All people in both groups will participate in a brief asthma education program of 90 minutes. The educational program will be conducted in a class through group discussions and video presentations. Educational topics will include asthma pathophysiology, medication and peak flowmeter use, self-monitoring of symptoms, environmental hygiene [1,26], and physical activity recommendations and benefits [17].

Patients will undergo aerobic physical training on a treadmill twice weekly for 16 sessions, totaling 8 weeks of intervention. Each AT session will last 45 minutes, divided into 5 minutes of warm-up, 35 minutes of aerobic exercise, and 5 minutes of cool-down (2 sessions per week, 45 minutes each). The intensity will be based on the heart rate (HR) corresponding to one third of the difference between the anaerobic threshold and the respiratory compensation point (RCP), and is determined by CPET [27]. After 2 weeks of adaptation, the exercise intensity will be increased to two-thirds of the difference between anaerobic threshold and RCP, obtained via the CPET. If a patient proves capable of sustaining the new training intensity uninterruptedly for 2 consecutive sessions, without presenting respiratory symptoms, the exercise intensity will be increased by 5% of the HR up to a maximum of 85% of the participant’s maximum HR [2,3]. Before and after each exercise session, patients will be asked to measure the peak expiratory flow, and if the value is less than 70% of the predicted value or if patients present important symptoms of asthma before or during training, they will be instructed to use 400 μg of salbutamol via aerosol prescribed by their physician [28].

The BI will be based on social cognitive theory and the stages of behavior change to increase the practice of physical activity in people with asthma [12,29,30]. Strategies such as motivational interviews, feedback, and guidelines to overcome barriers will be used to make it easier for participants to reach their goals. Individuals will receive a commercially available smartwatch activity monitor (Mi Band 5; Xiaomi) with an alarm that vibrates when the recommended daily number of steps is reached and if the individual remains sedentary for 60 minutes [12]. The main objective of the BI for people with asthma will be to increase PADL at any intensity and reduce sedentary time. The program will be carried out in individual sessions once a week, lasting 90 minutes each, for 8 sessions. At the beginning of the protocol, a motivational interview will identify each participant’s behavioral stage for the practice of physical activity through an appropriate questionnaire [31]. In addition, the participants will be asked to complete a daily physical activity diary and sign a contract with their health care professional [12].

Data from each week will be reviewed at every session of the behavioral intervention. Each individual will receive advice based on the smartwatch data. Each session will address different topics related to the practice of physical activity and sedentary behavior. Individuals will be motivated and encouraged to make behavioral changes. In the last session, a final motivational interview will be carried out to identify the change in the patient’s behavioral stage, taking stock of the goals reached or not, the benefits acquired with the changes made, the strategies to overcome the most significant barriers, and the establishment of new long-term goals to stay physically active. The schedule and content of each session are detailed in Table 1, which is reproduced from Freitas et al [32]. The Freitas et al [32] protocol will be modified only by changing the activity smartwatch monitor (Mi Band 5; Xiaomi) during the intervention instead of the Fitbit device [32].

Clinical asthma control will be assessed using the ACQ, a reliable and validated tool [18,33] that comprises 7 questions [18]. Of those, 5 questions are related to asthma symptoms (waking up at night, activity limitations, shortness of breath, and wheezing), one on rescue medication (short-acting β₂-agonist use), and one on lung function (FEV₁ prebronchodilator, expressed as a percentage of predicted value). The questions are indicated on a 7-point scale ranging from 0 (no limitation) to 6 (maximum limitation), and the total score is the average of the 7 items, ranging from 0 (fully controlled) to 6 (severely uncontrolled). It is considered that values ≥1.5 indicate poorly controlled asthma, 0.75 to 1.5 indicate partially controlled asthma, and ≤0.75 indicate fully controlled asthma [18]. A change of at least 0.5 points in the ACQ score is considered clinically significant [34].

PADL will be objectively assessed using an activity monitor (ActiGraph GT9X, ActiGraph), a device that monitors frequency, intensity, and duration [35] in real time and is a sensitive and reliable method [36,37]. This triaxial monitor provides measurements for the amount and intensity of PADL and posture monitoring [35,38] through variations in acceleration. The “counts” obtained during a given period are linearly related to the intensity of the patient’s physical activity in that period [37]. Patients will be instructed to use the accelerometer for 7 consecutive days on the hip secured with an elastic belt. All accelerometers will be initialized to collect data in 60-second “epochs” in the 3 axes via ActiLife software (version 6.9.5; ActiGraph). The data will be analyzed using the same software, including the number of daily steps; the time spent engaging in sedentary behavior; and light, moderate, and vigorous activities. Moderate to vigorous physical activity will also be assessed.

Health-related quality of life will be evaluated using the Asthma Quality of Life Questionnaire [39,40]. This questionnaire consists of 32 questions related to the previous 2 weeks and is divided into 4 domains: activity limitation (11 items), symptoms (12 items), emotional function (5 items), and environmental stimulus (4 items). The Asthma Quality of Life Questionnaire score ranges from 0 to 7; a higher score will be associated with better quality of life. A difference of 0.5 points is considered clinically significant [41].

Sleep quality will be assessed via a monitor (ActiGraph GT9X, ActiGraph) worn on the participant’s nondominant wrist. The participants will be instructed to wear the device for 7 consecutive nights. The results for sleep latency (the amount of time required to fall asleep) and sleep efficiency (the number of sleep minutes divided by the total number of minutes the participant was in bed) will be analyzed [8]. The device is valid and reliable for detecting sleep/wake diurnal patterns [42]. In addition, participants will receive a diary for routine analyses covering these 7 nights (time participants went to sleep, time they woke up, and went to sleep on a scale of 0-10).

Asthma exacerbation is defined as the patients’ need for urgent medical action and a change in pharmacological treatment [43]. During the study, at least one of the following criteria will be used to determine an exacerbation: the use of ≥4 puffs of rescue medication per 24 hours during a 48-hour period; the need for the administration of systemic corticosteroids (pills or injections); or unscheduled medical appointments, visits to the emergency room, or hospitalization [26,32,43].

The “readiness for change” assessment will be graded through a questionnaire to assess the following behavioral stages for physical activity: precontemplation, contemplation, preparation, action, and maintenance [31,44]. Information will be revealed as frequency.

Barriers to the practice of PADL will be assessed via a questionnaire that contains the most common barriers in adults [45,46]. The answer options for each question will include never, rarely, sometimes, almost always, and always, with the score for each item ranging from 0 to 4. Higher scores indicate greater barriers. At the end of the questionnaire, a question regarding the limitations of PADL resulting from the disease will be added, which will receive the same score as the previous questions.

Octopolar InBody 720 equipment (Biospace) will be used to measure body weight, fat mass, fat-free mass, visceral adiposity area, and skeletal muscle mass. The InBody 720 uses 8 electrodes to assess body composition according to total body water, protein, mineral, and fat mass. The contact points for the electrode connection will be cleaned with an electrolytic cloth, according to the manufacturer’s instructions. At the time of testing, the patient should not be menstruating and will also be instructed not to ingest water for 4 hours and caffeine or alcohol for 12 hours before the test, or to perform physical activity or take a sauna the day before the test, and not to urinate 30 minutes before the test. The data will be electronically imported into Excel via LookingBody 3.0 software (Biospace). Anthropometric data, including height, body weight, abdominal circumference, waist and hip circumference, and waist-to-hip ratio, will be measured according to standardized protocols [47,48]. BMI will be calculated by dividing body weight (in kg) by height (in m²) [49].

The Brazilian Portuguese version of the Hospital Anxiety and Depression Scale will be used to assess the symptoms of anxiety and depression [50]. The Hospital Anxiety and Depression Scale consists of 14 questions divided into 2 subscales: anxiety and depression (7 questions each). Each question ranges from 0 to 3 points, with a maximum score of 21 points for each subscale. In this study, a cutoff score (≥9) will be used to classify the presence or absence of anxiety or depression [51].

CPET will be performed via an electrical cycle ergometer (Corival; Lode BV Medical Technology) equipped with an electronic system (CPX System; CareFusion) [52]. Peripheral oxygen saturation (SpO₂) and electrocardiography will be continuously monitored during the tests. The following variables will be recorded: work rate, oxygen consumption (VO₂), minute ventilation, carbon dioxide production (VCO₂), respiratory exchange rate, and HR [9]. Blood pressure, leg discomfort, and dyspnea will also be monitored using the Borg scale [53]. The participants will perform the CPET, which is limited by symptoms, consisting of 2 minutes of rest, 2 minutes of warm-up (unloaded pedaling), and a period of work on a ramp (from 5 to 15 W), with increments every minute, according to the participants’ daily activity level [9]. AT will be identified as the VO₂ at which the change in the slope of the VCO₂-to-CO₂ ratio occurs. The RCP will be determined by the increased ventilation/VCO₂ values, accentuated tachypnea, and a progressive reduction in end‐tidal CO₂ pressure [9]. A 10% correction will be made in the HR at anaerobic threshold and RCP [54,55] because the test will be carried out on a bicycle, and training on a treadmill.

The test interruption criteria will include diastolic blood pressure above 140 mm Hg, sustained drop in systolic blood pressure, systolic blood pressure above 240 mm Hg, motor incoordination, feelings of imbalance, mental confusion, and clinical manifestations of respiratory distress exacerbated by increased workload or associated with electrocardiographic changes in ischemia and severe manifestations of exercise-induced bronchospasm, such as an excessive increase in ventilatory effort, audible wheezing, and signs of respiratory distress [56]. Patients will be instructed to use 400 μg of salbutamol via aerosols if necessary (peak flow, 70% predicted) [6,19,57].