, M, Gharaat, M, Khalili, E, Agha-Alinejad, H, Rahmaninia, F, and Arazi, H. Low-volume high-intensity interval versus continuous endurance training: effects on hematological and cardiorespiratory system adaptations in professional canoe polo athletes. J Strength Cond Res 32(7): 1852-1860, 2018-The aim of this study was to compare the effect of 2 paddling-based high-intensity interval training (HIIT) and continuous endurance training (CET) on hematological, immunological, and cardiorespiratory adaptations in professional canoe polo athletes. A total of 21 male canoe polo athletes were randomly divided into 1 of 3 groups (N = 7): (a) HIIT with variable intensity (VIHIIT) (6 × 60 seconds at 100, 110, 120, 130, 130, 130, 120, 110, 100% vV[Combining Dot Above]O2peak from first to ninth session, respectively, 1:3 work to recovery ratio); (b) HIIT with variable volume (VVHIIT) (6, 7, 8, 9, 9, 9, 8, 7, 6 repetitions/session from first to ninth session, respectively) × 60 seconds at lowest velocity that elicited V[Combining Dot Above]O2peak (vV[Combining Dot Above]O2peak), 1:3 work to recovery ratio); and (c) the CET group performed 3 times × 60 minutes paddling sessions (75% vV[Combining Dot Above]O2peak) per week for 3 weeks. Significant increases in V[Combining Dot Above]O2peak (ml·kg·min) (VIHIIT = 7.6%, VVHIIT = 6.7%), ventilation (V[Combining Dot Above]E) at V[Combining Dot Above]O2peak (VIHIIT = 11.5%, VVHIIT = 15.2%), respiratory frequency (Rf) at V[Combining Dot Above]O2peak (VVHIIT = 21.1%), V[Combining Dot Above]O2 at ventilatory threshold (VT) (VIHIIT = 10.5%, VVHIIT = 25.1%), V[Combining Dot Above]E at VT (VIHIIT = 12.4%, VVHIIT = 34.0%), tidal volume at VT (VIHIIT = 11.7%, VVHIIT = 33.3%), Rf at VT (VIHIIT = 9.7%), V[Combining Dot Above]E/V[Combining Dot Above]O2 at VT (VVHIIT = 13.1%), V[Combining Dot Above]O2/heart rate (HR) at VT (VIHIIT = 12.9%, VVHIIT = 21.4%), and V[Combining Dot Above]E/HR at VT (VIHIIT = 7.8%, VVHIIT = 27.2%) were seen compared with pretraining. Training interventions resulted in significant increases in mean platelet volume (VIHIIT = 2.7%, VVHIIT = 1.9%), mean corpuscular hemoglobin concentration (CET = 3.3%), and significant decrease in red blood cell distribution width (VVHIIT = -4.3), and cell numbers of lymphocyte (CET = -27.1) compared with pretraining. This study demonstrated that paddling-based HIIT enhances aerobic capacity and respiratory makers, without negatively affecting the immune system over 3 weeks.

Effects of expiratory muscle training on the frail elderly's respiratory function

[Purpose] The present study examined the effects of expiratory muscle training on elderly day care service users, who had been classified into Care Grades 1 and 2 based on Japan’s long-term care insurance system. [Subjects and Methods] Intervention was provided for 29 Care Grade 1 or 2 day care service users. During intervention, expiratory muscle training was performed by slowly expiring using the abdominal muscles and a device after maximal inspiration. Each intervention session lasted for approximately 10 minutes, and 2 sessions were held weekly for 3 months to compare respiratory function test values before and after intervention. [Results] The results were favorable. The vital capacity (VC) and peak expiratory flow (PEF) significantly varied between before and after intervention. [Conclusion] Expiratory muscle training generally improved their respiratory function, particularly their VC and PEF that significantly varied between before and after intervention. As both of these items influence the cough capacity, they may be key to the prevention of aspiration pneumonia. Expiratory muscle training may also contribute to activities of daily living (ADL) and the quality of life, and it is expected to play an important role in rehabilitation as a field of preventive medicine.

Influence of Inspiratory Muscle Training on Ventilatory Efficiency and Cycling Performance in Normoxia and Hypoxia

The aim of this study was to analyse the influence of inspiratory muscle training (IMT) on ventilatory efficiency, in normoxia and hypoxia, and to investigate the relationship between ventilatory efficiency and cycling performance. Sixteen sport students (23.05 ± 4.7 years; 175.11 ± 7.1 cm; 67.0 ± 19.4 kg; 46.4 ± 8.7 ml·kg⁻¹·min⁻¹) were randomly assigned to an inspiratory muscle training group (IMTG) and a control group (CG). The IMTG performed two training sessions/day [30 inspiratory breaths, 50% peak inspiratory pressure (Pimax), 5 days/week, 6-weeks]. Before and after the training period subjects carried out an incremental exercise test to exhaustion with gas analysis, lung function testing, and a cycling time trial test in hypoxia and normoxia. Simulated hypoxia (FiO₂ = 16.45%), significantly altered the ventilatory efficiency response in all subjects (p < 0.05). Pimax increased significantly in the IMTG whereas no changes occurred in the CG (time × group, p < 0.05). Within group analyses showed that the IMTG improved ventilatory efficiency (V_E/VCO₂ slope; EqCO₂VT₂) in hypoxia (p < 0.05) and cycling time trial performance [W_{TTmax (W)}; W_{TTmean (W)}; PTF_(W)] (p < 0.05) in hypoxia and normoxia. Significant correlations were not found in hypoxia nor normoxia found between ventilatory efficiency parameters (V_E/VCO₂ slope; LEqCO₂; EqCO₂VT₂) and time trial performance. On the contrary the oxygen uptake efficiency slope (OUES) was highly correlated with cycling time trial performance (r = 0.89; r = 0.82; p < 0.001) under both conditions. Even though no interaction effect was found, the within group analysis may suggest that IMT reduces the negative effects of hypoxia on ventilatory efficiency. In addition, the data suggest that OUES plays an important role in submaximal cycling performance.

Effects of inspiratory muscle training on respiratory muscle electromyography and dyspnea during exercise in healthy men

Inspiratory muscle training (IMT) has consistently been shown to reduce exertional dyspnea in health and disease; however, the physiological mechanisms remain poorly understood. A growing body of literature suggests that dyspnea intensity can be explained largely by an awareness of increased neural respiratory drive, as measured indirectly using diaphragmatic electromyography (EMGdi). Accordingly, we sought to determine whether improvements in dyspnea following IMT can be explained by decreases in inspiratory muscle electromyography (EMG) activity. Twenty-five young, healthy, recreationally active men completed a detailed familiarization visit followed by two maximal incremental cycle exercise tests separated by 5 wk of randomly assigned pressure threshold IMT or sham control (SC) training. The IMT group (n = 12) performed 30 inspiratory efforts twice daily against a 30-repetition maximum intensity. The SC group (n = 13) performed a daily bout of 60 inspiratory efforts against 10% maximal inspiratory pressure (MIP), with no weekly adjustments. Dyspnea intensity was measured throughout exercise using the modified 0-10 Borg scale. Sternocleidomastoid and scalene EMG was measured using surface electrodes, whereas EMGdi was measured using a multipair esophageal electrode catheter. IMT significantly improved MIP (pre: -138 ± 45 vs. post: -160 ± 43 cmH₂O, P < 0.01), whereas the SC intervention did not. Dyspnea was significantly reduced at the highest equivalent work rate (pre: 7.6 ± 2.5 vs. post: 6.8 ± 2.9 Borg units, P < 0.05), but not in the SC group, with no between-group interaction effects. There were no significant differences in respiratory muscle EMG during exercise in either group. Improvements in dyspnea intensity ratings following IMT in healthy humans cannot be explained by changes in the electrical activity of the inspiratory muscles.NEW & NOTEWORTHY Exertional dyspnea intensity is thought to reflect an increased awareness of neural respiratory drive, which is measured indirectly using diaphragmatic electromyography (EMGdi). We examined the effects of inspiratory muscle training (IMT) on dyspnea, EMGdi, and EMG of accessory inspiratory muscles. IMT significantly reduced submaximal dyspnea intensity ratings but did not change EMG of any inspiratory muscles. Improvements in exertional dyspnea following IMT may be the result of nonphysiological factors or physiological adaptations unrelated to neural respiratory drive.

Special Training of Inspiratory Muscles in Fitness Activities and Exercise Capacity in Young Women

Purpose. The aim of the study was to determine if an 8-week-long endurance fitness training with elastic belts would increase the strength-endurance of the inspiratory muscles and lung function characteristics, and to assess whether these changes were consistent with an increase in aerobic power and exercise capacity in healthy young women. Methods. Twenty-two females aged 20-25 years were randomly allocated into 2 groups. The experimental group preformed 8-week-long exercises on stationary bikes with an elastic belt on the lower part of the chest. The control group underwent the same workout, without elastic belts. Vital capacity, forced vital capacity, maximal voluntary ventilation, maximal inspiratory and expiratory pressure, sustained maximal inspiratory pressure, physical activity status, and perceived exertion scores were measured. In the incremental exercise test, work capacity and maximal oxygen uptake were assessed. Tidal volume, minute ventilation (VE), oxygen uptake (VO

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.

The effect of exercise training with an additional inspiratory load on inspiratory muscle fatigue and time-trial performance

The purpose was to determine the effect of moderate-intensity exercise training (ET) on inspiratory muscle fatigue (IMF) and if an additional inspiratory load during ET (ET+IL) would further improve inspiratory muscle strength, IMF, and time-trial performance. 15 subjects were randomly divided to ET (n=8) and ET+IL groups (n=7). All subjects completed six weeks of exercise training three days/week at ∼70%V̇O2peak for 30min. The ET+IL group breathed through an inspiratory muscle trainer (15% PImax) during exercise. 5-mile, and 30-min time-trials were performed pre-training, weeks three and six. Inspiratory muscle strength increased (p<0.05) for both groups to a similar (p>0.05) extent. ET and ET+IL groups improved (p<0.05) 5-mile time-trial performance (∼10% and ∼18%) and the ET+IL group was significantly faster than ET at week 6. ET and ET+IL groups experienced less (p<0.05) IMF compared to pre-training following the 5-mile time-trial. In conclusion, these data suggest ET leads to less IMF, ET+IL improves inspiratory muscle strength and IMF, but not different than ET alone.

Human Physiology in an Aquatic Environment

Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system.

Forced inspiratory volume in the first second as predictor of front-crawl performance in young sprint swimmers

The purposes of this study were to determine the extent to which specific anthropometric, conditional, and pulmonary function variables predict 100-m front-crawl performance in national swimmers and compare anthropometric, conditional, and pulmonary function variables between both genders. Two groups (male, n = 8 and female, n = 9) of sprint swimmers (mean age ± SD = 19.4 ± 0.7 years and 16.9 ± 3.2 years, respectively) of national competitive level volunteered for this study. Swimmers performed an all-out 100-m front-crawl swimming test. Physiological parameters of lung function were measured using portable spirometer. Basic anthropometry included body height, body mass, and skinfold thickness. Lower limb strength was measured by countermovement and squat jump tests. Correlation and regression analyses were calculated to quantify the relationships between trial time and each variable potentially predictive. Differences between means of both gender groups were analyzed. Results showed that 100-m race performance correlated significantly with forced inspiratory volume in the first second (FIV1) in male swimmers and with FIV1 and forced vital capacity in female swimmers. Stepwise multiple regressions revealed that FIV1 was the only predictor of 100-m race performance, explaining 66% of 100-m time trial variance in male swimmers and 58% in female swimmers. Gender comparisons indicated significant differences in anthropometric, conditional, pulmonary function, and performance variables. The findings suggest that FIV1 could be a good predictor of performance and it should be evaluated routinely and used by coaches in front-crawl sprint swimmers.

Acute versus chronic supplementation of sodium citrate on 200 m performance in adolescent swimmers

BACKGROUND

A double-blinded, placebo-controlled, cross-over design was used to investigate whether two different sodium citrate dihydrate (Na-CIT) supplementation protocols improve 200 m swimming performance in adolescent swimmers.

METHODS

Ten, male swimmers (14.9 ± 0.4 years of age; 63.5 ± 4 kg) performed four 200 m time trials with the following treatments: acute (ACU) supplementation (0.5 g kg(-1) administered 120 min pre-trial), acute placebo (PLC-A), chronic (CHR) supplementation (0.1 g∙kg(-1) for three days and 0.3 g kg(-1) on the forth day 120 min pre-trial), and chronic placebo (PLC-C). The order of the trials was randomized, with at least a six-day wash-out period between trials. Blood samples were collected by finger prick pre-ingestion, 100 min post-ingestion, and 3 min post-trial. Performance time, rate of perceived exertion, pH, base excess, bicarbonate and lactate concentration were measured.

RESULTS

Post-ingestion bicarbonate and base excess were higher (P < 0.05) in both the ACU and CHR trials compared to placebo showing adequate pre-exercise alkalosis. However, performance time, rate of perceived exertion as well as post-trial pH and lactate concentration were not significantly different between trials. Further analysis revealed that five swimmers, identified as responders, improved their performance time by 1.03% (P < 0.05) and attained higher post-trial lactate concentrations in the ACU versus PLC-A trial (P < 0.05). They also had significantly higher post-trial lactate concentrations compared to the non-responders in the ACU and CHR trials.

CONCLUSIONS

Acute supplementation of Na-CIT prior to 200 m swimming performance led to a modest time improvement and higher blood lactate concentrations in only half of the swimmers while the chronic Na-CIT supplementation did not provide any ergogenic effect in this group of adolescent swimmers.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01835912.

Inspiratory and expiratory respiratory muscle training as an adjunct to concurrent strength and endurance training provides no additional 2000 m performance benefits to rowers

The purpose of this study was to examine respiratory muscle training (RMT) combined with 9 weeks of resistance and endurance training on rowing performance and cardiopulmonary responses. Twenty-seven rowers (mean ± SD: age = 27 ± 9 years; height = 176.9 ± 10.8 cm; and body mass = 76.1 ± 12.6 kg) were randomly assigned to an inspiratory only (n = 13) or expiratory only (n = 14) training group. Both RMT programs were 3 sets of 10 reps, 6 d/wk in addition to an identical 3 d/wk resistance and 3 d/wk endurance training program. Both groups showed similar improvements in 2000 m rowing performance, cardiorespiratory fitness, strength, and maximum inspiratory (PImax) and expiratory (PEmax) pressures (p < .05). It was concluded that there were no additional benefits of 9 weeks of inspiratory or expiratory RMT on simulated 2000 m rowing performance or cardiopulmonary responses when combined with resistance and endurance training in rowers.

Effects of concurrent respiratory resistance training on health-related quality of life in wheelchair rugby athletes: a pilot study

PURPOSE

To compare the effects of 9 weeks of training with a concurrent flow resistance (CFR) device versus a concurrent pressure threshold resistance (CPTR) device on health-related quality of life (HRQoL) in wheelchair rugby (WR) athletes.

METHOD

Twenty-four male WR athletes (22 with tetraplegia, 1 with a spastic cerebral palsy, and 1 with congenital upper and lower limb deformities) were matched by lesion level, completeness of injury, and rugby classification prior to being randomly assigned to 1 of 3 groups: (1) CPTR (n=8), (2) CFR (n=8), or (3) controls (CON, n=8). Pre/post testing included assessment of HRQoL as measured by the Short-Form Health Survey Version 2.0 (SF-36v2). Manufacturer protocol guidelines for the CFR and CPTR groups were followed for breathing exercises.

RESULTS

Sixteen participants completed the study (CPTR=4, CFR=5, CON=7). The Mann-Whitney U rank order revealed significantly greater reductions in bodily pain (P = .038) and improvements in vitality (P = .028) for CFR versus CON.

CONCLUSION

Results from this study suggest that training with a CFR device improves some aspects of HRQoL (eg, vitality and bodily pain) in WR athletes. Further research with a larger sample size is needed to examine the impact of these devices on improving HRQoL for wheelchair athletes.

Exercise-training intervention studies in competitive swimming

Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three sets in relevant muscle-groups (ES 1.05), and after a regimen of resisted- and assisted-sprint training with elastic surgical tubes (ES 1.21). Secondly, several studies suggest that high training volumes do not pose any immediate advantage over lower volumes (with higher intensity) for swim performance. Overall, very few studies were eligible for the current review although the search strategy was broad and fairly liberal. The included studies predominantly involved freestyle swimming and, overall, there seems to be more questions than answers within intervention-based competitive swimming research. We believe that this review may encourage other researchers to pursue the interesting topics within the physiology of competitive swimming.

Inspiratory muscle training lowers the oxygen cost of voluntary hyperpnea

The purpose of this study was to determine if inspiratory muscle training (IMT) alters the oxygen cost of breathing (V̇o2RM) during voluntary hyperpnea. Sixteen male cyclists completed 6 wk of IMT using an inspiratory load of 50% (IMT) or 15% placebo (CON) of maximal inspiratory pressure (Pimax). Prior to training, a maximal incremental cycle ergometer test was performed to determine V̇o2and ventilation (V̇E) at multiple workloads. Pre- and post-training, subjects performed three separate 4-min bouts of voluntary eucapnic hyperpnea (mimic), matching V̇Ethat occurred at 50, 75, and 100% of V̇o2 max. Pimaxwas significantly increased ( P < 0.05) by 22.5 ± 8.7% from pre- to post-IMT and remained unchanged in the CON group. The V̇o2RMrequired during the mimic trial corresponded to 5.1 ± 2.5, 5.7 ± 1.4, and 11.7% ± 2.5% of the total V̇o2(V̇o2T) at ventilatory workloads equivalent to 50, 75, and 100% of V̇o2 max, respectively. Following IMT, the V̇o2RMrequirement significantly decreased ( P < 0.05) by 1.5% (4.2 ± 1.4% of V̇o2T) at 75% V̇o2 maxand 3.4% (8.1 ± 3.5% of V̇o2T) at 100% V̇o2 max. No significant changes were shown in the CON group. IMT significantly reduced the O2cost of voluntary hyperpnea, which suggests that a reduction in the O2requirement of the respiratory muscles following a period of IMT may facilitate increased O2availability to the active muscles during exercise. These data suggest that IMT may reduce the O2cost of ventilation during exercise, providing an insight into mechanism(s) underpinning the reported improvements in whole body endurance performance; however, this awaits further investigation.

Remote preconditioning improves maximal performance in highly trained athletes

BACKGROUND

Remote ischemic preconditioning (RIPC) induced by transient limb ischemia releases a dialysable circulating protective factor that reduces ischemia-reperfusion injury. Exercise performance in highly trained athletes is limited by tissue hypoxemia and acidosis, which may therefore represent a type of ischemia-reperfusion stress modifiable by RIPC.

METHODS AND RESULTS

National-level swimmers, 13-27 yr, were randomized to RIPC (four cycles of 5-min arm ischemia/5-min reperfusion) or a low-pressure control procedure, with crossover. In study 1, subjects (n=16) performed two incremental submaximal swimming tests with measurement of swimming velocity, blood lactate, and HR. For study 2, subjects (n=18) performed two maximal competitive swims (time trials). To examine possible mechanisms, blood samples taken before and after RIPC were dialysed and used to perfuse mouse hearts (n=10) in a Langendorff preparation. Infarct sizes were compared with dialysate obtained from nonathletic controls. RIPC released a protective factor into the bloodstream, which reduced infarct size in mice (P<0.05 for controls and swimmers). There was no statistically significant difference between the effect of RIPC and the low-pressure control protocol on submaximal exercise performance. However, RIPC was associated with a mean improvement of maximal swim time for 100 m of 0.7 s (P=0.04), an improvement in swim time relative to personal best time (-1.1%, P=0.02), and a significant improvement in average International Swimming Federation points (+22 points, P=0.01).

CONCLUSIONS

RIPC improves maximal performance in highly trained swimmers. This simple technique may be applicable to other sports and, more importantly, to other clinical syndromes in which exercise tolerance is limited by tissue hypoxemia or ischemia.

Concurrent respiratory resistance training and changes in respiratory muscle strength and sleep in an individual with spinal cord injury: case report

CONTEXT

Quality sleep possesses numerous benefits to normal nighttime and daytime functioning. High-level spinal cord injury (SCI) often impacts the respiratory muscles that can lead to poor respiratory function during sleep and negatively affect sleep quality. The impact of respiratory muscle training (RMT) on sleep quality, as assessed by overnight polysomnography (PSG), is yet to be determined among the spinal cord-injured population. This case report describes the effects of 10 weeks of RMT on the sleep quality of a 38-year-old male with cervical SCI.

METHODS

Case report.

FINDINGS/RESULTS

The subject completed overnight PSG, respiratory muscle strength assessment, and subjective sleepiness assessment before and after 10 weeks of RMT. The post-test results indicated improvements in sleep quality (e.g. fewer electroencephalographic (EEG) arousals during sleep) and daytime sleepiness scores following RMT.

CONCLUSION/CLINICAL RELEVANCE

Respiratory activity has been proven to impact EEG arousal activity during sleep. Arousals during sleep lead to a fragmented sleeping pattern and affect sleep quality and daytime function. Our subject presented with a typical sleep complaint of snoring and excessive sleepiness. The subject's pre-test PSG demonstrated a large number of arousals during sleep. It is important for all individuals complaining of problems during sleep or daytime problems associated with sleep (i.e. excessive daytime sleepiness) to seek medical attention and proper evaluation.

Chest wall volume changes during inspiratory loaded breathing

We assessed the effect of inspiratory loaded breathing (ILB) on respiratory muscle strength and investigated the extent to which respiratory muscle fatigue is associated with chest wall volume changes during ILB. Twelve healthy subjects performed ILB at 76 ± 11% of maximal inspiratory mouth pressure (MIP) for 1h. MIP and breathing pattern during 3 min of normocapnic hyperpnea (NH) were measured before and after ILB. Breathing pattern and chest wall volume changes were assessed by optoelectronic plethysmography. After ILB, six subjects decreased MIP significantly (-16 ± 10%; p < 0.05), while the other six subjects did not (0 ± 7%, p = 0.916). Only subjects with decreased MIP after ILB lowered end-expiratory rib cage volume (volume at which inspiration is initiated) below resting values during ILB. During NH after ILB, tidal volume was smaller in subjects with decreased MIP (-19 ± 16%, p < 0.05), while it remained unchanged in the other group (-3 ± 11%, p = 0.463). These results suggest that respiratory muscle fatigue depends on the lung volume from which inspiratory efforts are made during ILB.

Ventilatory function in breath-hold divers: effect of glossopharyngeal insufflation

This study was conducted to determine whether ventilatory parameters would change in breath-hold divers (BHDs) after they performed the glossopharyngeal technique for lung insufflation. Fifteen elite BHDs, 16 non-expert BHDs and 15 control subjects participated in this cross-sectional study. Volumes and expiratory flow rates were measured twice, before and after the glossopharyngeal technique performed at rest. Before the technique, greater forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) and lower FEV(1)/FVC were noted in the elite and non-expert BHDs compared with controls. No difference was noted regarding the other pulmonary parameters. After the technique, increases were noted in FVC, FEV(1) and maximal voluntary ventilation in the elite BHDs (P < 0.001, respectively). The FEF(25-75%)/FVC ratios were lower in the BHDs both before and after the technique, indicating possible dysanapsis. The ventilatory parameters observed after the glossopharyngeal technique indicated (1) higher lung volumes in expert BHDs and (2) a correlation with BHD performance (maximal dynamic BH performance). This correlation became more significant after the technique, indicating a positive effect of glossopharyngeal insufflation on performance.

Aquatic therapy: scientific foundations and clinical rehabilitation applications

The aquatic environment has broad rehabilitative potential, extending from the treatment of acute injuries through health maintenance in the face of chronic diseases, yet it remains an underused modality. There is an extensive research base supporting aquatic therapy, both within the basic science literature and clinical literature. This article describes the many physiologic changes that occur during immersion as applied to a range of common rehabilitative issues and problems. Because of its wide margin of therapeutic safety and clinical adaptability, aquatic therapy is a very useful tool in the rehabilitative toolbox. Through a better understanding of the applied physiology, the practitioner may structure appropriate therapeutic programs for a diverse patient population.

Exercise and physical activity in children with cystic fibrosis

Regular exercise and habitual physical activity are important for patients with cystic fibrosis (CF). Research has demonstrated the benefits of aerobic, anaerobic, and strength exercise training programs for health and quality of life, however, the CF patient is faced with unique barriers and challenges to participation. Recently, increased levels of habitual physical activity have been shown to slow the decline in lung function in patients with CF, and regular participation in a variety of activities may result in greater adherence in the long term. Research is now available to justify the incorporation of exercise into the routine care of patients with CF. This paper provides the background and rationale for the implementation of exercise and habitual physical activity recommendations by the health care team. Education of health care providers regarding the importance of exercise and habitual physical activity for patients with CF is needed in order for exercise and physical activity to be incorporated as key components of clinical practice and into the lives of patients with CF.

Assessment of physiological capacities of elite athletes & respiratory limitations to exercise performance

Physiological assessment of athletes is an important process for the characterization of the athlete, monitoring progress and the trained state or 'level of preparedness' of an athlete, as well as aiding the process of training program design. Interestingly, the majority of physiological assessments performed on athletes can also be performed on children with disease, and therefore clinicians can learn a great deal about physiology and assessment of patient populations through the examination of the physiological responses of elite athletes. This review describes typical physiological responses of elite athletes to tests of aerobic and anaerobic metabolism and provides a specific focus upon respiratory limitations to exercise performance. Typical responses of elite athletes are described to provide the scientist and clinician with a perspective of the upper range of physiological capacities of elite athletes.

Inspiratory flow resistive loading improves respiratory muscle function and endurance capacity in recreational runners

The purpose of this study was to assess the efficacy of inspiratory flow resistive loading (IFRL) on respiratory muscle function, exercise performance and cardiopulmonary and metabolic responses to exercise. Twenty-four recreational road runners (12 male) were randomly assigned from each gender into an IFRL group (n=8) and sham-IFRL group (n=8), which performed IFRL for 6 weeks, or a control group (n=8). Strength (+43.9%Delta), endurance (+26.6%Delta), maximum power output (+41.9%Delta) and work capacity (+38.5%Delta) of the inspiratory muscles were significantly increased (P<0.05) at rest following the study period in IFRL group only. In addition, ventilation (-25.7%Delta), oxygen consumption (-13.3%Delta), breathing frequency (-11.9%Delta), tidal volume (-16.0%Delta), heart rate (HR) (-13.1%Delta), blood lactate concentration (-38.9%Delta) and the perceptual response (-33.5%Delta) to constant workload exercise were significantly attenuated (P<0.05), concomitant with a significant improvement (P<0.05) in endurance exercise capacity (+16.4%Delta) during a treadmill run set at 80% VO2max in IFRL group only. These data suggest that IFRL can alter breathing mechanics, attenuate the oxygen cost, ventilation, HR, blood lactate and the perceptual response during constant workload exercise and improve endurance exercise performance in recreational runners.