The impact of exercise training intensity on change in physiological function in patients with chronic obstructive pulmonary disease

Assessing the importance and safety of hypoxia conditioning for patients with occupational pulmonary diseases: A recent clinical perspective

Occupational pulmonary diseases (OPDs) pose a significant global health challenge, contributing to high mortality rates. This review delves into the pathophysiology of hypoxia and the safety of intermittent hypoxic conditioning (IHC) in OPD patients. By examining sources such as PubMed, Relemed, NLM, Scopus, and Google Scholar, the review evaluates the efficacy of IHC in clinical outcomes for OPD patients. It highlights the complexities of cardiovascular and respiratory regulation dysfunctions in OPDs, focusing on respiratory control abnormalities and the impact of intermittent hypoxic exposures. Key areas include the physiological effects of hypoxia, the role of hypoxia-inducible factor-1 alpha (HIF-1α) in occupational lung diseases, and the links between brain ischemia, stroke, and OPDs. The review also explores the interaction between intermittent hypoxic exposures, mitochondrial energetics, and lung physiology. The potential of IHE to improve clinical manifestations and underlying pathophysiology in OPD patients is thoroughly examined. This comprehensive analysis aims to benefit molecular pathologists, pulmonologists, clinicians, and physicians by enhancing understanding of IHE's clinical benefits, from research to patient care, and improving clinical outcomes for OPD patients.

Mind-body exercise for patients with stable COPD on lung function and exercise capacity: a systematic review and meta-analysis of RCTs

Chronic Obstructive Pulmonary Disease (COPD) is a global health concern. Mind-body exercises like Tai Chi and Yoga are suggested as non-pharmacological interventions for COPD management. This meta-analysis evaluates mind-body exercises' impact on lung function and exercise capacity in stable COPD patients, aiming to assess their effectiveness in rehabilitation. A systematic search across various databases identified relevant randomized controlled trials until April 2024. Primary outcomes included lung function tests (FEV1, FVC, FEV1/FVC, FEV1%) and Six-Minute Walk Test (6MWT) results. The Standardized Mean Difference (SMD) measured intervention effects. Fifteen studies with 1047 participants were analyzed. Mind-body exercises significantly improved FEV1 (SMD = 0.87), FEV1/FVC (SMD = 0.19), FEV1% (SMD = 0.43), and 6MWT (SMD = 1.21) compared to standard care. Sensitivity and subgroup analyses confirmed result stability despite some heterogeneity.In conclusion, Mind-body exercises enhance lung function and exercise capacity in stable COPD patients. Integrating them into comprehensive rehabilitation programs is advisable. Further research should explore the specific impacts of different exercise types and intensities.

Dose-response relationship between leisure-time physical activity and biomarkers of inflammation and oxidative stress in overweight/obese populations

OBJECTIVES

This study aimed to analyze the dose-response relationship between leisure-time physical activity and biomarkers of inflammation and oxidative stress in overweight/obese populations and provide exercise recommendations to regulate inflammation and oxidative stress and reduce the risk of developing obesity-related diseases.

DESIGN

Second analysis of a cross-sectional study.

METHODS

A total number of 4978 overweight/obese adults were included from the 2015-2018 National Health and Nutrition Examination Survey. Multivariable regressions were conducted to investigate the dose-response relationship between leisure-time physical activity and biomarkers of inflammation and oxidative stress. Subgroup analyses based on the doses and intensities of physical activity and in different participants were performed to provide exercise recommendations.

RESULTS

The results demonstrated that leisure-time physical activity was negatively associated with inflammatory biomarkers in both overweight and obese populations, and positively associated with antioxidant markers in obese populations. Overweight/obese populations performing leisure-time physical activity at 660-760 min/week (dose calculated as moderate leisure-time physical activity, equals 330-380 min/week vigorous leisure-time physical activity) demonstrated the lowest levels of inflammatory markers. Vigorous leisure-time physical activity was superior to moderate one for overweight/obese populations, especially for inflammation regulation. In addition, the regulatory effect of leisure-time physical activity on inflammation was more significant in overweight/obese populations with hypertension or stroke.

CONCLUSIONS

The results suggest that overweight/obese populations can take vigorous-intensity leisure-time physical activity at 330-380 min/week (for example, 60 min/day, 6 days/week, metabolic equivalent = 8) to get the maximum health benefits in terms of inflammation and oxidative stress regulation.

A systematic review of exercise protocols applied to athymic mice in tumor-related experiments

Athymic mice are unable to produce T-cells and are then characterized as immunodeficient. This characteristic makes these animals ideal for tumor biology and xenograft research. New non-pharmacological therapeutics are required owing to the exponential increase in global oncology costs over the last 10 years and the high cancer mortality rate. In this sense, physical exercise is regarded as a relevant component of cancer treatment. However, the scientific community lacks information regarding the effect of manipulating training variables on cancer in humans, and experiments with athymic mice. Therefore, this systematic review aimed to address the exercise protocols used in tumor-related experiments using athymic mice. The PubMed, Web of Science, and Scopus databases were searched without restrictions on published data. A combination of key terms such as athymic mice, nude mice, physical activity, physical exercise, and training was used. The database search retrieved 852 studies (PubMed, 245; Web of Science, 390; and Scopus, 217). After title, abstract, and full-text screening, 10 articles were eligible. Based on the included studies, this report highlights the considerable divergences in the training variables adopted for this animal model. No studies have reported the determination of a physiological marker for intensity individualization. Future studies are recommended to explore whether invasive procedures can result in pathogenic infections in athymic mice. Moreover, time-consuming tests cannot be applied to experiments with specific characteristics such as tumor implantation. In summary, non-invasive, low-cost, and time-saving approaches can suppress these limitations and improve the welfare of these animals during experiments.

Evaluation of the intervention of home-based pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Objective

Chronic obstructive pulmonary disease (COPD) can be prevented and treated, although presenting with persistent airflow restriction; the airflow restriction caused by COPD is mostly progressive. In recent years, more attention has been paid to the home-based pulmonary rehabilitation (PR) and its influence on COPD. Exercise training is the basic constituent of PR. However, it is not clear which exercise trainings are the ideal ways to deliver home-based PR.

Methods

In this review, we focus on the effect of home-based exercise training on patients with COPD. We searched literature, which was necessarily required to be randomized controlled trails (RCTs) from the establishment of the four respective databases (Medline, PubMed, Web of Science, and China National Knowledge Infrastructure) from January 2008 to January 2018. We used the Cochrane collaborative “risk of bias” tool to assess the quality of evidence. A total of 21 trials (1694 participants) were included. Through the analysis of the literature, we find that a simple, low-cost, and low-intensity family-based lung-rehabilitation plan to adapt to the real life may lead to the improvement of the ability to exercise, the reduction of the difficulty in breathing, and the improvement of carrying out daily activities.

Results

In the exercise training of home-based PR, lower limb exercise (LLE) training demonstrated a more perceptible effect in improving the quality of life of patients with COPD. At the same time, the combination of LLE training, breathing training, and upper limb exercise training is more obvious than the simple LLE training. In addition, home-based low-intensity aerobic training may sometimes be no less than the outpatient or center intervention to improve dyspnea, health status, and exercise tolerance. In conclusion, the simple and easy home-based PR exercise program is useful. Long-term home-based PR may require an enhanced need for maintenance.

Conclusions

A simple, low-cost, and low-intensity high blood pressure response (HBPR) plan to adapt to the real life may lead to an augmentation in the ability to exercise, a reduction of the difficulty in breathing, and an improvement in carrying out day-to-day activities. HBPR strategies can benefit patients (elderly patients with COPD at home) in the long term.

Effectiveness of Continuous Chest Wall Vibration With Concurrent Aerobic Training on Dyspnea and Functional Exercise Capacity in Patients With Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial

OBJECTIVE

To investigate the effects of continuous chest wall vibration with concurrent aerobic training in addition to a 4-week pulmonary rehabilitation program on dyspnea and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Randomized, single-blind, placebo-controlled trial.

SETTING

The Cardiopulmonary Rehabilitation Unit of a tertiary referral subacute rehabilitation center.

PARTICIPANTS

A sample of 146 consecutive patients with COPD (Global Initiative for Chronic Obstructive Lung Disease II-III-IV) were assessed for eligibility. The final sample of 40 patients (N=40) was randomized into 3 groups (intervention, sham intervention, control).

INTERVENTIONS

All groups carried out 5 sessions per week for 4 weeks of standard pulmonary rehabilitation treatment. The 2 daily 30-minute sessions included aerobic training and resistance training or airway clearance techniques. The intervention group performed the aerobic training with the addition of continuous chest wall vibration applied during cycling, whereas the sham intervention group received continuous chest wall vibration as a placebo during cycling.

MAIN OUTCOME MEASURES

Six-minute walk distance (6MWD) and Barthel Index based on dyspnea (BID).

RESULTS

A total of 36 participants completed the study (69±7 years; forced expiratory volume in 1 second percentage of predicted, 40.15%±15.97%). Intention to treat analysis showed no significant differences between groups for 6MWD and BID. However, the increase in 6MWD was a clinically important difference in the intervention group (42.57±43.87m, P=.003), with a moderate effect size (d=0.58).

CONCLUSIONS

Continuous chest wall vibration with concurrent aerobic training in addition to a standard pulmonary rehabilitation program might improve functional exercise capacity compared with usual care, but there were no effects on dyspnea, respiratory muscle function, or quality of life in patients with COPD.

Intensity of physical exercise and its effect on functional capacity in COPD: systematic review and meta-analysis

Objective:

To evaluate the effects of high-intensity interval training (HIIT), in comparison with those of continuous exercise, on functional capacity and cardiovascular variables in patients with COPD, through a systematic review and meta-analysis of randomized controlled trials.

Methods:

We searched PubMed, the Physiotherapy Evidence Database, the Cochrane Central Register of Controlled Trials, and EMBASE, as well as performing hand searches, for articles published up through January of 2017. We included studies comparing exercise regimens of different intensities, in terms of their effects on functional capacity and cardiovascular variables in patients with COPD.

Results:

Of the 78 articles identified, 6 were included in the systematic review and meta-analysis. Maximal oxygen consumption (VO_2max) did not differ significantly between HIIT and control interventions. That was true for relative VO_2max (0.03 mL/kg/min; 95% CI: −3.05 to 3.10) and absolute VO_2max (0.03 L/min, 95% CI: −0.02 to 0.08).

Conclusions:

The effects of HIIT appear to be comparable to those of continuous exercise in relation to functional and cardiovascular responses. However, our findings should be interpreted with caution because the studies evaluated present a high risk of bias, which could have a direct influence on the results.

Impact of pulmonary rehabilitation on activities of daily living in patients with chronic obstructive pulmonary disease

A high proportion of patients with chronic obstructive pulmonary disease (COPD) experience problems during the performance of activities of daily living (ADLs). We aimed to determine the effects of a comprehensive 8-wk pulmonary rehabilitation program on the physiologic response to and performance of ADLs in patients with COPD. Before and after pulmonary rehabilitation, 31 patients with COPD [71% men; mean age: 64.2 (SD 8.4) years; mean forced expiratory volume in the first second: 54.6 (SD 19.9) % predicted] performed physical function tests, the Canadian Occupational Performance Measure (COPM), and an ADL test consisting of the following: putting on socks, shoes, and vest; stair climbing; washing up four dishes, cups, and saucers; doing groceries and putting away groceries in a cupboard; folding eight towels; and vacuum cleaning for 4 min. Metabolic load, ventilation, and dynamic hyperinflation were assessed using an Oxycon mobile device. In addition, symptoms of dyspnea and fatigue and time to complete ADLs were recorded. After rehabilitation, patients with COPD used a significantly lower proportion of their peak aerobic capacity and ventilation to perform ADLs, accompanied by lower Borg scores for dyspnea and fatigue. Furthermore, patients needed significantly less time to complete ADLs. Dynamic hyperinflation occurred during the performance of ADLs, which did not change following pulmonary rehabilitation. Changes in physical function, including six-min walk distance, constant work rate test, quadriceps muscle strength, and COPM were significantly correlated with change in average total oxygen uptake during the performance of the ADL test. A comprehensive pulmonary rehabilitation program can improve the physiologic response to and actual performance of ADLs in patients with COPD. NEW & NOTEWORTHY A high proportion of patients with chronic obstructive pulmonary disease (COPD) experience problems during the performance of activities of daily living (ADLs). This study clearly demonstrated that a comprehensive pulmonary rehabilitation program can improve the performance of ADLs in patients with COPD, indicated by a significantly shorter time to perform ADLs and a lower metabolic load and dyspnea sensation.

Intermittent and graded exercise effects on NK cell degranulation markers LAMP-1/LAMP-2 and CD8+CD38+ in chronic fatigue syndrome/myalgic encephalomyelitis

There is substantial evidence of immune system dysfunction in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) but little is understood of exercise training effects on lymphocyte function in this illness. This study investigated whether graded and intermittent exercise improved CD8+ lymphocyte activation and natural killer cell degranulation markers compared to no exercise. Twenty-four chronic fatigue syndrome (CFS) patients (50.2 ± 10 year) were randomized to graded exercise (GE), intermittent exercise (IE) or usual care (UC) groups; a control group (CTL) of 18 matched sedentary non-CFS/ME participants were included for immunological variable comparisons. Main outcome measures were pre- and postintervention expression of CD3+CD8+CD38+ and CD3-CD16+56+CD107a+ (LAMP-1) CD107b+ (LAMP-2) and aerobic exercise capacity. The postintervention percentage of NK cells expressing LAMP-1 and -2 was significantly higher in IE compared to UC, and higher in GE compared to UC and CTL LAMP-1 and LAMP-2 expression (absolute numbers and percent positive) increased significantly pre-to-postintervention for both GE and IE Preintervention, the absolute number of CD8+CD38+ cells was significantly lower in CTL compared to UC and IE There were no significant pre- to postintervention changes in CD8+CD38+ expression for any group. Aerobic exercise capacity was significantly improved by GE and IE Twelve weeks of GE and IE increased the expression of NK cell activation and degranulation markers, suggesting enhanced immunosurveillance. Low-intensity exercise may also reduce CD8+CD38+ expression, a marker of inflammation. Both GE and IE improved exercise capacity without worsening CFS/ME symptoms, and more robust trials of these exercise modalities are warranted.

High-intensity interval training, but not continuous training, reverses right ventricular hypertrophy and dysfunction in a rat model of pulmonary hypertension

Exercise is beneficial in pulmonary arterial hypertension (PAH), although studies to date indicate little effect on the elevated pulmonary pressures or maladaptive right ventricle (RV) hypertrophy associated with the disease. For chronic left ventricle failure, high-intensity interval training (HIIT) promotes greater endothelial stimulation and superior benefit than customary continuous exercise training (CExT); however, HIIT has not been tested for PAH. Therefore, here we investigated acute and chronic responses to HIIT vs. CExT in a rat model of monocrotaline (MCT)-induced mild PAH. Six weeks of treadmill training (5 times/wk) were performed, as either 30 min HIIT or 60 min low-intensity CExT. To characterize acute hemodynamic responses to the two approaches, novel recordings of simultaneous pulmonary and systemic pressures during running were obtained at pre- and 2, 4, 6, and 8 wk post-MCT using long-term implantable telemetry. MCT-induced decrement in maximal aerobic capacity was ameliorated by both HIIT and CExT, with less pronounced pulmonary vascular remodeling and no increase in RV inflammation or apoptosis observed. Most importantly, only HIIT lowered RV systolic pressure, RV hypertrophy, and total pulmonary resistance, and prompted higher cardiac index that was complemented by a RV increase in the positive inotrope apelin and reduced fibrosis. HIIT prompted a markedly pulsatile pulmonary pressure during running and was associated with greater lung endothelial nitric oxide synthase after 6 wk. We conclude that HIIT may be superior to CExT for improving hemodynamics and maladaptive RV hypertrophy in PAH. HIIT's superior outcomes may be explained by more favorable pulmonary vascular endothelial adaptation to the pulsatile HIIT stimulus.

Effects of Tai Chi on exercise capacity and health-related quality of life in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Tai Chi is a traditional Chinese mind-body exercise that has been widely practiced in the People's Republic of China for many centuries. This exercise has also been applied as a training modality in pulmonary rehabilitation programs for stable chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis aimed to assess the effects of Tai Chi on exercise capacity and health-related quality of life (HRQoL) in COPD patients.

METHODS

Electronic databases (PubMed, Embase, Web of Science, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov, China National Knowledge Infrastructure, and China Biology Medicine disc) were searched. Entries published from January 1980 to March 2014 were included in the search. Eligible studies included those that involved randomized controlled trials and those that lasted for at least 12 weeks. The primary outcome measures were six-minute walking distance (6 MWD), St George's Respiratory Questionnaire (SGRQ), and Chronic Respiratory Disease Questionnaire (CRQ). Effect estimates were pooled with random-effects meta-analysis.

RESULTS

Eleven articles involving 824 patients met the inclusion criteria. All included articles compared COPD patients in a Tai Chi group versus COPD patients in nonexercise and/or physical exercise groups. The meta-analysis showed that compared with the nonexercise group, the COPD patients practicing Tai Chi demonstrated significantly enhanced 6 MWD (mean difference 35.99, 95% confidence interval [CI] 15.63-56.35, P=0.0005), decreased SGRQ total score (mean difference -10.02, 95% CI -17.59, -2.45, P=0.009), and increased CRQ total score (mean difference 0.95, 95% CI 0.22-1.67, P=0.01). Compared with the physical exercise group, the Tai Chi group showed significantly reduced SGRQ total score (mean difference -3.52, 95% CI -6.07, -0.97, P=0.007), but no statistical significance was found for 6 MWD between the two groups (mean difference 13.65, 95% CI -1.06, 28.37, P=0.07) in COPD patients.

CONCLUSION

Preliminary evidence suggests that Tai Chi has beneficial effects on exercise capacity and HRQoL in COPD patients. This exercise can be recommended as an effective alternative training modality in pulmonary rehabilitation programs. Further studies are required to support the preliminary evidence and to observe the long-term effects of Tai Chi.

The Physiologic Effects of an Acute Bout of Supramaximal High-Intensity Interval Training Compared with a Continuous Exercise Bout in Patients with COPD

This study compared physiological responses and work performed during a supramaximal high-intensity interval exercise training session (HIIT) and a constant work rate (CWR) exercise session. Fourteen patients with COPD (mean FEV1   53±13% predicted (±SD)) completed an incremental cardiopulmonary exercise test (CPET) and a steep ramp anaerobic test (SRAT) and then two exercise bouts to symptom limitation on separate days, in random order: (1) a CWR trial at 80% of CPET peak work rate (mean 63±15 W) and (2) a HIIT trial using repeats of 30 s at 70% of SRAT peak work rate (mean 112±29 W) followed by 90 s at 20% of CPET peak work rate. Subjects ceased exercise primarily due to dyspnea for both HIIT and CWR (64% vs. 57%, resp.). End-exercise VE, HR, dyspnea, and leg fatigue were similar between the two exercise protocols. Average work rate was lower in HIIT than CWR (32 vs. 63 W, P<0.05); however, subjects performed HIIT longer (542 vs. 202 s, P<0.05) and for greater total work (23.3 vs. 12.0 kJ, P<0.05). The supramaximal HIIT protocol was well tolerated and demonstrated similar maximal physiologic responses to constant work rate exercise, but with greater leg muscle work performed and greater peak exercise intensity.

Nonlinear exercise training in advanced chronic obstructive pulmonary disease is superior to traditional exercise training. A randomized trial

RATIONALE

The optimal exercise training intensity and strategy for individualized exercise training in chronic obstructive pulmonary disease (COPD) is not clear.

OBJECTIVES

This study compares the effects of nonlinear periodized exercise (NLPE) training used in athletes to traditional endurance and progressive resistance (EPR) training in patients with severe COPD.

METHODS

A total of 110 patients with severe COPD (FEV1 32% predicted) were randomized to EPR or NLPE. Exercise training was performed three times per week for 10 weeks. The primary outcomes were cycling endurance time and health-related quality of life using the Chronic Respiratory Questionnaire. The difference in change between EPR and NLPE was assessed using linear mixed-effects modeling.

MEASUREMENTS AND MAIN RESULTS

NLPE resulted in significantly greater improvements in cycling endurance time compared with EPR. The difference in change was +300.6 seconds (95% confidence interval [CI] = 197.2-404.2 s; P < 0.001). NLPE also resulted in significantly greater improvements in all domains of the Chronic Respiratory Questionnaire compared with EPR, ranging from +0.48 (95% CI = 0.19-0.78) for the domain, emotions, to +0.96 (95% CI = 0.57-1.35) for dyspnea.

CONCLUSIONS

NLPE results in greater improvements in cycle endurance and health-related quality of life in patients with severe COPD than traditional training methods. Clinical trial registered with www.trialregister.nl (The Netherlands Trial Register; NTR 1045).

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA; body mass 102.6 ± 7.3 kg, mean ± SD) and 11 controls (CTRL; body mass 77.8 ± 6.0 kg). Pulmonary O2 uptake (Vo2) and vastus lateralis muscle fractional O2 extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross-sectional area, volume (determined by magnetic resonance imaging), and strength were greater in RTA vs. CTRL (by ∼40%, ∼33%, and ∼20%, respectively). Vo2peak during CE was higher in RTA vs. CTRL (4.05 ± 0.64 vs. 3.56 ± 0.30 l/min); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE), Vo2 peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, during both CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.7 ± 23.7 pmol O2·s(-1)·mg(-1) ww) vs. CTRL (35.7 ± 10.2 pmol O2·s(-1)·mg(-1) ww) and a tighter coupling of oxidative phosphorylation. In RTA, the greater muscle mass and maximal force and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise and unchanged efficiency and O2 cost at submaximal exercise, despite a much greater body mass.

Responsiveness of Various Exercise-Testing Protocols to Therapeutic Interventions in COPD

Exercise intolerance is a key element in the pathophysiology and course of Chronic Obstructive Pulmonary Disease (COPD). As such, evaluating exercise tolerance has become an important part of the management of COPD. A wide variety of exercise-testing protocols is currently available, each protocol having its own strengths and weaknesses relative to their discriminative, methodological, and evaluative characteristics. This paper aims to review the responsiveness of several exercise-testing protocols used to evaluate the efficacy of pharmacological and nonpharmacological interventions to improve exercise tolerance in COPD. This will be done taking into account the minimally important difference, an important concept in the interpretation of the findings about responsiveness of exercise testing protocols. Among the currently available exercise-testing protocols (incremental, constant work rate, or self-paced), constant work rate exercise tests (cycle endurance test and endurance shuttle walking test) emerge as the most responsive ones for detecting and quantifying changes in exercise capacity after an intervention in COPD.

Associations between isokinetic muscle strength, high-level functional performance, and physiological parameters in patients with chronic obstructive pulmonary disease

High-level activities are typically not performed by patients with chronic obstructive pulmonary disease (COPD), which results in reduced functional performance; however, the physiological parameters that contribute to this reduced performance are unknown. The aim of this study was to determine the relationships between high-level functional performance, leg muscle strength/power, aerobic power, and anaerobic power. Thirteen patients with COPD underwent an incremental maximal cardiopulmonary exercise test, quadriceps isokinetic dynamometry (isometric peak torque and rate of torque development; concentric isokinetic peak torque at 90°/sec, 180°/sec, and 270°/sec; and eccentric peak torque at 90°/sec), a steep ramp anaerobic test (SRAT) (increments of 25 watts every 10 seconds), and three functional measures (timed up and go [TUG], timed stair climb power [SCPT], and 30-second sit-to-stand test [STS]). TUG time correlated strongly (P < 0.05) with all muscle strength variables and with the SRAT. Isometric peak torque was the strongest determinant of TUG time (r = −0.92). SCPT and STS each correlated with all muscle strength variables except concentric at 270°/sec and with the SRAT. The SRAT was the strongest determinant of SCPT (r = 0.91), and eccentric peak torque at 90°/sec was most significantly associated with STS (r = 0.81). Performance on the SRAT (anaerobic power); slower-velocity concentric, eccentric, and isometric contractions; and rate of torque development are reflected in all functional tests, whereas cardiopulmonary exercise test performance (aerobic power) was not associated with any of the functional or muscle tests. High-level functional performance in patients with COPD is associated with physiological parameters that require high levels of muscle force and anaerobic work rates.

Test-Retest Reliability and Physiological Responses Associated with the Steep Ramp Anaerobic Test in Patients with COPD

The Steep Ramp Anaerobic Test (SRAT) was developed as a clinical test of anaerobic leg muscle function for use in determining anaerobic power and in prescribing high-intensity interval exercise in patients with chronic heart failure and Chronic Obstructive Pulmonary Disease (COPD); however, neither the test-retest reliability nor the physiological qualities of this test have been reported. We therefore, assessed test-retest reliability of the SRAT and the physiological characteristics associated with the test in patients with COPD. 11 COPD patients (mean FEV₁ 43% predicted) performed a cardiopulmonary exercise test (CPET) on Day 1, and an SRAT and a 30-second Wingate anaerobic test (WAT) on each of Days 2 and 3. The SRAT showed a high degree of test-retest reliability (ICC = 0.99; CV = 3.8%, and bias 4.5 W, error −15.3–24.4 W). Power output on the SRAT was 157 W compared to 66 W on the CPET and 231 W on the WAT. Despite the differences in workload, patients exhibited similar metabolic and ventilatory responses between the three tests. Measures of ventilatory constraint correlated more strongly with the CPET than the WAT; however, physiological variables correlated more strongly with the WAT. The SRAT is a highly reliable test that better reflects physiological performance on a WAT power test despite a similar level of ventilatory constraint compared to CPET.

Current best practice in pulmonary rehabilitation for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic condition that negatively affects several patient-centered outcomes. Among these, exercise capacity, dyspnea, and quality of life are the most relevant. In this article, factors contributing to exercise limitation, increase in exercise-induced dyspnea, quality of life deterioration, and other pathophysiological aspects in patients with COPD are analyzed in detail. Pulmonary rehabilitation (PR) is an evidence-based, multidisciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. PR has been clearly shown to induce favorable and long-lasting effects on all patient-centered outcomes. In addition, PR appears to have positive (even if not conclusively demonstrated) effects on other important outcomes in patients with COPD: number and severity of exacerbations, healthcare resource utilization, and survival. The organization of PR treatment, its components, outcome assessment, and future directions are discussed in light of the most robust scientific evidence.

Effects of exercise training on exercise capacity in patients with non-small cell lung cancer receiving targeted therapy

PURPOSE

Peak oxygen consumption (VO(2peak)) is an important predictive factor for long-term prognosis in patients with non-small cell lung cancer (NSCLC). The purpose of this study was to investigate whether 8 weeks of exercise training improves exercise capacity, as assessed by VO(2peak), and other related factors in patients with NSCLC receiving targeted therapy.

METHODS

A total of 24 participants with adenocarcinoma were randomly assigned to either the control group (n = 11) or the exercise group (n = 13). Subjects in the exercise group participated in individualized, high-intensity aerobic interval training of exercise. The outcome measures assessed at baseline and after 8 weeks were as follows: VO(2peak) and the percentage of predicted VO(2peak) (%predVO(2peak)), muscle strength and endurance of the right quadriceps, muscle oxygenation during exercise, insulin resistance as calculated by the homeostasis model, high-sensitivity C-reactive protein, and quality of life (QoL) questionnaire inventory.

RESULTS

No exercise-related adverse events were reported. After exercise training, VO(2peak) and %predVO(2peak) increased by 1.6 mL kg(-1) min(-1) and 5.3% (p < 0.005), respectively; these changes were associated with improvements in circulatory, respiratory, and muscular functions at peak exercise (all p = 0.001). The exercise group also had less dyspnea (p = 0.01) and favorably lower fatigue (p = 0.05) than baseline.

CONCLUSIONS

Patients with NSCLC receiving targeted therapy have quite a low exercise capacity, even with a relatively high QoL. Exercise training appears to improve exercise capacity and alleviate some cancer-related symptoms.

Optimal intensity and type of leg exercise training for people with chronic obstructive pulmonary disease

BACKGROUND

Intensity of exercise is considered a key determinant of training response, however, no systematic review has investigated the effects of different levels of training intensity on exercise capacity, functional exercise capacity and health-related quality of life (HRQoL) in people with chronic obstructive pulmonary disease (COPD). As type of training (continuous or interval) may also affect training response, the effects of the type of training in COPD also require investigation.

OBJECTIVES

To determine the effects of training intensity (higher versus lower) or type (continuous versus interval training) on primary outcomes in exercise capacity and secondary outcomes in symptoms and HRQoL for people with COPD.

SEARCH METHODS

We searched for studies in any language from the Cochrane Airways Group Specialised Register, CENTRAL, MEDLINE, EMBASE, CINAHL, AMED, PsycINFO and PubMed. Searches were current as of June 2011.

SELECTION CRITERIA

We included randomised controlled trials comparing higher training intensity to lower training intensity or comparing continuous training to interval training in people with COPD. We excluded studies that compared exercise training with no exercise training.

DATA COLLECTION AND ANALYSIS

We pooled results of comparable groups of studies and calculated the treatment effect and 95% confidence intervals (CI) using a random-effects model. We made two separate comparisons of effects between: 1) higher and lower training intensity; 2) continuous and interval training. We contacted authors of missing data.

MAIN RESULTS

We analysed three included studies (231 participants) for comparisons between higher and lower-intensity training and eight included studies (367 participants) for comparisons between continuous and interval training. Primary outcomes were outcomes at peak exercise (peak work rate, peak oxygen consumption, peak minute ventilation and lactate threshold), at isowork or isotime, endurance time on a constant work rate test and functional exercise capacity (six-minute walk distance). When comparing higher versus lower-intensity training, the pooled primary outcomes were endurance time and six-minute walk distance. There were no significant differences in endurance time improvement (mean difference (MD) 1.07 minutes; 95% CI -1.53 to 3.67) and six-minute walk distance improvement (MD 2.8 metres; 95% CI -10.1 to 15.6) following higher or lower-intensity training. However, heterogeneity of the endurance time results between studies was significant. When comparing continuous and interval training, there were no significant differences in any of the primary outcomes, except for oxygen consumption at isotime (MD 0.08; 95% CI 0.01 to 0.16) but the treatment effect was not considered clinically important. According to the GRADE system, studies were of low to moderate quality.

AUTHORS' CONCLUSIONS

Comparisons between the higher and lower training intensity were limited due to the small number of included studies and participants. Consequently, there are insufficient data to draw any conclusions on exercise capacity, symptoms and HRQoL for this comparison. For comparisons between continuous and interval training, both appear to be equally effective in improving exercise capacity, symptoms and HRQoL.

[High intensity training (HIT) for the improvement of endurance capacity of recreationally active people and in prevention & rehabilitation]

Although intensive exercise protocols are commonly used in practical training and scientific studies, there is recently a great scientific discussion about "high intensity (interval) training" (HIT). New are the large amounts of studies and the more detailed knowledge about the physiological responses and adaptations to HIT in comparison to the classic high volume, low intensity endurance training. The present article summarizes the current knowledge about HIT in endurance exercise for clinical applications. In the first part, molecular and cellular adaptations to HIT are discussed in comparison to low intensity high volume training. Furthermore, studies are summarized which compare HIT vs. HVT in the field of prevention and rehabilitation. Terminally the differences in physiological stimuli of both training interventions are considered.

High-intensity interval training in an adolescent with cystic fibrosis: a physiological perspective

Nutritional, musculoskeletal, and/or ventilatory status can lead to a decreased exercise capacity in children with cystic fibrosis (CF). Exercise training is already part of the usual care; however, the "optimal" intensity and volume of exercise training to improve exercise capacity is still unknown. Six weeks of high-intensity interval training (HIT) for a patient with CF with a ventilatory limitation was evaluated by a cardiopulmonary exercise test (CPET). Peak oxygen uptake and peak workload increased 19% and 16%, respectively, and there was a rise in peak ventilation from 50 L/min to 75 L/min, with an increase in both breathing depth and respiratory rate. A relative short period of HIT resulted in a significant increase in exercise capacity. In patients with CF, HIT might be an effective and efficient training regimen, especially in CF patients with a ventilatory limitation. Further research is necessary to investigate whether HIT is a better alternative than traditional aerobic training programs especially in ventilatory limited patients with CF.

Effects of hand cycle training on physical capacity in individuals with tetraplegia: a clinical trial

BACKGROUND

Regular physical activity is important for people with tetraplegia to maintain fitness but may not always be easily integrated into daily life. In many countries, hand cycling has become a serious option for daily mobility in people with tetraplegia. However, little information exists regarding the suitability of this exercise mode for this population.

OBJECTIVE

The purpose of this study was to evaluate the effects of a structured hand cycle training program in individuals with chronic tetraplegia.

DESIGN

Pretraining and posttraining outcome measurements of physical capacity were compared.

SETTING

Structured hand cycle interval training was conducted at home or in a rehabilitation center in the Netherlands.

PARTICIPANTS

Twenty-two patients with tetraplegia (American Spinal Injury Association Impairment Scale classification A-D) at least 2 years since injury participated.

INTERVENTION

The intervention was an 8- to 12-week hand cycle interval training program.

MEASURES

Primary outcomes of physical capacity were: peak power output (POpeak) and peak oxygen uptake (Vo(2)peak), as determined in hand cycle peak exercise tests on a motor-driven treadmill. Secondary outcome measures were: peak muscle strength (force-generating capacity) of the upper extremities (as assessed by handheld dynamometry), respiratory function (forced vital capacity and peak expiratory flow) and participant-reported shoulder pain.

RESULTS

Significant improvements following a mean of 19 (SD=3) sessions of hand cycle training were found in POpeak (from 42.5 W [SD=21.9] to 50.8 W [SD=25.4]), Vo(2)peak (from 1.32 L.min(-1) [SD=0.40] to 1.43 L.min(-1) [SD=0.43]), and mechanical efficiency, as reflected by a decrease in submaximal oxygen uptake. Except for shoulder abduction strength, no significant effects were found on the secondary outcomes.

LIMITATIONS

Common health complications, such as urinary tract infections, bowel problems, and pressure sores, led to dropout and nonadherence.

CONCLUSION

Patients with tetraplegia were able to improve their physical capacity through regular hand cycle interval training, without participant-reported shoulder-arm pain or discomfort.

Interval hypoxic training improves autonomic cardiovascular and respiratory control in patients with mild chronic obstructive pulmonary disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is associated with cardiac autonomic nervous system dysregulation. This study evaluates the effects of interval hypoxic training on cardiovascular and respiratory control in patients with mild COPD.

METHODS

In 18 eucapnic normoxic mild COPD patients (age 51.7 +/- 2.4 years, mean +/- SEM), randomly assigned to either training or placebo group, and 14 age-matched healthy controls (47.7 +/- 2.8 years), we monitored end-tidal carbon dioxide, airway flow, arterial oxygen saturation, electrocardiogram, and continuous noninvasive blood pressure at rest, during progressive hypercapnic hyperoxia and isocapnic hypoxia to compare baroreflex sensitivity to hypoxia and hypercapnia before and after 3 weeks of hypoxic training. In double-blind fashion, both groups received 15 sessions of passive intermittent hypoxia (training group) or normoxia (placebo group). For the hypoxia group, each session consisted of three to five hypoxic (15-12% oxygen) periods (3-5 min) with 3-min normoxic intervals. The placebo group inhaled normoxic air.

RESULTS

Before training, COPD patients showed depressed baroreflex sensitivity, as compared with healthy individuals, without evident chemoreflex abnormalities. After training, in contrast to placebo group, the training group showed increased (P < 0.05) baroreflex sensitivity up to normal levels and selectively increased hypercapnic ventilatory response (P < 0.05), without changes in hypoxic ventilatory response.

CONCLUSION

Eucapnic normoxic mild COPD patients already showed signs of cardiovascular autonomic abnormalities at baseline, which normalized with hypoxic training. If confirmed in more severe patients, interval hypoxic training may be a therapeutic strategy to rebalance early autonomic dysfunction in COPD patients.

At identical isowork rates, ageing influences cardiorespiratory adaptations in COPD out-patients

PURPOSE

To determine the extent to which younger COPD patients improve their cardiorespiratory function during exercise in comparison with older COPD patients, as a result of exercise training.

METHODS

Thirty-nine COPD patients underwent an exercise program. They were divided into two groups: a younger group (57.2+/-1.0 years, n=18 patients) and an older group (68.8+/-0.6 years, n=21 patients). Forced expiratory volume in 1s was lower than 55% of the predicted value for all patients.

RESULTS

After training, VO2 symptom-limited significantly improved by 10.3% and 8.4% for the younger and older COPD patients, respectively (P<0.05). Peak power significantly improved by 25.2% and 17.8% in the younger and older groups, respectively (P<0.05) with a greater improvement for the younger group (P<0.05). At submaximal exercise, ventilation and heart rate significantly decreased after training in the younger COPD patients (P<0.05) with no significant modification in the older COPD patients.

CONCLUSIONS

The results suggest that all patients with COPD benefit from exercise rehabilitation at maximal exercise workload, however, according to their age, submaximal cardiorespiratory adaptations were greater in younger patients.