The purpose of this study is to investigate the effect of inspiratory muscle training on physical fitness in Down syndrome children. Twenty Down syndrome children from both genders ranged in age chronologically from seven to ten years will be selected to participate in this study. Selection of the study sample and evaluation of physical fitness improvement as well as Inspiratory Muscle training will be conducted in the Down Syndrome Charitable Association (DSCA), Riyadh City.

The study sample will be divided randomly into two equal groups of (A & B). All the children participated in the current study will receive 30 minutes of treatment session of aerobic exercise, group B will receive first 30 minutes of IMT then take a period time of rest about 30 minutes before starting the aerobic exercise. Exercise frequency three times per week for a period of three successive months.

The Body mass index (BMI) of each participated child will be determined by measuring weight/ Kg and height/ m2 using Electronic weight and height scale to include BMI ≥ 29 Kg/ m2 to exclude the obese children. Also using Six Minute Walk Test (6MWT) for measuring the aerobic capacity and Pulse Oxymeter for measuring pulse rate and Oxygen saturation. In addition, The Gio Digital pressure gauge will be used to assess Respiratory Muscle Strength of children by determining the Maximal Inspiratory (MIP) and Expiratory Pressure (MEP) which used to detect the inspiratory training intensity and reflect the improvement in respiratory muscle strength after training program. Brockport Physical Fitness Test (BPFT) will be used to measure physical fitness of the participated children. The participated children will be assessed before and after three successive months .

The obtained results of this study will measure Maximal Inspiratory (MIP) and Expiratory Pressure (MEP), Aerobic capacity, Musculoskeletal Function and Maximum Heart Rate (HR Max.) to determine the significant improvement of participated children

Inclusion Criteria:

• children with a body mass index (BMI) ≥ 25 kg/m2, and
• children with the ability to understand and follow verbal commands and instructions used during training and tests

Exclusion Criteria:

• with neurological, visual, or auditory defect,
• with asthma or any chronic chest diseases,
• with significant tightness or deformities in the lower limbs,
• with obesity, or
• who performed regular physical activity