1. Start by measuring the vital capacity using a balloon to determine. The width of the balloon diameter for each blow and used the value to make a balloon size control device to give to the sample group and parents to use it for home training.
2. Participant sit on a chair. Inhale fully through their nose and hold for a full 3 second inhalation, then exhale through their mouth into the balloon fully. By having the balloon inflate until their touch the balloon size control device and hold the exhalation period for 1 second, cover the balloon immediately with your fingers count as 1 breath cycle, then replace the balloon immediately. Do this for 3 consecutive rounds, counted as 1 set, in each training, do a total of 3 sets, rest between sets for 1 minute, which takes about 15 minutes, 5 times per week for 8 weeks

Participants sitting in a chair, back and head close to the wall. Inhale through their nose fully and hold for 3 seconds for a full breath, then slowly exhale through their mouth and hold for 1 second of exhalation, counted as 1 breathing cycle.Do this 3 times in a row for 1 set. Practice each time doing a total of 3 sets, with 1 minute rest between sets. Participants were required to complete breathing exercise 5 times per week for 8 weeks.

Participant sit on a chair. Inhale fully through their nose and hold for a full 3 second inhalation, then exhale through their mouth into the balloon fully. By having the balloon inflate until their touch the balloon size control device and hold the exhalation period for 1 second, cover the balloon immediately with your fingers count as 1 breath cycle, then replace the balloon immediately. Do this for 3 consecutive rounds, counted as 1 set, in each training, do a total of 3 sets, rest between sets for 1 minute, which takes about 15 minutes, 5 times per week for 8 weeks

Respiratory muscle strength was assessed by measuring Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP) in cmH2O. The participants were in a sitting position using a portable handheld mouth pressure meter (i.e., MicroRPM) with a nose clip. For the MIP measurement, the participants were asked to exhale until they felt no air remaining in their lungs (starting with the functional residual capacity [FRC] point), then held the device on their mouth and inhaled forcefully for 1-2 seconds. For the MEP measurement, the participants were asked to inhale until their lungs were completely filled with air (starting with the total lung capacity [TLC] point), then they kept the device on their mouth and exhaled forcefully for 1-2 seconds.

Asthma control was measured by Childhood Asthma Control Test (C - ACT) questionnaire. The range of C-ACT scores is 0 to 27 (27 = totally controlled, 20-26 = well controlled, <26 = insufficiently controlled)

FVC is the total volume of air that can be exhaled during a maximal forced expiration effort. The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. FVC is measured in liters.