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Controlled-frequency breath swimming improves swimming performance and running economy
Abstract
Respiratory muscle fatigue can negatively impact athletic performance, but swimming has beneficial effects on the respiratory system and may reduce susceptibility to fatigue. Limiting breath frequency during swimming further stresses the respiratory system through hypercapnia and mechanical loading and may lead to appreciable improvements in respiratory muscle strength. This study assessed the effects of controlled-frequency breath (CFB) swimming on pulmonary function. Eighteen subjects (10 men), average (standard deviation) age 25 (6) years, body mass index 24.4 (3.7) kg/m(2) , underwent baseline testing to assess pulmonary function, running economy, aerobic capacity, and swimming performance. Subjects were then randomized to either CFB or stroke-matched (SM) condition. Subjects completed 12 training sessions, in which CFB subjects took two breaths per length and SM subjects took seven. Post-training, maximum expiratory pressure improved by 11% (15) for all 18 subjects (P < 0.05) while maximum inspiratory pressure was unchanged. Running economy improved by 6 (9)% in CFB following training (P < 0.05). Forced vital capacity increased by 4% (4) in SM (P < 0.05) and was unchanged in CFB. These findings suggest that limiting breath frequency during swimming may improve muscular oxygen utilization during terrestrial exercise in novice swimmers.
... However, applying breath-holding differently, that is, integrated in regular training sessions, may reveal some benefits for improving performance indicators (Figure 1, lower part). First, restricted breathing frequency, also called voluntary hypoventilation, during swimming, either at high (Karaula et al., 2016;Lavin et al., 2015) or at low (Trincat et al., 2017;Woorons et al., 2016) end-expiratory lung volume, has been shown to improve 100 m to 400 m swimming performance (Karaula et al., 2016;Lavin et al., 2015;Woorons et al., 2016) but not 50 m performance (Lemaitre et al., 2009) norV O 2 peak (Lavin et al., 2015;Woorons et al., 2008Woorons et al., , 2016. This method is effective in eliciting both hypoxic and hypercapnic stress although it is difficult to discern their respective effects . ...
... However, applying breath-holding differently, that is, integrated in regular training sessions, may reveal some benefits for improving performance indicators (Figure 1, lower part). First, restricted breathing frequency, also called voluntary hypoventilation, during swimming, either at high (Karaula et al., 2016;Lavin et al., 2015) or at low (Trincat et al., 2017;Woorons et al., 2016) end-expiratory lung volume, has been shown to improve 100 m to 400 m swimming performance (Karaula et al., 2016;Lavin et al., 2015;Woorons et al., 2016) but not 50 m performance (Lemaitre et al., 2009) norV O 2 peak (Lavin et al., 2015;Woorons et al., 2008Woorons et al., , 2016. This method is effective in eliciting both hypoxic and hypercapnic stress although it is difficult to discern their respective effects . ...
... However, applying breath-holding differently, that is, integrated in regular training sessions, may reveal some benefits for improving performance indicators (Figure 1, lower part). First, restricted breathing frequency, also called voluntary hypoventilation, during swimming, either at high (Karaula et al., 2016;Lavin et al., 2015) or at low (Trincat et al., 2017;Woorons et al., 2016) end-expiratory lung volume, has been shown to improve 100 m to 400 m swimming performance (Karaula et al., 2016;Lavin et al., 2015;Woorons et al., 2016) but not 50 m performance (Lemaitre et al., 2009) norV O 2 peak (Lavin et al., 2015;Woorons et al., 2008Woorons et al., , 2016. This method is effective in eliciting both hypoxic and hypercapnic stress although it is difficult to discern their respective effects . ...
Acute breath‐holding (apnoea) induces a spleen contraction leading to a transient increase in haemoglobin concentration. Additionally, the apnoea‐induced hypoxia has been shown to lead to an increase in erythropoietin concentration up to 5 h after acute breath‐holding, suggesting long‐term haemoglobin enhancement. Given its potential to improve haemoglobin content, an important determinant for oxygen transport, apnoea has been suggested as a novel training method to improve aerobic performance. This review aims to provide an update on the current state of the literature on this topic. Although the apnoea‐induced spleen contraction appears to be effective in improving oxygen uptake kinetics, this does not seem to transfer into immediately improved aerobic performance when apnoea is integrated into a warm‐up. Furthermore, only long and intense apnoea protocols in individuals who are experienced in breath‐holding show increased erythropoietin and reticulocytes. So far, studies on inexperienced individuals have failed to induce acute changes in erythropoietin concentration following apnoea. As such, apnoea training protocols fail to demonstrate longitudinal changes in haemoglobin mass and aerobic performance. The low hypoxic dose, as evidenced by minor oxygen desaturation, is likely insufficient to elicit a strong erythropoietic response. Apnoea therefore does not seem to be useful for improving aerobic performance. However, variations in apnoea, such as hypoventilation training at low lung volume and repeated‐sprint training in hypoxia through short end‐expiratory breath‐holds, have been shown to induce metabolic adaptations and improve several physical qualities. This shows promise for application of dynamic apnoea in order to improve exercise performance.
... The literature on studies on the week-to week variability in DLNO is scarce. From what is known to date, the reproducibility of DLNO is about ∼19−20 mL minmmHg −1 in healthy subjects (Desjardin et al., 2020;Lavin et al., 2015;Murias and Zavorsky, 2007) and about 13 mL min mmHg −1 in those with cystic fibrosis (Radtke et al., 2017). This is equivalent to about a 13-14 % week-to-week coefficient of variation in healthy individuals and in those with cystic fibrosis. ...
... This is equivalent to about a 13-14 % week-to-week coefficient of variation in healthy individuals and in those with cystic fibrosis. The reproducibility of DLCO is about ∼4−5 mL min mmHg −1 in both healthy subjects, those with cystic fibrosis and emphysema (Desjardin et al., 2020;Lavin et al., 2015;Murias and Zavorsky, 2007;Radtke et al., 2017;Robson and Innes, 2001). This is equivalent to about a ∼10 % week-to-week coefficient of variation in healthy individuals and about ∼17 to ∼35 % in those with cystic fibrosis and emphysema, respectively. ...
... The purpose of this study was to determine the week-to-week variability (reproducibility) of DLNO (4 s) and DLCO (4 s and 10 s) in a group of heart failure patients. In this group of heart failure patients, the reproducibility was about 19 mL min mmHg −1 for DLNO, which is similar to healthy subjects (Desjardin et al., 2020;Lavin et al., 2015;Murias and Zavorsky, 2007). As such, the smallest measurable change in DLNO, using less stringent criteria would be about 10 mL min mmHg −1 in heart failure patients, which is similar to the smallest measurable change of DLNO in the 2017 ERS technical standards paper (Zavorsky et al., 2017). ...
Background
As pulmonary diffusing capacity is related to mortality risk and prognosis in patients with heart failure (HF), it is measured frequently. As such, it would be essential to know the week-to-week variability (reproducibility) of pulmonary diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO). This variability would let clinicians understand what a clinically measurable change in DLCO and DLNO would be in these patients.
Methods
On three different days spanning over ten weeks, 40 H F patients underwent testing for DLCO and DLNO. DLCO was determined after a 4 s and 10 s breath-hold maneuver, while DLNO was determined after a 4 s breath-hold maneuver.
Results
Forty heart failure patients (66 ± 10 years; BMI = 28.4 ± 4.6 kg∙m⁻²; 28 males), that were referred to our clinic were able to complete the protocol. DLCO (4 s breath-hold) and DLNO (4 s breath-hold) were 79 ± 19% and 59 ± 14% predicted, respectively. Fifty percent of patients (n = 20) were below the lower limit of normal (LLN, below the 5th percentile) for predicted DLCO (4 s), while 78% of patients (n = 31) were below the LLN for predicted DLNO. All 16 patients that were below the LLN for DLCO were also below the LLN for DLNO. Over a ten week period, the reproducibility of DLNO (4 s) DLCO (4 s) and DLCO (10 s) was 18.9, 8.2, and 5.9 mL min·mmHg⁻¹, respectively.
Conclusions
The week-to-week fluctuation in DLNO (4 s), as a percentage, is less than DLCO (4 s) in patients with HF. The reproducibility of DLNO in patients with HF is like that of healthy subjects.
... Der Interventionszeitraum umfasste zwei [19] bis 16 Wochen [18]. Sechs Studien beschäftigten sich mit Effekten im Schwimmen [16,17,8,19,20,21]. Jeweils eine Studie untersuchte die Effekte im Laufen [12] bzw. ...
... In vier der zehn Studien wurden Freizeitsportler auf regionalem Niveau getestet [12,17,21,22]. Die restlichen sechs Studien erfolgten mit Athleten auf nationalem bzw. ...
... Zwischen dem Luftanhalten pausierte der Athlet in Form eines gesamten Atemzyklus. In der Studie von Lavin et al. [21] wurde ein kompletter Atemstillstand über 25m Schwimmen angewendet. ...
Background: High altitude training seems beneficial for
many athletes. However, training in altitude is always associated
with travel and high expenses. Thus, methods have
been developed to achieve similar effects as with high altitude
training. One method is voluntary hypoventilation training.
Although commonly used in training, the effectiveness
of this method has not been analysed sufficiently.
Methods: Intervention studies of voluntary hypoventilation
training were identified from searches in PubMed, SciVerse
Science Direct, Web of Science, Cochrane Library, EBSCOhost
and Google Scholar.
Results: Ten studies met the inclusion criteria. In seven studies,
an intervention of VHT lead to greater improvements of
the performance compared to a control programme.
Conclusions: The overall positive study results support the
usefulness of VHT for improving the performance and designing
a varied training. Due to the limited numbers of intervention
studies and the heterogeneous study designs, the
outcomes must be interpreted with caution.
... We contacted several authors that had data on VO 2peak and diffusing capacity (DL,NO, DL,CO) data. These data were obtained from previously published studies and they varied in cardiorespiratory fitness, age, height, sex, and body mass (Burtch et al., 2016;de Bisschop et al., 2010;de Bisschop et al., 2012;Flaherty et al., 2014;Lalande et al., 2012;Lavin et al., 2015;Lavin et al., 2012;Martinot et al., 2013;Zavorsky et al., 2010b). ...
... This suggests that changes in the alveolar membrane (D M ) may occur independently from the blood conductance component of pulmonary diffusing capacity (i.e., CO ·V c ). Four subjects (∼30%) in the interval training group surpassed the smallest measurable change in DL,NO of 9 mL/min/mmHg, 1 which was statistically determined elsewhere (Lavin et al., 2015). Other studies have demonstrated a 3-25% increase in DL,CO over a three year period in two marathon runners (Kaufmann and Swenson, 1981) or a 10% increase in DL,CO in swimmers after a 12-week swim training (Mickleborough et al., 2008). ...
... Several features unique to swimming are postulated to bring about such changes in lung volumes and diffusing capacities (Lavin et al., 2015). For example, inspirations are typically larger than those in land-based sports (Dicker et al., 1980) and breathing must be well-timed and coordinated (Seifert et al., 2005;Troup, 1999); additionally, the constant hydrostatic pressure exerted on the chest by the water creates a constant adaptive stressor for the lungs (Hong et al., 1969;Silvers et al., 2007) and the prone position facilitates perfusion and decreases respiratory dead space (Mostyn et al., 1963;Rohdin et al., 2003). ...
Pulmonary diffusing capacity for nitric oxide (DL,NO) and carbon monoxide (DL,CO) measured at rest (mL/min/mmHg) is strongly associated with aerobic capacity (cardiorespiratory fitness or peak oxygen uptake, VO2peak) measured in L/min. Data from healthy, non-obese individuals from various studies (n = 121 males and 81 females) were combined to examine this association. Subjects that were above the upper limit of normal (ULN, 97.5th percentile for age and sex and height) for DL,NO and DLCO had a higher median VO2peak compared to subjects below the ULN (Above the ULN = 4.2–4.5 L/min or 54–56 mL/kg/min; below the ULN = 3.0–3.2 L/min, 45–46 mL/kg/min, p < 0.001). Those that were classified as Superior or Excellent in cardiorespiratory fitness (≥80th percentile in VO2peak for the person’s age and sex) increased their odds of being above the ULN for DL,NO and DL,CO by about 6-fold and 8-fold, respectively, compared to those not classified as being Superior or Excellent in cardiorespiratory fitness. Approximately 65–68% of the variance in DL,NO and DL,CO, respectively, was shared by VO2peak (L/min) (p < 0.001). However, after controlling for alveolar volume, sex, height, body mass, and age, the shared variance between pulmonary diffusing capacity and VO2peak decreased to 16–20% (95% CI = 8–30%), and yet, remained statistically significant (p < 0.001). The reasons for the shared variance between pulmonary diffusing capacity and VO2peak are discussed.
... One study in particular has linked a performance benefit with CFB in recreational swimmers (i.e., novice triathletes). They found that CFB training over a 4-week intervention period improved 150-yard swim time by 8% (;13 seconds, effect size [ES] = 0.50) and reduced the oxygen cost of running (i.e., improved running economy) by 6% (a reduction of 15 ml$kg 21 $km 21 , ES = 0.57) in novice triathletes (23). In contrast, the group that took one breath every 2 strokes showed no improvement in either variable. ...
... To the best of the authors' knowledge, only one study has investigated the effects of CFB training on performance in an SCY format (23). In that study, the subjects were novice triathletes and the performance measure was a noncompetition length of 150 yards (137 m). ...
... Specifically, spirometry and diffusing capacity were completed at the same time of day for each subject between baseline and follow-up measures. For the measurement of oxygen and energy cost of running and aerobic capacity, the procedures set by Lavin et al. (2015) were followed using a calibrated Woodway ELG Treadmill (Woodway USA, Waukesha, WI, USA). A Parvo Medics TrueOne 2400 metabolic cart (Parvo Medics, Sandy, UT, USA) was used for running economy and aerobic capacity assessments. ...
Controlled frequency breathing (CFB) is a common swim training modality involving holding one's breath for about 7 to 10 strokes before taking another breath. We sought to examine the effects of CFB training on reducing respiratory muscle fatigue. Competitive college swimmers were randomly divided into either the CFB group that breathed every 7 to 10 strokes, or a control group that breathed every 3-4 strokes. Twenty swimmers completed the study. The training intervention included 5-6 weeks (16 sessions) of 12x50-m repetitions with breathing 8-10 breaths per 50m (control group), or 2-3 breaths per 50-m (CFB group). Inspiratory muscle fatigue was defined as the decrease in maximal inspiratory mouth-pressure (MIP) between rest and 46s after a 200 yard free-style swimming race [115s (SD 7)]. Aerobic capacity, pulmonary diffusing capacity, and running economy were also measured pre and post-training. Pooled results demonstrated a 12% decrease in MIP at 46s post-race [-15 (SD 14) cm H2O, Effect size = -0.48, p < 0.01]. After four weeks of training, only the CFB group prevented a decline in MIP values pre to 46 s post-race [-2 (13) cm H2O, p > 0.05]. However, swimming performance, aerobic capacity, pulmonary diffusing capacity, and running economy did not improve (p > 0.05) post-training in either group. In conclusion, CFB training appears to prevent inspiratory muscle fatigue yet no difference was found in performance outcomes.
... Although many favourable physiological changes take place following exercise training in healthy individuals, pulmonary function remains largely unchanged. Some studies have shown improvement in pulmonary diffusing capacity with chronic exercise training in adults (Hanson, 1969;Kaufmann & Swenson, 1981), while others did not (Reuschlein et al. 1968;Dempsey et al. 1977;Lavin et al. 2013). Thus, there is still debate about whether pulmonary diffusing capacity can be augmented in adult humans. ...
... In order to remove the confounding effects of haemoglobin concentration and pulmonary capillary blood volume that may arise with exercise training, the measurement of DL NO was chosen to reflect changes specifically to the alveolar-capillary membrane. Furthermore, the day-to-day variation in the measurement of DL NO is less than that for DL CO (Murias & Zavorsky, 2007;Lavin et al. 2013), which would allow for easier detection of changes in pulmonary diffusion, should those changes arise. ...
... The small observed changes in DL NO over the data collection period are within the week-to-week variability observed elsewhere (Murias & Zavorsky, 2007;Lavin et al. 2013). This implies that these small changes in DL NO are likely to be natural biological variation and/or technical variation of the equipment. ...
New Findings
What is the central question of this study?
Alveolar–capillary membrane conductance for nitric oxide (measured as lung diffusion of NO; DL NO ) is not thought to be improved with regular exercise training in adult humans. The purpose was to examine the effect of regular exercise training on DL NO in unfit adult women.
What is the main finding and its importance?
Women performing moderate‐intensity physical activity (4–6 metabolic equivalent tasks, or METS, 800 kcal week ⁻¹ , for 6 weeks) can improve DL NO to a similar extent compared to women performing vigorous‐intensity physical activity (>6 METS, 700 kcal week ⁻¹ , for 6 weeks); however, the magnitude of improvement in DL NO will probably be small and physiologically questionable. This demonstrates that interval training may not provide additional improvements in DL NO compared with moderate‐intensity physical activity.
The purpose of the study was to determine whether short‐term high‐intensity aerobic interval training improves resting pulmonary diffusing capacity for nitric oxide (DL NO ) and carbon monoxide (DL CO ). Twenty‐eight sedentary women [mean (SD) age 32 (11) years, body mass index 24.3 (5.7) kg m ⁻² ] were randomly assigned to either a self‐directed moderate‐intensity physical activity ( n = 14) group or a supervised high‐intensity aerobic interval training group ( n = 14). The moderate physical activity group and the aerobic interval training group increased weekly physical activity energy expenditure by 800 and 1600 kcal week ⁻¹ , respectively. After 6 weeks, aerobic capacity increased to a similar exent in both groups (mean improvement 8%, effect size 0.39). The DL NO , but not DL CO , increased to a similar extent in both groups, by 4% or 3.0 (5.7) [95% confidence interval 0.8, 5.2] ml min ⁻¹ mmHg ⁻¹ m ⁻² from pre‐ to post‐training (effect size 0.27). There was no correlation between the change in aerobic capacity and the change in DL NO ( P > 0.05) or between the change in aerobic capacity and the change in total weekly physical activity energy expenditure ( P > 0.05). Interval training does not provide additional improvements in DL NO or aerobic capacity compared with self‐directed moderate‐intensity physical activity (4–6 metabolic equivalent tasks, 800 kcal week ⁻¹ , for 6 weeks) in unfit women. Despite the slight improvement in both DL NO and aerobic capacity, true meaningful physiological changes in these parameters remain questionable.
... The zscores for DLCO, V A and K CO were obtained using Mexican Hispanic reference equations (Gochicoa-Rangel et al., 2024). The day-to-day variability (SD or measurement error) in FEV 1 and FVC is 130 and 170 mL, respectively (Lavin et al., 2015). This is converted to a dayto-day z-score variability of 0.345 SD units for both, based on the spirometry reference equations (Bowerman et al., 2023). ...
... The day-to-day variability (SD or measurement error) in DLCO and V A is 1.6 mL/min/mmHg and 0.31 L, respectively (Lavin et al., 2015). This is converted to a day-to-day z-score variability of 0.38 and 0.613 SD units, respectively, based on the Mexican Hispanic reference equations (Gochicoa-Rangel et al., 2024). ...
The long‐term effects of COVID‐19 on lung function are not understood, especially for periods extending beyond 1 year after infection. This observational, longitudinal study investigated lung function in Mexican Hispanics who experienced severe COVID‐19, focusing on how the length of recovery affects lung function improvements. At a specialized COVID‐19 follow‐up clinic in Yucatan, Mexico, lung function and symptoms were assessed in patients who had recovered from severe COVID‐19. We used z‐scores, and Wilcoxon's signed rank test to analyse changes in lung function over time. Lung function was measured twice in 82 patients: the first and second measurements were taken a median of 94 and 362 days after COVID‐19 diagnosis, respectively. Initially, 61% of patients exhibited at least one of several pulmonary function abnormalities (lower limit of normal = –1.645), which decreased to 22% of patients by 390 days post‐recovery. Considering day‐to‐day variability in lung function, 68% of patients showed improvement by the final visit, while 30% had unchanged lung function from the initial assessment. Computed tomography (CT) scans revealed ground‐glass opacities in 33% of patients. One year after infection, diffusing capacity of the lungs for carbon monoxide z‐scores accounted for 30% of the variation in CT fibrosis scores. There was no significant correlation between the length of recovery and improvement in lung function based on z‐scores. In conclusion, 22% of patients who recovered from severe COVID‐19 continued to show at least one lung function abnormality 1 year after recovery, indicating a prolonged impact of COVID‐19 on lung health.
... Freestyle swimming is the most common technique which requires proper breathing at various stroke cycle (Tovin, 2006). Swimming, either competitive or amateur, requires good skeletal muscle strength and endurance in addition to strong respiratory muscle function (Lavin et al., 2015). Good respiratory muscle strength and good breathing techniques are needed to complete the whole cycle at a given time. ...
... The benefits of the IT program were seen via the improvement of the sports performance among various sports fields (Harms, 2007;Illi et al., 2012;HajGhanbari et al., 2013;Jiménez-reyes et al., 2017). Although the effect of the individualized training program is not yet proven among swimmers, limited researches have been carried out on the effects of respiratory muscle training in improving swimming performance (HajGhanbari et al., 2013;Lemaitre et al., 2013;Lavin et al., 2015). Nevertheless, the individualized training performance should also be taken into consideration in improving the swimming performance. ...
Previous researches have been conducted to determine the types of training to improve swimming performance. Nevertheless, no study has been done on the individualized training approach among swimmers. Hence, this study aimed (i) to examine the effects of respiratory muscle training on swimming performance (ii) to examine the effects of combined respiratory muscle training with individualized training on swimming performance, and (iii) to compare the differences between the isolated respiratory muscle training, combined intervention of respiratory muscle training with individualized training and usual training on swimming performance. For this, 45 collegiate swimmers with no previous injuries and swims regularly for at least 1 hour per week participated in the study. Participants were randomly assigned into three groups; Group A: Respiratory muscle training and Individualized Training, Group B: Respiratory muscle training alone, and Group C: Usual training session. The difference within the groups after four weeks of the intervention was analyzed using Paired T-test, while the differences between intervention groups were analyzed using repeated measure two-way ANOVA. Both the intervention groups (Group A and B) showed significant improvement after four weeks of intervention, whereas in group comparison, Group A showed tremendous improvement in swimming performance (F (17,238) = 8.385, p<0.05, np2 = 0.375). Thus, the current study has proven that the combination of respiratory muscle training with individualized training could further enhance the swimming performance in terms of heart rate, Vo2 max, stroke volume, perceived exertion, and SWOLF score. Future studies on athletic swimmers with a larger sample size are recommended to further examine the individualized training approach.
... After HSCT, there were mild but statistically significant reductions of VC and FEV 1 exceeding their respective smallest meaningful change (Lavin et al., 2013) in thirteen and twelve patients, without significant differences between patients undergoing allogeneic and autologous HSCT (Table 2). TLC tended to decrease more in the allogeneic (4±5%; p<0.001) than autologous group but the interaction (p=0.06 for groups x times) remained insignificant after exclusion of patients without GvHD (p=0.09) or high-dose total body irradiation (p=0.26). ...
... The contribution of NO back pressure due to repeated testing can be considered negligible (Zavorsky et al., 2013). Second, in our control group we did not measure lung function at the same time-point as in patients, but their medium-term (months) changes were determined to be between -8.00 and +7.68 mL·min -1 ·mmHg -1 for DL NO and between -2.10 and +1.94 mL·min -1 ·mmHg -1 for DL CO , which are within the reported range of their smallest meaningful changes (Lavin et al., 2013). Third, measurements of ROMs level in bronchoalveolar lavage fluid rather than serum may better represent pulmonary oxidative stress, but bronchoscopy might have been difficult in the presence of GvHD-related mucositis. ...
Lung diffusing capacity for CO (DLCO) is compromised in haematopoietic stem-cell transplantation (HSCT) recipients. We derived alveolar-capillary membrane conductance (DM,CO) and pulmonary capillary volume (VC) from DLCO and diffusing capacity for NO (DLNO). Forty patients were studied before and 6 weeks after HSCT. Before HSCT, DLNO and DLCO were significantly lower than in 30 healthy controls. DM,CO was ~40% lower in patients than in controls (p<0.001), whereas VC did not differ significantly. After HSCT, DLNO and DM,CO further decreased, the latter by ~22% from before HSCT (p<0.01) while VC did not change significantly. Lung density, serum CRP and reactive oxygen metabolites were significantly increased, with the latter being correlated (R2=0.71, p<0.001) with the decrement in DLNO. We conclude that DLNO and, to a lesser extent, DLCO are compromised before HSCT mainly due to a DM,CO reduction. A further reduction of DM,CO without VC loss occurs after HSCT, possibly related to development of oedema, or interstitial fibrosis, or both.
... Previous studies have found that RMT leads to an extension of dynamic apnea in finswimmers [21,50]. However, extending the underwater phase carries the risk of increased physiological fatigue in swimmers due to excessively high hypoxic stimulation [27,55]. Therefore, the distance travelled underwater should be evaluated together with the underwater velocity, which is considered a more relevant parameter for underwater phase assessment [32,56]. ...
Maximal athletic performance can be limited by various factors, including restricted respiratory function. These limitations can be mitigated through targeted respiratory muscle training, as supported by numerous studies. However, the full potential of respiratory training in competitive finswimming has not been fully investigated. This case study aims to evaluate performance variability during underwater phases in an elite Bi-Fins swimmer (current world record holder and multiple world championship medallist) over a 200m race simulation after an eight-week respiratory training using Airofit PRO™. Performance variability was assessed based on pre-test, inter-test, and post-test data. Each measurement included pulmonary function, body composition, and swim performance evaluations. The swimmer followed a 28-day training program with the AiroFit PRO™ respiratory trainer between tests. Significant improvements were observed in Wilcoxon paired-sample test between the pre-test and post-test in underwater distance (p=0.012; d=1.26), underwater time (p=0.012; d=1.26), and number of underwater kicks (p=0.043; d=1.01), resulting in a 14.23% longer underwater distance, 14.08% longer underwater time, and 14.94% increase in underwater kicks. Despite increased distance and time, underwater velocity remained stable, indicating improved underwater performance efficiency. The results suggest that the AiroFit PRO™ respiratory trainer has practical applications in finswimming training programs.
... We analyzed these data using GraphPad Prism 9.3 (GraphPad Software Inc., La Jolla, CA). Finally, using Fisher's exact test, we compared the incidence of increases or decreases in the following variables from pretraining to posttraining that exceeded the threshold for reproducibility or the smallest measurable change between groups: FVC, FEV 1 , peak expiratory flow, FEF 25%-75%, MVV, DL CO , peak W,VO 2peak , and HR max (48,49). We did not create a dichotomous line of significance/ nonsignificance (50,51). ...
Introduction:
Pulmonary function is lower after a severe burn injury, which could influence ventilatory responses during exercise. It is unclear whether exercise training improves pulmonary function or ventilatory responses during exercise in adults with well-healed burn injuries. Therefore, we tested the hypothesis that exercise training improves pulmonary function and ventilatory responses during exercise in adults with well-healed burn injuries.
Methods:
Thirty-nine adults (28 with well-healed burn injuries & 11 non-burn-injured controls) completed six months of unsupervised, progressive exercise training including endurance, resistance, and high-intensity interval components. Before and after exercise training, we performed comprehensive pulmonary function testing and measured ventilatory responses during cycling exercise. We compared variables using two-way ANOVA (group x time (i.e., pre/post-exercise training) [repeated factor]).
Results:
Exercise training did not increase percent predicted spirometry, lung diffusing capacity, or airway resistance measures (time: p ≥ 0.14 for all variables). However, exercise training reduced minute ventilation (V̇E; time: p ≤ 0.05 for 50 & 75 watts) and the ventilatory equivalent for oxygen (V̇E/V̇O2; time: p < 0.001 for 75 watts) during fixed-load exercise for both groups. The ventilatory equivalent for carbon dioxide (V̇E/V̇CO2) during exercise at 75 watts was reduced after exercise training (time: p = 0.04). The percentage of age-predicted maximum heart rate at the ventilatory threshold was lower in adults with well-healed burn injuries before (p = 0.002), but not after (p = 0.22), exercise training. Lastly, exercise training increased V̇E and reduced V̇E/V̇O2 during maximal exercise (time: p = 0.005 for both variables).
Conclusions:
These novel findings demonstrate that exercise training can improve ventilatory responses during exercise in adults with well-healed burn injuries.
... The available data reported a non-relevant clinical impact on health such as cardiorespiratory, physiological (Fikenzer et al., 2020;Shaw et al., 2020;Epstein et al., 2021;Hopkins et al., 2021;Samannan et al., 2021), perceptual (Hopkins et al., 2021), or cognitive (Spang and Pieper, 2020) parameters. The respiratory rate and the activity of the muscles involved are increased (Lavin et al., 2015;Porcari et al., 2016;Chan et al., 2020), CO 2 fluctuations alter the respiratory drive (Patel et al., 2022), and although the CO 2 trapped between the mask and the mouth/nose does not become toxic (Xu et al., 2015), it can trigger an alarm without an actual decrease in available O 2 (Guyenet and Bayliss, 2015). In some people, this available oxygen variation causes anxiety due to hypersensitivity to the increase in CO 2 (Smoller et al., 2014). ...
Objective
COVID-19 caused a complete stop in non-professional sports. The use of face masks for team sports is not a widely used measure in non-professional sports. The study aimed to evaluate the perception about using the mask and the adaptation difficulties related to training and competition in team sports following the FISICOVID-DXTGALEGO protocol.
Methods
Seven hundred eighty-seven handball players from the Galician Handball Federation were followed during their return to participation after months of confinement through an electronic questionnaire of perception and experience on the use of a mask.
Results
There is an excellent adaptation to the mask in training and competition with medium and high correlations. The 86,41% of players reported an adaptation to the mask in 3 weeks with a three times a week training frequency. The negative opinion on the mask was drastically reduced (-66.86%) after use. The 80,44% of players considered the use of a mask as an essential measure to resume competitions.
Conclusions
It is very feasible to adapt to training and compete with a mask (hygienic or surgical) in a short period. The use of a mask following these protocols changed previous opinions on the disadvantages of the mask during training and competition.
... Controlled frequency breathing swimming is often used during daily training by swimmers. 18 The reason for choosing the test was to assess the impact of IMST on swimming performance by improving breath holding during swimming. The breathing condition was randomly assigned. ...
Purpose:
Inspiratory muscle strength training (IMST) can improve exercise performance. Increased maximal inspiratory mouth pressure (MIP) could be beneficial for swimmers to enhance their performance. This study aimed to clarify the effect of high-intensity IMST for 6 weeks on MIP and swimming performance in highly trained competitive swimmers.
Methods:
Thirty male highly trained competitive swimmers were assigned to high-intensity IMST (HI; n = 10), moderate-intensity IMST (MOD; n = 10), and control (n = 10) groups. The 6-week IMST intervention comprised twice daily sessions for 6 d/wk at inspiratory pressure threshold loads equivalent to 75% MIP (HI) and 50% MIP (MOD). Before and after the intervention, MIP and swimming performance were assessed. Swimming performance was evaluated in free and controlled frequency breathing 100-m freestyle swimming time trials in a 25-m pool. For controlled frequency breathing, participants took 1 breath every 6 strokes.
Results:
The MIP values after 2 and 6 weeks of IMST in the HI and MOD groups were significantly higher than those before IMST (P = .0001). The magnitudes of the MIP increases after 6 weeks of IMST did not differ between the HI (13.4% [8.7%]) and MOD (13.1% [10.1%]) groups (P = .44). The 100-m freestyle swimming times under the controlled frequency condition were significantly shorter after IMST than those before IMST in both the HI (P = .046) and MOD (P = .042) groups.
Conclusions:
Inspiratory pressure threshold load equivalent to 50% MIP could be sufficient to improve MIP and swimming performance under the controlled frequency breathing condition in highly trained competitive swimmers.
... They ascribed the performance enhancements to improved respiratory parameters and increased hypercapnic tolerance. in contrast, lavin et al., 26 who applied a similar ...
Background:
Apnea training enhances bradycardia and improves competitive apnea performance, and has been proposed as a training method for other sports, such as swimming. We evaluated the effects of apneic underwater swimming, i.e. dynamic apnea (DYN), in 9 competitive swimmers (TR) who completed ten DYN sessions over 2 weeks.
Methods:
TR performed pre- and post-training tests including a static apnea test with continuous heart rate (HR) and peripheral oxygen saturation measurements, all-out 50m and 100m freestyle tests and an all-out DYN test. Control groups were competitive swimmers (SC; n=10) that trained swimming without DYN, and a non-swimmer group (AC; n=10) performing only static apnea tests.
Results:
Post-training, TR mean±SD time for 50m freestyle improved from 25.51±2.01s to 24.64±2.02s (p<0.01) and for 100m from 55.5±4.2s to 54.1±4.4s (p<0.05). SC also improved their 100m time from 56.7±3.3s to 56.0±3.1s (p<0.01; p=0.07 between groups). Only TR performed DYN tests; DYN distance increased from 62.1±11.5m to 70.9±18.9m (p<0.05) while DYN speed decreased from 0.74±0.14m/s to 0.64±0.18m/s (p<0.01). Static apnea duration did not change in any of the groups, but HR-reduction was enhanced posttraining only in TR (24.8±14.8% to 31.1±10.9%, p<0.01; p<0.001 between groups).
Conclusions:
We conclude that 2 weeks of DYN training enhanced DYN performance, which may be caused by the enhanced apnea-induced diving bradycardia. Further research is required to determine whether DYN training enhances short distance freestyle swimming performance.
... W hen training, athletes swim the initial distance with held breath and then continue swimming with a minimum number of breaths. Prolonged holding of breath allows swimmers to swim more efficiently and faster, but this leads to the accumulation of carbon dioxide in the blood and the formation of hypercapnic hypoxia (HCH) (Kapus et al., 2003;Lavin et al., 2015). ...
Ivonina, Natalya I., Andrey A. Fokin, and Irina M. Roshchevskaya. Body surface potential mapping during heart ventricular repolarization in male swimmers and untrained persons under hypoxic and hypercapnic hypoxia. High Alt Med Biol. 00:000-000, 2021. Background: In swimmers, as a result of prolonged breath-holding during swimming, first hypoxic hypoxia (HH) and then hypercapnic hypoxia (HCH) occurs, which may influence the electrical activity of the heart (EAH). What type of normobaric hypoxia more strongly affects the EAH-normocapnic HH or HCH? Methods: The electrical activity of swimmers' hearts (n = 7) and untrained persons (n = 10) was studied by using electrocardiography (ECG) and body surface potential mapping (BSPM) during the period of ventricular repolarization at baseline, at normocapnic HH, at HCH, and in the recovery period. Results: HH led to more significant changes in the EAH in all participants in comparison with HCH. There was no change in the amplitude of T waveECG at hypoxic and HCH, but a change in the amplitude of the minimum was noted in BSPM. The minimum in athletes changed by the end of the exposure (from -0.40 ± 0.12 mV to -0.26 ± 0.11 mV, p = 0.001); in the control, it decreased earlier (after 8 minutes of exposure to HH, the amplitude of the minimum was -0.24 ± 0.08 mV, p = 0.026). With HH, the duration of the QT interval in athletes was shortened due to the shortening of the J-Tpeak (from 250 to 188 ms, p = 0.001) and the Tpeak-Tend (from 98 to 86 ms) intervals. In controls, the decrease in the QT interval was due to the J-Tpeak shortening only (from 280 to 200 ms, p = 0.026). Conclusions: In the study of the effect of hypoxia on the EAH during ventricular repolarization, the use of the BSPM has proven to be more informative than the use of traditional ECG. When using potential mapping, more significant changes in ventricular repolarization at HH than at HCH were revealed, whereas the parameters changed less in swimmers compared with the baseline than in controls during both exposures.
... This study also found that the week-to-week variability in FEV 1 and FVC in these heart failure patients was higher than in normal, healthy individuals in absolute terms, perhaps due to minor changes in the patients' clinical conditions. Indeed, compared to healthy controls (Lavin et al., 2015), the reproducibility of FEV 1 and FVC was 0.11 and 0.13 L larger (worse) in patients with heart failure in the present study. Alveolar-capillary gas diffusion abnormalities are frequently observed in heart failure patients, although they are rarely part of patients' routine clinical assessment. ...
Background
Alveolar-capillary membrane diffusing capacity for carbon monoxide (DMCO) and pulmonary capillary volume (Vcap) can be estimated by the multi-step Roughton and Foster (RF, original method from 1957) or the single-step NO-CO double diffusion technique (developed in the 1980s). The latter method implies inherent assumptions. We sought to determine which combination of the alveolar membrane diffusing capacity for nitric oxide (DMNO) to DMCO ratio, an specific conductance of the blood for NO (θNO) and CO (θCO) gave the lowest week-to-week variability in patients with heart failure.
Methods
44 heart failure patients underwent DMCO and Vcap measurements on three occasions over a ten-week period using both RF and double dilution NO-CO techniques.
Results
When using the double diffusing method and applying θNO = infinity, the smallest week-to-week coefficient of variation for DMCO was 10%. Conversely, the RF method derived DMCO had a much greater week-to-week variability (2x higher coefficient of variation) than the DMCO derived via the NO-CO double dilution technique. The DMCO derived from the double diffusion technique most closely matched the DMCO from the RF method when θNO = infinity and DMCO = DLNO/2.42. The Vcap measured week-to-week was unreliable regardless of the method or constants used.
Conclusions
In heart failure patients, the week-to-week DMCO variability was lowest when using the single-step NO-CO technique. DMCO obtained from double diffusion most closely matched the RF DMCO when DMCO/2.42 and θNO = infinity. Vcap estimation was unreliable with either method.
... 1 This condition modifies the respiratory mechanics towards a low respiratory frequency and a high tidal volume pattern which lead to increases in work of breathing 8 and inspiratory muscle strength. 9 Possible metabolic pathways related with hypoxia-activated genes and mechanical stress in the alveoli capillaries are also related with lung growth 10 suggesting that either repeated pulmonary expansion to TLC, 11 or repeated exposure to apnoeic periods 10 during swimming could stimulate lung growth in swimmers. A longitudinal study or a twin study should be performed to fully elucidate the influence of swimming training in lung function. ...
... 1 This condition modifies the respiratory mechanics towards a low respiratory frequency and a high tidal volume pattern which lead to increases in work of breathing 8 and inspiratory muscle strength. 9 Possible metabolic pathways related with hypoxia-activated genes and mechanical stress in the alveoli capillaries are also related with lung growth 10 suggesting that either repeated pulmonary expansion to TLC, 11 or repeated exposure to apnoeic periods 10 during swimming could stimulate lung growth in swimmers. A longitudinal study or a twin study should be performed to fully elucidate the influence of swimming training in lung function. ...
... It has been reported that a horizontal body position and water immersion stimulate an increase in lung capacity and diffusion. During exercise in the aquatic environment, swimmers are also exposed to the hydrostatic forces produced by the water, which necessitate stronger inspirations that improve the strength of the inspiratory muscles 13 and longer breathing cycles, mimicking intermittent hypoxic training in which hypercapnia and hypoxia occur. 14 This divergence between land and water sports may also have implications for the treatment of respiratory diseases and has been studied in the treatment of lung diseases such as asthma 15 and chronic obstructive pulmonary disease (COPD), 16 with positive lung function outcomes demonstrated in patients who practiced aquatic exercise. ...
Background
The diffusion capacity of carbon monoxide (DLCO) provides a measure of gas transfer in the lungs. Endurance training does not increase lung volumes or diffusion in land-based athletes. However swimmers have larger lungs and better diffusion capacity than other matched athletes and controls.
Purpose
The aim of this study was to evaluate pulmonary alveoli-capillary diffusion and lung volumes in elite aquatic athletes, specifically swimmers, artistic swimmers and water polo players.
Methods
The participants were 64 international level aquatic athletes including 31 swimmers (11 female and 20 male), 12 artistic swimmers (only female), and 21 water polo players (10 female and 11 male). The single-breath method was used to measure DLCO and pulmonary parameters.
Results
The main finding of this study is that DLCO is high in aquatic athletes, clearly above their reference values, both in females (33.4 ± 9.4 mL min⁻¹·mmHg⁻¹; 135%) and males (48.0 ± 5.83 mL min⁻¹·mmHg⁻¹; 148%). There was no difference in DLCO between female swimmers, artistic swimmers and water polo players (34.7 ± 8.3 to 33.4 ± 4.0 to 32.1 ± 5.6 mL min⁻¹·mmHg⁻¹), but male swimmers had a higher DLCO compared to water polo players (50.4 ± 5.3 to 43.4 ± 7.0, p = 0.014).
Conclusions
Aquatic athletes have larger lungs and better diffusion capacity than the percentage predicted by age and height. Therefore, swimming-based sports could help to improve pulmonary function in many different segments of the population.
... 2 This condition modifies the respiratory mechanics towards a low respiratory frequency and a high tidal volume pattern which lead to increases in inspiratory muscle strength. 22 hydrostatic pressure also places mean±Sd of the 10 training sessions studied. There was a significant interaction between changes in DL co and training, (f 1, 14 =17.32, ...
Background:
Swimmers have larger lungs and a higher diffusion capacity than other athletes, but it remains unknown whether swimming exercise changes lung diffusing properties. This study aimed to evaluate modifications in pulmonary alveolar-capillary diffusion after swimming exercise.
Methods:
The participants were 21 elite level swimmers, including 7 females and 14 males, with a training volume of 45-70 kilometres of swimming per week. The singlebreath method was used to measure the lung diffusing capacity for carbon monoxide (DLCO and the transfer coefficient of the lungs for carbon monoxide (KCO) before and after 10 training sessions over 4 weeks along 207 pre- to post- evaluations.
Results:
Swimming training consistently decreased lung diffusion capacity during the follow-up period, both DLCO (44.4 ± 8.1 to 43.3 ± 8.9 mL·min-1·mmHg-1, P = 0.047, ŋ2p = 0.55) and KCO (5.92 ± 0.79 to 5.70 ± 0.81 mL·min-1·mmHg-1·L-1, P = 0.003, ŋ2p = 0.75).
Conclusions:
Elite swimmers experience a subclinical impairment in lung diffusing capacity after swimming exercise, but the stress caused by swimming on the lungs and the acute reduction in DLCO does not lead to physiological dysfunction.
... (Pozo, 2007;Wakefield, Shipherd, & Lee, 2017;Hatzigeorgiadis, Galanis, Zourbanos, & Theodorakis, 2014) El entrenamiento en este deporte debe estar encaminado a garantizar el desarrollo especializado de las sensaciones táctiles, visuales, auditivas y propioceptivas del individuo que permiten la estabilidad y factibilidad del desplazamiento sobre el agua. Por ello, la bibliografía especializada destaca las ventajas y desventajas de la práctica de la natación, no solo en deportistas, sino en otros sectores sociales de diferentes rangos etarios, (Rendón, y otros, 2017;Torres, y otros, 2017), siendo de importancia establecer las variables de rendimiento que inciden significativamente, como es el caso de la efectividad del movimiento técnico, (Apolo, Villalba, Benavides, & Saavedra, 2017; Corley, Godfrey, Quinlan, & ÓLaighin, Inertial sensor technology for elite swimming performance analysis: A systematic review, 2015; Lavin, Guenette, Smoliga, & Zavorsky, 2015;Dubnov-Raz, Livne, Raz, Cohen, & Constantini, 2015) y de las percepciones como componente psicológico de la preparación del deportista del natación. (Mooney, y otros, Analysis of swimming performance: perceptions and practices of US-based swimming coaches, 2016), como es el caso de la relación entre las conductas percibidas del entrenamiento, las percepciones en las habilidades, la motivación general de los nadadores, el apoyo a la autonomía, la satisfacción y las autopercepciones en la iniciativa y la identidad de los nadadores jóvenes, tal y como establecen algunas literaturas. ...
Las percepciones especializadas en el accionar deportivo (espacio, tiempo y movimiento) condicionan el éxito motriz, sobre la base de la experiencia acumulada, la ejercitación y la sistematización de las acciones, así como de la alta complejidad de los analizadores que participan en el ejercicio físico. Por ello, se planteó como objetivo desarrollar a partir de la implementación de ejercicios físicos especiales la percepción del tiempo y el movimiento técnico en nadadores de iniciación de la Federación Deportiva de Santo Domingo de los Tsachilas. Se estudiará la población de nadadores de iniciación de la Federación mencionada, concerniente a 10 niños (9-11 años), a los cuales se les aplicarán ejercicios físicos especiales para mejorar aspectos concernientes al campo de estudio. Por otra parte, serán encuestados a 20 especialistas de natación de la República del Ecuador. Los ejercicios elaborados como parte del tercer capítulo mejoraron significativamente el movimiento técnico a partir de la potenciación de 5 indicadores.
... For instance, due to the UW nature AS competitions, practicing prolonged periods UW combined with intense muscle contraction could be utilized in combination with technical elements to improve overall AS performance. Previous studies in swimming has suggested short term periods of swimming with controlled/regulated breathing frequency or full apnea results in an elevated pulmonary function and capacity [73][74][75], which in turn may improve oxygen demand during periods UW through repeated periods of hypercapnia and the associated increase in P CO 2 and decrease in pH, all of which serve as mechanisms to encourage physiological adaptation [76][77][78]. In addition, other studies advocate the use of respiratory muscle training to improve pulmonary function and improve swimming performance [79]. ...
Artistic swimming (AS) is a very unique sport consisting of difficult artistically choreographed routines ranging in the number of athletes (one to ten: solo, duet, team, combination, highlight routine) and with elements performed quickly and precisely above, below, and on the surface of the water. As a result, the physical and physiological demands placed on an athlete are unique to the sport with the most pronounced adaptation being the bradycardic response to long apneic periods spent underwater while performing strenuous movements. This indeed influences training prescription and the desired training outcomes. This review paper explores the physiological demands of AS, the physiological characteristics that influence AS performance, and innovative approaches to enhancing training and performance in elite performers.
... Aynı zamanda nefes frekanslarını limitleme ile yapılan yüzme egzersizlerinin akciğer kapasitesinin yanı sıra yüzme performansını da artırdığını belirtmişlerdir. 24 SONUÇ Yapmış olduğumuz araştırma, literatürdeki bilgilerle paralellik göstermektedir. Gerek performans gerekse sağlık açısından nefes çalışmaları ile birlikte olan yüzme egzersizleri olumlu yönde fizyolojik etki göstermektedir. ...
ocukların psikolojik ve fiziksel açıdan sağlıklı olarak büyümeleri ancak spor ile mümkündür. Çocuklar spor aracılığıyla sosyal ilişki-lerini düzenlerken, kendine güvenme, rekabet, güdülenme ve kont-rol gibi özelliklerini de geliştirmektedir. 1 Hayat boyu spor alışkanlığının Turkiye Klinikleri J Sports Sci 2015;7(2) 35 Yüzme Sporu Yapan 10-14 Yaş Grubundaki Çocukların Solunum Parametrelerinin Karşılaştırılması Ö ÖZ ZE ET T A Am ma aç ç: : Bu çalışmanın amacı, yüzme sporuyla uğraşan 10-14 yaş grubundaki çocukların diriller arası balonla nefes egzersizleri ile birlikte sekiz haftalık yüzme egzersizi öncesi ve sonrasındaki solunum para-metrelerinin karşılaştırılması ve akciğer kapasitesi üzerine etkisinin araştırılmasıdır. G Ge er re eç ç v ve e Y Yö ön nt te em ml le er r: : Çalışmaya yüzme bilen 30 çocuk sporcu alındı. Çalışma periyodu öncesinde çocukların solunum değerleri Cosmed marka portatif Pony spirometre ile ölçüldü. Haftada üç gün ve 1,5 saat düzenli olarak yüzen ço-cukların sekiz haftalık çalışma dönemi sonrasında solunum ölçümleri tekrar yapıldı. Elde edilen Best-FVC, Best-FEV1, FVC, FEV1, PEF1/s, PIF1/s, FEV1/FVC%, FEF25-75 1/s, Vmax-25 1/s, Vmax-50 1/s, Vmax-75 1/s ve FET100% s verileri arasında karşılaştırma yapıldı. B Bu ul lg gu ul la ar r: : İlk ve son ölçüm değerleri karşılaştırıl-dığında, yüzücülerin Best-FVC, Best-FEV1, FVC, FEV1, PIF1/s, FEV/FVC%, FEF25-75 1/s, Vmax-50 1/s, Vmax-75 1/s ve FET100% değerleri arasında anlamlı bir fark bulunamaz iken, PEF ve V max-25 1/s değer-lerinin sekiz haftalık yüzme egzersizi sonrasında istatistiksel olarak anlamlı ölçüde yükseldiği saptandı (p<0,05). S So on nu uç ç: : Diriller arası balonla nefes egzersizleri ile birlikte sekiz haftalık düzenli yüzme antrenma-nının 10-14 yaş grubundaki çocukların solunum parametreleri üzerinde olumlu artış meydana getirdiği gözlenmiştir. A An na ah h t ta ar r K Ke e l li i m me e l le er r: : Solunum parametreleri; çocuklar; yüzme A AB BS S T TR RA AC CT T O Ob bj je ec ct ti iv ve e: : The aim of this study is comparing the group's respiratory parameters which included 10-14 age children who drills between balloon breath with exercise involved in the sport of swimming according to the measurements at the beginning and the end of the 8 weeks swimming exercises and to investigate the effects on the lung capacity. M Ma at te er ri ia al l a an nd d M Me et th ho od ds s: : 30 child athletes who can swim were used for this study. Respiratory values were measured by portable pony spirometry Cosmed brand before the study period. Respiratory values of these children swimming 3 days in a week and 1,5 hours in a day were measured again after the 8 week study period. Obtained data as; Best-FVC, Best-FEV1, FVC, FEV1, PEF1/s, PIF1/s, FEV1/FVC%, FEF25-75 1/s, Vmax-25 1/s, Vmax-50 1/s, Vmax-75 1/s and FET100% s was compared. R Re es su ul lt ts s: : When the first and last measured values of the swimmers compared; Best-FVC, Best-FEV1, FVC, FEV1, PIF1/s, FEV/FVC%, FEF25-75 1/s, Vmax-50 1/s, Vmax-75 1/s and FET100% a statistically significant difference couldn't be found between the values. PEF and Vmax-25 1/values were significantly higher than the first measurement values in statistical size (p<0.05). C Co on nc cl lu us si io on n: : As a result, it was observed that regular drills between balloon breath with exercise at swimming trainings for 8 weeks on the 10-14 age group children provide a positively rising on the children's respiratory parameters. K Ke ey y W Wo or rd ds s: : Respiratory parameters; children; swimming T Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J S Sp po or rt ts s S Sc ci i 2 20 01 15 5; ;7 7((2 2)): :3 35 5-4 40 0
... In studies conducted in swimmers untrained in apnoea, the breathing pattern was often manipulated in order to induce short periods of apnoea through voluntary hypoventilation (Key et al., 2014;Lavin, Guenette, Smoliga, & Zavorsky, 2015;West, Drummond, Vanness, & Ciccolella, 2005;Woorons, Gamelin, Lamberto, Pichon, & Richalet, 2014). It appears that performing voluntary hypoventilation at high lung volume, (i.e. ...
The aim of this study was to determine the influence of swim intensity on acute responses to dynamic apnoea. 9 swimmers performed one 50 m front crawl trial in four different conditions: at 400 m velocity (V400) with normal breathing (NB), at V400 in complete apnoea (Ap), at maximal velocity (Vmax) with NB and at Vmax in Ap. Peak heart rate (HRpeak), blood lactate concentration after exercise (Lacpost ex) and Borg rating of perceived exertion (RPE) were measured. Arterial oxygen saturation (SpO2) was monitored with a pulse oximeter at forehead level during and after exercise. In Ap, swimming at V400 induced a significantly lower HRpeak and Lacpost ex than swimming at Vmax whilst RPE and the kinetics of SpO2 were not different at V400 and at Vmax. The minimal value of SpO2 in Ap was reached 10 to 11 s after the end of V400 and Vmax (81.7 ± 10.1% and 84.4 ± 10.6%, respectively). Swimming a 50 m front crawl in Ap resulted in a large decrease in SpO2 which occurred only after the cessation of exercise. The higher duration of apnoea during submaximal exercise could explain why SpO2 and RPE reached the same values as for maximal exercise.
... Aynı zamanda nefes frekanslarını limitleme ile yapılan yüzme egzersizlerinin akciğer kapasitesinin yanı sıra yüzme performansını da artırdığını belirtmişlerdir. 24 SONUÇ Yapmış olduğumuz araştırma, literatürdeki bilgilerle paralellik göstermektedir. Gerek performans gerekse sağlık açısından nefes çalışmaları ile birlikte olan yüzme egzersizleri olumlu yönde fizyolojik etki göstermektedir. ...
The aim of this study is comparing the group’s respiratory parameters which in-cluded 10-14 age children who drills between balloon breath with exercise involved in the sport of swiming according to the measurements at the beginning and the end of the 8 weeks swimming exercises anto investigate the effects on the lung capacity. Material and Methods: 30 child athletes who can swim were
used for this study. Respiratory values were measured by portable pony spirometry Cosmed brand before
the study period. Respiratory values of these children swimming 3 days in a week and 1,5 hours in a day
were measured again after the 8 week study period. Obtained data as; Best-FVC, Best-FEV1, FVC, FEV1,
PEF1/s, PIF1/s, FEV1/FVC%, FEF25-75 1/s, Vmax-25 1/s, Vmax-50 1/s, Vmax-75 1/s and FET100% s was
compared. Results: When the first and last measured values of the swimmers compared; Best-FVC, Best-
FEV1, FVC, FEV1, PIF1/s, FEV/FVC%, FEF25-75 1/s, Vmax-50 1/s, Vmax-75 1/s and FET100% a statisti-
cally significant difference couldn’t be found between the values. PEF and Vmax-25 1/values were
significantly higher than the first measurement values in statistical size (p<0.05). Conclusion: As a result,
it was observed that regular drills between balloon breath with exercise at swimming trainings for 8 weeks
on the 10-14 age group children provide a positively rising on the children’s respiratory parameters.
Key Words: Respiratory parameters; children; swimming
... Of particular interest are methods for the assessment of bio-behavioral (e.g. metabolic and cardioventilatory responses [23]) and endocrinological (e.g. cortisol, testosterone, insulin [24][25][26]) markers to investigate the effects of swim training and their relation to performance outcome. ...
Background and objectives:
Professionals in the domain of swimming have a strong interest in implementing research methods in evaluating and improving training methods to maximize athletic performance and competitive outcome. Heart rate variability (HRV) has gained attention in research on sport and exercise to assess autonomic nervous system activity underlying physical activity and sports performance. Studies on swimming and HRV are rare. This review aims to summarize the current evidence on the application of HRV in swimming research and draws implications for future research.
Methods:
A systematic search of databases (PubMed via MEDLINE, PSYNDEX and Embase) according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (a) empirical investigation (HRV) in humans (non-clinical); (b) related to swimming; (c) peer-reviewed journal; and (d) English language.
Results:
The search revealed 194 studies (duplicates removed), of which the abstract was screened for eligibility. Fourteen studies meeting the inclusion criteria were included in the review. Included studies broadly fell into three classes: (1) control group designs to investigate between-subject differences (i.e. swimmers vs. non-swimmers, swimmers vs. other athletes); (2) repeated measures designs on within-subject differences of interventional studies measuring HRV to address different modalities of training or recovery; and (3) other studies, on the agreement of HRV with other measures.
Conclusions:
The feasibility and possibilities of HRV within this particular field of application are well documented within the existing literature. Future studies, focusing on translational approaches that transfer current evidence in general practice (i.e. training of athletes) are needed.
... Of particular interest are methods for the assessment of bio-behavioral (e.g. metabolic and cardioventilatory responses [23]) and endocrinological (e.g. cortisol, testosterone, insulin [24][25][26]) markers to investigate the effects of swim training and their relation to performance outcome. ...
Background and Objectives: Professionals in the domain of swimming have a strong interest in implementing research methods in evaluating and improving training methods to maximize athletic performance and competitive outcome. Heart rate variability (HRV) has gained attention in research on sport and exercise to assess
autonomic nervous system activity underlying physical activity and sports performance. Studies on swimming and HRV are rare. This review aims to summarize the current evidence on the application of HRV in swimming research and draws implications for future research. Methods: A systematic search of databases (PubMed via MEDLINE, PSYNDEX and Embase) according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (a) empirical investigation (HRV) in humans (non-clinical); (b) related to swimming; (c) peer-reviewed journal; and (d) English language. Results: The search revealed 194 studies (duplicates removed) of which the abstract was screened for eligibility. Fourteen studies meeting the inclusion
criteria were included in the review. Included studies broadly fell into three classes (1) control group designs to investigate between subject differences (i.e. swimmers vs. non-swimmers, swimmers vs. other athletes); (2) repeated measures designs on within-subject differences of interventional studies measuring HRV to address different modalities of training or recovery and (3) other studies, on the agreement of HRV with other measures. Conclusions: The feasibility and possibilities of HRV within this particular field of application are well documented within the existing literature. Future studies, focusing on translational approaches that transfer current evidence in general practice (i.e. training of athletes) are needed.
Background: This systematic review and meta-analysis aimed to assess the impact of inspiratory muscle training (IMT) on lung function parameters (MIP, MEP, FEV1, and FVC) between both elite and non-elite swimmers. Methods: We searched for controlled clinical trials (CCT) and prospective longitudinal studies (PLS) in elite and non-elite swimmers following an inspiratory muscle training (IMT) protocol with a standardized device, published between 2012 and 2023. The databases used in the search were PubMed, Science Direct, Scopus, Springer, Cochrane Central Register of Controlled Trials, and Google Scholar. The primary outcome assessed was the impact of IMT on lung function parameters, including MIP, MEP, FEV1, and FVC. Results: We selected 13 articles involving 277 subjects aged 11-21 years, with 61.4% being male, and 84.6% being elite swimmers. The most commonly used IMT device was the PowerBreathe ® , prescribed for 3-12 weeks, 1-2 sessions per day, 3-6 times per week, with 30 repetitions, starting at 50% of MIP and progressing up to 80%. The meta-analysis showed that IMT was associated with a higher MIP (MD = 29.35 cmH2O, 95% CI: 13.04-45.65 cmH2O, p < 0.01) without affecting FEV1 and FVC. Conclusion: The swimmers that used IMT improved muscle strength, specifically MIP, without changes in MEP, FEV1, and FVC.
Mixed martial arts (MMA) is a multidimensional combat sport combining various forms of grappling and striking methodologies. The sport challenges the strength and conditioning professional because of the conflicting metabolic demands, high degree of variability, and a lack of a fixed competitive schedule. The existing literature identifies the need for highly developed neuromuscular qualities and high aerobic and anaerobic capacities. Although previous research has identified the physiological profile of a high-level MMA athlete, there is limited peer-reviewed research identifying the most optimal periodization strategy to improve performance. Furthermore, there seems to be no existing literature investigating the implementation of velocity-based training (VBT). This training methodology uses movement velocity to assign training loads to mitigate fatigue and improve strength and power adaptations. Existing literature on VBT suggests that it is a superior method of assigning training load compared with traditional percentage-based training. Therefore, this article serves to identify the physiological profile of the MMA athlete, outline VBT, and provide a guideline for designing an MMA strength and conditioning program to optimize performance using VBT.
Introduction:
There is limited, large sample size, healthy control data comparing measurement of diffusing capacity of the lungs for carbon monoxide (DLCO) via the 10 s single-breath carbon monoxide uptake method (DLCO10) using a DLCO-DLNO double diffusion test performed with a 5 s time of apnoea (DLCO5).
Objectives:
The primary objective was to compare DLCO5 and DLCO10 in healthy participants. The secondary objective was to evaluate the reproducibility of DLCO5.
Material and methods:
We included medical students at Caen University Hospital, from 2008 to 2011. We performed a standard single-breath carbon monoxide uptake and combined DLCO and DLNO measurement for each participant. The combined test was repeated one week later.
Results:
Among the 153 study participants, there was no statistically significant difference between the mean values of DLCO10 (10.2 ± 2.2 mmol.min-1.kPa-1) and DLCO5, (10.3 ± 2.2 mmol.min-1.kPa-1; paired t-test p = 0.19). Corrected for the same FiO2, DLCO5 was calculated at 10.5 ± 2.3 mmol.min-1.kPa-1 and was significantly different from DLCO10 (paired t-test p < 0.001). DLCO5 deviates from 1,6 mmol.min-1.kPa-1 (4,6 mL.min-1. mmHg-1) or 15% of DLCO10 (17% above and 13% below, for 95% of the subjects). Forty-seven participants were included in the DLCO5 reproducibility test. The 2 test sessions were carried out at 6 ± 2 day intervals. Reproducibilities for DLCO, DLNO, DmCO and Vc was respectively 1.2 (11%), 6.8 (13%), 16.5 (32%), 12.5 (17%) mmol.min-1.kPa-1.
Conclusion:
In healthy participants, discrepancies between DLCO measured during the double diffusion and DLCO measured on an apnoea of 10 seconds are quite large. It may be an indication that the Roughton and Forster interpretation to describe this type of measurements is inadequate.
Background:
Physical activity has a positive effect on the function of the whole human body system. The influence of physical activity on the development of the respiratory system is still a matter for debate. Swimming is considered the sport with the most profound effect on the lungs.
Aim:
The first aim was to determine pulmonary function and to correlate it with anthropometric features of sportsmen, represented by land- and the water-based elite athletes comparing with their sedentary counterparts; the second aim was to examine whether the training factors (frequency and amount) influence pulmonary function in swimmers, when controlled for anthropometric features.
Methods:
Thirty-eight elite male swimmers were matched for age and sex with two hundred and seventy-one elite football players and one hundred controls who were not involved in any routine exercise. Lung volumes were recorded by Pulmonary Function test and analyzed statistically.
Results and conclusion:
Swimmers had statistically higher values of VC, FVC, FEV1 and FEV1/FVC when compared to both the football players and the controls, as the latter two showed no in-between differences. There was significant positive correlation between age, body weight and body height and each of the above named pulmonary parameters, when presented separately for swimmers, football players and the control group. When controlled for the anthropometric features, larger lung volumes in swimmers were not influenced by training period, age at the beginning of training and weekly extent of personal training. Further comprehensive longitudinal studies are needed to confirm these observations.
Purpose: This study aimed to determine whether hypoventilation training at supramaximal intensity could improve swimming performance more than the same training carried out under normal breathing conditions.
Methods: Over a 5-week period, sixteen triathletes (12 men, 4 women) were asked to include twice a week into their usual swimming session one supramaximal set of 12 to 20 x 25m, performed either with hypoventilation at low lung volume (VHL group) or with normal breathing (CONT group). Before (Pre-) and after (Post-) training, all triathletes performed all-out front crawl trials over 100, 200 and 400m.
Results: Time performance was significantly improved in VHL in all trials [100m: - 3.7 ± 3.7s (- 4.4 ± 4.0%); 200m: - 6.9 ± 5.0s (- 3.6 ± 2.3%); 400m: - 13.6 ± 6.1s (-3.5 ± 1.5%)] but did not change in CONT. In VHL, maximal lactate concentration (+ 2.35 ± 1.3 mmol.L-1 on average) and the rate of lactate accumulation in blood (+ 41.7 ± 39.4%) were higher at Post- than at Pre- in the three trials whereas they remained unchanged in CONT. Arterial oxygen saturation, heart rate, breathing frequency and stroke length were not altered in both groups at the end of the training period. On the other hand, stroke rate was higher at Post- compared to Pre- in VHL but was not different in CONT. The measurements of gas exchange over the 400-m trial revealed no change in peak oxygen consumption as well as in any pulmonary variable in both groups.
Conclusion: This study demonstrated that VHL training, when performed at supramaximal intensity, represents an effective method for improving swimming performance, partly through an increase in the anaerobic glycolysis activity.
Babcock, Mark A., David F. Pegelow, Bruce D. Johnson, and Jerome A. Dempsey. Aerobic fitness effects on exercise-induced low-frequency diaphragm fatigue. J. Appl. Physiol. 81(5): 2156–2164, 1996.—We used bilateral phrenic nerve stimulation (BPNS; at 1, 10, and 20 Hz at functional residual capacity) to compare the amount of exercise-induced diaphragm fatigue between two groups of healthy subjects, a high-fit group [maximal O 2 consumption (V˙o 2 max ) = 69.0 ± 1.8 ml ⋅ kg ⁻¹ ⋅ min ⁻¹ , n = 11] and a fit group (V˙o 2 max = 50.4 ± 1.7 ml ⋅ kg ⁻¹ ⋅ min ⁻¹ , n = 13). Both groups exercised at 88–92% V˙o 2 max for about the same duration (15.2 ± 1.7 and 17.9 ± 2.6 min for high-fit and fit subjects, respectively, P > 0.05). The supramaximal BPNS test showed a significant reduction ( P< 0.01) in the BPNS transdiaphragmatic pressure (Pdi) immediately after exercise of −23.1 ± 3.1% for the high-fit group and −23.1 ± 3.8% ( P > 0.05) for the fit group. Recovery of the BPNS Pdi took 60 min in both groups. The high-fit group exercised at a higher absolute workload, which resulted in a higher CO 2 production (+26%), a greater ventilatory demand (+16%) throughout the exercise, and an increased diaphragm force output (+28%) over the initial 60% of the exercise period. Thereafter, diaphragm force output declined, despite a rising minute ventilation, and it was not different between most of the high-fit and fit subjects. In summary, the high-fit subjects showed diaphragm fatigue as a result of heavy endurance exercise but were also partially protected from excessive fatigue, despite high ventilatory requirements, because their hyperventilatory response to endurance exercise was reduced, their diaphragm was utilized less in providing the total ventilatory response, and possibly their diaphragm aerobic capacity was greater.
The aim of the present study was to ascertain whether maximal 200 m front crawl swimming strategies and breathing patterns influenced blood gas and acid-base parameters in a manner which gives advantage to former competitive swimmers in comparison with their recreational colleagues. Twelve former competitive male swimmers (the CS group) and nine recreational male swimmers (the RS group) performed a maximal 200 m front crawl swimming with self-selected breathing pattern. Stroke rate (SR) and breathing frequency (BF) were measured during the swimming test. Measures also included blood lactate concentration ([LA]) and parameters of blood acid-base status before and during the first minute after the swimming test. The CS group swam faster then the RS group. Both groups have similar and steady SR throughout the swimming test. This was not matched by similar BF in the CS group but matched it very well in the RS group (r = 0.89). At the beginning of swimming test the CS group had low BF, but they increased it throughout the swimming test. The BF at the RS group remained constant with only mirror variations throughout the swimming test. Such difference in velocity and breathing resulted in maintaining of blood Po 2 from hypoxia and Pco2 from hypercapnia. This was similar in both groups. [LA] increased faster in the CS group than in the RS group. On the contrary, the rate of pH decrease remained similar in both groups. The former competitive swimmers showed three possible advantages in comparison to recreational swimmers during maximal 200 m front crawl swimming: a more dynamic and precise regulation of breathing, more powerful bicarbonate buffering system and better synchronization between breathing needs and breathing response during swimming.
Running performance depends on maximal oxygen uptake (V̇O2max), the ability to sustain a high percentage of V̇O2max for an extended period of time and running economy. Running economy has been studied relatively less than the other factors. Running economy, measured as steady state oxygen uptake V̇O2) at intensities below the ventilatory threshold is the standard method. Extrapolation to a common running speed (268 m/min) or as the V̇O2 required to run a kilometer is the standard method of assessment. Individuals of East African origin may be systematically more economical, although a smaller body size and a thinner lower leg may be the primary factors. Strategies for improving running economy remain to be developed, although it appears that high intensity running may be a common element acting to improve economy.
Several measurements of the same quantity on the same subject will not in general be the same. This may be because of natural variation in the subject, variation in the measurement process, or both. For example, table 1 shows four measurements of lung function in each of 20 schoolchildren (taken from a larger study1). The first child shows typical variation, having peak expiratory flow rates of 190, 220, 200, and 200 1/min.View this table:In this windowIn a new windowTable 1 Repeated peak expiratory flow rate (PEFR) measurements for 20 schoolchildrenLet us suppose that the child has a “true” average value over all possible measurements, which is what we really want to know when we make a measurement. Repeated measurements on the same subject will vary around the true value because of measurement error. The standard deviation of repeated measurements on the same subject enables …
(1) to examine the relation between pulmonary diffusing capacity and marathon finishing time, and (2), to evaluate the accuracy of pulmonary diffusing capacity for nitric oxide (DLNO) in predicting marathon finishing time relative to that of pulmonary diffusing capacity for carbon monoxide (DLCO).
28 runners [18 males, age = 37 (SD 9) years, body mass = 70 (13) kg, height = 173 (9) cm, percent body fat = 17 (7) %] completed a test battery consisting of measurement of DLNO and DLCO at rest, and a graded exercise test to determine running economy and aerobic capacity prior to the 2011 Steamtown Marathon (Scranton, PA). One to three weeks later, all runners completed the marathon (range: 2∶22:38 to 4∶48:55). Linear regressions determined the relation between finishing time and a variety of anthropometric characteristics, resting lung function variables, and exercise parameters.
In runners meeting Boston Marathon qualification standards, 74% of the variance in marathon finishing time was accounted for by differences in DLNO relative to body surface area (BSA) (SEE = 11.8 min, p<0.01); however, the relation between DLNO or DLCO to finishing time was non-significant in the non-qualifiers (p = 0.14 to 0.46). Whereas both DLCO and DLNO were predictive of finishing time for all finishers, DLNO showed a stronger relation (r(2) = 0.30, SEE = 33.4 min, p<0.01) compared to DLCO when considering BSA.
DLNO is a performance-limiting factor in only Boston qualifiers. This suggests that alveolar-capillary membrane conductance is a limitation to performance in faster marathoners. Additionally, DLNO/BSA predicts marathon finishing time and aerobic capacity more accurately than DLCO.
The modality of exercise that is most beneficial and easy to perform has become a topic of research. Yogic exercises are being widely studied; however, postulated benefits of yogic exercises over other exercises must be scientifically explored. Prospective randomized comparative studies involving yoga and other endurance exercises are conspicuous by their absence.
This study was, therefore, designed to assess and compare the effects of yogic training and swimming on pulmonary functions in normal healthy young volunteers.
100 volunteers were inducted into the study and randomly divided into two groups: One group underwent 12 weeks training for yogic exercises and other for swimming. The training and data acquisition was done in small cohorts of 10 subjects each. The subjects were assessed by studying their anthropometric parameters and pulmonary function parameters (FVC, FEV1/FVC ratio, PEFR, FEF25-75%, FEF 0.2-1.2 l and MVV) both before and after training.
All parameters showed statistically significant improvements after both yoga and swimming. Comparison of these improvements for different parameters statistically analyzed by unpaired t test or Mann Whitney U test depicted a statistically better improvement in FVC, FEF25-75% and MVV with swimming as compared to yogic exercises.
The output of this study gives slight edge to swimming as a preferred modality of exercise though either yoga or swimming can be advocated as an exercise prescription as both the modalities cause significant improvement of respiratory health. However, other factors like ability of any exercise regime to keep continued motivation and interest of the trainees must be taken into account for exercise prescription.
Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers), more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as 'hitting the wall'), and thousands drop out before reaching the finish lines (approximately 1-2% of those who start). Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making 'hitting the wall' seem inevitable), or implied that maximal glycogen loading is required in order to complete a marathon without 'hitting the wall.' The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity) of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding 'the wall.' The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.
Thesis (PhD (Sport Science))—University of Stellenbosch, 2008. The aims of this study were (1) to determine the effect of concurrent respiratory muscle training (RMT) on respiratory muscle (RM) function and aerobic exercise performance in women competitive field hockey players, (2) to determine the effect and time duration of RM detraining on RM function in those who underwent RMT, and (3) to determine the predictors of RM strength and endurance in an athletic population. Twenty two women hockey players underwent a series of kinanthropometric and respiratory muscle function measurements, and were then randomly assigned to an experimental group (EXP, n = 15) who underwent concurrent RMT, and a control group (CON, n = 7) who underwent sham training. Twenty subjects took part in the RM detraining study. Significant improvements in pulmonary function and RM endurance (5 – 9%) were found in both groups after the HT-RMT and HT-ST interventions, while EXP also showed a significant improvement in RM strength variables (13% in MIP, 9% in MEP). MEF50% was the only variable that showed a significant difference in the changes over time after 20 weeks of DT between EXP and CON. RM strength in both groups remained relatively unchanged over the DT period. RM endurance in both groups remained unchanged after 9 weeks of DT, but decreased significantly after 20 weeks of DT in EXP. It was concluded that the intensity and duration of both the HT-RMT and HT-ST programmes were adequate to elicit training adaptations in the RM. In both groups there was a complete reversal in lung volumes after 9 weeks and a tendency of a reversal in RM endurance after 20 weeks of DT. It is suggested that a RMT programme should be incorporated every 9 weeks in the training schedule of field hockey players, to maintain improved RM function.
Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are simple, convenient, and noninvasive indices of respiratory muscle strength at the mouth, but standards are not clearly established. We review recent literature, update the 2002 American Thoracic Society/European Respiratory Society statement, and propose as the best choice using a flanged mouthpiece for reference values and lower limit of normal (LLN) values as a function of age for adults age up to about 70 years. Because male pressures are higher than female and MEP exceeds MIP, we present 4 linear regression reference equations as a function of age for adults age up to approximately 70 years: Male MIP=120-(0.41xage), and male MIP LLN=62-(0.15xage). Male MEP=174-(0.83xage), and male MEP LLN=117-(0.83xage). Female MIP=108-(0.61xage), and female MIP LLN=62-(0.50xage). Female MEP=131-(0.86xage), and female MEP LLN=95-(0.57xage). (Pressure in cm H2O and age in years.) We discuss normal values in older subjects, estimation of LLN values, and the relationship between vital capacity and respiratory muscle strength, and offer a guide to interpretation of maximal pressure measurements. The approach should allow direct implementation of MIP and MEP in a pulmonary function laboratory.
Lung volumes and inspiratory muscle (IM) function tests were measured in 16 competitive female swimmers (age 19 +/- 1 yr) before and after 12 wk of swim training. Eight underwent additional IM training; the remaining eight were controls. Vital capacity (VC) increased 0.25 +/- 0.25 liters (P less than 0.01), functional residual capacity (FRC) increased 0.39 +/- 0.29 liters (P less than 0.001), and total lung capacity (TLC) increased 0.35 +/- 0.47 (P less than 0.025) in swimmers, irrespective of IM training. Residual volume (RV) did not change. Maximum inspiratory mouth pressure (PImax) measured at FRC changed -43 +/- 18 cmH2O (P less than 0.005) in swimmers undergoing IM conditioning and -29 +/- 25 (P less than 0.05) in controls. The time that 65% of prestudy PImax could be endured increased in IM trainers (P less than 0.001) and controls (P less than 0.05). All results were compared with similar IM training in normal females (age 21.1 +/- 0.8 yr) in which significant increases in PImax and endurance were observed in IM trainers only with no changes in VC, FRC, or TLC (Clanton et al., Chest 87: 62-66, 1985). We conclude that 1) swim training in mature females increases VC, TLC, and FRC with no effect on RV, and 2) swim training increases IM strength and endurance measured near FRC.
Variation in the aerobic demand (VO2) of submaximal running was quantified among trained and untrained subjects stratified by performance capability. Based on a retrospective analysis of seven published studies, maximal aerobic power (VO2max), and submaximal VO2 values were analyzed in three groups of trained distance runners (Category 1 (C1) (elite runners; N = 22), Category 2 (C2) (sub-elite runners; N = 41), and Category 3 (C3) (good runners; N = 16), and one group (N = 10) of untrained subjects (Category 4; C4). Results indicated that VO2max differed significantly (P < 0.05) across groups, such that C1 > C2 > C3 > C4. Analysis of submaximal VO2 data also revealed that C4 was more uneconomical than C1, C2, and C3 and that C2 and C3 were less economical than C1. Average within-group variability in submaximal VO2 was similar across categories and a marked overlap of minimum, mean and maximal economy values existed across categories. These data suggest that 1) trained subjects are more economical than untrained subjects, 2) elite runners display better economy compared to less-talented counterparts, and 3) economical and uneconomical runners can be found in all performance categories.
We used bilateral phrenic nerve stimulation (BPNS; at 1, 10, and 20 Hz at functional residual capacity) to compare the amount of exercise-induced diaphragm fatigue between two groups of healthy subjects, a high-fit group [maximal O2 consumption (VO2max) = 69.0 +/- 1.8 ml.kg-1.min-1, n = 11] and a fit group (VO2max = 50.4 +/- 1.7 ml.kg-1.min-1, n = 13). Both groups exercised at 88-92% VO2max for about the same duration (15.2 +/- 1.7 and 17.9 +/- 2.6 min for high-fit and fit subjects, respectively, P > 0.05). The supramaximal BPNS test showed a significant reduction (P < 0.01) in the BPNS transdiaphragmatic pressure (Pdi) immediately after exercise of -23.1 +/- 3.1% for the high-fit group and -23.1 +/- 3.8% (P > 0.05) for the fit group. Recovery of the BPNS Pdi took 60 min in both groups. The high-fit group exercised at a higher absolute workload, which resulted in a higher CO2 production (+26%), a greater ventilatory demand (+16%) throughout the exercise, and an increased diaphragm force output (+28%) over the initial 60% of the exercise period. Thereafter, diaphragm force output declined, despite a rising minute ventilation, and it was not different between most of the high-fit and fit subjects. In summary, the high-fit subjects showed diaphragm fatigue as a result of heavy endurance exercise but were also partially protected from excessive fatigue, despite high ventilatory requirements, because their hyperventilatory response to endurance exercise was reduced, their diaphragm was utilized less in providing the total ventilatory response, and possibly their diaphragm aerobic capacity was greater.
Spirometric reference values for Caucasians, African-Americans, and Mexican-Americans 8 to 80 yr of age were developed from 7,429 asymptomatic, lifelong nonsmoking participants in the third National Health and Nutrition Examination Survey (NHANES III). Spirometry examinations followed the 1987 American Thoracic Society recommendations, and the quality of the data was continuously monitored and maintained. Caucasian subjects had higher mean FVC and FEV1 values than did Mexican-American and African-American subjects across the entire age range. However, Caucasian and Mexican-American subjects had similar FVC and FEV1 values with respect to height, and African-American subjects had lower values. These differences may be partially due to differences in body build: observed Mexican-Americans were shorter than Caucasian subjects of the same age, and African-Americans on average have a smaller trunk:leg ratio than do Caucasians. Reference values and lower limits of normal were derived using a piecewise polynomial model with age and height as predictors. These reference values encompass a wide age range for three race/ethnic groups and should prove useful for diagnostic and research purposes.
The arterial blood PO(2) is increased in the prone position in animals and humans because of an improvement in ventilation (VA) and perfusion (Q) matching. However, the mechanism of improved VA/Q is unknown. This experiment measured regional VA/Q heterogeneity and the correlation between VA and Q in supine and prone positions in pigs. Eight ketamine-diazepam-anesthetized, mechanically ventilated pigs were studied in supine and prone positions in random order. Regional VA and Q were measured using fluorescent-labeled aerosols and radioactive-labeled microspheres, respectively. The lungs were dried at total lung capacity and cubed into 603-967 small ( approximately 1.7-cm(3)) pieces. In the prone position the homogeneity of the ventilation distribution increased (P = 0.030) and the correlation between VA and Q increased (correlation coefficient = 0.72 +/- 0.08 and 0.82 +/- 0.06 in supine and prone positions, respectively, P = 0.03). The homogeneity of the VA/Q distribution increased in the prone position (P = 0.028). We conclude that the improvement in VA/Q matching in the prone position is secondary to increased homogeneity of the VA distribution and increased correlation of regional VA and Q.
The factors that may modulate ventilatory muscle fatigue during exercise are controversial. In this study the contribution of acidosis to exercise-induced diaphragmatic fatigue was investigated, using measurements of the twitch mouth pressure response (tw, P mo ) to cervical magnetic stimulation.
After learning sessions, 14 healthy subjects performed two cycling tests (at 60% of maximal aerobic power for 16 min), one while breathing spontaneously (mean minute ventilation ( V ′e) 67.9 L·min ⁻¹ ) and the other while hypoventilating voluntarily (mean V ′ E 53.8 L·min ⁻¹ ). Exercise was voluntarily set at a moderate power to avoid a fatiguing effect of exercise per se .
As compared with spontaneous breathing (SB), voluntary hypoventilation (VHV) significantly increased mean carbon dioxide tension in arterial blood ( P a,CO 2 ) (51 mmHg versus 41 mmHg) and significantly decreased arterial pH (7.28 versus 7.34). After 10 min of SB test, tw, P mo was unchanged compared to the baseline value (19.1 versus 18.5 cmH 2 O) whereas tw, P mo fell significantly as compared to baseline (17.1 versus 18.5 cmH 2 O) and to SB (17.1 versus 19.1 cmH 2 O) after the VHV test.
The results of this study suggest that exposure to hypercapnia may impair respiratory muscle function. This impairment could be more clinically relevant in patients with chronic obstructive lung disease.
The objective of this study was to test the hypothesis that high-intensity hypoxic training improves sea-level performances more than equivalent training in normoxia. Sixteen well-trained collegiate and Masters swimmers (10 women, 6 men) completed a 5-wk training program, consisting of three high-intensity training sessions in a flume and supplemental low- or moderate-intensity sessions in a pool each week. Subjects were matched for gender, performance level, and training history, and they were assigned to either hypoxic [Hypo; inspired O2 fraction (Fi(O(2))) = 15.3%, equivalent to a simulated altitude of 2,500 m] or normoxic (Norm; Fi(O(2)) = 20.9%) interval training in a randomized, double-blind, placebo-controlled design. All pool training occurred under Norm conditions. The primary performance measures were 100- and 400-m freestyle time trials. Laboratory outcomes included maximal O(2) uptake (Vo(2 max)), anaerobic capacity (accumulated O(2) deficit), and swimming economy. Significant (P = 0.02 and <0.001 for 100- and 400-m trials, respectively) improvements were found in performance on both the 100- [Norm: -0.7 s (95% confidence limits: +0.2 to -1.7 s), -1.2%; Hypo: -0.8 s (95% confidence limits: -0.1 to -1.5 s), -1.1%] and 400-m freestyle [Norm: -3.6 s (-1.8 to -5.5 s), -1.2%; Hypo: -5.3 s (-2.3 to -8.3 s), -1.7%]. There was no significant difference between groups for either distance (ANOVA interaction, P = 0.91 and 0.36 for 100- and 400-m trials, respectively). Vo(2 max) was improved significantly (Norm: 0.16 +/- 0.23 l/min, 6.4 +/-8.1%; Hypo: 0.11 +/- 0.18 l/min, 4.2 +/- 7.0%). There was no significant difference between groups (P = 0.58). We conclude that 5 wk of high-intensity training in a flume improves sea-level swimming performances and Vo(2 max) in well-trained swimmers, with no additive effect of hypoxic training.
Both in normal subjects exposed to hypergravity and in patients with acute respiratory distress syndrome, there are increased hydrostatic pressure gradients down the lung. Also, both conditions show an impaired arterial oxygenation, which is less severe in the prone than in the supine posture. The aim of this study was to use hypergravity to further investigate the mechanisms behind the differences in arterial oxygenation between the prone and the supine posture. Ten healthy subjects were studied in a human centrifuge while exposed to 1 and 5 times normal gravity (1 G, 5 G) in the anterioposterior (supine) and posterioanterior (prone) direction. They performed one rebreathing maneuver after approximately 5 min at each G level and posture. Lung diffusing capacity decreased in hypergravity compared with 1 G (ANOVA, P = 0.002); it decreased by 46% in the supine posture compared with 25% in the prone (P = 0.01 for supine vs. prone). At the same time, functional residual capacity decreased by 33 and 23%, respectively (P < 0.001 for supine vs. prone), and cardiac output by 40 and 31% (P = 0.007 for supine vs. prone), despite an increase in heart rate of 16 and 28% (P < 0.001 for supine vs. prone), respectively. The finding of a more impaired diffusing capacity in the supine posture compared with the prone at 5 G supports our previous observations of more severe arterial hypoxemia in the supine posture during hypergravity. A reduced pulmonary-capillary blood flow and a reduced estimated alveolar volume can explain most of the reduction in diffusing capacity when supine.
Running performance depends on maximal oxygen uptake (VO(2max)), the ability to sustain a high percentage of VO(2max) for an extended period of time and running economy. Running economy has been studied relatively less than the other factors. Running economy, measured as steady state oxygen uptake (VO(2)) at intensities below the ventilatory threshold is the standard method. Extrapolation to a common running speed (268 m/min) or as the VO(2) required to run a kilometer is the standard method of assessment. Individuals of East African origin may be systematically more economical, although a smaller body size and a thinner lower leg may be the primary factors. Strategies for improving running economy remain to be developed, although it appears that high intensity running may be a common element acting to improve economy.
Because the anomalous respiratory characteristics of competitive swimmers have been suggested to be due to inspiratory muscle work, the respiratory muscle and pulmonary function of 30 competitively trained swimmers was assessed at the beginning and end of an intensive 12-week swim training (ST) program. Swimmers (n = 10) combined ST with either inspiratory muscle training (IMT) set at 80% sustained maximal inspiratory pressure (SMIP) with progressively increased work-rest ratios until task failure for 3-days per week (ST + IMT) or ST with sham-IMT (ST + SHAM-IMT, n = 10), or acted as controls (ST only, ST, n = 10). Measures of respiratory and pulmonary function were assessed at the beginning and end of the 12 week study period. There were no significant differences (P > 0.05) in respiratory and pulmonary function between groups (ST + IMT, ST + SHAM-IMT and ST) at baseline and at the end of the 12 week study period. However, within all groups significant increases (P < 0.05) were observed in a number of respiratory and pulmonary function variables at the end of the 12 week study, such as maximal inspiratory and expiratory pressure, inspiratory power output, forced vital capacity, forced expiratory and inspiratory volume in 1-s, total lung capacity and diffusion capacity of the lung. This study has demonstrated that there are no appreciable differences in terms of respiratory changes between elite swimmers undergoing a competitive ST program and those undergoing respiratory muscle training using the flow-resistive IMT device employed in the present study; as yet, the causal mechanisms involved are undefined.
The purpose of this study was to perform a systematic review to determine if respiratory muscle training (RMT) improves sport performance, and respiratory muscle strength and endurance. Methodology followed the Cochrane Collaboration protocol. MEDLINE, CINAHL, SPORTDiscus, PEDro, EMBASE, EBM reviews, and COCHRANE electronic databases were searched until July 2011. Articles were included if: (1) participants were athletes; (2) RMT was compared to sham or control in a randomized controlled design and included outcomes of respiratory muscle and sport performance; (3) published in English. Quality assessment using PEDro and data abstraction was performed by two authors. Outcomes evaluated were measures of sport performance, exercise capacity, spirometry, and respiratory muscle strength and endurance. Metaanalyses were performed on outcomes reported in two or more papers. Results of this systematic review revealed that of the 6,918 citations retrieved from the search strategy, twenty-one met the inclusion criteria. Meta-analyses demonstrated a significant positive effect of RMT on sport performance outcomes of time trials, exercise endurance time and repetitions on Yo Yo tests. Inspiratory muscle strength and endurance improved in most studies, which in part, was dependent on the type of RMT employed. Determination of the type of athlete that may benefit most from RMT was limited by small sample sizes, differing RMT protocols, and differences in outcome measures across studies. In conclusion, RMT can improve sport performance. Closer attention to matching the ventilatory demands of RMT to those required during athletic competition and more aggressive progression of training intensity may show greater improvements in future studies.
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.
The aim of the present study was to assess the influence of 2 different breathing frequencies on the magnitude of inspiratory muscle fatigue after high-intensity front crawl swimming. The influence of different breathing frequencies on postexercise blood lactate ([La]) and heart rate (HR) was also examined. Ten collegiate swimmers performed 2 x 200-m front crawl swims at 90% of race pace with the following breathing frequencies: 1) 1 breath every second stroke (B2), and 2) 1 breath every fourth stroke (B4). Maximal inspiratory pressure (PImax) was measured at the mouth from residual volume before (baseline) and after swimming, in a standing position. The HR and [La] were assessed at rest and immediately at the cessation of swimming. The PImax decreased by 21% after B4 and by 11% after B2 compared with baseline (p < 0.05). The [La] was lower by 15% after B4 than after B2 (p < 0.05). The HR was not significantly different between B2 and B4. These data suggest that there is significant global inspiratory muscle fatigue after high-intensity swimming. Inspiratory muscle fatigue is, however, greater when breathing frequency is reduced during high-intensity front crawl swimming. Respiratory muscle training should be used to improve respiratory muscle strength and endurance in swimmers.
Surgical patients often show physiological and metabolic distress, muscle weakness, and long hospital stays. Physical conditioning might help recovery. We attempted to identify the most responsive measure of aerobic fitness from a four-week pre-surgical aerobic exercise program (prehabilitation) in patients undergoing major bowel resection. Twenty-one subjects randomized two to one (exercise: control) scheduled for colorectal surgery. Fourteen subjects [Body Mass Index (BMI) = 27 +/- 6 kg/m(2); maximal oxygen uptake (VO(2max)) = 22 +/- 10 ml/kg/min] underwent 3.8 +/- 1.2 weeks (27 +/- 8 sessions) of progressive, structured pre-surgical aerobic exercise training at 40 to 65% of heart rate reserve (%HRR). Peak power output was the only maximal measure that was responsive to training [26 +/- 27%, Effects Size (ES) = 0.24; Standardized Response Mean (SRM) = 1.05; p < 0.05]. For the submaximal measures, heart rate and oxygen uptake during submaximal exercise was most responsive to training (decrease by 13% +/- 15%, ES = -0.24; SRM = -0.57; and 7% +/- 6%, ES = -0.40; SRM -0.97; p < 0.05) at an exercise intensity of 76 +/- 47 W. There was no change to maximal or submaximal measures in the control group. The distance walked over six minutes improved in both groups (by approximately 30 m), but the effect size and t-statistic were higher in the exercise group. Heart rate and oxygen uptake during submaximal exercise, and peak power output are the most responsive measures to four weeks of prehabilitation in subjects with low initial fitness.
In most circumstances in health, efficient alveolar ventilation and alveolar-to-arterial exchange of O2 and CO2 are among the strongest of links in the gas-transport chain during maximal exercise. Indeed, in most instances, the metabolic cost of ventilation represents the only significant contribution of the pulmonary system to the limitation of O2 transport of locomotor muscles and thus to the limitation of maximum performance. Of the "weaknesses" inherent in the healthy pulmonary system response to exercise, the most serious one may well be its absence of structural adaptability to physical training or to the trained state. Thus, the lung's diffusion capacity and pulmonary capillary blood volume remain unaltered in the highly trained human or horse, while maximum pulmonary blood flow rises linearly with the enhanced max VO2. Similarly, ventilatory requirement rises markedly, with no alteration in the capability of the airways to produce higher flow rates or of the lung parenchyma to stretch to higher tidal volumes, and little or no change in the pressure-generating capability of inspiratory muscles. The case of the elderly athlete who remains capable of achieving high maximum pulmonary blood flows and ventilatory requirements and whose lung undergoes a normal aging process underscores the importance of deficits (from "normal") on the capacity end of this continuum of cost versus capacity in the pulmonary system. The asthmatic athlete may represent another such example of limited flow-generating capacity; and the healthy, young, highly fit athlete who shows marked reductions in SaO2 and in max VO2 at even moderately high altitudes demonstrates that, in many situations, precious little room can be added to the demand side or removed from the capacity side before signs of failure can be seen.
We examined the influence of lung volume on the ability of normal subjects to sustain breathing against inspiratory resistive loading. Four normal subjects breathed on a closed circuit in which inspiration was loaded by a flow resistor. Subjects were assigned a series of breathing tasks over a range of pressures and flows. In each task there was a specified resistor and also targets for either mean esophageal or airway opening pressure, respiratory frequency, and duty cycle. Endurance was assessed as the length of time to failure of the assigned task. The prime experimental variable was lung volume, which was increased by approximately 1 liter during some tasks; 8 cmH2O continuous positive airway pressure was applied to increase lung volume without increasing elastic load. As previously shown (McCool et al.J. Appl. Physiol. 60: 299-303, 1986), for tasks that could be sustained for the same time, there was an inverse linear relationship of mean esophageal pressure with inspiratory flow rate. This trade-off of pressure and flow was apparent both with and without the increase of lung volume. Comparable tasks, however, could not be sustained as long at the higher lung volumes. This effect of volume on endurance was greater for tasks characterized by high inspiratory pressures and low flow rates than for tasks that could be sustained for the same time but that had lower inspiratory pressures and higher flow rates. This is probably due to the effects of shortening of the sarcomere on fatiguability. Increased lung volume, per se, may contribute to respiratory failure because of increased inspiratory muscle fatiguability by mechanisms independent of elastic load.
The question of respiratory factors limiting exercise has been examined in terms of possible limitations arising from the function of gas exchange, the respiratory mechanics, the energetics of the respiratory muscles, or the development of respiratory muscle fatigue. Exercise capacity is curtailed in the presence of marked hypoxia, and this is readily observed in patients with chronic airflow limitation and interstitial lung disease and in some athletes at high intensities of exercise. In patients with interstitial lung disease, gas exchange abnormality--partly the result of diffusion disequilibrium for oxygen transfer--occurs during exercise despite abnormally high ventilations. In contrast, in certain athletes arterial hypoxemia has been documented during heavy exercise, apparently as a result of relative hypoventilation. During strenuous exercise the maximum expiratory flow volume curves are attained both by patients with chronic airflow limitation and by normal subjects, in particular when they breathe dense gas, so that a mechanical constraint is imposed on further increases in ventilation. Similarly, the force velocity characteristics of the inspiratory muscles may also impose a constraint to further increases in inspiratory flows that affects the ability to increase ventilation. In addition, the oxygen cost of maintaining high ventilations is large. Analysis of results from blood flow experiments reveal a substantial increase in blood flow to the respiratory muscles during exercise, with the result that oxygen supply to the rest of the body may be lessened. Alternatively, high exercise ventilations may not be sustained indefinitely owing to the development of respiratory muscle fatigue that results in hypoventilation and reduced arterial oxygen tension.
Poor subject cooperation during pulmonary function testing for disability evaluation can be detected by noting a reduction in maximum voluntary ventilation (MVV). The MVV was compared with the forced expiratory volume in one second (FEV1) from normal subjects and persons with airways obstructive diseases. The MVV was found to be related to the FEV1, and the MVV can be estimated by multiplying the FEV1 by 40. The actual MVV value can then be compared with the estimated value to assess subject cooperation. Since upper airway obstruction and restriction due to chest wall or neuromuscular disease can also reduce the actual MVV, subjects who have a decrease in MVV should have a more through evaluation of their ventilatory status.
The purpose of this study was to investigate the respiratory and heart rate (fH) responses to tethered controlled frequency breathing (CFB) swimming. Controlled frequency breathing swimming is an aquatic training technique in which ventilatory rate is voluntarily reduced in order to induce systemic hypoxia during training. Nine elite college swimmers experienced with CFB were studied. The tethered swimming tests were discontinuous, with 4 min work bouts interspersed with equal duration rest periods. The resisting forces during tethered swimming were 5.63, 6.82, and 7.95 kg. Each subject was tested breathing every two (control), three, four, and five arm strokes. Subjects performed all four breathing frequencies at a constant arm stroke rate of 30/min during freestyle swimming. As ventilatory volume decreased due to CFB, O2 extraction and estimated tidal volume significantly increased (P less than .05) to maintain a constant O2 consumption for a given workload. Carbon dioxide production, respiratory exchange ratio, and fH did not change significantly in response to CFB. Estimated alveolar partial pressure of O2 (PAO2) decreased and PACO2 increased significantly during CFB. However, estimated saturation of arterial blood with O2 (SAO2) was essentially undiminished during CFB. These responses do not indicate hypoxia, but rather hypercapnia during CFB.
Several measurements of the same quantity on the same subject will not in general be the same. This may be because of natural variation in the subject, variation in the measurement process, or both. For example, table 1 shows four measurements of lung function in each of 20 schoolchildren (taken from a larger study1). The first child shows typical variation, having peak expiratory flow rates of 190, 220, 200, and 200 l/min.
View this table:
Table 1
Repeated peak expiratory flow rate (PEFR) measurements for 20 schoolchildren
Let us suppose that the child has a “true” average value over all possible measurements, which is what we really want to know when we make a measurement. Repeated measurements on the same subject will vary around the true value because of measurement error. The standard deviation of repeated measurements on the same subject …
Fast swimming, either in the pool, in open water swimming, or in water polo and synchronized swimming, requires maximizing the efficiencies with which the human body can move through a liquid medium. A multitude of factors can affect the ability to swim fast as well as the final outcome. Physiology and biomechanics are the present tools used by sports scientists to determine which factors are important to fast swimming and, subsequently, to determine how the swimmer may maximize these factors to improve performance.
The normal respiratory muscle effort at maximal exercise requires a significant fraction of cardiac output and causes leg blood flow to fall. We questioned whether the high levels of respiratory muscle work experienced in heavy exercise would affect performance. Seven male cyclists [maximal O(2) consumption (VO(2)) 63 +/- 5 ml. kg(-1). min(-1)] each completed 11 randomized trials on a cycle ergometer at a workload requiring 90% maximal VO(2). Respiratory muscle work was either decreased (unloading), increased (loading), or unchanged (control). Time to exhaustion was increased with unloading in 76% of the trials by an average of 1.3 +/- 0.4 min or 14 +/- 5% and decreased with loading in 83% of the trials by an average of 1.0 +/- 0.6 min or 15 +/- 3% compared with control (P < 0.05). Respiratory muscle unloading during exercise reduced VO(2), caused hyperventilation, and reduced the rate of change in perceptions of respiratory and limb discomfort throughout the duration of exercise. These findings demonstrate that the work of breathing normally incurred during sustained, heavy-intensity exercise (90% VO(2)) has a significant influence on exercise performance. We speculate that this effect of the normal respiratory muscle load on performance in trained male cyclists is due to the associated reduction in leg blood flow, which enhances both the onset of leg fatigue and the intensity with which both leg and respiratory muscle efforts are perceived.
Reliability refers to the reproducibility of values of a test, assay or other measurement in repeated trials on the same individuals. Better reliability implies better precision of single measurements and better tracking of changes in measurements in research or practical settings. The main measures of reliability are within-subject random variation, systematic change in the mean, and retest correlation. A simple, adaptable form of within-subject variation is the typical (standard) error of measurement: the standard deviation of an individual's repeated measurements. For many measurements in sports medicine and science, the typical error is best expressed as a coefficient of variation (percentage of the mean). A biased, more limited form of within-subject variation is the limits of agreement: the 95% likely range of change of an individual's measurements between 2 trials. Systematic changes in the mean of a measure between consecutive trials represent such effects as learning, motivation or fatigue; these changes need to be eliminated from estimates of within-subject variation. Retest correlation is difficult to interpret, mainly because its value is sensitive to the heterogeneity of the sample of participants. Uses of reliability include decision-making when monitoring individuals, comparison of tests or equipment, estimation of sample size in experiments and estimation of the magnitude of individual differences in the response to a treatment. Reasonable precision for estimates of reliability requires approximately 50 study participants and at least 3 trials. Studies aimed at assessing variation in reliability between tests or equipment require complex designs and analyses that researchers seldom perform correctly. A wider understanding of reliability and adoption of the typical error as the standard measure of reliability would improve the assessment of tests and equipment in our disciplines.
To identify the most responsive method of measuring gait speed, to estimate the responsiveness of other outcome measures, and to determine whether gait speed predicts discharge destination in acute stroke.
A prospective cohort study.
Five acute-care hospitals.
Fifty subjects with residual gait deficits after a first-time stroke.
Five- (5mWT) and 10-meter walk tests (10mWT) at comfortable and maximum speeds, with 2 evaluations conducted an average +/- standard deviation (SD) of 8 +/- 3 and 38 +/- 5 days poststroke.
Standardized response mean (SRM = mean change/SD of change) was used to estimate responsiveness for each walk test, the Berg Balance Scale, the Barthel Index, the Stroke Rehabilitation Assessment of Movement (STREAM), and the Timed Up and Go (TUG).
The SRMs were 1.22 and 1.00 for the 5mWT, and.92 and.83 for the 10mWT performed at a comfortable and maximum pace, respectively. The SRMs for the Berg Balance Scale, the Barthel Index, the STREAM, and the TUG were 1.04,.99,.89, and.73, respectively. The probability of discharge to a rehabilitation center for persons walking at < or = 0.3m/s or > 0.6m/s at the first evaluation was.95 and.22, respectively.
The 5mWT at a comfortable pace is recommended as the measure of choice for clinicians and researchers who need to detect longitudinal change in walking disability in the first 5 weeks poststroke.
Oxygen consumption, along with lactic and pyruvic acid in blood, have been measured throughout the performance of heavy muscular exercise of different intensities, all leading to exhaustion in 1–10 min. Oxygen consumption increases exponentially with time; the maximum level attained seems to be independent of the intensity of exercise except in exercises of very high intensity and short duration, when it seems to be slightly increased. The rate of increase of oxygen consumption increases with the intensity of exercise. Pyruvic acid in blood increases exponentially also, and a steady state is reached at a level which tends to be higher, the heavier the exercise. Lactic acid increases as a linear function of time, the line eventually flattening down only toward the end of the exercise when the maximal values of lactic acid are reached. The lactic acid increase, grams per minute, is a linear function of the intensity of exercise; no lactic acid is produced if the exercise is below 220 cal/kg min, or a higher value for athletes. The caloric equivalent of lactic acid production from glycogen can be calculated at about 222 cal/g. This value in man is discussed in relation to previous values given. The kinetic of the lactic acid increase during exercise is in agreement with the hypothesis of an additional (alactacid) mechanism of oxygen debt contraction.
Submitted on July 31, 1962
Champion swimmers have been found to have significantly higher steady-state pulmonary diffusing capacities than those measured in normal subjects of comparable age at the same exercise level. Nonactive and moderately active normal subjects, swimmers of average ability, long distance runners, and older ex-athletes were found to show no significant deviation from predicted values of Dl CO , either in absolute terms or in relation to body surface area or lung midcapacity. The high Dl CO in champion swimmers results from a larger than normal pulmonary capillary blood volume (V c ). It has been observed that normal subjects can increase the measured steady-state Dl during exercise by a “held inspiration“ maneuver, but this increase is caused by an increased membrane diffusion component (D m ) per liter midcapacity and not by an increased V c . Champion swimmers have a particular need of a high Dl since they must be able to transfer large volumes of oxygen across the lung when the alveolar pO 2 has fallen to low levels.
Submitted on August 20, 1962
Exercise training enhances every component of the O(2) transport and metabolic system--except the lungs. Consequently, the lungs can contribute to the limitation of VO(2)max. Only hypoxia early in life and substantial lung resection reproducibly stimulate growth in normal lungs across species. Possible pathways involve genes activated by hypoxia or mechanical strain, or both, including growth factors, hormones, nitric oxide, and retinoids.
This study analysed the relationships among arm coordination symmetry, motor laterality and breathing laterality during a 100-m front crawl, as a function of expertise. Ten elite swimmers (G1), 10 mid-level swimmers (G2), and 8 non-expert swimmers (G3) composed three skill groups, which were distinguished by velocity, stroke rate, stroke length, breathing frequency (BF) and the mean number of strokes between two breaths – the stroke breath (SB) – over a 100-m front crawl. Four stroke phases were identified by video analysis (catch, pull, push and recovery) and the index of coordination (IdC) measured the lag time between the propulsive phases of the two arms. The three modes of coordination are catch-up (IdC < 0%), opposition (IdC = 0%) and superposition (IdC > 0%). The IdC was established as the mean of IdC1 and IdC2, which measured the lag time between the propulsive phases of the left and right arms, respectively. The coordination symmetry was analysed by comparing IdC1 and IdC2, and the breathing effect was studied by distinguishing IdC1 (and IdC2) with and without breathing. Motor laterality was determined by an adaptation of the Edinburgh Handedness Inventory. Breathing laterality was determined by a questionnaire and observation during the 100-m trial.
Respiratory muscle fatigue develops during exhaustive exercise and can limit exercise performance. Respiratory muscle training, in turn, can increase exercise performance. We investigated whether respiratory muscle endurance training (RMT) reduces exercise-induced inspiratory and expiratory muscle fatigue. Twenty-one healthy, male volunteers performed twenty 30-min sessions of either normocapnic hyperpnoea (n = 13) or sham training (CON, n = 8) over 4-5 wk. Before and after training, subjects performed a constant-load cycling test at 85% maximal power output to exhaustion (PRE(EXH), POST(EXH)). A further posttraining test was stopped at the pretraining duration (POST(ISO)) i.e., isotime. Before and after cycling, transdiaphragmatic pressure was measured during cervical magnetic stimulation to assess diaphragm contractility, and gastric pressure was measured during thoracic magnetic stimulation to assess abdominal muscle contractility. Overall, RMT did not reduce respiratory muscle fatigue. However, in subjects who developed >10% of diaphragm or abdominal muscle fatigue in PRE(EXH), fatigue was significantly reduced after RMT in POST(ISO) (inspiratory: -17 +/- 6% vs. -9 +/- 10%, P = 0.038, n = 9; abdominal: -19 +/- 10% vs. -11 +/- 11%, P = 0.038, n = 9), while sham training had no significant effect. Similarly, cycling endurance in POST(EXH) did not improve after RMT (P = 0.071), while a significant improvement was seen in the subgroup with >10% of diaphragm fatigue after PRE(EXH) (P = 0.017), but not in the sham training group (P = 0.674). However, changes in cycling endurance did not correlate with changes in respiratory muscle fatigue. In conclusion, RMT decreased the development of respiratory muscle fatigue during intensive exercise, but this change did not seem to improve cycling endurance.
When monitoring nitric oxide diffusing capacity (DL(NO)) in patients, it is necessary to distinguish natural biological variation from a real change in alveolar-membrane conductance. The short-term variability of single-breath DL(NO) has not been established. The aim was to determine the short-term variability DL(NO) in healthy subjects. Twelve healthy subjects performed single-breath hold diffusing capacity tests at rest over a 2-month period (eight separate sessions with 8+/-3 days between each session). Each subject inhaled 41+/-4 ppm NO and a standard diffusion mixture. DL(NO), which is a multiple of the membrane diffusing capacity for carbon monoxide (Dm(CO)), as well as carbon monoxide diffusing capacity (DL(CO)) and pulmonary capillary blood volume (V(c)) remained unaltered over the 2-month period (P>0.05). Reproducibility (calculated as 2.77 multiplied by the within-subject standard deviation) over eight sessions was 20, 5 and 8 mL min(-1)mmHg(-1) for DL(NO), DL(CO) and Dm(CO), respectively, and 19 mL for V(c) (when Dm(CO)=DL(NO)/2.42). DL(NO), DL(CO), Dm(CO) and V(c) remain unchanged over a period of 2 months. Since the inter-session variability is 20, 5 and 8 mL min(-1)mmHg(-1) for DL(NO), DL(CO) and Dm(CO), and 19 mL for V(c), a meaningful change should equal or exceed those values. While there is a small chance that week-to-week variation can also be partly due to mild pathophysiological changes, any differences that are below the reproducibility values are likely to be natural biological variation or technical variation of the equipment, rather than true physiological change.
Aquatic treadmill exercise has traditionally been used for aerobic training during rehabilitation; however, its ability to elicit comparable cardiorespiratory stress compared with land exercise is unclear. The purpose of this study was to investigate the cardiorespiratory (CR) responses elicited during maximal-effort protocols using an aquatic treadmill (ATM) and a land treadmill (TM).
Twenty-three college runners participated in two continuous, incremental peak oxygen consumption protocols (ATM and TM) until volitional exhaustion. For the ATM protocol, subjects were submerged in 28 degrees C water to the xiphoid process. ATM speed was increased incrementally to 206.8+/-23.1 m.min, and water jet resistance was increased 10% every minute thereafter. For the TM protocol, speed was increased to 205.3+/-22.3 m.min, and grade was increased 2% every minute thereafter. Rest between sessions was at least 48 h. Oxygen consumption (VO2), heart rate (HR), minute ventilation (VE), tidal volume (VT), breathing frequency (f), and respiratory exchange ratio (RER) were measured continuously, with peak values used for analysis. Rating of perceived exertion (RPE) was recorded immediately after each test, and blood lactate (LA) was measured 3 min afterward.
VE and f were significantly greater in ATM versus TM; however, VO2, HR, VT, RER, LA, RPE, speed, and exercise times were similar for both protocols.
Despite differences in VE and f, it seems that the fluid resistance created by water and jets in an ATM elicits peak CR responses comparable with those seen with inclined TM. These findings suggest that ATM running may be as effective as TM running for aerobic conditioning in fit individuals.
Our objective was to create reference values for single-breath DLNO based on a sample of non-smoking healthy males and females using a short breath-hold time. The sample included 130 individuals varied in age (18-85 yr), height (149-190 cm), and weight (49.4-102.6 kg). The subjects performed single-breath-hold maneuvers at rest inhaling 41 +/- 6 ppm NO and a standard diffusion mixture. The breath-hold time was 5.5 +/ -0.6 s. Multiple linear regression with backward elimination of the independent variables age, weight, gender, and either measured lung volume (called alveolar volume or VA) or height revealed specific prediction equations for DLNO. Inserting VA instead of height into the regression equation determined how much of an abnormality of DLNO was due to gas exchange versus low lung volume. The predicted DLNO adjusted for lung volume (ml/min/mmHg) = DLNO = 73.1 + 17.26 x (VA)+17.56 x (gender) - 1.0 x (age). The predicted DLNO unadjusted for lung volume (ml/min/mmHg) = -20.1 + 1.167 x (height)+31.81 x (gender) - 1.21 x (age). For gender, 1 = males, 0 = females; VA = liters; height = cm. Age, gender and VA (lung volume) were the best predictors of DLNO and DLCO. Weight was not a good independent predictor of DLNO or DLCO. When normalizing for height and age, women have 650 ml lower forced vital capacity, 660 ml lower VA, and a 6 and 32 ml/min/mmHg lower DLCO and DLNO, respectively, compared to men. Normalizing for lung volume and age, women have, on average, a 3.2 and 18 ml/min/mmHg lower DLCO and DLNO, respectively, compared to men.
Variation in the aerobic demand of
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New insights into respiratory muscle function in an athletic population. [Doctoral dissertation]: Stellenbosch University Library and Information Service Alveolar-membrane diffusing capacity limits performance in Boston marathon qualifiers
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Kroff J. New insights into respiratory muscle function in an athletic population. [Doctoral dissertation]: Stellenbosch University Library and Information Service, 2008. Lavin KM, Straub AM, Uhranowsky KA, Smoliga JM, Zavorsky GS. Alveolar-membrane diffusing capacity limits performance in Boston marathon qualifiers. PLoS ONE 2012: 7: e44513.
Training content and its effects on performance in 100 and 200 m swimmers
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Mujika I, Busson T, Geyssant A, Chatard
JC. Training content and its effects on
performance in 100 and 200 m
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Spirometric reference values from a sample of the general U.S. population
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Hankinson JL, Odencrantz JR, Fedan KB.
Spirometric reference values from a
sample of the general U.S. population.