Physical activity level is an important determinant of quality of life in persons post-stroke. There is a lack of knowledge regarding the effects of aerobic training on physical activity levels in subjects post-stroke. Therefore, the primary objective will be to investigate the effects of aerobic treadmill training on physical activity levels and sedentary behavior in subjects post-stroke. The secondary aim will be to investigate the effects of the training on cardiorespiratory fitness, endurance, depression, mobility, quality of life, and participation.

A randomized controlled trial with blinded assessment will assign eligible participants to either: 1) aerobic treadmill training (experimental group, at 60-80% of heart rate reserve), or 2) overground walking (control group, below 40% of heart rate reserve). Both groups will receive 40-minute training sessions three times/week over 12-weeks, in groups of 2-4 participants, by a trained physiotherapist. Primary outcomes: physical activity levels and sedentary behavior (Multisensor SenseWear Mini® and Human Activity Profile). Secondary outcomes: cardiorespiratory fitness (peak oxygen uptake (VO2peak) and ventilatory threshold), endurance, depression, mobility, quality of life, and participation. The effects of the trainings will be analyzed from the collected data and intention-to-treat analysis. Between-groups differences will be measured by two-way ANOVA with repeated measures considering the baseline, post-training, and a 4-week follow-up.

The results of this trial will likely provide valuable new information about the effects of aerobic treadmill training in improving physical activity levels and sedentary behavior, through changes in cardiorespiratory fitness, for individuals following stroke.

The sample size has been calculated considering the physical activity levels measured by the Human Activity Profile (HAP). The effect size has been derived from the study of Teixeira-Salmela et al. 1999, who performed aerobic training in addition to lower limbs resistance training, and home exercises with subjects with chronic stroke. The experimental group (n=6) showed an increase on HAP on average of 20±6.1 points after the intervention, and the control group (n=7) had an average reduction of 1.86±0.19 points. Considering a significance level of 5% and a desired power of 80%, 9 participants per group was found, or 18 participants in total. Assuming an expected dropout rate of 20%, a target of 22 participants in total was set (11 participants per group).

Statistical analyses: A code will be given to each participant. Two independent examiners, blinded to the group allocation, will perform data entry, and verify missing or apparently wrong values. Original paper forms will be kept in a secure place. Electronic files will be available only to the research team. An independent examiner, blinded to the group allocation, will perform the statistical analysis by SPSS (SPSS Inc., Chicago, IL, USA). Descriptive statistics will be performed for all outcome variables. Baseline variables will be compared between groups using independent Student's t-tests, to investigate differences among the groups regarding the clinical-demographical characteristics. If differences between the groups at baseline exist, analysis of covariance will be used to eliminate the influence of extraneous factors. The effects of the interventions will be analyzed from the collected data and the intention-to-treat analysis. Data from the last available assessment will be considered as the values of missed sessions. Between-groups differences will be measured with two-way ANOVA with repeated measures considering the baseline, post-training, and follow-up measures. Level of significance will be set at 0.05 and adjusted for multiple comparisons. Normality and equality of variance will also be analyzed to ensure correct use of parametric data. Study results will be spread regardless of the magnitude and direction of the effects.

Inclusion Criteria:

• ≥ 20years of age;
• diagnosis of stroke (>6months);
• sedentary or insufficiently active;
• have a writing medical permission to participate in the training program.

Exclusion Criteria:

• cognitive impairment (Mini-Mental Status Examination score: illiterate 13 points; elementary and middle school 18 points; and high-school 26 points; or inability to respond to verbal command);
• inability to walk independently for at least 10 minutes, with or without walking devices;
• pain or other disorders precluding their participation.