Determining the anaerobic threshold in postpolio syndrome: comparison with current guidelines for training intensity prescription.

OBJECTIVES: To determine whether the anaerobic threshold (AT) can be identified in individuals with postpolio syndrome (PPS) using submaximal incremental exercise testing, and to compare current guidelines for intensity prescription in PPS with the AT. DESIGN: Cohort study. SETTING: Research laboratory. PARTICIPANTS: Individuals with PPS (N=82). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Power output, gas exchange variables, heart rate, and rating of perceived exertion (RPE) were measured in an incremental submaximal cycle ergometry test. Two independent observers identified the AT. Comparison of current guidelines for training intensity prescription in PPS (40%-60% heart rate reserve [HRR] or RPE of 12) with the AT was based on correlations between recommended heart rate and the heart rate at the AT. In addition, we determined the proportion of individuals that would have been recommended to train at an intensity corresponding to their AT. RESULTS: The AT was identified in 63 (77%) of the participants. Pearson correlation coefficients between the recommended heart rate and the heart rate at the AT were lower in cases of 40% HRR (r=.56) and 60% HRR (r=.50) than in cases of prescription based on the RPE (r=.86). Based on the RPE, 55% of the individuals would have been recommended to train at an intensity corresponding to their AT. This proportion was higher compared with 40% HRR (41%) or 60% HRR (18%) as criterion. CONCLUSIONS: The AT can be identified in most individuals with PPS offering an individualized target for aerobic training. If the AT cannot be identified (eg, because gas analysis equipment is not available), intensity prescription can best be based on the RPE.

Barriers and facilitators for physical fitness training in orthopedic geriatric rehabilitation. A qualitative study.

PURPOSE: The aim of this explorative, qualitative study is to identify factors that potentially influence the execution of physical fitness training in inpatient orthopedic geriatric rehabilitation (GR), from the perspectives of patients, their relatives and professionals. MATERIALS AND METHODS: In GR wards of skilled nursing facilities in the Netherlands, semi-structured interviews were held with triads of patients, their relatives and responsible nurses, and focus groups with members of the multidisciplinary teams. Verbatim reports were analyzed according to the framework method. RESULTS: We found twelve categories of barriers and facilitators related to characteristics of the patients, their family, staff, training program and organization. CONCLUSIONS: The barriers and facilitators found largely correspond with those found for participation in exercise in related settings, but also show important differences. This overview of barriers and facilitators enables multidisciplinary teams to design improvements at the level of the organization and interventions, as well as at the level of the individual training program, tailoring it to the patient's circumstances and needs. Further research should focus on weighing these barriers and facilitators to develop a feasible guidance for daily practice, as well as testing their effect on the adherence to existing physical fitness training guidelines.

Physical fitness training is important in reaching functional goals in orthopedic geriatric rehabilitation.Practicing outside of therapy can be stimulated by clarity about expectations, proper training equipment and tailored stimulation/assistance.Training volume and intensity should meet the guidelines, but be tailored to the patient.Characteristics of the program, staff and organization need to be considered as they impact the physical fitness training.

Neuromuscular properties of the thigh muscles in patients with Ehlers-Danlos syndrome.

INTRODUCTION: Ehlers-Danlos syndrome (EDS), a connective tissue disorder, may lead to impaired contractile function of lower limb muscles. METHODS: To test this hypothesis and to understand the possible mechanisms involved, isometric function of the thigh muscles was investigated at different joint angles (30°, 60°, and 90° of knee flexion) in 7 tenascin-X (TNX)-deficient EDS patients. RESULTS: There was reduced maximal voluntary torque of the knee extensors (but not knee flexors) across all joint angles in the patients. Time to reach maximal rate of torque development was delayed, and voluntary activation capacity was reduced in patients compared with controls, particularly at 30°. CONCLUSIONS: EDS is associated with muscle weakness, most likely due to increased compliance of the series-elastic component of muscle tissue and failure of maximal voluntary muscle activation. Further research is required to understand the influence of reduced voluntary activation on the severe fatigue reported by EDS patients.

Exercise testing and training in frail older adults with an orthopedic impairment participating in a geriatric rehabilitation program: an international Delphi study.

BACKGROUND: Little is known about exercise testing and training in orthopedic geriatric rehabilitation. This study aims to obtain expert-consensus-based recommendations on this matter. METHODS: Using an online Delphi study we aimed to reach international expert consensus on statements related to testing and training of endurance capacity and muscle strength. Participants needed to have relevant research or clinical expertise. Statements were evaluated and explanatory comments could be provided. After each round anonymous results were presented to participants. Statements could be adjusted or new ones could be formulated if necessary. Consensus was defined as > 75% of participants agreeing. RESULTS: Thirty experts completed the first round. Twenty-eight (93%) the second and 25 (83%) completed the third round. The majority of experts were physical therapists. Consensus was reached on a total of 34 statements. The statements and comments reflected the need for a pragmatic and tailored approach in this population both for testing and training. For example, for testing endurance capacity, a 6 Minute walk test was promoted and for testing muscle strength, performance in a functional activity was suggested. Ratings of perceived exertion were promoted for monitoring intensity of endurance and muscle strength training in patients without cognitive impairment. CONCLUSION: In orthopedic GR, endurance and muscle strength testing should be pragmatic and is preferably performed in functional activities. For endurance training existing guidelines of the American College of Sports Medicine can be strived for but adapted as needed and for muscle strength training only lower intensities are agreed upon.

Effectiveness and characteristics of physical fitness training on aerobic fitness in vulnerable older adults: an umbrella review of systematic reviews.

OBJECTIVES: To present an overview of effectiveness and training characteristics of physical training on aerobic fitness, compared with alternative or no training, in adults aged over 65 years with various health statuses, providing a basis for guidelines for aerobic training of vulnerable older adults that can be used in geriatric rehabilitation. DESIGN: An umbrella review of systematic reviews that included both randomised controlled trials and other types of trials. DATA SOURCES: MEDLINE, Embase, CINAHL and the Cochrane Library were searched on 9 September 2019. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included systematic reviews reporting on physical training interventions that are expected to improve aerobic fitness, presenting results for adults aged 65 years and older, describing at least one of the FITT-characteristics: Frequency, Intensity, Time or Type of exercise, and measuring aerobic fitness at least before and after the intervention. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted the data and assessed the risk of bias. A narrative synthesis was performed. RESULTS: We included 51 papers on 49 reviews. Positive effect of training on aerobic fitness was reported by 33 reviews, 11 reviews remained inconclusive and 5 reviews reported no effect. Training characteristics varied largely. Frequency: 1-35 sessions/week, Intensity: light-vigorous, Time: <10-120 min/session and Types of exercise: many. The methodological quality was most often low. Subgroup analyses revealed positive effects for all health conditions except for trauma patients. Exercise characteristics from current existing guidelines are widely applicable. For vulnerable older adults, lower intensities and lower frequencies were beneficial. Some health conditions require specific adjustments. Information on adverse events was often lacking, but their occurrence seemed rare. CONCLUSION: Physical fitness training can be effective for vulnerable older adults. Exercise characteristics from current existing guidelines are widely applicable, although lower frequencies and intensities are also beneficial. For some conditions, adjustments are advised. PROSPERO REGISTRATION NUMBER: CRD42020140575.

Skeletal muscle alterations in patients with acute Covid-19 and post-acute sequelae of Covid-19.

Skeletal muscle-related symptoms are common in both acute coronavirus disease (Covid)-19 and post-acute sequelae of Covid-19 (PASC). In this narrative review, we discuss cellular and molecular pathways that are affected and consider these in regard to skeletal muscle involvement in other conditions, such as acute respiratory distress syndrome, critical illness myopathy, and post-viral fatigue syndrome. Patients with severe Covid-19 and PASC suffer from skeletal muscle weakness and exercise intolerance. Histological sections present muscle fibre atrophy, metabolic alterations, and immune cell infiltration. Contributing factors to weakness and fatigue in patients with severe Covid-19 include systemic inflammation, disuse, hypoxaemia, and malnutrition. These factors also contribute to post-intensive care unit (ICU) syndrome and ICU-acquired weakness and likely explain a substantial part of Covid-19-acquired weakness. The skeletal muscle weakness and exercise intolerance associated with PASC are more obscure. Direct severe acute respiratory syndrome coronavirus (SARS-CoV)-2 viral infiltration into skeletal muscle or an aberrant immune system likely contribute. Similarities between skeletal muscle alterations in PASC and chronic fatigue syndrome deserve further study. Both SARS-CoV-2-specific factors and generic consequences of acute disease likely underlie the observed skeletal muscle alterations in both acute Covid-19 and PASC.

Exercise therapy and cognitive behavioural therapy to improve fatigue, daily activity performance and quality of life in postpoliomyelitis syndrome: the protocol of the FACTS-2-PPS trial.

BACKGROUND: Postpoliomyelitis Syndrome (PPS) is a complex of late onset neuromuscular symptoms with new or increased muscle weakness and muscle fatigability as key symptoms. Main clinical complaints are severe fatigue, deterioration in functional abilities and health related quality of life. Rehabilitation management is the mainstay of treatment. Two different therapeutic interventions may be prescribed (1) exercise therapy or (2) cognitive behavioural therapy (CBT). However, the evidence on the effectiveness of both interventions is limited. The primary aim of the FACTS-2-PPS trial is to study the efficacy of exercise therapy and CBT for reducing fatigue and improving activities and quality of life in patients with PPS. Additionally, the working mechanisms, patients' and therapists' expectations of and experiences with both interventions and cost-effectiveness will be evaluated. METHODS/DESIGN: A multi-centre, single-blinded, randomized controlled trial will be conducted. A sample of 81 severely fatigued patients with PPS will be recruited from 3 different university hospitals and their affiliate rehabilitation centres. Patients will be randomized to one of three groups i.e. (1) exercise therapy + usual care, (2) CBT + usual care, (3) usual care. At baseline, immediately post-intervention and at 3- and 6-months follow-up, fatigue, activities, quality of life and secondary outcomes will be assessed. Costs will be based on a cost questionnaire, and statistical analyses on GEE (generalized estimated equations). Analysis will also consider mechanisms of change during therapy. A responsive evaluation will be conducted to monitor the implementation process and to investigate the perspectives of patients and therapists on both interventions. DISCUSSION: A major strength of the FACTS-2-PPS study is the use of a mixed methods design in which a responsive and economic evaluation runs parallel to the trial. The results of this study will generate new evidence for the rehabilitation treatment of persons with PPS. TRIAL REGISTRATION: Dutch Trial Register NTR1371.

Intrinsic properties of the knee extensor muscles after subacute stroke.

UNLABELLED: Horstman AM, Gerrits KH, Beltman MJ, Koppe PA, Janssen, TW, de Haan A. Intrinsic properties of the knee extensor muscles after subacute stroke. OBJECTIVE: To characterize muscle properties of paretic lower-limb (PL) and nonparetic lower-limb (NL) knee extensors in patients with subacute stroke. DESIGN: Case-control study. SETTING: Rehabilitation center research laboratory. PARTICIPANTS: Patients with subacute stroke (n=14) and able-bodied age-matched control subjects (n=12). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Half relaxation times (HRTs) and maximal rates of torque development (MRTDs) were assessed as indicators of contractile speed using both voluntary and electrically evoked contractions. Moreover, changes in torque were measured during a fatigue protocol (35 electrically evoked intermittent contractions; 1.5s on, 2s off) and recovery. RESULTS: No differences among groups were found for normalized MRTDs during electrically evoked contractions (P=.117). However, during voluntary contractions both PLs (53% of control, P=.022) and NL (71% of control, P<.001) had significantly lower MRTD compared with control. Both PL (134% of control, P=.001) and NL (123% of control, P=.032) had significantly higher HRTs than control, indicating muscle slowing in patients with subacute stroke. PLs fatigued more and faster than control (P=.011) and both PL and NL recovered slower (P<.001). CONCLUSIONS: The changes in HRTs and fatigue suggest adaptations in muscle properties toward slower, more fatigable muscle shortly after stroke. The inability to make use of contractile speed because of impaired neural activation seems the most limiting factor during the initial phase of torque development in PL. Thus, besides strengthening, muscle endurance and speed should also be addressed during rehabilitation.

Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke.

OBJECTIVE: (1) To examine the isometric strength, speed, and fatigue resistance of the knee extensors of the paretic limb and nonparetic limb in patients with stroke and compare these with able-bodied subjects. (2) To relate the contractile properties with different indices of functional performance. DESIGN: Case-control study. SETTING: Rehabilitation center research laboratory. PARTICIPANTS: Eighteen stroke patients and 10 able-bodied controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Maximal voluntary torque (MVT), maximal rate of torque development, time to maximal rate of torque development, half relaxation time ((1/2)RT), and fatigue index. Scores on the Functional Ambulation Category scale, Berg Balance Scale, and Rivermead Mobility Index as well as distance walked during the six-minute walk test were obtained. RESULTS: MVT of the paretic leg was lower than of the nonparetic leg (P<.05), and both limbs had lower MVT than controls (P<.05). Both the paretic and the nonparetic leg showed longer (1/2)RT compared with controls (P<.05). The fatigue index was reduced in the paretic leg (P<.05) but not in the nonparetic leg compared with controls. MVT and fatigue index of the paretic leg were related to indices of functional performance (r=0.49-0.64; P<.05). CONCLUSIONS: Apart from bilateral weakness, knee extensors in patients with stroke showed a lower rate of torque development and relaxation (both paretic and nonparetic leg) and lower fatigue resistance (paretic leg only) than controls, which in part may be a consequence of changes within the muscles. Strength and fatigue resistance relate to functional performance, indicating that these muscle properties should be addressed during rehabilitation. However, future research is needed to elucidate the efficacy of exercise programs.

Effects of electric stimulation-assisted cycling training in people with chronic stroke.

OBJECTIVE: To evaluate whether leg cycling training in subjects with chronic stroke can improve cycling performance, aerobic capacity, muscle strength, and functional performance and to determine if electric stimulation (ES) to the contralateral (paretic) leg during cycling has additional effects over cycling without ES. DESIGN: A randomized controlled trial, with a partial double-blind design. SETTING: A rehabilitation center. PARTICIPANTS: Twelve stroke patients (range, 18-70 y), more than 5 months poststroke, with lower-extremity hemiparesis. INTERVENTION: Subjects were randomly assigned to groups that performed cycling exercise, one with ES evoking muscle contractions and a control group with ES not evoking muscle contractions. Subjects, blinded for group assignment, trained twice a week for 6 weeks. MAIN OUTCOME MEASURES: Changes in aerobic capacity and maximal power output, functional performance, and lower-limb muscle strength. RESULTS: Aerobic capacity and maximal power output significantly increased by 13.8%+/-19.1% and 38.1%+/-19.8%, but muscle strength was not significantly enhanced after training. Functional performance improved (ie, scores on the Berg Balance Scale increased by 6.9%+/-5.8% (P=.000) and the six-minute walk test improved by 14.5%+/-14.1% (P=.035). There was no significant effect on the Rivermead Mobility Index (P=.165). Training-induced changes were not significantly different between the 2 groups. Changes in cycling performance and aerobic capacity were not significantly related to changes in functional performance. CONCLUSIONS: This study showed that a short cycling training program on a semirecumbent cycle ergometer can markedly improve cycling performance, aerobic capacity, and functional performance of people with chronic stroke. The use of ES had no additional effects in this specific group of subjects with chronic stroke.

Intrinsic muscle strength and voluntary activation of both lower limbs and functional performance after stroke.

The objective of this study was to assess the nature of muscle weakness in both legs after stroke compared with able-bodied control individuals and to examine whether there is a relationship between the degree of muscle weakness and coactivation of knee extensors and flexors as well as voluntary activation capacity of knee extensors of both paretic and non-paretic legs and indices of functional performance. Maximal voluntary isometric torques of knee extensors (MVCe) and flexors (MVCf) were determined in 14 patients (bilaterally) and 12 able-bodied controls. Simultaneous measurements were made of torque and surface EMG from agonist and antagonist muscles. Coactivation was calculated. Supramaximal triplets were evoked with electrical stimulation to estimate maximal torque capacity and degree of voluntary activation of knee extensors. MVCs, activation and coactivation parameters were correlated to scores of seven functional performance tests. MVCe, MVCf and voluntary activation were lower in paretic lower limb (PL) compared with both non-paretic lower limb (NL) and control. Besides, all these parameters of NL were also lower than control. Electrically evoked torque capacity of knee extensors of PL was about 60% of both NL and control, which were not significantly different from each other. Strong significant correlations between strength, as well as voluntary activation, and functional performance were found. Coactivation did not correlate well with functional performance. Thus, whereas for NL activation failure can explain weakness, for PL both activation failure and reduced intrinsic torque capacity are responsible for the severe weakness. Activation capacity and muscle strength correlated strongly to functional performance, while coactivation did not.

Correction: Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial.

[This corrects the article DOI: 10.1371/journal.pone.0159280.].

Muscle slowness in a family with nemaline myopathy.

All patients of a large family with nemaline myopathy complained of slowness in movement. We confirmed this clinical complaint physiologically by showing lower contractile speed in quadriceps muscle. Electrically evoked contractions of the quadriceps muscle elicited a lower rate of relaxation and a tendency for slower torque generation. Here, we demonstrate for the first time slow muscle characteristics as a physiological correlate for the clinical complaint of slowness.

Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial.

OBJECTIVE: To explore reasons for the lack of efficacy of a high intensity aerobic exercise program in post-polio syndrome (PPS) on cardiorespiratory fitness by evaluating adherence to the training program and effects on muscle function. DESIGN: A process evaluation using data from an RCT. PATIENTS: Forty-four severely fatigued individuals with PPS were randomized to exercise therapy (n = 22) or usual care (n = 22). METHODS: Participants in the exercise group were instructed to exercise 3 times weekly for 4 months on a bicycle ergometer (60-70% heart rate reserve). RESULTS: The attendance rate was high (median 89%). None of the participants trained within the target heart rate range during >75% of the designated time. Instead, participants exercised at lower intensities, though still around the anaerobic threshold (AT) most of the time. Muscle function did not improve in the exercise group. CONCLUSION: Our results suggest that severely fatigued individuals with PPS cannot adhere to a high intensity aerobic exercise program on a cycle ergometer. Despite exercise intensities around the AT, lower extremity muscle function nor cardiorespiratory fitness improved. Improving the aerobic capacity in PPS is difficult through exercise primarily focusing on the lower extremities, and may require a more individualized approach, including the use of other large muscle groups instead. TRIAL REGISTRATION: Netherlands National Trial Register NTR1371.

Recovery of walking ability using a robotic device in subacute stroke patients: a randomized controlled study.

PURPOSE: This study investigates the effectiveness of Lokomat + conventional therapy in recovering walking ability in non-ambulatory subacute stroke subjects involved in inpatient rehabilitation. METHOD: Thirty first-ever stroke patients completed 8 weeks of intervention. One group (n = 16) received Lokomat therapy twice a week, combined with three times 30 min a week of conventional overground therapy. The second group (n = 14) received conventional assisted overground therapy only, during a similar amount of time (3.5 h a week). The intervention was part of the normal rehabilitation program. Primary outcome measure was walking speed. Secondary outcome measures assessed other walking- and mobility-related tests, lower-limb strength and quality of life measures. All outcome measures were assessed before and after the intervention and at wk 24 and wk 36 after start of the intervention. RESULTS: Patients showed significant (p < 0.05) gains in walking speed, other walking- and mobility related tests, and strength of the paretic knee extensors relative to baseline at all assessments. However, there were no significant differences in improvements in any of the variables between groups at any time during the study. CONCLUSION: These results indicate that substituting Lokomat therapy for some of conventional therapy is as effective in recovering walking ability in non-ambulatory stroke patients as conventional therapy alone. Implications for Rehabilitation Recovery of walking after stroke is important. Robot-assisted therapy is currently receiving much attention in research and rehabilitation practice as devices such as the Lokomat seem to be promising assistive devices. Technical developments, sub-optimal study designs in literature and new therapy insights warrant new effectiveness studies. RESULTS of a financially and practically feasible study indicate that substituting Lokomat therapy for some of conventional therapy is as effective in recovering walking ability in non-ambulatory stroke patients as compared to conventional overground therapy alone.

Increased vascular resistance in paralyzed legs after spinal cord injury is reversible by training.

The purpose of the present study was to determine the effect of a spinal cord injury (SCI) on resting vascular resistance in paralyzed legs in humans. To accomplish this goal, we measured blood pressure and resting flow above and below the lesion (by using venous occlusion plethysmography) in 11 patients with SCI and in 10 healthy controls (C). Relative vascular resistance was calculated as mean arterial pressure in millimeters of mercury divided by the arterial blood flow in milliliters per minute per 100 milliliters of tissue. Arterial blood flow in the sympathetically deprived and paralyzed legs of SCI was significantly lower than leg blood flow in C. Because mean arterial pressure showed no differences between both groups, leg vascular resistance in SCI was significantly higher than in C. Within the SCI group, arterial blood flow was significantly higher and vascular resistance significantly lower in the arms than in the legs. To distinguish between the effect of loss of central neural control vs. deconditioning, a group of nine SCI patients was trained for 6 wk and showed a 30% increase in leg blood flow with unchanged blood pressure levels, indicating a marked reduction in vascular resistance. In conclusion, vascular resistance is increased in the paralyzed legs of individuals with SCI and is reversible by training.

Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.

OBJECTIVE: To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals. METHODS: Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean). RESULTS: In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016). CONCLUSIONS: In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability. SIGNIFICANCE: This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Fatigue resistance of the knee extensor muscles is not reduced in post-polio syndrome.

The present study investigated whether intrinsic fatigability of the muscle fibers is reduced in patients with post-polio syndrome (PPS). This may contribute to the muscle fatigue complaints reported by patients with PPS. For this purpose, we assessed contractile properties and fatigue resistance of the knee extensor muscles using repeated isometric electrically evoked contractions in 38 patients with PPS and 19 age-matched healthy subjects. To determine whether any difference in fatigue resistance between both groups could be attributed to differences in aerobic capacity of the muscle fibers, 9 patients with PPS and 11 healthy subjects performed the same protocol under arterial occlusion. Results showed that fatigue resistance of patients with PPS was comparable to that in controls, both in the situation with intact circulation and with occluded blood flow. Together, our findings suggest that there are no differences in contractile properties and aerobic muscle capacity that may account for the increased muscle fatigue perceived in PPS.

Effect of robotic gait training on cardiorespiratory system in incomplete spinal cord injury.

The objectives in this study were to investigate the effect of robot-assisted gait training on cardiorespiratory fitness in subjects with motor incomplete spinal cord injury and document the exercise intensity of robotic walking in comparison with the recommended guidelines. Ten patients followed a 24-session training program with a robotic gait orthosis in addition to physiotherapy sessions completed within 10 to 16 wk. Cardiorespiratory fitness was determined in a graded arm crank exercise test before and after the training program. To assess the intensity of robot-assisted walking, oxygen consumption (VO2) and heart rate (HR) were measured during a training session early in and at the end of the training program, and exercise intensity measures (percentage of VO2 reserve [%VO2R], percentage of HR reserve [%HRR], and metabolic equivalents [METs]) were calculated. Whereas no changes were found in peak VO2, the resting and submaximal HR at a constant work load were significantly lower after training. Most subjects exercised at low intensity (<30%VO2R, <30%HRR, <3.0 METs), and only two subjects exercised at moderate intensity (>3.0 METs). In spite of the low exercise intensity of the training program and no changes in peak VO2, robot-assisted gait training induced some improvement in cardiorespiratory fitness, as suggested by lower resting and submaximal HR values.