Bokov P; Université de Paris, AP-HP, Hôpital Robert Debré, Service de Physiologie Pédiatrique Paris, France.
Dudoignon B; Fikiri Bavurhe R; Couque N; Matrot B; Delclaux C;

Pediatric research [Pediatr Res] 2024 Jun 08.
Date of Electronic Publication: 2024 Jun 08.

Background: It has been stated that patients with congenital central hypoventilation syndrome (CCHS) do not perceive dyspnea, which could be related to defective CO ₂ chemosensitivity.
Methods: We retrospectively selected the data of six-minute walk tests (6-MWT, n = 30), cardiopulmonary exercise test (CPET, n = 5) of 30 subjects with CCHS (median age, 9.3 years, 17 females) who had both peripheral (controller loop gain, CG0) and central CO ₂ chemosensitivity (hyperoxic, hypercapnic response test [HHRT]) measurement.
Main Results: Ten subjects had no symptom during the HHRT, as compared to the 20 subjects exhibiting symptoms, their median ages were 14.7 versus 8.8 years (p = 0.006), their maximal PETCO ₂ were 71.6 versus 66.7 mmHg (p = 0.007), their median CO ₂ response slopes were 0.28 versus 0.30 L/min/mmHg (p = 0.533) and their CG0 values were 0.75 versus 0.50 L/min/mmHg (p = 0.567). Median dyspnea Borg score at the end of the 6-MWT was 1/10 (17/30 subjects >0), while at the end of the CPET it was 3/10 (sensation: effort). This Borg score positively correlated with arterial desaturation at walk (R = 0.43; p = 0.016) and did not independently correlate with CO ₂ chemosensitivities.
Conclusion: About half of young subjects with CCHS do exhibit mild dyspnea at walk, which is not related to hypercapnia or residual CO ₂ chemosensitivity.
Impact: Young subjects with CCHS exhibit some degree of dyspnea under CO ₂ exposure and on exercise that is not related to residual CO ₂ chemosensitivity. It has been stated that patients with CCHS do not perceive sensations of dyspnea, which must be tempered. The mild degree of exertional dyspnea can serve as an indicator for the necessity of breaks.

D’Hulst G; Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.
Hodžić D; Leuenberger R; Arnet J; Westerhuis E; Roth R; Schmidt-Trucksäss A; Knaier R; Wagner J

International journal of sports physiology and performance [Int J Sports Physiol Perform] 2024 Jun 07, pp. 1-12.
Date of Electronic Publication: 2024 Jun 07.

Objective: To (1) establish extensive physiological profiles of highly trained CrossFit® athletes using gold-standard tests and (2) investigate which physiological markers best correlate with CrossFit Open performance.
Methods: This study encompassed 60 participants (30 men and 30 women), all within the top 5% of the CrossFit Open, including 7 CrossFit semifinalists and 3 CrossFit Games finalists. Isokinetic dynamometers were employed to measure maximum isometric and isokinetic leg and trunk strength. Countermovement-jump height and maximum isometric midthigh-pull strength were assessed on a force plate. Peak oxygen uptake (VO2peak) was measured by a cardiopulmonary exercise test, and critical power and W’ were evaluated during a 3-minute all-out test, both on a cycle ergometer.
Results: Male and female athletes’ median (interquartile range) VO2peak was 4.64 (4.43, 4.80) and 3.21 (3.10, 3.29) L·min-1, critical power 314.5 (285.9, 343.6) and 221.3 (200.9, 238.9) W, and midthigh pull 3158 (2690, 3462) and 2035 (1728, 2347) N. Linear-regression analysis showed strong evidence for associations between different anthropometric variables and CrossFit Open performance in men and women, whereas for markers of cardiorespiratory fitness such as VO2peak, this was only true for women but not men. Conventional laboratory evaluations of strength, however, manifested minimal evidence for associations with CrossFit Open performance across both sexes.
Conclusions: This study provides the first detailed insights into the physiology of high-performing CrossFit athletes and informs training optimization. Furthermore, the results emphasize the advantage of athletes with shorter limbs and suggest potential modifications to CrossFit Open workout designs to level the playing field for athletes across different anthropometric characteristics.

Sarullo FM; U.O.S.D. di Riabilitazione Cardiovascolare Ospedale Buccheri La Ferla Fatebenefratelli, Palermo, Italy.
Nugara C; Sarullo S; Iacoviello M; Di Gesaro G; Miani D; Driussi M; Correale M; Bilato C; Passantino A; Carluccio E; Villani A; Degli Esposti L; D’Agostino C; Peruzzi E; Poli S; Di Lenarda A;

Frontiers in cardiovascular medicine [Front Cardiovasc Med] 2024 May 10; Vol. 11, pp. 1347908.
Date of Electronic Publication: 2024 May 10 (Print Publication: 2024).

Background: Heart failure (HF) significantly affects the morbidity, mortality, and quality of life of patients. New therapeutic strategies aim to improve the functional capacity and quality of life of patients while controlling HF-related risks. Real-world data on both the functional and cardiopulmonary exercise capacities of patients with HF with reduced ejection fraction upon sacubitril/valsartan use are lacking.
Methods: A multicenter, retrospective, cohort study, called REAL.IT, was performed based on the data collected from the electronic medical records of nine specialized HF centers in Italy. Cardiopulmonary exercise testing was performed at baseline and after 12 months of sacubitril/valsartan therapy, monitoring carbon dioxide production (VCO ₂ ) and oxygen consumption (VO ₂ ).
Results: The functional capacities of 170 patients were evaluated. The most common comorbidities were hypertension and diabetes (i.e., 53.5 and 32.4%, respectively). At follow-up, both the VO ₂ peak (from 15.1 ± 3.7 ml/kg/min at baseline to 17.6 ± 4.7 ml/kg/min at follow-up, p  < 0.0001) and the predicted % VO ₂ peak (from 55.5 ± 14.1 to 65.5 ± 16.9, p  < 0.0001) significantly increased from baseline. The VO ₂ at the anaerobic threshold (AT-VO ₂ ) increased from 11.5 ± 2.6 to 12.5 ± 3.3 ml/kg/min ( p  = 0.021), and the rate ratio between the oxygen uptake and the change in work (ΔVO ₂ /Δwork slope) improved from 9.1 ± 1.5 to 9.9 ± 1.6 ml/min/W ( p  < 0.0001).
Conclusions: Sacubitril/valsartan improves the cardiopulmonary capacity of patients with HFrEF in daily clinical practice in Italy.
Competing Interests: MI: Lectures or consultant for Novartis, Vifor Pharma, Boehringer, Lilly, Bayer, AstraZeneca, Roche Diagnostics, Neopharmed Gentili. ADL: Lectures for Novartis, Vifor Pharma, Boheringer, Daiichi, Bayer, Pfizer, AstraZeneca, Research Funds from Novartis, Amgen, AstraZeneca, Vifor Pharma, Bayer. CDA, EP, and SP are employees of Novartis. LDE was employed by company CliCon S.r.l. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision. The authors declare that this study received funding from Novartis Farma. The funder had the following involvement in the study: study design, data collection and analysis, supporting manuscript preparation.

Durstenfeld MS; Division of Cardiology at ZSFG and Department of Medicine, University of California, San Francisco (UCSF), USA.
Wilson MP; Jankowski CM; Ditzenberger GL; Longenecker CT; Erlandson K

The Journal of infectious diseases [J Infect Dis] 2024 May 28.
Date of Electronic Publication: 2024 May 28.

Background: People with HIV (PWH) have lower exercise capacity compared to peers without HIV, which may be explained by chronotropic incompetence (CI), the inability to increase heart rate during exercise.
Methods: The Exercise for Healthy Aging Study included adults ages 50-75 with and without HIV. Participants completed 12 weeks of moderate intensity exercise, before randomization to moderate or high intensity for 12 additional weeks. We compared adjusted heart rate reserve (AHRR; CI <80%) on cardiopulmonary exercise testing by HIV serostatus and change from baseline to 12 and 24 weeks using mixed effects models.
Results: Among 32 PWH and 37 controls (median age 56, 7% female, mean BMI 28 kg/m2), 28% of PWH compared to 11% of controls had CI at baseline (p = 0.067). AHRR was lower among PWH (91 vs 101%; difference 10%, 95% CI 1.9-18.9; p = 0.02). At week 12, AHRR normalized among PWH (+8%, 95% CI 4-11; p < 0.001) and was sustained at week 24 (+5, 95%CI 1-9; p = 0.008) compared to no change among controls (95%CI -4 to 4; p = 0.95; pinteraction = 0.004). After 24 weeks of exercise, only 15% PWH and 10% of controls had CI (p = 0.70).
Conclusions: Chronotropic incompetence contributes to reduced exercise capacity among PWH and improves with exercise training.

Stastna N; Department of Pulmonology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic.
Hrabovska L;Homolka P; Homola L; Svoboda M; Brat K;Fila L;

BMC pulmonary medicine [BMC Pulm Med] 2024 May 28; Vol. 24 (1), pp. 260.
Date of Electronic Publication: 2024 May 28.

Background: Physical activity is a crucial demand on cystic fibrosis treatment management. The highest value of oxygen uptake (VO _2peak ) is an appropriate tool to evaluate the physical activity in these patients. However, there are several other valuable CPET parameters describing exercise tolerance (W _peak , VO _2VT1 , VO _2VT2, VO ₂ /HR _peak , etc.), and helping to better understand the effect of specific treatment (V _E , V _T , V _D /V _T etc.). Limited data showed ambiguous results of this improvement after CFTR modulator treatment. Elexacaftor/tezacaftor/ivacaftor medication improves pulmonary function and quality of life, whereas its effect on CPET has yet to be sufficiently demonstrated.
Methods: We performed a single group prospective observational study of 10 adolescent patients with cystic fibrosis who completed two CPET measurements between January 2019 and February 2023. During this period, elexacaftor/tezacaftor/ivacaftor treatment was initiated in all of them. The first CPET at the baseline was followed by controlled CPET at least one year after medication commencement. We focused on interpreting the data on their influence by the novel therapy. We hypothesized improvements in cardiorespiratory fitness following treatment. We applied the Wilcoxon signed-rank test. The data were adjusted for age at the time of CPET to eliminate bias of aging in adolescent patients.
Results: We observed significant improvement in peak workload, VO _{2 peak} , VO _2VT1 , VO _2VT2 , V _E /VCO ₂ slope, V _E , V _T , RQ, VO ₂ /HR peak and RR peak. The mean change in VO ₂  peak was 5.7 mL/kg/min, or 15.9% of the reference value (SD ± 16.6; p= 0.014). VO _2VT1 improved by 15% of the reference value (SD ± 0.1; p= 0.014), VO _2VT2  improved by 0.5 (SD ± 0.4; p= 0.01). There were no differences in other parameters.
Conclusion: Exercise tolerance improved after elexacaftor/tezacaftor/ivacaftor treatment initiation. We suggest that the CFTR modulator alone is not enough for recovering physical decondition, but should be supplemented with physical activity and respiratory physiotherapy. Further studies are needed to examine the effect of CFTR modulators and physical therapy on cardiopulmonary exercise tolerance.

Martens P; Department of Cardiovascular Medicine, Heart, Vascular and Thoracic Institute, Cleveland Clinic, OH. USA
Van Iterson EH; Tang WHW; Finet JE;

Circulation. Heart failure [Circ Heart Fail] 2024 May 31, pp. e010807.
Date of Electronic Publication: 2024 May 31.

No abstract available

Bhammar DM; Center for Tobacco Research, Division of Medical Oncology, Ohio State University, Columbus
Nusekabel CW; Wilhite DP;Daulat S;Liu Y; Glover RIS; Babb TG;

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2024 May 15.
Date of Electronic Publication: 2024 May 15.

Purpose: Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children.
Methods: Thirty-four 8-12-year-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow-volume loops during exercise and maximal expiratory flow-volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise.
Results: Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8 ± 0.7%TLC; EELV: 41.2 ± 0.5%TLC) compared with children without obesity (EILV: 73.7 ± 0.8%TLC; EELV: 44.8 ± 0.6%TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity (P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females (P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity, however the prevalence of EFL in females was significantly different with 57% of females with obesity experiencing EFL compared with 17% of females without obesity (P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity (P = 0.002).
Conclusions: Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females.
Competing Interests: Conflict of Interest and Funding Source: This research was supported by NIH R01 HL136643, Texas Health Presbyterian Hospital Dallas, King Charitable Foundation Trust, and unrestricted funds from Dr. Pepper Snapple. The authors have no relevant conflicts of interest to disclose.

Nemoto S; Showa University School of Nursing and Rehabilitation Sciences,  Yokohama, Kanagawa,  Japan.
Nakabo T; Tashiro N; Kishino A; Yoshikawa A; Nakamura D; Geshi E;

Scientific reports [Sci Rep] 2024 May 22; Vol. 14 (1), pp. 11676.
Date of Electronic Publication: 2024 May 22.

Peak oxygen uptake (VO ₂ ), evaluated as exercise tolerance, is a strong predictor of life prognosis regardless of health condition. Several previous studies have reported that peak VO ₂ is higher in those with a greater decrease in muscle oxygen saturation (SmO ₂ ) in the active muscles during incremental exercise. However, the skeletal muscle characteristics of individuals exhibiting a greater decrease in SmO ₂ during active muscle engagement in incremental exercise remain unclear. This study aimed to clarify the relationship among muscle strength, muscle endurance, and skeletal muscle oxygenation dynamics in active leg muscles during incremental exercise. Twenty-four healthy young men were included and categorized into the non-moderate-to-high muscular strength and endurance group (those with low leg muscle strength, endurance, or both; n = 11) and the moderate-to-high muscular strength and endurance group (those with both moderate-to-high leg muscle strength and endurance; n = 13). All participants underwent cardiopulmonary exercise testing combined with near-infrared spectroscopy to assess whole-body peak VO ₂ and the change in SmO ₂ at the lateral vastus lateralis from rest to each exercise stage as skeletal muscle oxygenation dynamics. A linear mixed-effects model, with the change in SmO ₂ from rest to each stage as the dependent variable, individual participants as random effects, and group and exercise load as fixed effects, revealed significant main effects for both group (P = 0.001) and exercise load (P < 0.001) as well as a significant interaction between the two factors (P < 0.001). Furthermore, multiple-comparison test results showed that the change in SmO ₂ from rest to 40%-100% peak VO ₂ was significantly higher in the moderate-to-high muscular strength and endurance group than in the non-moderate-to-high muscular strength and endurance group. Maintaining both muscle strength and endurance at moderate or higher levels contributes to high skeletal muscle oxygenation dynamics (i.e., greater decrease in SmO ₂ ) during moderate- or high-intensity exercise.

Thron M; Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Karlsruhe, Germany.
Woll A; Doller L; InQuittmann OJ; Härtel S; Ruf L; Altmann S;

Journal of strength and conditioning research [J Strength Cond Res] 2024 May 24.
Date of Electronic Publication: 2024 May 24.

Physiological and locomotor profiling enables to differentiate between sprinters, 400-m runners, and middle-distance runners. [J Strength Cond Res XX(X): 000-000, 2024]-Different approaches exist for characterizing athletes, e.g., physiological and locomotor profiling. The aims of this study were to generate and compare physiological and locomotor profiles of male and female runners and to evaluate relationships between the different approaches. Thirty-four highly trained adolescent and young adult female and male athletes (n = 11 sprinters; n = 11,400-m runners; n = 12 middle-distance runners) performed two 100-m sprints on a running track to determine maximal sprinting speed (MSS) and maximal lactate accumulation rate (ċLamax).
A cardiopulmonary exercise test was performed on a treadmill to determine maximal aerobic speed (MAS) and maximal oxygen uptake (V̇o2max). Anaerobic speed reserve (ASR) was calculated as the difference between MSS and MAS. Group comparisons were conducted with a 2-way ANOVA (discipline × sex; p < 0.05) and Bonferroni post hoc tests and Cohen’s d as effect size. Parameters were correlated by Pearson’s correlation coefficients. Maximal aerobic speed and V̇o2max were higher in 400-m and middle-distance runners compared with sprinters (p ≤ 0.02; -2.24 ≤ d ≤ -1.29). Maximal sprinting speed and ċLamax were higher in sprinters and 400-m runners compared with middle-distance runners (0.03 ≤ p ≤ 0.28; 0.73 ≤ d ≤ 1.23). Anaerobic speed reserve was highest in sprinters and lowest in middle-distance runners (p ≤ 0.03; 1.24 ≤ d ≤ 2.79). High correlations were found between ASR and MAS, MSS, and ċLamax (p < 0.01; -0.55 ≤ r ≤ 0.91) and between ċLamax and MSS (p < 0.01; r = 0.74).
Our results indicate that athletes of different sprinting and running disciplines show differing physiological and locomotor profiles, and that the parameters of these approaches are related to each other. This can be of interest for assessing strengths and weaknesses (e.g., for talent identification) or training prescription in these disciplines.

de Souza IPMA; Author Affiliations: D’Or Institute for Research and Education, Cardio Pulmonar Hospital, Salvador, Bahia, Brazil (Mss de Souza and de Oliveira, Drs Darzé and Ritt); Bahiana School of Medicine and Public Health, Salvador, Bahia, Brazil (Ms de Souza, Drs Ramos, Ribeiro, Pazelli, Darzé, and Ritt); and Clinicas Hospital, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Drs da Silveira and Stein).
Ramos JVSP; da Silveira AD; Stein R; Ribeiro RS; Pazelli AM; de Oliveira QB; Darzé ES; Ritt LEF;

Journal of cardiopulmonary rehabilitation and prevention [J Cardiopulm Rehabil Prev] 2024 May 07.
Date of Electronic Publication: 2024 May 07.

Purpose: The objective of this study was to evaluate the independent and added value of a cardiopulmonary exercise test (CPX) to New York Heart Association (NYHA) functional analysis in patients with heart failure (HF) and ejection fraction (EF) <50%.
Methods: Patients (n = 613) with HF and EF < 50% underwent CPX and were followed for 28 ± 17 mo with respect to primary outcomes (death or heart transplantation).
Results: Mean patient age was 57 ± 12 yr and 64% were male. Most patients were classified as NYHA class II (41%). The composite rate of primary outcomes was 12%; death occurred in 9% and heart transplant in 4%. Independent predictors of primary outcomes were: EF (HR = 0.95: 95% CI, 0.92-0.98; P = .001) and NYHA (HR = 2.06: 95% CI, 1.54-2.75; P < .0001). When added to the model, peak oxygen uptake (peak) was an independent predictor (HR = 0.90: 95% CI, 0.84-0.96; P = .001), as was the percentage of predicted peak (HR = 0.03: 95% CI, 0.007-0.147; P < .001), minute ventilation/carbon dioxide production slope (HR = 1.02: 95% CI, 1.01-1.04; P = .012), and CPX score (HR = 1.16: 95% CI, 1.06-1.27; P = .001).
Conclusions: CPX variables were independent predictors of HJ prognosis, even when controlled by NYHA functional class. Despite being independent predictors, the value added to NYHA classification was modest and lacked statistical significance.