Influence of acute dietary nitrate supplementation on oxygen delivery/consumption and limit of tolerance during progressive forearm exercise in men: a randomized crossover trial

Beetroot juice (BRJ) supplementation increases nitric oxide bioavailability with hypoxia and acidosis, characteristics of high-intensity exercise. We investigated whether BRJ improved forearm oxygen delivery:demand matching in an intensity-dependent manner. Healthy men (21 ± 2.5 years) participated in a randomized crossover trial between October 2017 and May 2018 (Queen's University, Kingston, ON, Canada). Participants completed a forearm incremental exercise test to limit of tolerance (IET-LOT) 2.5 h post placebo (PL) versus BRJ (2 completed PL/BRJ vs. 9 completed BRJ/PL) within a 2-week period. Data are presented as mean ± standard deviation. There was a significant main effect of drink (PL < BRJ; P = 0.042, ηp2 = 0.385) and drink × intensity interaction for arteriovenous oxygen difference (PL < BRJ; P = 0.03; ηp2= 0.197; 20%-50% and 90% LOT). BRJ did not influence oxygen delivery (P = 0.893, ηp2 = 0.002), forearm blood flow (P = 0.589, ηp2 = 0.03) (forearm vascular conductance (P = 0.262, ηp2 = 0.124), mean arterial pressure (P = 0.254,ηp2 = 0.128)), oxygen consumption (P = 0.194, ηp2 = 0.179) or LOT (P = 0.432, d = 0.247). In healthy men, BRJ did not improve forearm oxygen delivery (vasodilatory or pressor response) during IET-LOT. Increased arteriovenous oxygen difference at submaximal intensities did not significantly influence oxygen consumption or performance across the entire range of forearm exercise intensities. This study adds to the growing body of evidence that BRJ does not influence small muscle mass blood flow in humans regardless of exercise intensity.

SPECTRA Phase 2b Study: Impact of Sotatercept on Exercise Tolerance and Right Ventricular Function in Pulmonary Arterial Hypertension

BACKGROUND

This study aims to assess the impact of sotatercept on exercise tolerance, exercise capacity, and right ventricular function in pulmonary arterial hypertension.

METHODS

SPECTRA (Sotatercept Phase 2 Exploratory Clinical Trial in PAH) was a phase 2a, single-arm, open-label, multicenter exploratory study that evaluated the effects of sotatercept by invasive cardiopulmonary exercise testing in participants with pulmonary arterial hypertension and World Health Organization functional class III on combination background therapy. The primary end point was the change in peak oxygen uptake from baseline to week 24. Cardiac magnetic resonance imaging was performed to assess right ventricular function.

RESULTS

Among the 21 participants completing 24 weeks of treatment, there was a significant improvement from baseline in peak oxygen uptake, with a mean change of 102.74 mL/min ([95% CIs, 27.72-177.76]; P=0.0097). Sotatercept demonstrated improvements in secondary end points, including resting and peak exercise hemodynamics, and 6-minute walk distance versus baseline measures. Cardiac magnetic resonance imaging showed improvements from baseline at week 24 in right ventricular function.

CONCLUSIONS

The clinical efficacy and safety of sotatercept demonstrated in the SPECTRA study emphasize the potential of this therapy as a new treatment option for patients with pulmonary arterial hypertension. Improvements in right ventricular structure and function underscore the potential for sotatercept as a disease-modifying agent with reverse-remodeling capabilities.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03738150.

Effects of Dronabinol on Dyspnea and Quality of Life in Patients With COPD

Background

Dyspnea is frequently a debilitating symptom of chronic obstructive pulmonary disease (COPD). Cannabinoid receptor agonists have the potential to alter dyspnea in these patients.

Objective

Our objective was to determine if dronabinol, a pure cannabinoid, improves dyspnea and exercise tolerance in COPD.

Methods

In this double-blind randomized, crossover pilot study, COPD patients received up to 20mg of oral dronabinol or placebo daily for 6 weeks with an intervening washout period. Dyspnea and fatigue were assessed using the Borg scale at rest and after an incremental shuttle walk. Functional status, mood, and depression were measured using the St George's Respiratory Questionnaire (SGRQ), the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ), and the Geriatric Depression Scale (GDS).

Results

A total of 11 participants (with mean forced expiratory volume in 1 second 50.8 ± 24.8%) completed the study with no improvement in dyspnea at rest or postexercise taking dronabinol versus placebo (Borg scale 0.27, 95% confidence interval [CI] -0.59 to 1.14 versus 0.23 points, 95% CI -0.71 to 1.07 at rest and 0.82, 95% CI -0.59 to 2.22 versus 0.36 points, 95% CI 0.13 to 2.78 post exercise; p=0.94 and p=0.69 respectively). Dronabinol compared with placebo showed no significant change in PFSDQ dyspnea scores (0.64, 95% CI -3.92 to 5.20 versus 5.0, 95% CI -6.29 to 16.29; p=0.43) or shuttle walk distances (20.7m, 95% CI -21.5 to 62.8 versus 13.7m, 95% CI -24.8 to 52.2; p=0.69). There were no significant differences in fatigue at rest and postexercise, SGRQ scores, or GDS scores.

Conclusion

In this pilot study, dronabinol did not significantly improve dyspnea or exercise capacity compared with placebo.

An additional mechanism enhancing exercise tolerance in interstitial lung disease with high-flow nasal cannula

See related article

A Single Dose of Beetroot Juice not Enhance Performance during Intervallic Swimming Efforts

Despite the numerous scientific evidence on the topic, there is no clear and consistent answer that clarifies the true effects of beetroot juice (BJ) supplementation on different types of physical performance. This study examined whether an acute intake of BJ improves swimming performance, physiological variables of anaerobic metabolism, or subjective measures during high-intensity interval exercise with incomplete rest in competitive swimmers. Eighteen competitive swimmers (nine females and nine males) participated in this cross-over randomized, placebo-controlled, double-blind and counterbalanced study. In two trials, swimmers ingested BJ (70 mL, 6.4 mmol/400 mg NO3-) or placebo (PLA) (70 mL, 0.04 mmol/3 mg NO3-) three hours before a 2×6×100 m maximal effort with 40 seconds rest between repetitions and three minutes between blocks. The 100 m times showed no differences between groups (p > 0.05), but there was an interaction between block×repetition×condition (F5 = 3.10; p = 0.046; ηp2 = 0.54), indicating that the BJ group decreased the time of the sixth repetition of block2 compared to block1 (p = 0.01). Lactate concentration showed no differences between conditions (p > 0.05), but there was a main effect of block (ηp2 = 0.60) and a block×repetition interaction (ηp2 = 0.70), indicating higher values in block2 and increasing values between repetitions in block1. The subjective scales, perception of exertion (RPE) and Total Quality Recovery (TQR), showed no effects of condition (p > 0.05), but BJ swimmers had a greater TQR in the last repetitions of each block. In conclusion, a single dose of BJ did not enhance intermittent swimming performance or modified the physiological (lactate and heart rate) or subjective (RPE and TQR) variables; although there was a possible positive effect on the exercise tolerance at the end of effort.

The Effectiveness of Lifestyle Interventions in Heart Failure With Preserved Ejection Fraction: A Systematic Review and Network Meta-Analysis

OBJECTIVES

To perform a network meta-analysis to determine the effectiveness of lifestyle interventions in exercise tolerance and quality of life (QoL) in people with HFpEF.

METHODS

Ten databases were searched for randomized controlled trials that evaluated a diet and/or exercise intervention in people with heart failure with preserved ejection fraction until May 2022. The co-primary outcomes were peak oxygen uptake (V̇O2peak) and Quality of Life as assessed by the Minnesota Living with Heart Failure Questionnaire (MLHFQ). We synthesized data using network meta-analysis.

RESULTS

We identified 13 trials, including a total of 869 participants, and we incorporated 6 different interventions. Improvements in V̇O2peak compared to controls were seen for all exercise interventions (2.88 [95% CI: 1.36; 4.39] mL/kg/min) for high-intensity interval training (HIIT); 2.37 [95% CI: 1.02; 3.71] mL/kg/min for low-intensity exercise (LIT) combined with a hypocaloric diet; 2.05 [95% CI: 0.81; 3.29] mL/kg/min for moderate-intensity continuous training (MICT); 1.94 [95% CI: 0.59; 3.29] mL/kg/min for LIT; 1.85 [95% CI: 0.27; 3.44] mL/kg/min for MICT combined with resistance training) but not a hypocaloric diet alone (1.26 [95%CI: -0.08; 2.61] mL/kg/min). Only HIIT (-14.45 [95%CI: -24.81; -4.10] points) and LIT (95% CI: -11.05 [-20.55; -1.54] mL/kg/min) significantly improved MLHFQ scores. Network meta-analysis indicated that HIIT was the most effective intervention for improving both V̇O2peak (mean improvement 2.88 [95% CI: 1.36; 4.39] mL/kg/min, follow-up range, 4 weeks-3 years) and QoL (-14.45 [95% CI: -24.81; -4.10] points, follow-up range, 12-26 weeks) compared to usual care.

CONCLUSIONS

This network meta-analysis indicates that HIIT is the most effective lifestyle intervention studied to improve exercise capacity and QoL, with mean improvements exceeding the minimum clinically meaningful thresholds. HIIT is likely to be an underused management strategy in HFpEF, but further studies are needed to confirm long-term improvements in symptoms and clinical outcomes.

Cardiopulmonary Exercise Performance of Children Born Non-Extremely Preterm

Data on exercise tolerance of children born non-extremely preterm are sparse. We aimed to explore the cardiopulmonary exercise testing (CPET) characteristics in this population. We studied 63 children (age 7-12 years) born at 290/7-366/7 weeks of gestation (34 were late preterm, 29 were preterm) and 63 age-matched, term-born controls. All performed spirometry and CPET (cycle ergometry). There were no differences in activity levels and spirometric parameters between the group of preterm-born children and controls. A peak oxygen uptake (VO2peak) of <80% was noted in 25.4% of the term-born and 49.2% of preterm-born children (p = 0.001). Term-born participants presented similar VO2peak to late-preterm children but higher than those born at <340/7 weeks of gestation (p = 0.002). Ventilatory limitation was noted in 4.8% of term and 7.9% of preterm participants, while only one preterm child presented cardiovascular limitation. Children born before 34 weeks of gestation had higher respiratory rates and smaller tidal volumes at maximum exercise, as well as lower oxygen uptake for the level of generated work. We conclude that school-age children born at 29-34 weeks of gestation may present decreased exercise performance attributed to an altered ventilatory response to exercise and impaired O2 utilization by their skeletal muscles rather than other cardiopulmonary limiting factors.

Exercise Training Decreases Nitrite Concentration in the Heart and Locomotory Muscles of Rats Without Changing the Muscle Nitrate Content

BACKGROUND

Skeletal muscles are postulated to be a potent regulator of systemic nitric oxide homeostasis. In this study, we aimed to evaluate the impact of physical training on the heart and skeletal muscle nitric oxide bioavailability (judged on the basis of intramuscular nitrite and nitrate) in rats.

METHODS AND RESULTS

Rats were trained on a treadmill for 8 weeks, performing mainly endurance running sessions with some sprinting runs. Muscle nitrite (NO2-) and nitrate (NO3-) concentrations were measured using a high-performance liquid chromatography-based method, while amino acids, pyruvate, lactate, and reduced and oxidized glutathione were determined using a liquid chromatography coupled with tandem mass spectrometry technique. The content of muscle nitrite reductases (electron transport chain proteins, myoglobin, and xanthine oxidase) was assessed by western immunoblotting. We found that 8 weeks of endurance training decreased basal NO2- in the locomotory muscles and in the heart, without changes in the basal NO3-. In the slow-twitch oxidative soleus muscle, the decrease in NO2- was already present after the first week of training, and the content of nitrite reductases remained unchanged throughout the entire period of training, except for the electron transport chain protein content, which increased no sooner than after 8 weeks of training.

CONCLUSIONS

Muscle NO2- level, opposed to NO3-, decreases in the time course of training. This effect is rapid and already visible in the slow-oxidative soleus after the first week of training. The underlying mechanisms of training-induced muscle NO2- decrease may involve an increase in the oxidative stress, as well as metabolite changes related to an increased muscle anaerobic glycolytic activity contributing to (1) direct chemical reduction of NO2- or (2) activation of muscle nitrite reductases.

Chronic almond nut snacking alleviates perceived muscle soreness following downhill running but does not improve indices of cardiometabolic health in mildly overweight, middle-aged, adults

Introduction

As a popular food snack rich in protein, fiber, unsaturated fatty acids, antioxidants and phytonutrients, almond nut consumption is widely associated with improvements in cardiometabolic health. However, limited data exists regarding the role of almond consumption in improving exercise recovery. Accordingly, we aimed to investigate the impact of chronic almond snacking on muscle damage and cardiometabolic health outcomes during acute eccentric exercise recovery in mildly overweight, middle-aged, adults.

Methods

Using a randomized cross-over design, 25 mildly overweight (BMI: 25.8 ± 3.6 kg/m2), middle-aged (35.1 ± 4.7 y) males (n = 11) and females (n = 14) performed a 30-min downhill treadmill run after 8-weeks of consuming either 57 g/day of whole almonds (ALMOND) or an isocaloric amount (86 g/day) of unsalted pretzels (CONTROL). Muscle soreness (visual analogue scale), muscle function (vertical jump and maximal isokinetic torque) and blood markers of muscle damage (creatine kinase (CK) concentration) and inflammation (c-reactive protein concentration) were measured pre and post (24, 48, and 72 h) exercise. Blood biomarkers of cardiometabolic health (total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol), body composition and psycho-social assessments of mood (POMS-2 inventory), appetite and well-being were measured pre and post intervention.

Results

Downhill running successfully elicited muscle damage, as evidenced by a significant increase in plasma CK concentration, increased perception of muscle soreness, and impaired vertical jump performance (all p < 0.05) during acute recovery. No effect of trial order was observed for any outcome measurement. However, expressed as AUC over the cumulative 72 h recovery period, muscle soreness measured during a physical task (vertical jump) was reduced by ~24% in ALMOND vs. CONTROL (p < 0.05) and translated to an improved maintenance of vertical jump performance (p < 0.05). However, ALMOND did not ameliorate the CK response to exercise or isokinetic torque during leg extension and leg flexion (p > 0.05). No pre-post intervention changes in assessments of cardiometabolic health, body composition, mood state or appetite were observed in ALMOND or CONTROL (all p > 0.05).

Conclusion

Chronic almond supplementation alleviates task-specific perceived feelings of muscle soreness during acute recovery from muscle damaging exercise, resulting in the better maintenance of muscle functional capacity. These data suggest that almonds represent a functional food snack to improve exercise tolerance in mildly overweight, middle-aged adults.

Electroencephalography spectral coherence analysis during cycle ergometry in low- and high-tolerant individuals

The main objective of this study was to further understanding of the patterns of spectral connectivity during exercise in low- and high-tolerant individuals. Thirty-nine healthy individuals (i.e., 17 low- and 22 high-tolerant participants) took part in the present study. A state-of-the-art portable electroencephalography system was used to measure the brain's electrical activity during an incremental exercise test performed until the point of volitional exhaustion on a cycle ergometer. Spectral coherence was used to explore the patterns of connectivity in the frontal, central, and parietal regions of the brain. Physiological, perceptual, and affective responses were assessed throughout the exercise bout. The spontaneous eyeblink rate was also calculated prior to commencement and upon completion of the exercise trial as an indirect assessment of the dopaminergic system. The present findings indicate that high-tolerant individuals reported lower levels of perceived activation, especially during the preliminary stages of the exercise test. Participants in the high-tolerance group also reported greater levels of remembered pleasure upon completion of the exercise test. The data also revealed that high-tolerant individuals exhibited increased connectivity of theta waves between frontal, central, and parietal electrode sites and increased connectivity of beta waves, primarily within the parietal cortex. Correlational analysis indicated the possibility that low- and high-tolerant individuals make use of different neural networks to process and regulate their psychophysiological state during exercise-related situations. This strategy could potentially represent a conscious decision to downregulate affective arousal and facilitate the neural control of working muscles during situations of physical stress.

Relationship Between Increased Oxygen Uptake and Lactate Production With Progressive Incremental Electrode Skeletal Muscle Stimulation: A Pilot Study

Background Belt electrode skeletal muscle stimulation (B-SES) is an alternative exercise therapy for those with difficulty performing voluntary exercise. However, it is unknown whether oxygen uptake (VO2) in B-SES is comparable to cardiopulmonary exercise test (CPX) as assessed by voluntary exercise. This study aimed to evaluate oxygen uptake (VO2) and lactate (LA) production in incremental B-SES compared to ergometer CPX and to determine the relationship with ergometer CPX. Methods This study included 10 healthy young Japanese participants. Using a crossover design, all participants underwent incremental B-SES CPX and ergometer CPX using a 20 W ramp. Serum lactic acid concentration (LA) was measured serially before, during, and after B-SES. The tolerability of B-SES was adjusted with the change in LA level (⊿LA). Results Peak VO2 during B-SES (14.1±3.3 mL/kg/min) was significantly lower than ergometer peak VO2 (30.2±6.2 mL/kg/min, P<0.001). B-SES peak VO2 was similar to the anaerobic threshold (AT) VO2 on ergometer CPX (15.1±2.6 mL/kg/min). LA (Rest: 1.4±0.3, Peak: 2.8±0.8 mmol) and plasma noradrenalin (Rest: 0.2±0.1, Peak: 0.4±0.1 ng/mL) levels increased after B-SES. No significant correlation was observed between B-SES peak VO2 and ergometer CPX. However, after adjusting for B-SES, tolerability, it (peak VO2 of B-SES /⊿LA) correlated with peak VO2 (r=0.688, p=0.028) on the ergometer. Conclusion Peak VO2 of the passively progressive B-SES almost reached the AT value of the ergometer CPX without adverse events. Peak VO2 of B-SES adjusted with ⊿LA may be used to predict peak VO2 in ergometer CPX.

Thermographic ranges of dromedary camels during physical exercise: applications for physical health/welfare monitoring and phenotypic selection

Despite the relatively wide knowledge of camel biomechanics, research into the immediate functional response that accompanies the execution of physical exercise remains unapproached. Therefore, selective breeding programs lack an empirical basis to achieve genetic improvement of physical stress tolerance traits and monitor camel welfare in this regard. Given the fact that physical exercise increases net heat production, infrared thermography (IRT) was selected to study the temperature changes at the skin surface of the different body areas in clinically normal dromedary camels, mostly relegated to leisure activities. Specifically, a lower dispersion at the individual level of the surface temperature at the scapular cartilage region, shoulder joint, and pelvis region, as well as lower values for Tmax and Tmin at the region of the ocular region, pectoral muscles, semimembranosus-semitendinosus muscles, and hind fetlock after exercise, have to be considered as breeding criteria for candidate selection. Such thermophysiological responses can be used as indirect measures of tissue activity in response to exercise and hence are reliable indicators of animal tolerance to physical exercise-induced stress. Additionally, sex, castration, age, and iris pigmentation significantly impacted the thermo-physiological response to exercise in the study sample, which can be attributed to hormones, general vigor, and visual acuity-mediated effects. These specific factors' influence has to be considered for the evaluation of physical performance and the design of selection schemes for physical-related traits in dromedaries.

Time-Course of Changes in Multidimensional Fatigue and Functional Exercise Capacity and Their Associations during a Short Inpatient Pulmonary Rehabilitation Program

This study aimed to assess the time-course of changes in multidimensional fatigue and functional exercise capacity and their associations during an inpatient pulmonary rehabilitation (PR) program. Seventy COPD patients from three centres were enrolled for a four-week PR program and were evaluated before (T0) and at the end of each week (T1, T2, T3, and T4). Weekly change in multidimensional fatigue was assessed by the multidimensional inventory questionnaire (MFI-20) and functional exercise capacity by the 6-minute walking distance (6MWD). Reaction time (RT) and heart rate variability (HRV) were also assessed as complementary markers of fatigue. HRV did not change during the study (all p > 0.05). MFI-20 score and RT decreased during the first part of the program (p < 0.001) and levelled off at T2 (all p > 0.05 compared with each preceding time). While 6MWD improved by almost 70% during the first part of the PR, it continued to increase, albeit at a greatly reduced pace, between T2 and T4 (p < 0.05). In parallel, a negative association was found between MFI-20 score and 6MWD at each evaluation time (r ranged from 0.43 to 0.71), with a significantly stronger T3 correlation compared with the other time periods (all p < 0.05). The strengthening of the association between fatigue and functional exercise capacity at T3, which occurred concomitantly with the slowdown of functional exercise capacity improvement, is consistent with a role for fatigue in the limitation of performance changes during PR. The limitation of fatigue during PR is thus an interesting aspect to improve the magnitude of performance changes.

Effects of cardiorespiratory rehabilitation program on submaximal exercise in patients with long-COVID-19 conditions: a systematic review of randomized controlled trials and recommendations for future studies

INTRODUCTION

Long-COVID-19 patients (LC19Ps) often experience cardiovascular and respiratory complications. Cardiorespiratory rehabilitation programs (CRRPs) have emerged as promising interventions to enhance exercise capacity in this population. This systematic review aimed to assess the impact of CRRPs on submaximal exercise performance, specifically the 6-minute walk test (6MWT) outcomes, in LC19Ps through an analysis of available randomized controlled trials (RCTs).

METHODS

A systematic search was conducted in PubMed/Medline and Scopus to identify relevant RCTs. Six RCTs meeting inclusion criteria were included in this review, investigating the effects of CRRPs on 6MWT outcomes in LC19Ps.

RESULTS

The findings from the included RCTs provide compelling evidence supporting the effectiveness of CRRPs in improving submaximal exercise performance in LC19Ps. These results underscore the potential of CRRPs to enhance submaximal exercise capacity and overall functional well-being in this population. However, future research is imperative to determine optimal CRRPs, including duration, intensity, and specific intervention components. Additionally, the long-term sustainability and durability of CRRP-induced improvements warrant further exploration. Future studies should prioritize patient-centric outcomes and address potential implementation barriers.

CONCLUSION

CRRPs show promise in ameliorating submaximal exercise performance among LC19Ps. Further research is needed to refine these programs and ensure their lasting impact on this patient group.

SYSTEMATIC REVIEW REGISTRATION

https://doi.org/10.17605/OSF.IO/HMN38. [Figure: see text].

Lifestyle Intervention and Excess Weight in Chronic Obstructive Pulmonary Disease (COPD): INSIGHT COPD Randomized Clinical Trial

Rationale: Being overweight or obese is common among patients with chronic obstructive pulmonary disease (COPD), but whether interventions targeted at weight loss improve functional impairments is unknown. Objectives: INSIGHT (Intervention Study in Overweight Patients with COPD) tested whether a pragmatic low-intensity lifestyle intervention would lead to better physical functional status among overweight or obese participants with COPD. Methods: The trial was a 12-month, multicenter, patient-level pragmatic clinical trial. Participants were recruited from April 2017 to August 2019 from 38 sites across the United States and randomized to receive usual care or usual care plus lifestyle intervention. The intervention was a self-directed video program delivering the Diabetes Prevention Program's Group Lifestyle Balance curriculum. Results: The primary outcome was 6-minute-walk test distance at 12 months. Priority secondary outcomes were postwalk modified Borg dyspnea at 12 months and weight at 12 months. Participants (N = 684; mean age, 67.0 ± 8.0 yr [standard deviation]; 41.2% female) on average were obese (body mass index, 33.0 ± 4.6 kg/m2) with moderate COPD (forced expiratory volume in 1 second % predicted, 58.1 ± 15.7%). At 12 months, participants randomized to the intervention arm walked farther (adjusted difference, 42.3 ft [95% confidence interval (CI), 7.9-76.7 ft]; P = 0.02), had less dyspnea at the end of the 6-minute-walk test (adjusted difference, -0.36 [95% CI, -0.63 to -0.09]; P = 0.008), and had greater weight loss (adjusted difference, -1.34 kg [95% CI, -2.33 to -0.34 kg]; P = 0.008) than control participants. The intervention did not improve the odds of achieving clinically meaningful thresholds of walk distance (98.4 ft) or dyspnea (1 unit) but did achieve meaningful thresholds of weight loss (3% and 5%). Conclusions: Among participants with COPD who were overweight or obese, a self-guided low-intensity video-based lifestyle intervention led to modest weight loss but did not lead to clinically important improvements in physical functional status and dyspnea. Clinical trial registered with www.clinicaltrials.gov (NCT02634268).

The therapeutic role of inspiratory muscle training in the management of asthma: a narrative review

Asthma is a disorder of the airways characterized by chronic airway inflammation, hyperresponsiveness, and variable recurring airway obstruction. Treatment options for asthma include pharmacological strategies, whereas nonpharmacological strategies are limited. Established pharmacological approaches to treating asthma may cause unwanted side effects and do not always afford adequate protection against asthma, possibly because of an individual's variable response to medications. A potential nonpharmacological intervention that is most available and cost effective is inspiratory muscle training (IMT), which is a technique targeted at increasing the strength and endurance of the diaphragm and accessory muscles of inspiration. Studies examining the impact of IMT on asthma have reported increases in inspiratory muscle strength and a reduction in the perception of dyspnea and medication use. However, because of the limited number of studies and discordant methods between studies more evidence is required to elucidate in individuals with asthma the efficacy of IMT on inspiratory muscle endurance, exercise capacity, asthma control, symptoms, and quality of life as well as in adolescents with differing severities of asthma. Large randomized controlled trials would be a significant step forward in clarifying the effectiveness of IMT in individuals with asthma. Although IMT may have favorable effects on inspiratory muscle strength, dyspnea, and medication use, the current evidence that IMT is an effective treatment for asthma is inconclusive.

In Cardiac Patients β-Blockers Attenuate the Decrease in Work Rate during Exercise at a Constant Submaximal Heart Rate

PURPOSE

Exercise prescription based on fixed heart rate (HR) values is not associated with a specific work rate (WR) during prolonged exercise. This phenomenon has never been evaluated in cardiac patients and might be associated with a slow component of HR kinetics and β-adrenergic activity. The aims were to quantify, in cardiac patients, the WR decrease at a fixed HR and to test if it would be attenuated by β-blockers.

METHODS

Seventeen patients with coronary artery disease in stable conditions (69 ± 9 yr) were divided into two groups according to the presence (BB) or absence (no-BB) of a therapy with β-blockers, and performed on a cycle ergometer: an incremental exercise (INCR) and a 15-min "HR CLAMPED " exercise, in which WR was continuously adjusted to maintain a constant HR, corresponding to the gas exchange threshold +15%. HR was determined by the ECG signal, and pulmonary gas exchange was assessed breath-by-breath.

RESULTS

During INCR, HR peak was lower in BB versus no-BB ( P < 0.05), whereas no differences were observed for other variables. During HR CLAMPED , the decrease in WR needed to maintain HR constant was less pronounced in BB versus no-BB (-16% ± 10% vs -27 ± 10, P = 0.04) and was accompanied by a decreased V̇O 2 only in no-BB (-13% ± 6%, P < 0.001).

CONCLUSIONS

The decrease in WR during a 15-min exercise at a fixed HR (slightly higher than that at gas exchange threshold) was attenuated in BB, suggesting a potential role by β-adrenergic stimulation. The phenomenon may represent, also in this population, a sign of impaired exercise tolerance and interferes with aerobic exercise prescription.

Effects of Flavonoid Supplementation on Athletic Performance in Healthy Adults: A Systematic Review and Meta-Analysis

Flavonoids, known for their antioxidant properties, can prevent reactive oxygen species (ROS) and influence athletic performance through various physiological and metabolic mechanisms. However, there are conflicting results after summarizing and analyzing the relevant literature. Hence, it is warranted to evaluate the overall impact of flavonoids on athletic performance in healthy adults based on a comprehensive and systematic review and meta-analysis. After searching four databases for literature published since their respective establishments until February 2023 and conducting publication bias and quality assessments, a total of 22 studies were ultimately included. The names and doses of flavonoids, various outcome measurements, as well as types of training, were extracted from included studies. The athletic performance outcomes from the included studies were categorized into 'performance tests' and 'exercise tolerance,' depending on the type of training undertaken. Several statistical results, such as pooled effect size (ES), among others, were implemented by meta-analysis using the random effects model. The results of meta-analysis suggest that there is currently sufficient evidence (ES = -0.28; 95% confidence interval (CI): [-0.50, -0.07]; p = 0.01 and ES = 0.23; 95% CI: [0.07, 0.39]; p = 0.005) to support the notion that flavonoid supplementation enhanced athletic performance in performance tests and exercise tolerance. In addition, among the subgroups, nonsignificant results were observed for athletes (p = 0.28) and acute supplementation (p = 0.41) in performance tests, as well as athletes (p = 0.57) and acute supplementation (p = 0.44) in exercise tolerance. Meanwhile, significant results were found for non-athletes (p = 0.04) and long-term supplementation (p = 0.02) in performance tests, as well as non-athletes (p = 0.005) in performance tests and long-term supplementation (p = 0.006) in exercise tolerance. The nonsignificant results were likely due to the limitation in the number of related papers, sample sizes, optimal dosage, duration, type of flavonoids, and other factors. Therefore, future research should focus on further investigating these relationships with larger sample sizes, optimal dosage, duration, and type of flavonoids to provide more robust conclusions.

Efficacy of a Commercial Physical Activity Monitor in Longitudinal Tracking of Patients With Pulmonary Hypertension: A Pilot Study

BACKGROUND

Patients with pulmonary arterial hypertension have quality-of-life limitations, decreased exercise capacity, and poor prognosis if the condition is left untreated. Standard exercise testing is routinely performed to evaluate patients with pulmonary arterial hypertension but may be limited in its ability to monitor activity levels in daily living.

OBJECTIVE

To evaluate the validity of the commercial Fitbit Charge HR as a tool to assess real-time exercise capacity as compared with standard exercise testing.

METHODS

Ambulatory pediatric and adult patients were enrolled and given a Fitbit with instructions to continuously wear the device during waking hours. Patients underwent a 6-minute walk test, cardiopulmonary exercise test, and a 36-Item Short Form Health Survey on the day of enrollment and follow-up. Twenty-seven ambulatory patients with pulmonary arterial hypertension were enrolled, and 21 had sufficient data for analyses (median age, 25 years [range, 13-59 years]; 14 female participants).

RESULTS

Daily steps measured by the Fitbit had a positive correlation with 6-minute walk distance (r = 0.72, P = .03) and an inverse trend with World Health Organization functional class. On the 36-Item Short Form Health Survey, 77% of patients reported improvement in vitality (P = .055). At follow-up, there was a strong correlation between number of steps recorded by Fitbit and role limitations because of physical problems (r = 0.88, P = .02) and weaker correlations with other quality-of-life markers.

CONCLUSION

The findings of this pilot study suggest activity monitors may have potential as a simple and novel method of assessing longitudinal exercise capacity and activity levels in patients with pulmonary hypertension. Further study in larger cohorts of patients is warranted to determine which accelerometer measures correlate best with outcomes.

Effects of Pedometer-Based Step-Feedback on Physical Activity of Severe COPD Patients

Purpose

This study investigated whether adding step-feedback (step-FB) from a pedometer to pulmonary rehabilitation (PR) programs could increase the physical activity (PA) of low-activity patients with severe chronic obstructive pulmonary disease (COPD).

Patients and Methods

We included low-activity patients with severe COPD (step-FB group: 14 patients; control group: 17 patients) who underwent PR for the first time. The usual PR program for patients with severe COPD consisted of two 8-week sessions (PR session 1: PR1, PR session 2: PR2). The step-FB group was provided a program with step-FB added to PR2 (PR2+step-FB). Furthermore, all patients were evaluated at pre-intervention (baseline), PR1, and PR2. The primary outcome of this study was the number of daily steps (steps) and energy expenditure from activity (energy expenditure), as measured by a pedometer. The secondary outcomes were dyspnea and exercise tolerance.

Results

In PR1, dyspnea, exercise tolerance, steps, and energy expenditure were significantly improved as compared to baseline, in both groups. During PR2, dyspnea and exercise tolerance were significantly improved as compared to PR1, in both groups. Steps and energy expenditure were significantly improved in the step-FB group, but not in the control group.

Conclusion

PR improved PA by improving physical function in severe COPD patients. Adding step-FB improved PA in severe COPD patients by presenting an activity goal for improving PA. Therefore, pedometer-based step-FB is a viable addition to PR and has the potential to improve PA continuously in these patients.

Impact of COVID-19 critical illness on functional status, fatigue symptoms, and health-related quality of life one-year after hospital discharge: a systematic review and meta-analysis

Purpose: To estimate the prevalence and severity of impairments in functional status, fatigue, and health-related quality of life (HRQoL) among critical COVID-19 survivors one-year after hospital discharge. Methods: A systematic review was conducted following PRISMA statement and registered in PROSPERO (CRD42021258356), with searches in eight databases. Observational studies were selected. The prevalence meta-analysis of abnormalities was performed using random-effects models. Risk of bias was evaluated using the National Heart, Lung, and Blood Institute tool. Results: Twenty studies were included, with data collected between 12 and 13.5 months after hospital discharge and a total of 1828 participants. Of these, 71% were men, and 77.7% were intubated in the intensive care unit (ICU). Impairments and sequelae were identified in varying prevalence and degrees, with greater impact on functional capacity and physical components of fatigue and HRQoL. The prevalence of abnormalities of 32.3% [95% CI 23.9; 41.9] found in the meta-analysis is substantially high. Most studies were classified as having fair and poor quality. Conclusion: Critical COVID-19 survivors experience impairments in functional status, fatigue, and HRQoL to varying degrees one-year after hospital discharge, particularly among patients who stayed in the ICU and on MV for a prolonged period.

Effectiveness of Shenshu Guanxin recipe granules for improving exercise tolerance in patients with stable angina pectoris: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To assess the effectivess of Shenshu Guanxin recipe granules (, SGR) in improving exercise tolerance and the quality of life in patients with Stable Angina Pectoris (SAP).

METHODS

A total of 189 patients were consecutively enrolled between December 2012 and December 2014. The included patients were randomly assigned to SGR and placebo groups. The primary endpoints included mainly the results of treadmill exercise test and Seattle Angina Questionnaire (SAQ) during 12 weeks of treatment.

RESULTS

After 12 weeks of treatment, SGR extended the time of exercise-induced ST-segment depression of 0.1 MV, lowered the maximum ST-segment depression, and shortened the duration of ST-segment depression in patients with SAP in southern China. Besides, the study also proved that SGR could improve the quality of life and functional status of patients with SAP.

CONCLUSIONS

SGR showed a positive effect on exercise tolerance compared with the placebo besides optimal medical therapy. Also, the study proved that SGR could improve the SAQ score of the patients.

DMC (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone) enhances exercise tolerance via the AMPK-SIRT1-PGC-1α pathway in mice fed a high-fat diet

Obesity is caused by an imbalance between energy intake and energy expenditure. This study aimed to determine the effects and mechanisms of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) on exercise tolerance in high-fat diet (HFD)-fed mice. Male C57BL/6J mice were randomly divided into two categories (7 groups [n = 8]): sedentary (control [CON], HFD, 200 mg/kg DMC, and 500 mg/kg DMC) and swimming (HFD, 200 mg/kg DMC, and 500 mg/kg DMC). Except the CON group, all other groups were fed HFD with or without DMC intervention for 33 days. The swimming groups were subjected to exhaustive swimming (three sessions/week). Changes in swimming time, glucolipid metabolism, body composition, biochemical indicators, histopathology, inflammation, metabolic mediators, and protein expression were assessed. DMC combined with regular exercise improved endurance performance, body composition, glucose and insulin tolerance, lipid profile, and the inflammatory state in a dose-dependent manner. Further, DMC alone or combined with exercise could restore normal tissue morphology, reduce fatigue-associated markers, and boost whole-body metabolism and the protein expression of phospho-AMP-activated protein kinase alpha/total-AMP-activated protein kinase alpha (AMPK), sirtuin-1 (SIRT1), peroxisome-proliferator-activated receptor gamma coactivator 1alpha (PGC-1α), and peroxisome proliferator-activated receptor alpha in the muscle and adipose tissues of HFD-fed mice. DMC exhibits antifatigue effects by regulating glucolipid catabolism, inflammation, and energy homeostasis. Furthermore, DMC exerts a synergistic exercise-related metabolic effect via the AMPK-SIRT1-PGC-1α signaling pathway, suggesting that DMC is a potential natural sports supplement with mimicked or augmented exercise effects for obesity prevention.

Functional exercise capacity in patients with ankylosing spondylitis

OBJECTIVE

This study aimed to measure the functional exercise capacity of patients with ankylosing spondylitis (AS) with the incremental shuttle walk test (ISWT), and to determine the factors associated with this test.

METHODS

This cross-sectional study included 54 patients with AS (29 males, 25 females). The ISWT was performed to determine functional exercise capacity. The number of completed shuttles was recorded, and the total incremental shuttle walk distance (ISWD) was calculated. Disease activity was assessed with the Bath AS Disease Activity Index (BASDAI), physical functioning was assessed with the Bath AS Functional Index (BASFI), and spinal mobility was assessed with the Bath AS Mobility Index (BASMI). Upper body and core endurance were assessed by sit-up and push-up tests. Tests were performed in a single session in the order listed.

RESULTS

The mean ISWD of the patients was 462.41 ± 97.96 m, and the subjects reached 50.48% of the predicted ISWD. The ISWD of male subjects was significantly higher than that of females (p < .05). At the end of the test, male subjects reached 60.87% of the age-predicted maximal heart rate, and female subjects reached 55.25%. There was a significant positive moderate correlation between ISWD and height (r = 0.535, p < .01), sit-up test (r = 0.617, p < .01), and push-up test (r = 0.495, p < .01), while there was a negative weak correlation between BASFI (r = -0.344, p = .011) and BASMI (r = -0.280, p = .040).

CONCLUSION

The study showed that functional exercise capacity as assessed by the ISWT decreased in patients with AS. ISWT performance was associated with sex, height, functionality, spinal mobility, and muscular endurance.

2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease" provides an update to and consolidates new evidence since the "2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease" and the corresponding "2014 ACC/AHA/AATS/PCNA/SCAI/STS Focused Update of the Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease."

METHODS

A comprehensive literature search was conducted from September 2021 to May 2022. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

This guideline provides an evidenced-based and patient-centered approach to management of patients with chronic coronary disease, considering social determinants of health and incorporating the principles of shared decision-making and team-based care. Relevant topics include general approaches to treatment decisions, guideline-directed management and therapy to reduce symptoms and future cardiovascular events, decision-making pertaining to revascularization in patients with chronic coronary disease, recommendations for management in special populations, patient follow-up and monitoring, evidence gaps, and areas in need of future research. Where applicable, and based on availability of cost-effectiveness data, cost-value recommendations are also provided for clinicians. Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease" provides an update to and consolidates new evidence since the "2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease" and the corresponding "2014 ACC/AHA/AATS/PCNA/SCAI/STS Focused Update of the Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease."

METHODS

A comprehensive literature search was conducted from September 2021 to May 2022. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

This guideline provides an evidenced-based and patient-centered approach to management of patients with chronic coronary disease, considering social determinants of health and incorporating the principles of shared decision-making and team-based care. Relevant topics include general approaches to treatment decisions, guideline-directed management and therapy to reduce symptoms and future cardiovascular events, decision-making pertaining to revascularization in patients with chronic coronary disease, recommendations for management in special populations, patient follow-up and monitoring, evidence gaps, and areas in need of future research. Where applicable, and based on availability of cost-effectiveness data, cost-value recommendations are also provided for clinicians. Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Exercise Capacity in Very Low Birth Weight Adults: A Systematic Review and Meta-Analysis

There is an association between very low birth weight (VLBW) and cardiovascular morbidity and mortality in adulthood. Aerobic fitness, measured as the maximal oxygen consumption (VO2 max), is a good indicator of cardiopulmonary health and predictor of cardiovascular mortality. Our aim was to determine the effect of birth weight on aerobic exercise capacity and physical activity. We systematically identified studies reporting exercise capacity (VO2 max and VO2 peak) and physical activity levels in participants born at VLBW aged eighteen years or older compared to term-born controls from six databases (MEDLINE, OVID, EMBASE, CI NAHL, CENTRAL, and Google Scholar). Meta-analysis of eligible studies was conducted using a random effect model. We screened 6202 articles and identified 15 relevant studies, 10 of which were eligible for meta-analysis. VLBW participants had a lower VO2 max compared to their term counterparts (-3.35, 95% CI: -5.23 to -1.47, p = 0.0005), as did VLBW adults who had developed bronchopulmonary dysplasia (-6.08, 95% CI -11.26 to -0.90, p = 0.02). Five of nine studies reported significantly reduced self-reported physical activity levels. Our systematic review and meta-analysis demonstrated reduced maximal aerobic exercise capacity in adults born at VLBW compared to term-born controls.

Minimal important difference of the 6-minute walk test after allogenic hematopoietic stem cell transplantation

PURPOSE

The 6-min walk test (6MWT) of allogenic hematopoietic stem cell transplantation (allo-HSCT) recipients has been gaining attention; however, minimal differences have not been reported. This study aimed to determine the minimal important difference (MID) in the 6MWT among hospitalized patients with allo-HSCT.

MATERIALS AND METHODS

The MID of the 6MWT was calculated using three different methodologies based on an anchor-based method; basic anchor-based methods, linear regression analysis, and receiver operating characteristic (ROC) curve analysis. The decrease in the score of Question 2 of the European Organization for Research and Treatment of Cancer Quality of life questionnaire core-30 was included as an anchor question for calculating the MID. Both actual and percentage changes in 6MWT values from baseline and at discharge were used in the MID calculations. In the actual and percentage change of the 6MWT, the one with the larger the area under the curve in the ROC curve was recommended as the MID.

RESULTS

Among the three methods using actual values, the largest MID of the 6MWT was -37.5 m (sensitivity: 54%, specificity: 88%).

CONCLUSION

More careful follow-up after discharge is necessary for allo-HSCT patients who show a reduction of 37.5 m or more in the acute illness phase.

Effects of High-Intensity Warm-Up on 5000-Meter Performance Time in Trained Long-Distance Runners

Warm-up protocols with high intensities before continuous running provide potential benefits for middle-distance runners. Nevertheless, the effect of high-intensity warm-ups on long-distance runners remains unclear. The purpose of this study was to verify the effect of a high-intensity warm-up protocol on 5000 m performance in trained runners. Thirteen male runners (34 ± 10 years, 62 ± 6 kg, 62.7 ± 5.5 ml/kg/min) performed two 5000 m time trials, preceded by two different warm-ups. One high-intensity warm up (HIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (100% of the running intensity) and one low-intensity warm up (LIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (70% of the running intensity)), where the running intensities were calculated using the results obtained in the Cooper test. Physiological and metabolic responses, and endurance running performance parameters, were evaluated by the Counter Movement Jump (CMJ), running rating of perceived exertion (RPE), blood lactate concentration (BLa), and performance running. Total time for the 5000 m was lower using HIWU when compared to LIWU (1141.4 ± 110.4 s vs. 1147.8 ± 111.0 s; p = 0.03; Hedges' g = 0.66). The HIWU warm-up led to an improvement in pacing strategy during the time trial. After warm-up protocols, the performance on the CMJ was improved only when applying HIWU (p = 0.008). Post warm-up BLa was significantly higher for HIWU vs. LIWU (3.5 ± 1.0 mmol·L-1 vs. 2.3 ± 1.0 mmol·L-1; p = 0.02), with similar behavior for the RPE (p = 0.002), internal load of the session (p = 0.03). The study showed that a high-intensity warm-up protocol can improve performance in the 5000 m in trained endurance runners.

Impacts of self-confidence cultivation combined with family collaborative nursing on the hope level, stigma and exercise tolerance in patients undergoing radical resection of pulmonary carcinoma

Objective

To analyze the impacts of self-confidence cultivation combined with family collaborative nursing on the hope level, stigma and exercise tolerance in patients undergoing radical resection of pulmonary carcinoma.

Methods

In this expeirment, 79 patients who underwent radical resection of pulmonary carcinoma in our hospital from January 2018 to December 2021, were selected as research objects, and they were divided into two groups according to the date of admission. The control group (n = 39) was given routine care, while the study group (n = 40) was given self-confidence cultivation combined with family collaborative nursing on the basis of the control group. The hope level, stigma, exercise tolerance, and cancer-related fatigue of the two groups were comparatively analyzed.

Results

The scores of T, P, I dimensions in Herth Hope Inventory (HHI) as well as the total score in the two groups were higher after intervention than before intervention (all P < 0.05).The scores of T, P, I dimensions and total scores of the HHI in the study group were higher as compared with the control group (all P < 0.05). After intervention, the scores of each dimension of the Chinese version of the Lung Cancer Stigma Scale (CLCSS), the modified British Medical Research Council Dyspnea Scale (mMRC), and the scores of each dimension of the Cancer Fatigue Scale (CFS) were lower than before intervention (P < 0.05); the 6-min walk test (6 MWT) result was longer than before intervention (P < 0.05); the scores of each dimension of CLCSS scale, mMRC score, and each dimension of CFS scale in the study group were lower as compared with the control group (P < 0.05) (P < 0.05).

Conclusion

Self-confidence cultivation combined with family collaborative nursing can promote the hope level of patients undergoing radical resection of pulmonary carcinoma, reduce stigma, enhance exercise endurance, and relieve cancer-related fatigue.

Effect of optimized new Shengmai powder on exercise tolerance in rats with heart failure by regulating the ubiquitin-proteasome signaling pathway

Introduction

Decreased exercise tolerance is a common symptom in patients with heart failure, which is closely related to protein degradation and apoptosis regulated by the ubiquitin-proteasome signaling (UPS) pathway. In this study, the effect of Chinese medicine, optimized new Shengmai powder, on exercise tolerance in rats with heart failure was investigated via the UPS pathway.

Methods

The heart failure model was prepared by ligating the left anterior descending branch of the coronary artery in rats, in which the sham-operated group was only threaded and not ligated. Rats (left ventricular ejection fraction ≤ 45%) were randomly divided into the following groups: model group, YHXSMS group, Benazepril group, and proteasome inhibitor Oprozomib group, and they were administered the corresponding drugs by gavage for 4 weeks. The cardiac function of rats was evaluated by performing an echocardiography examination and a hemodynamic test and the exercise tolerance was done by conducting an exhaustive swimming test. The mechanism was revealed by TUNEL detection, immunohistochemistry, immunofluorescence analysis, Western blot, and quantitative real-time PCR.

Results

The study showed that there was a decrease in cardiac function and exercise tolerance of rats in the model group and also destruction of cardiac and skeletal muscle fibers, a proliferation of collagen tissue, and an increment of apoptosis. Our study suggested that optimized new Shengmai powder could exert antiapoptotic effects on myocardial and skeletal muscle cells and improve myocardial contractility and exercise tolerance by inhibiting the overactivation of the UPS pathway, downregulating MAFbx, and Murf-1 overexpression, inhibiting the activation of the JNK signaling pathway, upregulating bcl-2 expression, and decreasing bax and caspase-3 levels.

Conclusions

The study showed that the optimized new Shengmai powder could improve cardiac function and exercise tolerance in rats with heart failure through the UPS pathway.

Validation of the 25 level modified shuttle test in children with cystic fibrosis

OBJECTIVE

To evaluate the validity and reliability of the modified shuttle 25-level test (MST-25) in children with cystic fibrosis (CF).

METHODS

A prospective single center study in clinically stable children with CF. Participants undertook two testing conditions on different days: (1) 2xMST-25 tests; (2) cardiopulmonary exercise test (CPET). Test order was randomized. Nadir oxygen saturation (SpO₂ ), peak heart rate (HR), breathlessness (modified Borg), rate of perceived exertion (RPE), energy expenditure (EE) and metabolic equivalents (MET) from the MST-25 and CPET were compared to assess validity, while outcomes from 2xMST-25 tests were compared for reliability. CPET was performed using breath-by-breath analysis and EE from the MST-25 obtained using the SenseWear Armband.

RESULTS

Strong correlations were found between MST-25 distance and peak oxygen uptake, peak work and minute ventilation on CPET (all r > 0.7, p < 0.01). Moderate correlations were found between MST-25 distance and CPET for METs (r = 0.5) and HR (r = 0.6). Weak associations between tests were evident for nadir SpO₂ (r = 0.1), modified Borg (r_s  = 0.2) and RPE (r_s  = 0.2). Test-retest reliability was excellent for MST-25 distance (ICC 0.91), peak EE (ICC 0.99) and peak METs (ICC 0.90). Good reliability was achieved for HR (ICC 0.84) and modified Borg score (ICC 0.77), while moderate reliability for nadir SpO₂ (ICC 0.64) and RPE (ICC 0.68) was observed.

CONCLUSION

The MST-25 is a valid and reliable field test for the assessment of exercise capacity in children with CF. The MST-25 can be used to accurately monitor exercise capacity and prescribe exercise training, particularly when CPET is not available.

Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

Validity of the 30-Second Chair-Stand Test to Assess Exercise Tolerance and Clinical Outcomes in Patients with Esophageal Cancer: A Retrospective Study with Reference to 6-Minute Walk Test Results

This retrospective study aimed to investigate the validity of a 30-sec chair stand test (CS-30) as a simple test to assess exercise tolerance and clinical outcomes in 53 Japanese patients with esophageal cancer. There was a strong correlation between the results of CS-30 and the 6-min walk test (6MWT), the gold standard for assessing exercise tolerance (r=0.759). Furthermore, fewer patients whose CS-30 score was greater than 16 (the cutoff value defined based on 6MWT) experienced pneumonia in their postoperative course. These results suggest that exercise tolerance could be assessed using CS-30, and its cutoff value may be useful in predicting postoperative pneumonia risk.

Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

Exercise tolerance, fatigue, mental health, and employment status at 5 and 12 months following COVID-19 illness in a physically trained population

Failure to recover following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may have a profound impact on individuals who participate in high-intensity/volume exercise as part of their occupation/recreation. The aim of this study was to describe the longitudinal cardiopulmonary exercise function, fatigue, and mental health status of military-trained individuals (up to 12-mo postinfection) who feel recovered, and those with persistent symptoms from two acute disease severity groups (hospitalized and community-managed), compared with an age-, sex-, and job role-matched control. Eighty-eight participants underwent cardiopulmonary functional tests at baseline (5 mo following acute illness) and 12 mo; 25 hospitalized with persistent symptoms (hospitalized-symptomatic), 6 hospitalized and recovered (hospitalized-recovered); 28 community-managed with persistent symptoms (community-symptomatic); 12 community-managed, now recovered (community-recovered), and 17 controls. Cardiopulmonary exercise function and mental health status were comparable between the 5 and 12-mo follow-up. At 12 mo, symptoms of fatigue (48% and 46%) and shortness of breath (SoB; 52% and 43%) remain high in hospitalized-symptomatic and community-symptomatic groups, respectively. At 12 mo, COVID-19-exposed participants had a reduced capacity for work at anaerobic threshold and at peak exercise levels of deconditioning persist, with many individuals struggling to return to strenuous activity. The prevalence considered "fully fit" at 12 mo was lowest in symptomatic groups (hospitalized-symptomatic, 4%; hospitalized-recovered, 50%; community-symptomatic, 18%; community-recovered, 82%; control, 82%) and 49% of COVID-19-exposed participants remained medically nondeployable within the British Armed Forces. For hospitalized and symptomatic individuals, cardiopulmonary exercise profiles are consistent with impaired metabolic efficiency and deconditioning at 12 mo postacute illness. The long-term deployability status of COVID-19-exposed military personnel is uncertain.NEW & NOTEWORTHY Subjective exercise limiting symptoms such as fatigue and shortness of breath reduce but remain prevalent in symptomatic groups. At 12 mo, COVID-19-exposed individuals still have a reduced capacity for work at the anaerobic threshold (which best predicts sustainable intensity), despite oxygen uptake comparable to controls. The prevalence of COVID-19-exposed individuals considered "medically non-deployable" remains high at 47%.

Diaphragm excursion correlates with performance and ventilation on the 6-min walk test in children with sickle cell disease

INTRODUCTION

Diaphragm function may be impaired in children with sickle cell disease (SCD). We hypothesized that diaphragm function is related to performance and ventilation on the 6-min walk test (6MWT).

METHODS

Respiratory muscle testing, diaphragm ultrasonography, and the 6MWT with portable gas analysis were performed on children with SCD and age- and sex-matched controls.

RESULTS

Fourteen children with SCD were enrolled. Comparisons were made between nine children with SCD (9.89  ± $\pm $  2.93 years) and nine controls (10.33  ± $\pm $  2.35 years). Diaphragm thickness at total lung capacity, thickening fraction, and excursion time during quiet breaths and deep breaths (DB), all normalized by forced vital capacity, were greater in children with SCD ( p < $p\lt $ 0.05 for all). 6MWT distance was shorter in children with SCD (450.87  ± $\pm $  74.2 m vs. 579.22 ± $\pm $ 72.46 m, p = $p=$ 0.01). Tidal volume ( V T ${V}_{T}$ ), minute ventilation ( V ˙ E ${\dot{V}}_{E}$ ), and oxygen consumption ( V ˙ O 2 ${\dot{V}}_{{O}_{2}}$ ) were also lower ( p < $p\lt $ 0.05 for all). DB excursion correlated positively with 6MWT distance ( r = $r=$ 0.648, p = $p=$ 0.023) and negatively with rate of perceived exertion (RPE) ( r = $r=$ -0.759, p = $p=$ 0.003). RPE correlated negatively with distance ( r = $r=$ -0.680, p = $p=$ 0.015). DB excursion time correlated positively with distance ( r = $r=$ 0.611, p = $p=$ 0.035), V T ${V}_{T}$ ( r = $r=$ 0.770, p = $p=$ 0.009), V ˙ E ${\dot{V}}_{E}$ ( r = $r=$ 0.736, p = $p=$ 0.015), and V ˙ O 2 ${\dot{V}}_{{O}_{2}}$ ( r = $r=$ 0.751, p = $p=$ 0.012).

CONCLUSIONS

Increased diaphragm excursion may be a strategy used to relieve air hunger while longer excursion time may reflect compensations to increase lung recruitment. Further studies are needed to better understand how these mechanisms affect exercise tolerance in children with SCD.

Impact of Cardiovascular and Metabolic Comorbidities on Long-term Outcomes of Home-based Pulmonary Rehabilitation in COPD

Background

Cardiovascular and metabolic comorbidities in chronic obstructive pulmonary disease (COPD) are associated with higher symptoms burden. Few center-based studies have evaluated the impact of these comorbidities on short-term pulmonary rehabilitation outcomes with contrasting results.

Research Question

This study aimed to determine whether cardiovascular diseases and metabolic comorbidities impacted long-term outcomes of a home-based PR program in COPD patients.

Study Design and methods

Data of 419 consecutive COPD patients addressed to our pulmonary rehabilitation program between January 2010 and June 2016 were retrospectively analyzed. Our program consisted of once-weekly supervised home sessions, including therapeutic education and self-management support, with unsupervised retraining exercises and physical activities the other days for 8 weeks. Exercise capacity (6-min stepper test [6MST]), quality of life (visual simplified respiratory questionnaire), and anxiety and depression (hospital anxiety and depression scale) were assessed respectively, before (M0) and at the end (M2) of the pulmonary rehabilitation program, and at 6 (M8) and 12 months (M14) after its achievement.

Results

Patients (mean age 64.1±11.2 years, 67% males, mean forced expiratory volume in one second (FEV₁) 39.2±17.0% predicted) were classified as having cardiovascular comorbidities (n=195), only metabolic disorders (n=122) or none of these comorbidities (n=102). After adjustment, all outcomes appeared similar between groups at baseline and improved after pulmonary rehabilitation with a greater effect at M14 for patients with only metabolic disorders on anxiety and depression score (-5.0±0.7 vs -2.9±0.8 and -2.6±0.6, p=0.021). Quality of life and exercise capacity improvements were not significantly different between the three groups at M2 and M14.

Conclusion

Cardiovascular and metabolic comorbidities do not preclude COPD patients from obtaining clinically meaningful improvements in exercise capacity, quality of life and anxiety-depression up to 1 year after a home-based pulmonary rehabilitation.

Effect of ketogenic diet on exercise tolerance and transcriptome of gastrocnemius in mice

Ketogenic diet (KD) has been proven to be an optional avenue in weight control. However, the impacts of KD on muscle strength and exercise endurance remain unclear. In this study, mice were randomly allocated to normal diet and KD groups to assess their exercise tolerance and transcriptomic changes of the gastrocnemius. KD suppressed body-weight and glucose levels and augmented blood ketone levels of mice. The total cholesterol, free fatty acids, and β-hydroxybutyric acid levels were higher and triglycerides and aspartate aminotransferase levels were lower in KD group. There was no notable difference in running distance/time and weight-bearing swimming time between the two groups. Furthermore, KD alleviated the protein levels of PGC-1α, p62, TnI FS, p-AMPKα, and p-Smad3, while advancing the LC3 II and TnI SS protein levels in the gastrocnemius tissues. RNA-sequencing found that 387 differentially expressed genes were filtered, and Cpt1b, Acadl, Eci2, Mlycd, Pdk4, Ptprc, C1qa, Emr1, Fcgr3, and Ctss were considered to be the hub genes. Our findings suggest that KD effectively reduced body weight but did not affect skeletal muscle strength and exercise endurance via AMPK/PGC-1α, Smad3, and p62/LC3 signaling pathways and these hub genes could be potential targets for muscle function in KD-treated mice.

Effect of robot-assisted stair climbing training as part of a rehabilitation program to improve pulmonary function, gait performance, balance, and exercise capacity in a patient after severe coronavirus disease 2019: a case report

BACKGROUND

Severe coronavirus disease 2019 (COVID-19) infection may decrease respiratory and physical functions.

OBJECTIVE

To evaluate whether robot-assisted stair climbing training (RASCT) would improve pulmonary and physical functions in a patient post-severe COVID-19 infection.

CASE DESCRIPTION

A 48-year-old woman who had experienced severe COVID-19 underwent a 6-week inpatient rehabilitation. She persistently exhibited impaired pulmonary and physical functions, including walking and balance impairment. We provided a 30-min outpatient RASCT biweekly for 6 weeks.

OUTCOMES

After training, maximal inspiratory and maximal expiratory pressures improved from 81 and 74 cmH2O to 104 and 81 cmH2O, respectively. The walking speed improved from 1.15 to 1.21 m/s. In balance ability, physical performance battery score and timed up-and-go test improved from 8 to 11 s and 10.89 to 9.95 s, respectively. Regarding exercise capacity, the 6-min walk test distance improved from 453 to 482 m, and the number of 1-min sit-to-stand test improved from 20 to 23, with improved pulse rate and saturation level. The physical and psychological domain scores of the World Health Organization Quality-of-Life Scale-BREF improved from 44 to 63 and 69 to 81, respectively; Falls Efficacy Scale-International scores improved from 38 to 21.

CONCLUSION

RASCT, as part of a rehabilitation plan, was feasible and effective for this patient after severe COVID-19 infection.

Predictors of Improvement in Exercise Tolerance After Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

Background Balloon pulmonary angioplasty (BPA) improves exercise tolerance and hemodynamic parameters in patients with chronic thromboembolic pulmonary hypertension. However, it is still unclear which patient characteristics contribute to the improvement in exercise tolerance after BPA in chronic thromboembolic pulmonary hypertension. Methods and Results We retrospectively analyzed 126 patients with chronic thromboembolic pulmonary hypertension (aged 63±14 years; female, 65%) who underwent BPA without concomitant programmed exercise rehabilitation at Keio University between November 2012 and April 2018. Hemodynamic data and 6-minute walk distance (6MWD), as a measure of exercise tolerance, were evaluated before and 1 year after BPA. The clinical characteristics that contributed to improvement in exercise tolerance were elucidated. The 6MWD significantly increased from 372.0 m (256.5-431.3) to 462.0 m (378.8-537.0) 1 year after BPA (P<0.001). The improvement rate in the 6MWD after BPA exhibited a good correlation with age, height, mean pulmonary artery pressure, and 6MWD at baseline (Spearman rank correlation coefficients=-0.28, 0.24, -0.40, and 0.44, respectively). Additional multivariable linear regression analysis revealed that young age, tall height, high mean pulmonary artery pressure, short 6MWD at baseline, and high lung capacity at baseline were significant predictors of the improvement in 6MWD by BPA (standardized partial regression coefficient -0.39, 0.22, 0.19, -0.62, and 0.25, P<0.001, 0.007, 0.011, <0.001, and <0.001, respectively). Conclusions BPA without concomitant programmed exercise rehabilitation significantly improves exercise tolerance. This was particularly true in young patients with high stature, high mean pulmonary artery pressure, short 6MWD, and lung capacity at the time of diagnosis.

Does a single bout maximal effort forearm exercise test for determining critical impulse result in maximal oxygen delivery and consumption in men? A randomized crossover trial

In a single bout maximal effort isometric forearm handgrip exercise test (maximal effort exercise test, MXT), contraction impulse exhibits exponential decay to an asymptote equivalent to critical impulse (CI). It is unknown whether oxygen delivery (O_2del) and consumption (V˙O2) achieved at CI are maximal. Healthy men participated in a randomized crossover trial at Queen's University (Kingston, ON) between October 2017-May 2018. Participants completed an MXT and forearm incremental exercise test to limit of tolerance (IET-LOT) (7 completed MXT followed by IET-LOT vs. 4 completed IET-LOT followed by MXT) within a 2 week period. Data are presented as mean ± standard deviation. Maximal forearm blood flow (FBF) and O_2del were not different in 11 men (21 ± 2.5 years) between MXT and IET-LOT (FBF = 473.8 ± 132.2 mL/min vs. 502.3 ± 152.3 mL/min; P = 0.482, η_p² = 0.015; O_2del = 85.2 ± 23.5 mL/min vs. 92.2 ± 37.0 mL/min; P = 0.456, η_p² = 0.012). However, MXT resulted in greater maximal V˙O2 than IET-LOT (44.5 ± 15.2 mL/min > 36.8 ± 11.4 mL/min; P = 0.007, η_p² = 0.09), due to greater oxygen extraction (54.0 ± 10.0% > 44.4 ± 8.6%; P = 0.021, η_p² = 0.185). As CI was 88.6 ± 8.2% of IET-LOT contraction impulse, maximal O₂ cost of contractions in MXT was greater than IET-LOT (0.45 ± 0.14 mL/min/Ns > 0.33 ± 0.09 mL/min/Ns; P < 0.001, η_p² = 0.166). In healthy men, MXT identifying CI results in similar peak oxygen delivery but greater peak V˙O2 via increased extraction compared to an IET-LOT, indicating increased oxygen cost. MXT-CI may better estimate maximal V˙O2 than traditional IET-LOT for this exercise modality.

Female Sex Affects Respiratory Function and Exercise Ability in Patients Recovered from COVID-19 Pneumonia

Background: Coronavirus-19 Disease (COVID-19) may cause persistent symptoms and functional respiratory impairment, known as long COVID. Determinants of long COVID are unclear. Although males experience more severe acute illness, the impact of sex on the occurrence of long-term sequelae is unknown. The aim of this study was to establish whether sex affects pulmonary function, exercise capacity, and clinical outcomes in patients recovered from COVID-19 pneumonia. Materials and Methods: We performed a retrospective analysis on patients evaluated in our "Post-COVID Clinic" after a median follow-up of 128 days from the acute disease. Tests performed included standard spirometry, diffusion capacity of the lung for carbon monoxide (DLCO), and 6-minute walk test (6-MWT). Results: A total of 157 patients (mean age 59.9 ± 12, 91 males) recovered from mild to severe pneumonia, without previous respiratory disease, were included. No differences in demographic data and in the severity of the acute illness were observed between the two study groups, males and females. Abnormal alveolar diffusion was more common and severe among females (DLCO <80% in 31% of males vs. 53% of females, p < 0.01; DLCO <70%, in 20% of males vs. 40% of females, p < 0.01). Severe reduction in 6-MWT was observed in 20% of males versus 46% of females (p < 0.01). Multiple logistic regression showed that female sex was an independent predictor of abnormal DLCO and 6-MWT. The prevalence of symptoms and radiological abnormalities was similar in the two groups. Conclusions: These data show that at 4 months follow-up women recovered from COVID-19 pneumonia are more likely to exhibit a reduced alveolar diffusion capacity and exercise tolerance than men, although a similar severity of the acute disease.

Effects of continuous aerobic training associated with resistance training on maximal and submaximal exercise tolerance, fatigue, and quality of life of patients post-COVID-19

BACKGROUND AND PURPOSE

Dyspnea, fatigue, and reduced exercise tolerance are common in post-COVID-19 patients. In these patients, rehabilitation can improve functional capacity, reduce deconditioning after a prolonged stay in the intensive care unit, and facilitate the return to work. Thus, the present study verified the effects of cardiopulmonary rehabilitation consisting of continuous aerobic and resistance training of moderate-intensity on pulmonary function, respiratory muscle strength, maximum and submaximal tolerance to exercise, fatigue, and quality of life in post-COVID-19 patients.

METHODS

Quasi-experimental study with a protocol of 12 sessions of an outpatient intervention. Adults over 18 years of age (N = 26) with a diagnosis of COVID-19 and hospital discharge at least 15 days before the first evaluation were included. Participants performed moderate-intensity continuous aerobic and resistance training twice a week. Maximal and submaximal exercise tolerance, lung function, respiratory muscle strength, fatigue and quality of life were evaluated before and after the intervention protocol.

RESULTS

Cardiopulmonary rehabilitation improved maximal exercise tolerance, with 18.62% increase in peak oxygen consumption (VO2peak) and 29.05% in time to reach VO2 peak. VE/VCO2 slope reduced 5.21% after intervention. We also observed increased submaximal exercise tolerance (increase of 70.57 m in the 6-min walk test, p = 0.001), improved quality of life, and reduced perceived fatigue after intervention.

DISCUSSION

Patients recovered from COVID-19 can develop persistent dysfunctions in almost all organ systems and present different signs and symptoms. The complexity and variability of the damage caused by this disease can make it difficult to target rehabilitation programs, making it necessary to establish specific protocols. In this work, cardiopulmonary rehabilitation improved lung function, respiratory muscle strength, maximal and submaximal exercise tolerance, fatigue and quality of life. Continuous aerobic and resistance training of moderate intensity proved to be effective in the recovery of post-COVID-19 patients.

Effect of Resistance Training on Body Composition, Hemodynamic Parameters and Exercise Tolerance among Patients with Coronary Artery Disease: A Systematic Review

BACKGROUND

Effectiveness and safety of Resistance Training in treating various Cerebrovascular Disease diagnoses have drawn attention in recent years. Patients suffering with coronary artery disease should be offered individually tailored Resistance Training in their exercise regimen. Resistance Training was developed to help individuals with their functional status, mobility, physical performance, and muscle strength.

OBJECTIVE

The objective of this review was to collect, summarize and present information on the state of science focusing on usefulness, viability, safety and efficacy of Resistance Training in treating coronary artery disease and enhancing the aerobic capacity and improving overall health-related quality of life.

METHODS

The review is prepared in accordance with Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Searches were conducted in Cochrane Library, PubMed/MEDLINE, PEDro and Scopus database. PEDro scale was used for methodological quality assessment of included studies. Two independent reviewers determined the inclusion criteria of studies by classifying interventions based on core components, outcome measures, diagnostic population and rated the quality of evidence and strength of recommendations using GRADE criteria.

RESULTS

Total 13 studies with 1025 patients were included for the detailed analysis. Findings emphasize the importance of assessing effectiveness and safety of Resistance Training in individuals with coronary artery disease. Patient specific designed exercise programs as Resistance Training targets at enhancing patients' exercise tolerance, improves hemodynamic response and muscular strength with reduction in body fat composition.

CONCLUSION

Resistance Training is an effective exercise that should be incorporated to counteract the loss of muscle strength, muscle mass, and physiological vulnerability, as well as to combat the associated debilitating effects on physical functioning, mobility and overall independence and Quality of Life during rehabilitation of patients with coronary artery disease.

Reference Equation of a New Incremental Step Test to Assess Exercise Capacity in the Portuguese Adult Population

Step tests are important in community- and home-based rehabilitation programs to assess patients' exercise capacity. A new incremental step test was developed for this purpose, but its clinical interpretability is currently limited. This study aimed to establish a reference equation for this new incremental step test (IST) for the Portuguese adult population. A cross-sectional study was conducted on people without disabilities. Sociodemographic (age and sex), anthropometric (weight, height, and body mass index), smoking status, and physical activity (using the brief physical activity assessment tool) data were collected. Participants performed two repetitions of the IST and the best test was used to establish the reference equation with a forward stepwise multiple regression. An analysis comparing the results from the reference equation with the actual values was conducted with the Wilcoxon test. A total of 155 adult volunteers were recruited (60.6% female, 47.8 ± 19.7 years), and the reference equation was as follows: steps in IST = 475.52 - (4.68 × age years) + (30.5 × sex), where male = 1 and female = 0, and r² = 60%. No significant differences were observed between the values performed and those obtained by the equation (p = 0.984). The established equation demonstrated that age and sex were the determinant variables for the variability of the results.