Relationship between breath-hold time and physical performance in patients with cystic fibrosis

Effect of dry dynamic apnea on aerobic power in elite rugby athletes: a warm-up method

Objective: While long-term dynamic breath-holding training has been extensively studied to enhance cardiopulmonary function in athletes, limited research has explored the impact of a single breath-holding session on subsequent athletic capacity. In addition, Dry Dynamic Apnea (DA) has a more immediate physiological response than wet and static breath-holding. This study aims to assess the immediate effects of a single session of DA on the aerobic power and hematological parameters of elite athletes. Methods: Seventeen elite male rugby athletes (average age 23.5 ± 1.8) participated in this study. Two warm-up protocols were employed prior to incremental exercise: a standard warm-up (10 min of no-load pedaling) and a DA warm-up (10 min of no-load pedaling accompanied by six maximum capacity breath holds, with 30 s between each breath hold). Fingertip blood indicators were measured before and after warm-up. The incremental exercise test assessed aerobic parameters with self-regulation applied throughout the study. Results: Compared to the baseline warm-up, the DA warm-up resulted in a significant increase in VO2peak from 3.14 to 3.38 L/min (7.64% change, p < 0.05). HRmax increased from 170 to 183 bpm (7.34% change, p < 0.05), and HRpeak increased from 169 to 182 bpm (7.52% change, p < 0.05). Hematocrit and hemoglobin showed differential changes between the two warm-up methods (PHematocrit = 0.674; Phemoglobin = 0.707). Conclusion: This study investigates how DA influences physiological factors such as spleen contraction, oxygen uptake, and sympathetic nerve activation compared to traditional warm-up methods. Immediate improvements in aerobic power suggest reduced vagus nerve stimulation, heightened sympathetic activity, and alterations in respiratory metabolism induced by the voluntarily hypoxia-triggered warm-up. Further research is warranted to comprehensively understand these physiological responses and optimize warm-up strategies for elite athletic performance.

Wavelet Analysis of Respiratory Muscle sEMG Signals during the Physiological Breakpoint of Static Dry End-Expiratory Breath-Holding in Naive Apneists: A Pilot Study

The wavelet spectral characteristics of three respiratory muscle signals (scalenus (SC), parasternal intercostal (IC), and rectus abdominis (RA)) and one locomotor muscle (brachioradialis (BR)) were analyzed in the time-frequency (T-F) domain during voluntary breath-holding (BH), with a focus on the physiological breakpoint that is commonly considered the first involuntary breathing movement (IBM) that signals the end of the easy-going phase of BH. The study was performed for an end-expiratory BH physiological breaking point maneuver on twelve healthy, physically active, naive breath-holders/apneists (six professional athletes; six recreational athletes, and two individuals in the post-COVID-19 period) using surface electromyography (sEMG). We observed individual effects that were dependent on muscle oxygenation and each person's fitness, which were consistent with the mechanism of motor unit (MU) recruitment and the transition of slow-twitch oxidative (type 1) to fast-twitch glycolytic (type 2) muscle fibers. Professional athletes had longer BH durations (BHDs) and strong hypercapnic responses regarding the expiratory RA muscle, which is activated abruptly at higher BHDs in a person-specific range below 250 Hz and is dependent on the BHD. This is in contrast with recreational athletes, who had strong hypoxic responses regarding inspiratory IC muscle, which is activated faster and gradually in the frequency range of 250-450 Hz (independent of the person and BHD). This pilot study preliminarily indicates that it is possible to noninvasively assess the physiological characteristics of skeletal muscles, especially oxygenation, and improve physical fitness tests by determining the T-F features of elevated myoelectric IC and RA activity during BH.

Utility of the breath-holding test in patients with systemic sclerosis

OBJECTIVES

Cardiopulmonary involvement is a major cause of death in patients with SSc. This study evaluated the clinical utility and reliability of breath-holding test (BHT) in evaluating cardiopulmonary function in patients with SSc.

METHODS

Seventy-two prospectively enrolled patients with SSc underwent BHT and the 6 min walk test (6MWT), along with measurements of the Borg dyspnoea scale and Scleroderma Health Assessment Questionnaire (SHAQ). Data on pulmonary function test and echocardiography were also collected. Validity was assessed based on the correlations between the best BHT and relevant clinical parameters. To assess the reliability of BHT, an additional 31 patients with SSc underwent BHTs twice within 2 week intervals.

RESULTS

Mean (s.d.) best BHT time was 38.4 (15.7) s, and 6MWT distance was 473.5 (95.5) m. BHT showed significant correlations with the Borg dyspnoea scale before (r = -0.367, P < 0.001) and after (r = -0.285, P = 0.016) testing, whereas 6MWT were correlated with the Borg dyspnoea scale after (r = -0.351, P = 0.002) but not before (r = -0.113, P = 0.343) testing. BHT time was correlated with diffusing capacity for carbon monoxide (%, r = 0.426, P < 0.001), forced vital capacity (litres, r = 0.373, P = 0.001), pulmonary arterial systolic pressure (mmHg, r = -0.272, P = 0.031) and SHAQ score (r = -0.470, P < 0.001), but not with left ventricular ejection fraction (%, r = -0.135, P = 0.263). BHT showed excellent reliability, with an intraclass correlation coefficient (2, 1) of 0.943 (95% CI: 0.88, 0.97).

CONCLUSION

BHT, a simple and less time-consuming test, shows excellent reliability and significant correlation with the Borg scale, SHAQ and pulmonary parameters. These results suggest that BHT might be a useful surrogate marker of pulmonary capacity in SSc patients.

TRIAL REGISTRATION NUMBER

NCT04484948.

Six Weeks Effects of Dynamic Neuromuscular Stabilization (DNS) Training in Obese Postpartum Women With Low Back Pain: A Randomized Controlled Trial

BACKGROUND

The worldwide prevalence of obesity and low back pain (LBP) has recently dramatically increased and is mainly indicated among postpartum women, leading to a range of adverse health consequences.

OBJECTIVE

This study aimed to investigate the effects of 6 weeks of Dynamic Neuromuscular Stabilization training (DNS) in obese postpartum women with LBP.

METHOD

This was a pretest-posttest study design. The study was conducted with 40 obese postpartum women with LBP randomized to receive DNS (n = 20) or General Exercise (GE, n = 20) 6 times a week for 6 weeks. The data were gathered before and after the 6-week intervention.

RESULTS

Forty participants completed the study (mean ± SD, age 29.30 ± 3.77 years; weight 88.10 ± 6.09 kg; height 165.40 ± 6.31 cm; and BMI, 32.19 ± 1.07 kg/m²). The overall group-by-time interaction was significant for Numeric Pain-Rating Scale, Modified Oswestry Disability Questionnaire, Fear-Avoidance Beliefs Questionnaire, Inspiration and Expiration Breath Hold Time, and Respiratory Rate outcomes. The global rating of change was significantly different between groups (p < .05). The rate of improvement was higher in the DNS group compared to the GE group in all 6 tests.

CONCLUSION

The present study confirms that DNS is applicable in obese postpartum women with LBP and effectively improved NPRS, MODQ, FABQ, BHT, and RR. It is clinically suggested that DNS is imperative based on ideal ontogenetic patterns to attain optimal results for obese postpartum women with LBP.

Maximal Voluntary Breath-Holding Tele-Inspiratory Test in Patients with Chronic Obstructive Pulmonary Disease

Maximal voluntary inspiratory breath-holding time (MVIBHT) has proved to be of clinical utility in some obstructive ventilatory defects. This study aims to correlate the breath-holding time with pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD) and to determine the feasibility of using a breath-holding test in assessing the severity of COPD.

A cross-sectional study including male patients with stable COPD were conducted. Patients with respiratory comorbidities and severe or unstable cardiac diseases were excluded. Patients were interviewed and examined. Six-minute walk test (6MWT) and plethysmography were performed.For MVIBHT collection, the subject was asked to inspire deeply and to hold the breath as long as possible at the maximum inspiratory level. This maneuver was repeated three times. The best value was used for further analysis.

A total of 79 patients (mean age: 64.2 ± 8) were included in this study. The mean value of MVIBHT was 24.2 ± 8.5 s. We identified a positive and significant correlations between MVIBHT and forced vital capacity (r = .630; p < .001) as well as MVIBHT and forced expiratory volume in 1 s (FEV1%) (r = .671; p < .001). A significant inverse correlation with total lung capacity (r = −.328; p = .019) and residual volume to total lung capacity ratio (r = −.607; p < .001) was noted. MVIBHT was significantly correlated to the distance in the 6MWT (r = .494; p < .001). The mean MVIBHT was significantly different within spirometric grades (p < .001) and GOLD groups (p = .002). At 20.5 s, MVIBHT had a sensitivity of 72% and specificity of 96% in determining COPD patients with FEV1 <50%.

Our results provide additional evidence of the usefulness of MVIBHT in COPD patients as a pulmonary function parameter.

The effects of breathing exercises in comparison with other exercise programs on cardiorespiratory fitness among healthy female college students

BACKGROUND

We wished to determine the effects of breathing exercises (BE) on endurance performance compared to those of different fitness training programmes.

METHODS

Endurance was measured by the Cooper 12-minute Run Test and voluntary breath-holding time test before and after the training period. Altogether 69 healthy female college students were assigned into four groups. The first group (N.=15) participated in a breathing-exercise programme (BE). The 3 intensity training groups included constant-training (CT; N.=22), interval-training (IT; N.=17), and Fartlek-training groups (FT; (N.=15). All programmes were conducted for one hour twice a week for 7 weeks.

RESULTS

The results of the Cooper test improved significantly in all four groups (P<0.01). The voluntary breath-holding time test showed significant increase in all groups but the CT group. In the BE group the rate of improvement was 9.23% (P=0.014). In the FT group the intensity was 75-85% of maximal heart rate (HRmax), the rate of improvement was 15.2% (P=0.011). In the IT group, the percentage of increase was 9.94% (P=0.039). Finally, the CT resulted in an improvement 8.45% (P=0.063).

CONCLUSIONS

Results derived from the present study suggest that BE may be an effective alternative to improve endurance performance in healthy female college students.

Mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis children

AIM

To analyze breathing pattern and mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis (CF) children.

METHODS

Thirteen healthy children and 6 children with cystic fibrosis volunteered to perform an incremental test on a treadmill. Exercise tidal flow/volume loops were plotted every minute within a maximal flow/volume loop (MFVL). Expiratory flow limitation (expFL expressed in %Vt) was evaluated and end-expiratory and end-inspiratory lung volumes (EELV and EILV) were estimated from expiratory reserve volume relative to vital capacity (ERV/FVC) and from inspiratory reserve volume relative to vital capacity (IRV/FVC).

RESULTS

During the incremental exercise, expFL was first observed at 40% of maximal aerobic speed in both groups. At maximal exercise, 46% of healthy children and 83% of CF children presented expFL, without significant effect of cystic fibrosis on the severity of expFL. According to the two-way ANOVA results, both groups adopted similar breathing pattern and breathing strategies as no significant effect of CF has been revealed. But, according to one-way ANOVA results, a significant increase of ERV/FVC associated with a significant decrease of IRV/FVC from resting value shave been observed in healthy children at maximal exercise, but not in CF children.

DISCUSSION

The hypothesis of this study was based on the assumption that mild cystic fibrosis could induce more frequent and more severe mechanical ventilatory constraints due to pulmonary impairment and breathing pattern disturbances. But, this study did not succeed to highlight an effect of mild cystic fibrosis on the mechanical ventilatory constraints (expFL and dynamic hyperinflation) that occur during an incremental exercise. This absence of effect could be due to the absence of an impact of the disease on spirometric data, breathing pattern regulation during exercise and breathing strategy.