Global stroke epidemiology is changing rapidly. Although rates of stroke mortality have decreased worldwide in the past two decades, the absolute numbers of stroke survivors, referred as people who are living with the consequences of stroke are increasing. Over the 1990–2013 period, there was a significant increase in the absolute number of disability-adjusted life-years (DALYs) due to ischemic and hemorrhagic stroke.1 The burden of stroke is high and is likely to increase in future decades as a result of aging of population. Physical inactivity is a major risk factor for cardiovascular disease (CVD) and stroke.2 After a stroke it is recommended the promotion of lifestyle changes and the participation in exercise programs should be encouraged.3 The guidelines recommend that adults get at least 150min of moderate-intensity, such as brisk walking, or 75min of vigorous-intensity aerobic activity (or an equivalent combination) per week and perform muscle strengthening activities at least 2 days per week.4 It is known that High Intensity Training (HIT) has significant effects in stroke recovery.5 However, HIT could favor the risk of cardiovascular failure, falls and long term loss of adherence. It has been described beneficial associations between low intensity physical activity (PA) and health benefits such as CVD risk factors.6,7 It also has been described remarkable effects on reducing disease symptoms with low–moderate intensity therapeutic exercise8 In this context low to moderate intensity exercise training is considered as a sustainable and beneficial rehabilitation strategy for being safe.9

Additional benefits occur with more intense exercises as HIT, but the marginal benefit is less than that observed with increases in PA at lower levels, as low to moderate-intensity continuous training (for example, changing from not doing exercises to walking 10min/day).10 Benefits from PA are seen for all ages and groups, including older adults, and people with disabilities and chronic conditions.11,12 PA reduces premature mortality, improves risk factors for cardiovascular disease (CVD) (such as high blood pressure and high cholesterol), and reduces the likelihood of diseases related to CVD, including stroke, coronary heart disease (CHD), type 2 diabetes mellitus (DM), and sudden heart attacks.10 After stroke, a progressive aerobic deconditioning occurs that difficult the recovering of walking ability and basic activities of daily living (ADLs) and which worsens cardiovascular (CV) risk and quality of life (QoL).13 Although PA is beneficial in stroke recovery, stroke survivors often do not receive PA recommendations after hospital discharge.2 Potential approaches to improve this situation include outpatient structured rehabilitation exercise programs that include walking training14 and endurance training.15 Numerous studies have demonstrated the efficacy of aerobic exercise16 and resistance training (RT).17 It has been suggested that RT in stroke survivors can improve muscle resistance but may be it does not turn into a functional improvement.2 Therefore, there is strong evidence for exercise rehabilitation interventions favoring repetitive specific task-oriented training targeted on muscles that participate in a functional movement with deficit (e.g., to perform sit-to-stand transfer or stair climbing); muscular changes are activated with the performed task.18 There are few data on the long term effects of multimodal programs that incorporate aerobic exercise, complemented by task-oriented training and neuromotor training (including balance and tonic postural activities, flexibility, dynamic and static stretching and breathing), at low–moderate intensity. Therefore, the purpose of this study is to investigate the impact of a multimodal low–moderate intensity exercise rehabilitation program (LIERP) tailored to stroke survivors on walking speed and walking ability.

We conducted an observational study with a repeated measures design to evaluate changes on walking speed and walking ability after a multimodal low-intensity exercise rehabilitation program. Assessments were performed at baseline, post-intervention and at 6-month follow-up. To calculate simple size, according to the literature review, the change in the main outcome was determined of 0.175m/s19; considering a 95% confidence interval (CI) the sample required was of 29 participants (20% lost adjusted). Thirty-one participants were recruited from Hospital-Consorci Sanitari de Terrassa (Barcelona, Spain) over a period of one year. All of them had suffered a stroke and had completed a conventional rehabilitation program.

Inclusion criteria were: diagnosis of ischemic or hemorrhagic stroke; both genders; age ≥18; Functional Ambulation Classification (FAC) ≥3; Barthel Index ≥45. Exclusion criteria were: cognitive impairment (Mini Mental State Examination ≤24); unstable cardiovascular disease (acute heart failure, recent myocardial infarction, unstable angina and uncontrolled arrhythmias)20,21; alcohol or other toxic substances abuse and decompensated psychiatric disorders that prevented from following a group session.

Before the enrolment, participants underwent a medical examination to ensure that there were no circumstances that prevented their participation in the program, following the recommendations of the American College of Sports Medicine (ACSM) for patients with cardiovascular disease22 and the guidelines of the American Heart Association for stroke survivors.20

All experimental procedures were conducted according to the Declaration of Helsinki.23 The study was approved by the Ethics and Clinical Research Committee of Hospital-Consorci Sanitari de Terrassa. All participants provided written informed consent for the study.

The main finding of this study is that application of the LIERP in the subacute and chronic phase of stroke is associated with statistically significant and clinically meaningful increase in walking speed and walking distance. As suggested by Ivey and Macko,13 stroke survivors suffer a severe degradation of physical condition and low improvements of fitness could notably improve walking endurance. An increase in gait speed in the 10MWT of 0.175m/s or greater, in people with stroke undergoing outpatient rehabilitation, has been estimated as a meaningful improvement in walking ability.19 A change in walking distance of 30.1m has been considered a clinically important difference in the 6MWT.38 This coincides with the results obtained in this study: the increase in walking speed and walking distance at the end of the intervention allows participants a functional outdoors ambulation. At the beginning of the intervention, participants had a sedentary lifestyle, at most participating in low energy expenditure activities such as walking outdoors small distances at a low gait speed. At the end of the intervention, all participants were able to walk independently outdoors longer distances at a faster gait speed. These results, besides, are maintained at six month follow up indicating a good adherence to the program. The results suggest that high adherence rates achieved in the LIERP program may have led to better walking speed and walking endurance outcomes. These findings justify the importance to consider the most prominent predictors of exercise adherence. This issue is especially important among the elderly suffering stroke where the lowest adherence is registered. Our study coincides with the recommendations of the US Department of Health Services that suggests that increasing physical activity at lower intensity levels (changing from nothing to walking 10min/day is beneficial).10 The low–moderate intensity of the program could have facilitated participants’ engagement to the ambulation program at home, the reduction of the inactivity and overall satisfaction with the program. As concluded English it is important to reduce sitting time in order to reduce cardiovascular risk and improve stroke's recovery.39 Therefore, at six month follow-up it is observed a trend toward a reduction of walking time comparable to similar studies.40 It has been reported that persons with disabilities have lower QoL due to physical weakness and immobility and that regular exercise facilitates a better QoL.41 Therefore, it is important to establish strategies to promote physical activity in persons with disabilities such as stroke survivors. In particular, it would be very meaningful to establish a promotion strategy for these people who are not yet feeling the need for physical activity. The LIERP is a multimodal rehabilitation intervention aimed to promote a healthy lifestyle as a secondary prevention for stroke survivors in chronic phase. The innovation of this study is that it demonstrates that low–moderate intensity physical activity improves functional capacity of stroke survivors. It is targeted to different aspects of physical condition: aerobic, task-oriented strengthening muscles involved in impaired function (sitting and standing up, climbing stairs and propulsion phase of gait) and balance in order to promote a relearning of the impaired function and transfer gains to activities of daily living. Considering physical inactivity and functional decrease after stroke,42 the modality of multimodal low–moderate intensity exercise program facilitates long term adherence, reducing sedentary lifestyle and acting as secondary prevention of stroke. In spite the fact that at six months there was a trend toward decreasing walking time, we believe that the low–moderate intensity allows personalize the intensity of exercises to fit the individual needs of the participants and promote long term adherence. This coincides with other authors who conclude that it is possible to improve recovery using multimodal interventions in chronic phase after a stroke.43 This is a wide-range exercise protocol aimed at improving upright physical mobility in people with stroke. Besides, is a very efficient group intervention in terms of personnel resources involving only one therapist who led a session with 4–6 participants.

The main limitation of the present study is the lack of a control group, as improvements at the end of the intervention could be partially due to a spontaneous recovery. For further studies, randomized trials would be required to confirm the benefits of multimodal low–moderate intensity exercise rehabilitation programs.

The sample is small due to the difficulty of recruiting participants, as they had transport difficulties to come to the rehabilitation unit on their own. This may reduce the generalizability of results. Given the difficulty of recruiting larger samples in a single center, it would be interesting for future research to conduct multicenter randomized trials and to explore the effects of multimodal exercise rehabilitation programs on QoL.

Physical activity is an important component of the rehabilitation process. Physical exercise of low–moderate intensity is associated with enhanced gait speed, walking endurance and adherence to physical activity. Exercise programs for community people who have suffered stroke and self-managed rehabilitation strategies should be implemented to maintain the gains made in rehabilitation programs and adherence to exercise programs.

No scholarships or grants have been received for this work.

Authors declare that they do not have any conflict of interests.