Maximal Incremental Exercise Research Articles

Return to Play after SARS-CoV-2 Infection in Competitive Athletes of Distinct Sport Disciplines in Italy: A FMSI (Italian Federation of Sports Medicine) Study.

Background: SARS-CoV-2 can lead to several systemic complications, including myocardial injuries; these might be worsened by heavy physical activity. The optimal approach to cardiac risk stratification following SARS-CoV-2 infection in athletes for a safe return to play (RTP) still needs defining. The aim of this study was to assess the prevalence of abnormal RTP test results, according to the protocol of Italian Federation of Sport Medicine (FMSI), which was endorsed by the Italian Ministry of Health, potentially representing COVID-19-associated cardiac injuries. Methods: This was a prospective, multicenter, observational study. All consecutive competitive athletes who underwent COVID-19 RTP testing protocol from 1 May to 31 July 2021, across 60 Italian Centers of Sports Medicine, were enrolled in the study. Athletes were tested at least 30 days after negativization of the nasopharyngeal swab (or immediately after negativization in professional athletes or Probable Olympians). A 12-lead electrocardiography at rest and during maximal incremental exercise test with continuous O2 saturation monitoring and an echocardiographic examination were part of the protocol. In athletes with “moderate” disease (NHI classification), 24 h ECG monitoring (to be performed on a training day) and Magnetic Resonance Imaging (MRI) were also performed. Results: A total of 4143 athletes (67.8% males and 32.2% females) (53% > 18 years, 20% 18–35 years and 16% > 35 years), from more than 40 different sport disciplines, were included in the study. The mean age was 22.5 ± 13.3 years, with ages ranging from 8 to 80 years. Of these athletes, 52.3% were asymptomatic, 46.4% manifested mild symptoms, 1.1% and 0.14% had moderate or severe symptoms, respectively, while critical illness was evident in one athlete. Abnormal echocardiographic findings were detected in 80 cases (1.9%), and pericarditis in 7 cases (0.2%); all were from mildly symptomatic athletes. Arrhythmic events were recorded in 239 athletes, with 224 (5.4%) in the exercise test and 15 (0.4%) during 24 h ECG monitoring. Ventricular arrhythmias were observed in 101 (2.4%) athletes from the total population (mostly isolated or couples of premature ventricular beats): 91 in the exercise test and 10 during 24 h ECG monitoring. Cardiac magnetic resonance was performed in 34 athletes; the presence of myocarditis was confirmed in 5 athletes (0.12% of the total population, 14.7% of athletes in which MRI was performed). Conclusions: According to our results, cardiac complications from SARS-CoV-2 in asymptomatic or mildly symptomatic competitive athletes are rare, and an RTP assessment based on symptoms and ECG-monitored exercise test would ensure a safe RTP in these athletes.

The Effect of CT-Guided Artificial Pneumothorax plus Thoracoscopy and Central Venous Catheterization on the Drainage Effect of Pediatric Empyema and Pulmonary Function.

The aim of the study is to investigate the effect of CT-guided artificial pneumothorax combined with a thoracoscopic and central venous catheter on empyema drainage effect and pulmonary function in children. A total of 82 pediatric patients with empyema admitted to our hospital from January 2020 to December 2021 were retrospectively analyzed. The control group was treated with artificial pneumothorax combined with thoracoscopy. The study group was treated with a CT-guided and central venous catheter. The operation time, intraoperative bleeding, surgical field exposure, WBC, C-reactive protein, and pulmonary function were compared between the two groups. The size of effusion and sonographic staging were compared between the two groups. All children underwent spirometry and a maximal incremental cardiopulmonary exercise test. The operation indicators (operation time, intraoperative blood loss, etc.) and adverse reactions were compared between the two groups. The differences in the operation time, intraoperative blood loss, postoperative hospital stay, postoperative drainage volume, and surgical field exposure between the two groups had a statistical significance (P < 0.05); the differences in the body temperature, total peripheral white blood cell count, C-reactive protein, size of effusion, and sonographic staging between the two groups had no statistical significance (P > 0.05); before operation, the differences in the expression levels of FVC (%), FEV1 (%), FEV1/FVC, and MVV (%) and indicators of cardiopulmonary function including VE/VO2, breathing reserve(%), VD/VT(%), and VO2/work between the two groups had no statistical significance, but at 6 months after operation, FVC (%), FEV1 (%), FEV1/FVC, and MVV (%) in the study group were significantly higher than those in the control group (P < 0.05) and VE/VO2 and VD/VT(%) in the study group were obviously lower than those in the control group (P < 0.05); the incidence rate of chest pain, pulmonary edema, and skin infection in the study group was lower than that in the control group (P < 0.05). CT-guided artificial pneumothorax combined with thoracoscopic and central venous catheter drainage of empyema in children is more thorough, with less bleeding, less trauma, rapid recovery of pulmonary function, and is worthy of clinical promotion.

Brain Oxygenation in Post-concussion Combat Sport Athletes.

Purpose: Investigate the feasibility of a non-invasive method to evaluate the physical and cognitive repercussions of long-lasting post-concussion effects in professional combat sports athletes. To help athletes return to professional combat, there is a need for unbiased objective tools and techniques used as a prognostic method of recovery after Sport Related Concussion (SRC).Methods: Six mild Traumatic Brain Injury (mTBI) athletes, age 20 ÷ 43 yr (1 female, 5 males) and 7 not concussed (NC) participants (amateur), age 24 ÷ 38 yr (3 females, 4 males), were tested Inspired/expired gas concentration, Cerebral changes in oxygenated hemoglobin (Δ[HbO2]) and deoxygenated hemoglobin (Δ[HHb]) were measured using near infrared spectroscopy (NIRS) with a 3-step protocol: rest before maximal oxygen uptake (VO2max) test, hypercapnia, and recovery after VO2max test. The brain oxygenation and respiratory parameters of both sample sets were calculated using a non-parametric test (Mann-Whitney U test). Aerobic fitness outcome was quantified through mean average using the Bruce test. Participants performed Fitt's test using a laptop and analysis of medio-lateral and anterior-posterior range of oscillation was carried out via a force platform Romberg test.Results: mTBI group showed statistically significant differences in saturated hemoglobin Δ[HbO2] (p < 0.001) during rest and recovery phase after maximal incremental exercise, in medio-lateral sway eyes open (p = 0.008, NC 25.35 ± 4.11 mm and mTBI 17.65 ± 4.79 mm). VO2max revealed no significant differences between the two groups: NC 47.47 ± 4.91 mTBI 49.58 ± 5.19 ml/kg/min−1. The 2 groups didn't differ for maximum power output (NC 220 ± 34, mTBI 255 ± 50 W). End-tidal fractional concentration of O2 (FetO2 NC15.20 ± 0.41, mTBI 16.09 ± 0.68) throughout hypercapnia, saturated blood hemoglobin (Δ[HbO2]) revealed significant differences with the mTBI group. No differences emerged from Fitt's test.Conclusions: It emerges that NIRS is able to reveal differences in long time outcomes of mTBI. The medio-lateral variations cannot be considered as a marker of long-term damage in athletes specifically trained for balance.

Differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability in athletes and non-athletes

The study investigated the differential response to a single bout of maximal incremental treadmill exercise between athletes and non-athletes without dry eyes regarding tear secretion, tear film stability, visual acuity (VA), and stereoacuity. Additionally, the study examined the effect of gender and the duration of exercise on exercise-induced changes. Study participants included young university students aged 18–25 years who were athletes (male/female: 13/13) or non-athletes (male/female: 17/9). Participants underwent an aerobic exercise session using a treadmill and following the laid down Bruce treadmill test protocol till exhaustion. Measurements were taken in the order of distance VA, stereopsis, non-invasive tear break-up time (TBUT), and phenol red thread test, at baseline and after the exercise regimen. Within- and between-subject analyses using multiple t-tests with correction for multiple comparisons were performed to determine differences before and after exercise in athletes and non-athletes. Subsequently, ANCOVA was used to assess the influence of gender and the duration of exercise. The mean age (SD) of the athletes and the non-athletes was 22.4 ± 2.1 years and 21.8 ± 2.1 years, respectively (p = 0.357). Before exercise, the athletes had higher TBUT than non-athletes (14.6 ± 2.9 s vs. 11.9 ± 3.8 s; p = 0.021), but no difference was observed in any other ocular measurements. After exercise, the athletes showed significant improvement in tear secretion with the basal tear secretion increasing from 22.3 ± 2.5 mm to 25.8 ± 1.7 mm (p < 0.001). The non-athletes on the other hand had a borderline increase in tear secretion from 21.42 ± 2.85 mm to 23.73 ± 2.68 mm (p = 0.08). Also, the TBUT was much improved in the athletes after exercise compared to the non-athletes (17.7 ± 2.7 s vs. 14.8 ± 2.9 s, p = 0.004). Additionally, exercise improved the VA indifferently between the groups, while stereoacuity was unchanged after exercise in either group. Gender had no influence on the differences in the tear function measures between athletes and non-athletes after exercise. The duration of exercise, however, showed a borderline effect on the tear film stability (p = 0.068) after exercise. Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and non-athletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise.

Responses of different functional tests in candidates for bariatric surgery and the association with body composition, metabolic and lipid profile

Individuals with obesity can have metabolic disorders and may develop impairments that affect the ability to exercise. The maximal incremental cardiopulmonary exercise test is widely used to assess functional capacity. However, submaximal tests such as the two-minute step test (2MST) and the six-minute walk test (6MWT) also allow this assessment. We propose to analyze whether body composition, metabolic and lipid profile influence the maximal and submaximal performance, and investigate these variables in response to different functional tests. Forty-four individuals with obesity, aged 18–50 years, underwent analysis of body composition, metabolic and lipid profile, incremental treadmill test (ITMT), 6MWT, and 2MST. One-way ANOVA, Pearson or Spearman correlation, and Stepwise multiple linear regression analysis were performed. ITMT induced a greater metabolic, ventilatory, cardiovascular, and perceived exertion demand when compared to the 6MWT and 2MST (p < 0.05). In addition, 2MST elicited a higher chronotropic (HR) and metabolic (V̇O2) demand when compared to the 6MWT (p < 0.05). Significant correlations were found between tests and body composition, metabolic and lipid profile. Fat mass and low-density lipoprotein can explain 30% of the V̇O2 variance in the ITMT; and fat mass, glucose, and performance in the 2MST can explain 42% of the variance of the distance walked in the ITMT. Obesity and its metabolic impairments are capable of influencing responses to exercise. ITMT generated greater demand due to the high stress imposed, however, 2MST demanded greater metabolic and chronotropic demand when compared to the 6MWT.

Insulin resistance-related differences in the relationship between left ventricular hypertrophy and cardiorespiratory fitness in asymptomatic newly diagnosed hypertensive Black sub-Saharan Africans

Abstract Background Left ventricular hypertrophy (LVH) is associated with impaired cardiorespiratory fitness (CRF), a surrogate marker of poor outcome. Insulin resistance (IR) plays a central role in all stages of cardiovascular disease continuum. Purpose This study evaluates IR-related differences in the relationship between left ventricular mass (LVM) and CRF in asymptomatic newly diagnosed hypertensive patients. Methods In this cross-sectional observational study, 126 asymptomatic newly diagnosed hypertensive participants (50.5±9.5 years) underwent comprehensive resting transthoracic echocardiographic examination and maximal incremental cardiopulmonary exercise test (CPET). CRF was estimated in peak oxygen uptake (VO2 peak). CPET results were compared between participants with and without LVH. Multivariate analysis examined the influence of IR on the observed differences. Results Those with LVH had lower VO2 peak (15.7±5.5 mL min–1 kg–1 vs. 18.4±3.7 mL min–1 kg–1; p=0.001) than those without LVH. In patients with IR, LVM (r=−0.261, p=0.012), LVM indexed to body surface area (LVMIbsa; r=−0.229, p=0.027), and LVM indexed to height to an allometric power of 2.7 (LVMIh2.7; r=−0.351, p=0.001), and VO2 peak were negatively correlated. In hypertensive patients without IR, these same parameters and VO2 peak have no significant correlation. Body mass index (BMI), LVM, and LVMIbsa emerged as independent determinants of VO2 peak, explaining 46.9% of its variability (overall p=0.001) in IR participants, a relationship not found in participants without IR. Conclusions IR may participate in the deterioration of CRF associated with LVH. Targeting IR in hypertensive patients with LVH could improve prognosis. Funding Acknowledgement Type of funding sources: None.

Development of the A-STEP: A new incremental maximal exercise capacity step test in cystic fibrosis.

Exercise testing is important in people with cystic fibrosis (pwCF). The aim was to develop an incremental maximal step test to assess exercise capacity across the range of pwCF, without floor or ceiling effects, within restrictions of space, and infection prevention. The step test was developed in adults with stable CF. Subjects assisted in selecting: step height, start rate, increments, stage and test duration parameters. Equipment to externally pace and time the test and measure exercise parameters were selected. Reasons for stopping, criteria for achieving a maximal test, and key outcome measures were determined. Documentation to record and standardize the test and instructions to set up the metronome and timer App were developed. Infection control practices were considered. Eight subjects were recruited to develop the Alfred Step Test Exercise Protocol (A-STEP) on a 20 cm portable step. The A-STEP package included a pretest information sheet, clinical assessment and instructions, recording worksheet, and the metronome/timer instructions. The test started at 18 steps/min. Each level increased by two steps/min to a maximum of 48 steps (Level 16). Results were presented as mean (SD) [range] for: age 30.63 (5.89) [21-39] years; FEV1 58.13 (18.33) [32-89]%; levels: 10.31 (3.29) [6-15.5]. The A-STEP required space of 2 m2 and complied with current infection control guidelines. The A-STEP is a new incremental maximal step test to assess exercise capacity in pwCF, without floor or ceiling effects. It addresses the issues of space restrictions and the need for strict infection prevention in the clinical setting.

Intercostal Muscles Oxygenation and Breathing Pattern during Exercise in Competitive Marathon Runners.

The study aimed to evaluate the association between the changes in ventilatory variables (tidal volume (Vt), respiratory rate (RR) and lung ventilation (E)) and deoxygenation of m.intescostales (∆SmO2-m.intercostales) during a maximal incremental exercise in 19 male high-level competitive marathon runners. The ventilatory variables and oxygen consumption (O2) were recorded breath-by-breath by exhaled gas analysis. A near-infrared spectroscopy device (MOXY®) located in the right-hemithorax allowed the recording of SmO2-m.intercostales. To explore changes in oxygen levels in muscles with high demand during exercise, a second MOXY® records SmO2-m.vastus laterallis. The triphasic model of exercise intensity was used for evaluating changes in SmO2 in both muscle groups. We found that ∆SmO2-m.intercostales correlated with O2-peak (r = 0.65; p = 0.002) and the increase of E (r = 0.78; p = 0.001), RR (r = 0.54; p = 0.001), but not Vt (p = 0.210). The interaction of factors (muscles × exercise-phases) in SmO2 expressed as an arbitrary unit (a.u) was significant (p = 0.005). At VT1 there was no difference (p = 0.177), but SmO2-m.intercostales was higher at VT2 (p < 0.001) and O2-peak (p < 0.001). In high-level competitive marathon runners, the m.intercostales deoxygenation during incremental exercise is directly associated with the aerobic capacity and increased lung ventilation and respiratory rate, but not tidal volume. Moreover, it shows less deoxygenation than m.vastus laterallis at intensities above the aerobic ventilatory threshold.

Impact of Pharmacologically Left Shifting the Oxygen-Hemoglobin Dissociation Curve on Arterial Blood Gases and Pulmonary Gas Exchange During Maximal Exercise in Hypoxia.

Stewart, Glenn M., Troy J. Cross, Michael J. Joyner, Steven C. Chase, Timothy Curry, Josh Lehrer-Graiwer, Kobina Dufu, Nicholas E. Vlahakis, and Bruce D. Johnson. Impact of pharmacologically left shifting the oxygen-hemoglobin dissociation curve on arterial blood gases and pulmonary gas exchange during maximal exercise in hypoxia. High Alt Med Biol. 22:249-262, 2021. Introduction: Physiological and pathological conditions, which reduce the loading of oxygen onto hemoglobin (Hb), can impair exercise capacity and cause debilitating symptoms. Accordingly, this study examined the impact of pharmacologically left shifting the oxygen-hemoglobin dissociation curve (ODC) on arterial oxygen saturation (SaO2) and exercise capacity. Methods: Eight healthy subjects completed a maximal incremental exercise test in hypoxia (FIO2: 0.125) and normoxia (FIO2: 0.21) before (Day 1) and after (Day 15) daily ingestion of 900 mg of voxelotor (an oxygen/Hb affinity modulator). Pulmonary gas exchange and arterial blood gases were assessed throughout exercise and at peak. Data for a 1,500 mg daily drug dose are reported in a limited cohort (n = 3). Results: Fourteen days of drug administration left shifted the ODC (p50 measured under standard conditions, Day 1: 28.0 ± 2.1 mmHg vs. Day 15: 26.1 ± 1.8 mmHg, p < 0.05). Throughout incremental exercise in hypoxia, SaO2 was systematically higher after drug (peak exercise SaO2 on Day 1: 71 ± 2 vs. Day 15: 81% ± 2%, p < 0.001), whereas oxygen extraction (Ca-vO2 diff) and consumption (VO2) were similar (peak exercise Ca-vO2 diff on Day 1: 11.5 ± 1.7 vs. Day 15: 11.0 ± 1.8 ml/100 ml blood, p = 0.417; peak VO2 on Day 1: 2.59 ± 0.39 vs. Day 15: 2.47 ± 0.43 l/min, p = 0.127). Throughout incremental exercise in normoxia, SaO2 was systematically higher after drug, whereas peak VO2 was reduced (peak exercise SaO2 on Day 1: 93.9 ± 1.8 vs. Day 15: 95.8% ± 1.0%, p = 0.008; peak VO2 on Day 1: 3.62 ± 0.55 vs. Day 15: 3.26 ± 52 l/min, p = 0.001). Conclusion: Pharmacologically increasing the affinity of Hb for oxygen improved SaO2 during hypoxia without impacting exercise capacity; however, left shifting the ODC in healthy individuals appears detrimental to exercise capacity in normoxia. Left shifting the ODC to different magnitudes and under more chronic forms of hypoxia warrants further study.

Can exercise test intensity and modality affect the prevalence of arrhythmic events in young athletes?

ABSTRACT Pre-participation screening is performed to identify underlying cardiac conditions that may also lead to sudden cardiac death. Our aim is to compare submaximal Harvard Step Test (HST) with incremental Maximal Exercise Test (MET) on treadmill to induce and detect arrhythmias in younger athletes. A total of 1000 athletes (mean age 14.6 ± 4.7 years) were evaluated, 500 with MET and 500 with HST, all with continuous ECG monitoring until three minutes of recovery. Pre-test evaluation includes medical history, clinical evaluation and resting electrocardiogram. Ventricular and/or supraventricular arrhythmias were observed in 2.6% of athletes performing HST and in 8.4% during MET (p < 0.001). Incidence of arrhythmias remained higher for MET also considering separately exercise phase (0.8% vs. 5.2%; p < 0.001) and recovery phase (2.0% vs. 6.0%; p < 0.01). No gender differences were observed. Results suggest that MET induces more arrhythmias than submaximal HST, regardless of test phase. Higher test intensity and longer exercise duration might influence test outcomes, making MET more arrhythmogenic.

Reference values and validation of the 1-minute sit-to-stand test in healthy 5–16-year-old youth: a cross-sectional study

ObjectivesIt is essential to have simple, reliable and valid tests to measure children’s functional capacity in schools or medical practice. The 1-minute sit-to-stand (STS) test is a quick fitness test...

Effects of Post-Exertional Malaise on Markers of Arterial Stiffness in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Background: Evidence is emerging that individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) may suffer from chronic vascular dysfunction as a result of illness-related oxidative stress and vascular inflammation. The study aimed to examine the impact of maximal-intensity aerobic exercise on vascular function 48 and 72 h into recovery. Methods: ME/CFS (n = 11) with gender and age-matched controls (n = 11) were randomly assigned to either a 48 h or 72 h protocol. Each participant had measures of brachial blood pressure, augmentation index (AIx75, standardized to 75 bpm) and carotid-radial pulse wave velocity (crPWV) taken. This was followed by a maximal incremental cycle exercise test. Resting measures were repeated 48 or 72 h later (depending on group allocation). Results: No significant differences were found when ME/CFS were directly compared to controls at baseline. During recovery, the 48 h control group experienced a significant 7.2% reduction in AIx75 from baseline measures (p < 0.05), while the matched ME/CFS experienced no change in AIx75. The 72 h ME/CFS group experienced a non-significant increase of 1.4% from baseline measures. The 48 h and 72 h ME/CFS groups both experienced non-significant improvements in crPWV (0.56 ms−1 and 1.55 ms−1, respectively). Conclusions: The findings suggest that those with ME/CFS may not experience exercise-induced vasodilation due to chronic vascular damage, which may be a contributor to the onset of post-exertional malaise (PEM).

Sex-Related Differences in Dynamic Right Ventricular-Pulmonary Vascular Coupling in Heart Failure With Preserved Ejection Fraction

Right ventricular (RV) dysfunction is associated with poorer outcomes in heart failure with preserved ejection fraction (HFpEF). Although female subjects are more likely to have HFpEF, male subjects have worse prognosis and resting RV function. The contribution of dynamic RV-pulmonary arterial (RV-PA) coupling between sex and its impact on peak exercise capacity (VO2) in HFpEF is not known. The goal of this study was to investigate the differential effects of sex on RV-PA coupling during maximum incremental exercise in patients with HFpEF. This study examined rest and exercise invasive pulmonary hemodynamics in 22 male patients with HFpEF and 27 female patients with HFpEF. To further investigate the discrepancy in RV-PA response between sex, 26 age-matched control subjects (11 male subjects and 15 female subjects) were included. Single beat analysis of RV pressure waveforms was used to determine the end-systolic elastance (Ees) and pulmonary arterial elastance. RV-PA coupling was determined as the ratio of end-systolic elastance/PA elastance. Both HFpEF groups experienced decreased peak VO2 (%predicted). However, male patients with HFpEF experienced a greater decrement in peak VO2 compared with female patients (58 ± 16%vs70 ± 15%; P< .05). Male patients with HFpEF had a more pronounced increase in RV afterload, Ea (1.8 ± 0.6mmHg/mL/m2 vs1.3 ± 0.4mmHg/mL/m2; P< .05) and failed to increase RV contractility during exercise, resulting in dynamic RV-PA uncoupling (0.9 ± 0.4 vs1.2 ± 0.4; P< .05) and subsequent reduced stroke volume index augmentation. In contrast, female patients with HFpEF were able to augment RV contractility in the face of increasing afterload, preserving RV-PA coupling during exercise. Male patients with HFpEF were more compromised regarding dynamic RV-PA uncoupling and reduced peak VO2 compared with female patients. This finding was driven by both RV contractile impairment and afterload mismatch. In contrast, female patients with HFpEF had preserved RV-PA coupling during exercise and better peak exercise VO2 compared with male patients with HFpEF.

Unilateral diaphragmatic paralysis: inspiratory muscles, breathlessness and exercise capacity.

BackgroundPatients with unilateral diaphragmatic paralysis (UDP) may present with dyspnoea without specific cause and limited ability to exercise. We aimed to investigate the diaphragm contraction mechanisms and nondiaphragmatic inspiratory muscle activation during exercise in patients with UDP, compared with healthy individuals.MethodsPulmonary function, as well as volitional and nonvolitional inspiratory muscle strength were evaluated in 35 patients and in 20 healthy subjects. Respiratory pressures and electromyography of scalene and sternocleidomastoid muscles were continuously recorded during incremental maximal cardiopulmonary exercise testing until symptom limitation. Dyspnoea was assessed at rest, every 2 min during exercise and at the end of exercise with a modified Borg scale.Main resultsInspiratory muscle strength measurements were significantly lower for patients in comparison to controls (all p<0.05). Patients achieved lower peak of exercise (lower oxygen consumption) compared to controls, with both gastric (−9.8±4.6 cmH2O versus 8.9±6.0 cmH2O) and transdiaphragmatic (6.5±5.5 cmH2O versus 26.9±10.9 cmH2O) pressures significantly lower, along with larger activation of both scalene (40±22% EMGmax versus 18±14% EMGmax) and sternocleidomastoid (34±22% EMGmax versus 14±8% EMGmax). In addition, the paralysis group presented significant differences in breathing pattern during exercise (lower tidal volume and higher respiratory rate) with more dyspnoea symptoms compared to the control group.ConclusionThe paralysis group presented with exercise limitation accompanied by impairment in transdiaphragmatic pressure generation and larger accessory inspiratory muscles activation compared to controls, thereby contributing to a neuromechanical dissociation and increased dyspnoea perception.

Effect of normobaric hypoxic exercise on blood pressure in old individuals

PurposeTo test the hypothesis that the combination of endurance training and hypoxia leads to greater improvements in resting and exercise blood pressure in old sedentary individuals compared to endurance training only.MethodsWe randomly assigned 29 old overweight participants (age: 62 ± 6 years, body mass index (BMI): 28.5 ± 0.5 kg/m2, 52% men) to single blind 8-week bicycle exercise in hypoxia (fraction of inspired oxygen (FIO2) = 0.15) or normoxia (FIO2 = 0.21). Brachial blood pressure was measured at rest, during maximal incremental exercise testing, and during a 30 min constant work rate test, at baseline and after the training period.ResultsWork rate, heart rate and perceived exertion during training were similar in both groups, with lower oxygen saturation for participants exercising under hypoxia (88.7 ± 1.5 vs. 96.2 ± 1.2%, t(27) = − 13.04, p < 0.001, |g|= 4.85). Office blood pressure and blood pressure during incremental exercise tests did not change significantly in either group after the training program. Systolic blood pressure during the constant work rate test was reduced after training in hypoxia (160 ± 18 vs. 151 ± 14 mmHg, t(13) = 2.44 p < 0.05, |d|= 0.55) but not normoxia (154 ± 22 vs. 150 ± 16 mmHg, t(14) = 0.75, p = 0.46, |d|= 0.18) with no difference between groups over time (F = 0.08, p = 0.77, η2 = 0.01).ConclusionIn old individuals hypoxia in addition to exercise does not have superior effects on office or exercise blood pressure compared to training in normoxia.Trial registration numberClinicalTrials.gov No. NCT02196623 (registered 22 July 2014).

Analysis of the recovery phase after maximal exercise in children with repaired tetralogy of Fallot and the relationship with ventricular function.

BackgroundFew studies demonstrate delayed recovery after exercise in children and adults with heart disease. We assess the recovery patterns of gas exchange parameters and heart rate (HR) in children with repaired Tetralogy of Fallot (rToF) compared to healthy peers and investigate the correlation with ventricular function and QRS duration.Methods45 children after rToF and 45 controls performed a maximal incremental cardiopulmonary exercise test. In the subsequent recovery period, patterns of VO2, VCO2 and HR were analysed. Half-life time (T1/2) of the exponential decay and drop per minute (Recmin) were compared between groups. In the rToF group, correlations were examined between the recovery parameters and QRS-duration and ventricular function, described by fractional shortening (FS) and tricuspid annular plane systolic excursion (TAPSE) measured at baseline prior to exercise.ResultsRecovery of VO2 and VCO2 was delayed in rToF patients, half-life time values were higher compared to controls (T1/2VO2 52.51 ±11.29 s vs. 44.31 ± 10.47 s; p = 0.001 and T1/2VCO2 68.28 ± 13.84 s vs. 59.41 ± 12.06 s; p = 0.002) and percentage drop from maximal value was slower at each minute of recovery (p<0.05). Correlations were found with FS (T1/2VO2: r = -0.517; p<0.001; Rec1minVO2: r = -0.636, p<0.001; Rec1minVCO2: r = -0.373, p = 0.012) and TAPSE (T1/2VO2: r = -0.505; p<0.001; Rec1minVO2: r = -0.566, p<0.001; T1/2VCO2: r = -0.466; p = 0.001; Rec1minVCO2: r = -0.507, p<0.001), not with QRS-duration. No difference was found in HR recovery between patients and controls.ConclusionsChildren after rToF show a delayed gas exchange recovery after exercise. This delay correlates to ventricular function, demonstrating its importance in recovery after physical activity.

Circulating MicroRNA Profiling Reveals Specific Subsignatures in Response to a Maximal Incremental Exercise Test.

Fernández-Sanjurjo, M, Díaz-Martínez, ÁE, Díez-Robles, S, González-González, F, de Gonzalo-Calvo, D, Rabadán, M, Dávalos, A, Fernández-García, B, and Iglesias-Gutiérrez, E. Circulating microRNA profiling reveals specific subsignatures in response to a maximal incremental exercise test. J Strength Cond Res 35(2): 287-291, 2021-Circulating microRNAs (c-miRNAs) have been described as emergent regulators and biomarkers of exercise. The aim of this study was to analyze the c-miRNA response to a maximal incremental exercise test (MIET) and its relationship with markers of exercise response and adaptation. Two blood samples were collected from 9 male amateur runners (31-50 years), before (Pre) and after (Post) a MIET. The maximal oxygen uptake (V̇o2max), maximum heart rate (HRmax), and maximal aerobic speed (MAS) were recorded. Lactate and creatine kinase (CK) plasma concentrations were measured. A panel of 752 miRNAs was analyzed using standardized protocols and relative quantification to Pre. A total of 13 miRNAs were found significantly upregulated at Post. By focusing on the exercise markers that correlate with the expression of these miRNAs, they were clustered into different functional groups or subsignatures. Thus, miR-21-5p, miR-29b-3p, and miR-183-5p showed a strong correlation with HRmax and a validated target signature related to fatty acid metabolism. Furthermore, let-7c-5p, miR-340-5p, miR-425-3p, and miR-629-5p were significantly correlated with CK, and the most significantly enriched pathways for these subsignatures were the Hippo signaling pathway and signaling pathways regulating pluripotency of stem cells. Finally, Pre miR-106b-5p expression showed an inverse association with MAS and Post lactate concentration, which highlights its relevance as biomarker of training status and its predictive value for performance. No significant correlations were observed with V̇o2max. Our results define for the first time specific functional c-miRNA subsignatures, adding novel evidence about their potential regulatory role in exercise response.

Effects of a vibrational proprioceptive stimulation on recovery phase after maximal incremental cycle test.

Global Proprioceptive Resonance (GPR) is a recently developed approach conceived to solicit the various cutaneous mechanoreceptors, through application of mechanical multifocal vibration at low amplitude and at definite body sites, limiting the stimulation of the profound structures. This interventional study evaluated the effects of GPR on cardiorespiratory function during the post-exertional recovery period. A group of volunteers involved in Triathlon (a multisport discipline consisting of sequential swim, cycle, and run disciplines higly demanding in terms of metabolic engagment), underwent two maximal incremental exercise tests until exhaustion followed alternatively to (a) a 13 minutes section of GPR or (b) a standard low intensity exercise acute trend of the same duration. These effects of these two approaches were compared in terms of recovery of: heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2) and venous lactate concentration (Lac). The physiological parameters (HR, RR, SpO2 and Lac) recorded in the pre-exertion session showed similar values between the 40 volunteers while several differences were recorded in the post-exertion phase. After 6 min of GPR recovery it was recorded a drop in RR below baseline (19.4±4.15 min-1 vs. 12.2± 0.4 min-1; p<0.001) coupled with an increase in peripheral oxygen saturation above the baseline (GPR: 99.0%±0.16% vs. 96.6%±0.77%, p<0.001). Moreover, the most striking result was the drop in lactate concentration measured after 13 min of GPR recovery: 84.5±3.5% in GPR vs 2.9±7.6% reduction in standard recovery (p<0.001). Notably no differences were recorded recovery of heart rate. GPR has promising effects on post-exercise recovery on RR, SpO2 and lactate level on young athletes.

Abstract 16698: Cardiopulmonary Exercise Testing With an In-Line Filter During the COVID-19 Pandemic

Introduction: During maximum incremental exercise expiratory flow rates increase &gt; 10-fold and minute ventilation can exceed 100L/min, raising concern for possible spread of COVID-19 in asymptomatic patients undergoing exercise testing. Moreover, use of surgical or N95 masks that limit airflow are recognized to limit the ability to perform maximum exercise. Hypothesis: Use of an in-line filter during cardiopulmonary exercise testing is feasible and will not adversely impact measurements of exercise capacity. Methods: We conducted a proof-of-principle study in which a commercially available electrostat filter (Figure 1A), which has &gt;99.9% viral efficiency without affecting spirometry measurements during pulmonary function testing, was placed in-line, upstream of the flow meter and gas analyzer sample line for use during cardiopulmonary exercise testing. A single healthy subject completed incremental exercise with a 3 min period of unloaded exercise followed by 4-min stages of exercise at 50, 100, 150, and 200W with and without the filter in place on the same day. Mechanical dead space was 53 ml with the filter and 45 ml without. Results: In comparison to no internal filter, use of an in-line filter resulted in VO 2 measurements of 99%, 97%, 98%, and 97% during 50W, 100W, 150W, and 200W, respectively (Figure 1A). VO 2 /work slope measurements and measurements of minute ventilation were also highly consistent throughout exercise with and without use of an in-line filter (Figure 1B). Conclusions: Exercise testing is an integral part of cardiovascular care delivery. Our findings require further validation but suggest that an in-line filtration system can be utilized in an effort to reduce droplet and viral dissemination without impacting measures of cardiopulmonary performance.

The Relationship Between Repeated-Sprint Ability, Aerobic Capacity, and Oxygen Uptake Recovery Kinetics in Female Soccer Athletes.

This study investigated the relationship between repeated-sprint ability, aerobic capacity, and oxygen uptake kinetics during the transition between exercise and recovery (off-transient) in female athletes of an intermittent sport modality. Eighteen professional soccer players completed three tests: 1) a maximal incremental exercise test; 2) a constant speed time-to-exhaustion test; and 3) a repeated-sprint ability test consisting of six 40-m sprints with 20 s of passive recovery in-between. Correlations between time-to-exhaustion, repeated-sprint ability, and oxygen uptake kinetics were calculated afterwards. The level of significance was set at p < 0.05. A performance decrement during repeated-sprint ability was found to be related to: 1) time-to-exhaustion (e.g., exercise tolerance; r = -0.773, p < 0.001); 2) oxygen uptake recovery time (r = 0.601, p = 0.008); and 3) oxygen uptake mean response time of recovery (r = 0.722, p < 0.001). Moreover, the best sprint time (r = -0.601, p = 0.008) and the mean sprint time (r = -0.608, p = 0.007) were found to be related to maximal oxygen uptake. Collectively, these results reinforce the relation between oxygen uptake kinetics and the ability to maintain sprint performance in female athletes. These results may contribute to coaches and training staff of female soccer teams to focus on training and improve their athletes’ aerobic capacity and recovery capacity to improve intermittent exercise performance.