Mapelli M; Centro Cardiologico Monzino, IRCCS, Milan, Italy.;
Salvioni E; Mattavelli I; Grilli G; Zerboni G; Nava A; Capra N; Galotta A;Biroli M; Bellini G; Dall’Asta M;Pasini E; De Paola A; Torzolini L; Mani N; Turri S; Campodonico J; Agostoni P;

PloS one [PLoS One] 2025 Jul 16; Vol. 20 (7), pp. e0326661.
Date of Electronic Publication: 2025 Jul 16 (Print Publication: 2025).

Background: Nasal and oral exclusive breathing modes have benefits and drawbacks during submaximal exercise. It is less known whether these responses would extend to anaerobic work performed at high intensity. The purpose of this study is to find the most efficient mode of breathing during different phases of a maximal exercise at cardiopulmonary exercise test (CPET).
Methods: Healthy subjects were recruited to perform 4 maximal CPETs (standard conditions (STD), exclusively nasal breathing (eNAS), exclusively oral breathing (eOR), partial nasal breathing (pNAS) with just one blocked nostril) using the same ramp protocol on an electronically braked cycle ergometer. Before the exercise a standard spirometry was executed in the same order. Twelve healthy subjects (28.6 ± 5.2 y, 50% males) performed the 4 CPETs within one month. Variables were analysed at rest, at anaerobic threshold (AT), at intermediate exercise steps, and at peak.
Results: Compared to STD, eOR, and pNAS conditions, eNAS was associated with a significant lower peakVO2, peakVCO2, peak ventilation, respiratory rate, VE/VCO2 slope, respiratory exchange ratio, and workload (p < 0.05 for all). Moreover, peak inspiration and peak expiration time were augmented, while forced expiratory volume and vital capacity at rest were reduced. Only minor differences were detected at rest or AT. eNAS breathing Borg scale was higher in all phases of the exercise.
Conclusions: In young healthy subjects, an exclusively nasal respiration induces significant impairment on peak exercise capacity at CPET due to ventilatory limitation, with only minor effects on metabolic parameters at rest and in submaximal effort.

Phinicarides R; University Hospital Düsseldorf, Medical Faculty, Division of Cardiology, Düsseldorf, Germany.
Reuter I ; Wolff G; Karathanos A;Heidari H; Masyuk M; Pillekamp F; Kelm M;, Zeus T;, Klein K;

Diagnostics (Basel). 2025 Jun 30;15(13):1672.

Background: Congenital heart disease (CHD) affects approximately 9 per 1000 live births worldwide, with increasing prevalence due to improved survival. Today, over 90% of individuals with CHD reach adulthood, resulting in a growing population of adults with congenital heart disease (ACHD). Despite its clinical relevance, iron deficiency (ID) and anemia have been insufficiently studied in this group.
Objectives: To evaluate the prevalence and clinical impact of iron deficiency and anemia in ACHD, particularly their relationship with exercise capacity. Methods: We retrospectively analyzed 310 ACHD patients at University Hospital Düsseldorf between January 2017 and January 2019. Iron status was assessed using serum ferritin, transferrin saturation (TSAT), and hemoglobin levels. Exercise capacity was measured by cardiopulmonary exercise testing (VO2 max). Prevalence and clinical associations were compared with those reported in heart failure populations, using ESC guideline criteria. Analyses were adjusted for age, sex, and defect complexity.
Results: Iron deficiency (ID) was present in 183 patients (59.0%). Anemia was observed in 13 patients (4.2%), with 6 (46.2%) classified as microcytic and 5 (38.5%) as normocytic. Reduced exercise capacity, defined as VO2 max <80% of predicted, was present in 51 patients (16.5%), occurring more frequently in those with complex CHD (31.3% vs. 11.3%, p < 0.001). ID was associated with a trend toward lower VO2 max (21.3 vs. 23.5 mL/min/kg, p = 0.068), while anemia correlated with significantly reduced performance (19.8 ± 4.1 vs. 22.9 ± 6.3 mL/min/kg, p = 0.041).
Conclusions: Iron deficiency is highly prevalent, and anemia-though less common-was consistently associated with reduced functional capacity in ACHD. These findings highlight the need for targeted screening and management strategies in this growing patient population.

Seese L; Faculty Pavilion, Suite FP5210, UPMC Children’s Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224-1334, USA.
Schiff M; Olivieri L; Da Fonseca Da Silva L;  Da Silva JP; Christopher A; Harris TH; Morell V;Castro Medina M; Rathod RH; Kreutzer J; Diaz Castrillon C; Viegas M; Alsaied T; The Force Investigators;

Journal of clinical medicine [J Clin Med] 2025 Jun 09; Vol. 14 (12).
Date of Electronic Publication: 2025 Jun 09.

Background: To explore the differences in exercise capacity between the extracardiac conduit (ECC) and lateral tunnel (LT) Fontan.
Methods: 2169 patients (36% LT ( n = 774); 64% ECC ( n = 1395)) underwent a Fontan operation between 2000 to 2023 in a multi-institutional Fontan registry. LT patients were age-matched to ECC patients, and cardiopulmonary exercise test (CPET) results were compared. Following age-matching and exclusion of those without CPET data, 470 patients emerged with 235 LT and 235 ECC patients.
Results: ECC achieved higher peak heart rates (174 vs. 169 bpm, p = 0.0008) and heart rates at ventilatory anaerobic threshold (VAT) (130 vs. 119 bpm p = 0.0005). Oxygen saturations at peak (93.0 vs. 90.0%, p = 0.0003) and baseline (95 vs. 92.5%, p &lt; 0.0001) were higher in the ECC group. The VO ₂ at VAT was higher in the ECC (17.8 vs. 16.4 mL/kg/min p = 0.0123). Baseline pre-exercise heart rate, peak oxygen pulse, VE/VCO ₂ slope, peak VO ₂ , peak % of predicted VO ₂ , peak work rate, and peak % of predicted work rate were similar (all, p &gt; 0.05). Notably, less than 35% of the cohort had a documented CPET.
Conclusions: We found that the ECC performed statistically better on many parameters of exercise capacity, including the ability to increase heart rate, have higher peak and baseline saturations, and to achieve superior VO ₂ at VAT. However, the magnitude of difference was small, suggesting that the translational value into the clinical realm may be limited. With a minority of the registry patients having CPET completed, this illuminates the need for the implementation of CPET surveillance for Fontan patients.

Blumberg Y; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA.
de Monts C; Montalvo S; Tang WJ; Hageman N;   Sanchis-Gomar F; Ashley EA; Amar D; Myers J; Wheeler MT; Day JW; Duong T; Christle JW;

Journal of clinical medicine [J Clin Med] 2025 Jun 12; Vol. 14 (12).
Date of Electronic Publication: 2025 Jun 12.

Background: Individuals with neuromuscular diseases (NMDs) have low physical activity levels and an increased risk of cardiovascular and pulmonary diseases. Respiratory gas kinetics obtained during cardiopulmonary exercise testing (CPET) may provide valuable insights into disease mechanisms and cardiorespiratory fitness in individuals with NMD. Recovery from exercise is an important marker of exercise performance and overall physical health, and impaired recovery is strongly associated with poor health outcomes. This study evaluates recovery metrics in individuals with NMD after performing maximal exertion during CPET.
Methods: A total of 34 individuals with NMD and 15 healthy volunteers were recruited for the study. CPET was performed using a wearable metabolic system and a wheelchair-accessible total body trainer to peak exertion. Recovery metrics assessed were (i) the time to reach 50% O ₂ recovery compared with peak exercise and (ii) the ratios of ventilation and respiratory gases between peak exercise and the highest values observed during recovery (overshoot).
Results: The NMD group had a significantly longer time to reach 50% O ₂ recovery (T1/2 VO ₂ : 105 ± 43.4 vs. 76 ± 36.4 s, p = 0.02), lower respiratory overshoot (17.1 ± 13.0% vs. 28.8 ± 9.03%), and lower ventilation/VO ₂ (31.9 ± 28.3 vs. 52.2 ± 23.5) compared to the control group.
Conclusions: This study observes significantly impaired recovery metrics following peak exercise in individuals with NMD compared to controls. These insights may improve the understanding of exercise recovery and mechanics, thus improving prognostication and optimizing exercise prescriptions for individuals with NMD.

Ferguson C; The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA.
Furrer R; Murach KA; Hepple RT; Rossiter HB;

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2025 Jun 23.
Date of Electronic Publication: 2025 Jun 23.

Abstract: Introduction. Peak neuromuscular power and endurance are distinct qualities of dynamic exercise performance. Dynamometry is used to assess peak neuromuscular power, often during performance across a single joint e.g., isotonic or isokinetic torque, while aptitude for endurance exercise may be inferred by measurement of critical power/speed or cardiopulmonary exercise testing to determine e.g., gas exchange threshold (GET), maximum oxygen uptake (V̇O2max) and exercise economy. Specificity is a critical component of any training program, but oversimplification of the specificity principle has contributed to the view that training adaptations to increase peak neuromuscular power or the ability to endure high power outputs are mutually exclusive, due to: (i) differences in the types of motor units recruited and their patterns of activation; and (ii) induction of distinct, antagonistic molecular signaling pathways in response to resistance and endurance exercise training (the “interference effect”).
Methods, Results and Conclusion. This review explores evidence for reciprocation between peak neuromuscular power and endurance performance in sport, aging and among general and clinical populations. We also review the molecular events that mediate peak neuromuscular power and endurance training adaptations and their interactions. Finally, we describe the musculo-cardio-pulmonary exercise test (mCPET) to demonstrate that peak neuromuscular power and aerobic mediators of endurance performance are less polar opposites and more willing partners.
Competing Interests: Conflict of Interest and Funding Source: Carrie Ferguson is supported by a grant from NIH (R01HL166850; 5UH3HL155798). She is involved in contracted clinical research with United Therapeutics, Genentech, Regeneron, Respira Therapeutics and Mezzion. She reports consulting fees from Respira Therapeutics. Kevin Murach is supported by NIH R00 AG063994 and R01 AG080047. Russell Hepple is supported by grants from NIH (R21AR084591, R01AG059416, and R01AG076490). Harry Rossiter is supported by grants from NIH (R01HL151452, R01HL166850, R01HL153460, P50HD098593, R01DK122767), Tobacco Related Disease Research Program (T31IP1666) and Department of Defense / USAMRAA (HT9425-24-1-0249). He reports consulting fees from the NIH RECOVER-ENERGIZE working group (1OT2HL156812), and is involved in contracted clinical research with Astellas, GlaxoSmithKline, Genentech, Intervene Immune, Mezzion, Regeneron, Respira, Roche, and United Therapeutics.

Kwon Y; Department of Physical Therapy, Yeungnam University College, Daegu, Korea.
Nam KS; Chang JS; DepartKang KW;

The talk test (TT) is a subjective, self-administered method used to gauge aerobic exercise intensity based on a person’s ability to speak comfortably during physical activity. This study aimed to validate the TT by examining its relationship with physiological markers collected during cardiopulmonary exercise testing (CPX) on both a treadmill and stationary bicycle in healthy adults. Twenty-two healthy participants (17 males and 5 females), with no known musculoskeletal, cardiovascular, or pulmonary conditions, completed two exercise sessions-one on a treadmill and another on a stationary bicycle. Each session was structured into three stages of increasing intensity based on the TT. During each stage, various psychophysiological and cardiorespiratory variables were measured, including heart rate, rating of perceived exertion, metabolic equivalents, arterial oxygen saturation, respiratory rate, minute ventilation, oxygen uptake, carbon dioxide production, respiratory exchange ratio, and ventilatory threshold. Significant differences were found across the three TT stages for all measured variables, with values increasing linearly as intensity progressed. However, no significant differences were observed between exercise modalities (treadmill vs. bicycle) or in the interaction between TT stages and modality. The findings support the TT as a valid indicator of exercise intensity, correlating well with physiological responses measured during CPX. The consistency across both exercise modalities suggests that TT is a practical, effective tool for guiding aerobic exercise intensity, particularly in clinical and rehabilitation settings.

Morris MJ; Drs. Morris, Anderson, McInnis, Gonzales, Mr. Barber, Ms. Murillo, and Dr. Walter are affiliated withPulmonary/Critical Care Service, Department of Medicine, Brooke Army Medical Center, Joint Base San Antonio, Fort Sam Houston, Texas, USA.
Holley AB; Dr. Holley is affiliated withMedStar Washington Hospital Center, Pulmonary/Critical Care, Washington, District of Columbia, USA.
Anderson JT; McInnis IC;Gonzales MA; Rosas MM; Dr. Barber BS; Murillo CG; Aden JK; Huprikar NA; Walter RJ;

Respiratory care [Respir Care] 2025 Jun 30.
Date of Electronic Publication: 2025 Jun 30.

Background: Chronic respiratory symptoms are reported after military deployment in support of combat operations. The spectrum of clinical lung diseases was initially defined by the STudy of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures (STAMPEDE) III study. Does cardiopulmonary exercise testing (CPET) performed during this evaluation demonstrate differences based on established clinical diagnoses? Methods: Military personnel with chronic respiratory symptoms underwent a standardized evaluation as reported in the STAMPEDE III study. CPET was performed on a treadmill using a Bruce protocol, and all participants exercised to maximal exertion. Standard cardiac and respiratory CPET parameters were compared based on diagnosis, pulmonary function testing, and underlying comorbidities. Historical control patients included asymptomatic, nondeployed military personnel with normal imaging and spirometry who previously performed identical CPET testing.
Results: In total, 356 participants from STAMPEDE III (38.3 ± 8.7 years) completed a single CPET study during the standardized evaluation. Values were compared with 108 nondeployed controls (28.8 ± 3.9 years). Participants versus controls demonstrated a significant reduction in exercise capacity based on time (10:09 ± 1:51 vs 12:58 ± 2:11, P &lt; .001), metabolic equivalents (10.9 ± 1.7 vs 12.8 ± 1.7, P &lt; .001), and V̇ _{O 2} peak (mL/kg/min) (37.3 ± 7.1 vs 46.7 ± 6.9, P &lt; .001). In the comparison of respiratory parameters, both minute ventilation/maximum voluntary ventilation (0.80 ± 0.18 vs 0.69 ± 0.15) and breathing reserve percentage (20.3 ± 17.5 vs 25.9 ± 13.1) identified significant differences ( P &lt; .05) driven by asthma and lower airway categories, whereas breathing frequency and tidal volume/inspiratory capacity were not different. Differences in exercise capacity were influenced by the presence of post-traumatic stress disorder/traumatic brain injury, mental health disorders, and body mass index &gt;30 kg/m ² .
Conclusions: The use of CPET for postdeployment pulmonary diagnoses showed a decrease in exercise capacity compared with normal controls. Although several ventilatory parameters were elevated in asthma and lower airway diseases, individuals diagnosed with only exertional dyspnea did not demonstrate changes. Propensity matching confirmed that CPET does not suggest undiagnosed respiratory disease during a normal postdeployment pulmonary evaluation.