The Integrative Physiology of Exercise Training in Patients with COPD

Patterns of physical activity of people with COPD during participation in a pulmonary rehabilitation program

INTRODUCTION

Very few studies have examined patterns of physical activity (PA) during a pulmonary rehabilitation (PR) program in people with COPD.

AIMS

To compare the patterns of PA in: 1) the week before commencing PR (pre-PR) with a week during PR (PR week); 2) PR days and non-PR days during a PR week; 3) pre-PR and the week following PR completion (post-PR).

METHODS

This was a multicenter, prospective cohort study. Participants attended twice weekly supervised PR for 8-12 weeks. Daily step count (primary outcome), time in light activities, time in moderate to vigorous PA (MVPA), total sedentary time and sit-to-stand (STS) transitions were measured using a thigh worn accelerometer for seven days, at each assessment time point: pre-PR, PR week and post-PR.

RESULTS

29 participants, mean age (SD) 69years(7), FEV1 53%pred(16). The PR week compared to pre-PR, showed higher daily: step count (mean difference (95%CI)), 941steps(388-1494); and MVPA, 11mins(6-15), with no difference in: time in light activities, -1min(-6-5); total sedentary time, 7mins(-21-36); or STS transitions, 0(-5-6). PR days compared to non-PR days showed higher: step count, 2810steps(1706-3913); time in light activities 11mins(1-20); time in MVPA, 27mins(17-35) and STS transitions, 8(4-12), with no difference in total sedentary time: -33mins(-80-15). There were no differences in any PA measures post-PR compared to pre-PR (p < 0.05).

CONCLUSION

Daily step count and time spent in MVPA increased significantly during the PR week, solely due to increased PA on days participants attended PR.

Low-load blood flow restriction strength training in patients with COPD: a randomised single-blind pilot study

OBJECTIVE

The objective of this study is to compare the effectiveness of lower limb low-load blood flow restriction training (LL-BFRT) with high-load strength training (HL-ST) as part of an outpatient pulmonary rehabilitation programme on leg strength in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Participants were randomised to LL-BFRT or HL-ST (24 sessions). LL-BFRT was done at 30% 1-repetition maximum (1-RM) with 70% arterial occlusion pressure. HL-ST was done at 70% 1-RM. Primary outcome was isometric strength of knee extensors and flexors. Secondary outcomes were 1-RM, functional exercise capacity, physical activity, symptom burden and health-related quality of life. Perceptions of dyspnoea and leg fatigue were recorded after every exercise. We compared groups with t-tests.

RESULTS

We included 30 participants (13 women, 17 men, 64 (9) years, forced expiratory volume in 1 s 47 (18)% pred.), 24 completed the study. Isometric knee extensor strength improved to a clinically relevant degree in both legs in both groups (LL-BFRT: right leg 9 (20) Nm, left leg 10 (18) Nm; HL-ST: right leg 15 (26) Nm, left leg 16 (30) Nm, data are mean (SD)), without statistically significant or clinically relevant between-group differences (right leg mean difference= -6.4, 95% CI= -13.20 to 25.92 Nm, left leg mean difference= -5.6, 95% CI= -15.44 to 26.55 Nm). 1 min sit-to-stand test performance improved to a clinically relevant degree only in the LL-BFRT group (4 (4) vs 1 (5) repetitions). Interestingly, physical activity improved to a clinically relevant degree only in the LL-BFRT group (1506 (2441) vs -182 (1971) steps/day). LL-BFRT lowered perceived in-exercise dyspnoea and increased leg fatigue compared with HL-ST in the initial 12 trainings.

CONCLUSION

In patients with stable COPD undergoing outpatient pulmonary rehabilitation, LL-BFRT was not superior to HL-ST in improving leg strength. LL-BFRT led to similar strength gains as HL-ST while reducing perceptions of dyspnoea in the initial training phase.

TRIAL REGISTRATION NUMBER

NCT04151771.

Effects of Combined Endurance and Resistance Eccentric Training on Muscle Function and Functional Performance in Patients With Chronic Obstructive Pulmonary Disease: Randomized Controlled Trial

OBJECTIVE

To evaluate the adherence to treatment and efficacy of an eccentric-based training (ECC) program on peripheral muscle function and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective, assessor-blinded, randomized controlled trial.

SETTING

The cardiopulmonary rehabilitation unit of a tertiary subacute referral center.

PARTICIPANTS

Thirty (N=30) stable inpatients (mean age 68±8 years; FEV1 44±18% of predicted) with COPD were included in the study.

INTERVENTIONS

Inpatients were randomly assigned to 4 weeks of a combined endurance and resistance ECC (n=15) or conventional training (CON; n=15).

MAIN OUTCOME MEASURES

Quadriceps peak torque (PT) was the primary outcome measure for muscle function. Rate of force development (RFD), muscle activation and quality (quadriceps PT/leg lean mass), 6-min walk distance (6MWD), 4-meter gait speed (4mGS), 10-meter gait speed, 5-repetition sit-to-stand (5STS), dyspnea rate, and mortality risk were the secondary outcomes. Evaluations were performed at baseline and repeated after 4 weeks and 3 months of follow-up.

RESULTS

Quadriceps PT, RFD, and muscle quality improved by 17±23% (P<.001), 19±24%, and 16±20% (both P<.05) within the ECC group. Besides, a significant between-group difference for RFD (56±94 Nm/s, P=.038) was found after training. Both groups showed clinically relevant improvements in 6MWD, 4mGS, dyspnea rate, and mortality risk, with no significant differences between groups.

CONCLUSION

Combined endurance and resistance ECC improved lower limbs muscle function compared with CON in inpatients with COPD. In contrast, ECC did not further improve functional performance, dyspnea, and mortality risk. ECC may be of particular benefit to effect on skeletal muscle function in patients with COPD.

High-intensity interval training improves the outcomes of patients with chronic obstructive pulmonary disease: A meta-analysis of randomized controlled trials

BACKGROUND

Pulmonary exercise is an important part in the treatment of chronic obstructive pulmonary disease (COPD). We aimed to evaluate the effects and safety of high-intensity interval training (HIIT) in patients with COPD, to provide insights to the COPD treatment and care.

METHODS

Two investigators searched PubMed, Medline, Embase, web of Science, Cochrane library, China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu databases up to Sept 15, 2022 for randomized controlled trials (RCTs) on the effects and safety of HIIT for COPD patients. RevMan5.3 software was used for statistical analysis.

RESULTS

A total of 20 RCTs involving 962 COPD patients were finally included. 514 patients underwent HIIT interventions. Meta-analysis showed that HIIT increased the peak oxygen consumption (SMD = 0.30, 95%CI:0.14-0.46), peak minute ventilation (SMD = 0.26, 95%CI: 0.05-0.47), peak work rate (SMD = 0.34, 95%CI: 0.17-0.51), 6-min walking distance (SMD = 0.39, 95%CI: 0.23-0.55) in COPD patients (all P < 0.05). HIIT improved the quality of life (SMD = 0.30, 95%CI: 0.06-0.54) and reduced the dyspnea (SMD = -0.27, 95%CI: -0.51∼-0.03) in COPD patients (all P < 0.05). There were no significant differences in the forced expiratory volume in 1 s/forced vital capacity (SMD = 0.28, 95%CI: -0.01-0.56) and St. George's Respiratory Questionnaire score (SMD = -0.35, 95%CI: -0.73-0.03) between HIIT and control group (all P > 0.05). There was no publication bias analyzed by the Egger test and funnel plots (all P > 0.05).

CONCLUSIONS

HIIT may be beneficial to improve the pulmonary function, exercise capacity and quality of life of patients with COPD, which is worthy of clinical promotion for COPD treatment and care.

Neuromuscular and acute symptoms responses to progressive elastic resistance exercise in patients with chronic obstructive pulmonary disease: Cross-sectional study

Background

Quadriceps muscle training is a key part in the rehabilitation of chronic obstructive pulmonary disease (COPD) patients. However, exercise intensity prescription and progression with the typically used elastic bands is challenging. We aimed to evaluate neuromuscular, acute symptoms and cardiorespiratory responses (heart rate and dyspnea) during progressive elastic resistance exercise in patients with COPD.

Methods

Fourteen patients diagnosed with moderate-very severe COPD performed knee extensions at different elastic resistance levels (i.e., colors). The neuromuscular activity was recorded using surface electromyography for the rectus femoris, vastus lateralis and vastus medialis, together with rate of perceived exertion, perceived quadriceps fatigue, dyspnea, oxygen saturation and heart rate.

Results

For the vastus lateralis and rectus femoris, increase of muscle activity was evident from a two-level increment when using the red color. For the vastus medialis, there were no muscle activity progressions. Dyspnea, quadriceps fatigue and especially rate of perceived exertion increased in a dose-response fashion and were correlated with the resistance level and muscle activity at the three muscles.

Conclusion

Heavy elastic resistance exercise is feasible in COPD patients without excessive dyspnea and a stable cardiorespiratory response. In general, at least two elastic resistance increments are needed to enhance muscle activity for the vastus lateralis and rectus femoris, while there is no increase for the vastus medialis. These results may help to individualize exercise dosing during elastic resistance training in patients with COPD.

Multicomponent Exercise Program to Improve the Immediate Sequelae of COVID-19: A Prospective Study with a Brief Report of 2-Year Follow-Up

COVID-19 placed teams of professionals in a hostile and unfamiliar environment where the lack of knowledge of its pathology led to the adaptation of programs used so far for other conditions to try to address the immediate sequelae of COVID-19 infection. That is why the aim of this study was to assess the effects of a multicomponent exercise program (MEP) in improving cardio-respiratory performance, health status, disability due to dyspnea, aerobic capacity and endurance, and the immediate sequelae of COVID-19. Thirty-nine patients referred from different hospital services were included in this study. An intervention of seven weeks with sessions twice a week was carried out, where patients underwent intervallic training sessions followed by strengthening exercises and individualized respiratory physiotherapy exercises. The results of this study show a significant improvement in cardio-respiratory performance, health status, disability due to dyspnea, and aerobic capacity and endurance after intervention; and an increase in health status and reduction in disability due to dyspnea at the 2-year follow-up. In addition, none of the patients had any adverse effects either pre-post treatment or at the 2-year follow-up. Individualized and monitored MEP in survivors of COVID-19 showed positive effects in a pre-post evaluation and the 2-year follow up, improving the immediate sequelae of post-COVID-19 patients. This highlights the importance of the professional background of the rehabilitation teams in adapting to an unknown clinical environment.

The Exercising Brain: An Overlooked Factor Limiting the Tolerance to Physical Exertion in Major Cardiorespiratory Diseases?

“Exercise starts and ends in the brain”: this was the title of a review article authored by Dr. Bengt Kayser back in 2003. In this piece of work, the author highlights that pioneer studies have primarily focused on the cardiorespiratory-muscle axis to set the human limits to whole-body exercise tolerance. In some circumstances, however, exercise cessation may not be solely attributable to these players: the central nervous system is thought to hold a relevant role as the ultimate site of exercise termination. In fact, there has been a growing interest relative to the “brain” response to exercise in chronic cardiorespiratory diseases, and its potential implication in limiting the tolerance to physical exertion in patients. To reach these overarching goals, non-invasive techniques, such as near-infrared spectroscopy and transcranial magnetic stimulation, have been successfully applied to get insights into the underlying mechanisms of exercise limitation in clinical populations. This review provides an up-to-date outline of the rationale for the “brain” as the organ limiting the tolerance to physical exertion in patients with cardiorespiratory diseases. We first outline some key methodological aspects of neuromuscular function and cerebral hemodynamics assessment in response to different exercise paradigms. We then review the most prominent studies, which explored the influence of major cardiorespiratory diseases on these outcomes. After a balanced summary of existing evidence, we finalize by detailing the rationale for investigating the “brain” contribution to exercise limitation in hitherto unexplored cardiorespiratory diseases, an endeavor that might lead to innovative lines of applied physiological research.

Prehabilitation sessions can be provided more frequently in a shortened regimen with similar or better efficacy in people with non-small cell lung cancer: a randomised trial

QUESTION

In people with non-small cell lung cancer, what is the effect of condensing 15 prehabilitation sessions into a 3-week regimen compared with a 5-week regimen?

DESIGN

Randomised controlled trial with concealed allocation, intention-to-treat analysis and blinded assessment of the primary outcome.

PARTICIPANTS

People with diagnosed or suspected non-small cell lung cancer and moderate-to-high risk of postoperative complications.

INTERVENTION

Fifteen supervised prehabilitation sessions delivered with either a dense regimen of five sessions/week for 3 weeks (experimental group) or a non-dense regimen of three sessions/week for 5 weeks (control group).

OUTCOME MEASURES

The primary outcome was the change in cardiorespiratory fitness measured by the V̇O_2peak in ml/kg/min. The secondary outcomes were the change in other variables of interest measured during cardiopulmonary exercise testing, non-invasive nutritional markers, quadriceps maximal voluntary isometric contractions, maximal inspiratory pressure, quality of life, adherence and postoperative complications.

RESULTS

Changes with the experimental regimen were similar to or better than changes with the control regimen for: V̇O_2peak (MD 1.2 ml/kg/min, 95% CI -0.1 to 2.6); V̇E/V̇CO₂ slope (MD -3.6 points, 95% CI -8.7 to 1.5); and work rate at ventilatory threshold (MD 3.7 W, 95% CI -5.6 to 13.0). The two regimens had similar effects on: peak work rate (MD 1.3 W, 95% CI -6.4 to 9.0), V̇O₂ at ventilatory threshold (MD 0.0 ml/kg/min, 95% CI -1.4 to 1.4); body mass index (MD -0.2 kg/m², 95% CI -0.5 to 0.1); and maximal inspiratory pressure (MD -0.7 cmH₂O, 95% CI -9.8 to 8.4). The relative effect was uncertain for quadriceps maximal voluntary isometric contractions, quality of life and complications.

CONCLUSION

Condensing prehabilitation sessions led to similar or better improvement in cardiorespiratory fitness and did not decrease adherence or increase adverse events. This could increase the number of patients who can be referred for prehabilitation, despite short presurgical periods.

TRIAL REGISTRATION

NCT03936764.

Cardiac Ultrasound under Speckle Tracking Technology Based Analysis of Efficacy of Respiratory Rehabilitation on Chronic Obstructive Pulmonary Disease

The study shined spotlight on the effect of respiratory rehabilitation training on chronic obstructive pulmonary disease (COPD), which was evaluated using speckle ultrasound algorithm-based cardiac ultrasound. Then, 90 patients with stable COPD, who were admitted to the hospital from January 2018 to December 2019, were randomly rolled into three groups, namely, the fast inhalation and slow exhalation (A) group, abdominal breathing (B) group, and control (C) group. For group A, on the basis of the conventional treatment, the method of rapid inhalation and slow exhalation was adopted. The group B (n = 30) adopted the abdominal breathing method besides the conventional treatment. In addition, the group C (n = 30) received only conventional treatment. Finally, the efficacy and parameters of the three treatment methods were compared. The echocardiographic parameters and echocardiographic images were calculated and processed by the speckle tracking method. Three kinds of operators were used to track the myocardial spots successfully, and the corresponding points in the image were obtained and calculated. It was found that there was no significant difference in the degree of dyspnea, exercise endurance, lung function, respiratory muscle function, and quality of life (QOL) before treatment (P > 0.05). After treatment, in contrast with group C, the previously mentioned indicators in groups A and B were obviously better (P < 0.05). Further, both the echocardiographic images and echocardiographic parameters of groups A and B were obviously improved, and there was no obvious difference between groups A and B. Hence, some degree of respiratory rehabilitation was very effective in the diagnosis of patients with chronic pulmonary obstruction. In conclusion, the speckle tracking algorithm-based cardiac ultrasound improves the image quality. At the same time, respiratory rehabilitation training is effective on COPD and worthy of clinical promotion.

Pulmonary Rehabilitation in Noncystic Fibrosis Bronchiectasis

BACKGROUND

Current guidelines for the treatment of noncystic fibrosis bronchiectasis (NCFB) recommend pulmonary rehabilitation (PR), but to date, there are few studies that have proven its effectiveness.

OBJECTIVE

The main objective of this study was to examine the effect of PR on pulmonary function tests and exercise capacity.

METHOD

The aim of this study was to systematically review the effects of PR in NCFB on (1) forced expiratory volume in the first second (FEV1) and (2) exercise capacity evaluated by the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT). This meta-analysis was undertaken according to PRISMA recommendations.

RESULTS

This pair-wise meta-analysis included data obtained from studies that enrolled 529 NCFB patients. The FEV1 assessment after PR between the active and control group did not show any significant increase (FEV1 difference 0.084 mL; CI: -0.064, +0.233; p = 0.264), and there was an increasing trend (188 mL; CI: -0 to 0.009, +0.384) at the limits of statistical significance (p = 0.061). Walked distance showed a significant increase in the PR group compared to the control group (ISWT distance difference 070.0 m; CI: 55.2, 84.8; p < 0.001), and this finding was confirmed before and after PR both by the ISWT (68.85 m greater than baseline; CI: 40.52, 97.18; p < 0.001) and by the 6MWT (37.7 m greater than baseline; CI: 20.22, 55.25; p < 0.001).

CONCLUSIONS

PR improves exercise tolerance in NCFB patients, but it has a modest impact on respiratory function.

Supportive and palliative care for people with chronic respiratory disease and frailty

PURPOSE OF REVIEW

Frailty is a multidimensional syndrome associated with increased risk of poor outcomes. It is estimated that at least one in five people with chronic respiratory disease is also living with frailty. In this review, we consider recent advances in how frailty can be recognized, and its associated impact on people with chronic respiratory disease. We then discuss advances in supportive and palliative care for those with both chronic respiratory disease and frailty.

RECENT FINDINGS

The interconnectedness of chronic respiratory disease and frailty is being better understood. An increasing number of factors associated with frailty in respiratory disease have been identified, from increased symptom burden (e.g. breathlessness, fatigue) to increased exacerbations and higher mortality. These contribute to accumulating multidimensional losses in reserve, and unpredictable health. Recent advances in respiratory research, while not always with people with frailty, may inform supportive and palliative care to address frailty in chronic respiratory disease. These include rehabilitation interventions to strengthen reserves, advance care planning interventions to help manage unpredictable trajectories, and integrated models of care (e.g. incorporating respiratory, geriatric, and palliative care) to address multidimensional needs.

SUMMARY

Recent evidence supporting the role of rehabilitation, advance care planning, and early palliative care, may be of benefit to people living with chronic respiratory disease and frailty. Models showing integration across multiple specialities and professionals may have the most potential to meet the multidimensional needs of this group. Future research should develop and test models of care that address frailty and/or explore the role of frailty in triggering integrated multidisciplinary input.

Physiological Changes Differ between Responders and Nonresponders to Pulmonary Rehabilitation in COPD

PURPOSE

Not all patients with chronic obstructive pulmonary disease (COPD) experience similar benefits after pulmonary rehabilitation (PR). This pre-post PR study used a large sample of patients with COPD to determine whether PR-induced changes of oxygen uptake (V˙O2) kinetics and exercise responses of V˙O2, carbon dioxide output (V˙CO2), minute ventilation (V˙E), V˙E/V˙CO2, breathing frequency, and tidal volume differed between responders and nonresponders to PR.

METHODS

Responders to PR were defined as patients with a minimal clinically important increase in endurance time of 105 s. Isotime (=180 s) values of V˙O2, V˙CO2, V˙E, V˙E/V˙CO2, breathing frequency, and tidal volume; gains of V˙O2, V˙CO2, and V˙E; and V˙O2 mean response time of 183 patients with COPD (forced expiratory volume in 1 s: 56% ± 19% predicted) were compared between pre- and post-PR constant work rate tests.

RESULTS

After PR, only the group of responders significantly decreased V˙O2 mean response time (P < 0.05), V˙CO2 gain, V˙E gain, and isotime values of V˙CO2, V˙E, and V˙E/V˙CO2 (all, P < 0.001), while also improving their breathing pattern (e.g., decreased breathing frequency isotime value; P < 0.0001). These changes were not observed in the group of nonresponders. Changes in physiological exercise responses were correlated with changes in physical performance (e.g., correlation between changes in V˙O2 mean response time and endurance time: P = 0.0002, r = -0.32).

CONCLUSIONS

PR-induced changes in physiological exercise responses differed between responders and nonresponders. Physiological changes are relevant to explain the variable improvements of physical performance after PR in patients with COPD.

The role of peripheral muscle fatigability on exercise intolerance in COPD

INTRODUCTION

Exercise limitation in chronic obstructive pulmonary disease (COPD) is multi-factorial; however, growing evidence indicates that muscle dysfunction may contribute in some patients.

AREAS COVERED

This work outlines current evidence for and against increased peripheral muscle fatigability in COPD through a comprehensive review of relevant literature available on PubMed/MEDLINE until May 2020. The authors first discuss key methodological issues relative to muscle fatigue assessment by non-volitional techniques, particularly magnetic stimulation. The authors then provide a detailed discussion of critical studies to have objectively measured skeletal muscle fatigue in individuals with COPD.

EXPERT OPINION

Current evidence indicates that localized (knee extension) and cycling exercise are associated with increased quadriceps fatigability in most COPD patients. Increased fatigability, however, has not been consistently found in response to walking, likely reflecting the tendency of 'central' respiratory constraints to overshadow potential functional impairments in the appendicular muscles in this form of exercise. Thus, addressing skeletal muscle abnormalities may be critical to translate improvements in lung mechanics (e.g., due to bronchodilator therapy) into better exercise tolerance. The positive effects of pulmonary rehabilitation on muscle fatigability are particularly encouraging and suggest a role for these measurements to test the efficacy of emerging adjunct training strategies focused on the peripheral muscles.

ERS International Congress, Madrid, 2019: highlights from the Sleep and Clinical Physiology Assembly

The 2019 European Respiratory Society (ERS) International Congress took place in Madrid, Spain, and served as a platform to find out the latest advances in respiratory diseases research. The research aims are to understand the physiology and consequences of those diseases, as well as the improvement in their diagnoses, treatments and patient care. In particular, the scientific sessions arranged by ERS Assembly 4 provided novel insights into sleep-disordered breathing and new knowledge in respiratory physiology. This article, divided by session, will summarise the most relevant studies presented at the ERS International Congress. Each section has been written by Early Career Members specialising in the different fields of this interdisciplinary assembly.

Exercise training increases respiratory muscle strength and exercise capacity in patients with chronic obstructive pulmonary disease and respiratory muscle weakness

BACKGROUND

How respiratory muscle strength influences the effectiveness of pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD) is unclear.

OBJECTIVE

To investigate the benefits of PR in subjects with COPD according to respiratory muscle strength.

METHODS

Ninety-seven subjects with COPD were evaluated using maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), pulmonary function tests, the cardiopulmonary exercise test (CPET), and the St. George's Respiratory Questionnaire (SGRQ). Subjects were divided into four groups: 1 (normal MIP and MEP); 2 (low MIP); 3 (low MEP); and 4 (low MIP and MEP). Subjects underwent PR for 3 months; MIP, MEP, SGRQ, and CPET were evaluated post-PR.

RESULTS

Subjects with both poor MIP and MEP had the highest dyspnea score, lowest exercise capacity, and poorest health-related quality of life (HRQoL). PR improved exercise capacity and HRQoL in all groups, with more improvement in MIP, MEP, tidal volume (on exercise), and dyspnea (at rest) in subjects with both low MIP and MEP.

CONCLUSIONS

Patients with respiratory muscle weakness had worse dyspnea, lower exercise capacity, and poorer HRQoL at baseline. Exercise training improved respiratory muscle strength with concurrent improvement of exercise capacity, HRQoL, and dyspnea score. Subjects with both poor baseline MIP and MEP showed greater benefits of PR.

Locomotor Muscles in COPD: The Rationale for Rehabilitative Exercise Training

Exercise training as part of pulmonary rehabilitation is arguably the most effective intervention to improve tolerance to physical exertion in patients with chronic obstructive pulmonary disease (COPD). Owing to the fact that exercise training has modest effects on exertional ventilation, operating lung volumes and respiratory muscle performance, improving locomotor muscle structure and function are key targets for pulmonary rehabilitation in COPD. In the current concise review, we initially discuss whether patients’ muscles are exposed to deleterious factors. After presenting corroboratory evidence on this regard (e.g., oxidative stress, inflammation, hypoxemia, inactivity, and medications), we outline their effects on muscle macro- and micro-structure and related functional properties. We then finalize by addressing the potential beneficial consequences of different training strategies on these muscle-centered outcomes. This review provides, therefore, an up-to-date outline of the rationale for rehabilitative exercise training approaches focusing on the locomotor muscles in this patient population.