Cerebral palsy (CP) is a group of eternal movement disorders caused by non-progressive disturbances in the developing brain. These disorders lead to significant motor impairments and activity limitations. Individuals with CP often experience reduced cardiopulmonary endurance, which is the ability of the cardiovascular and respiratory systems to supply oxygen to the muscles during sustained physical activity. This reduction in endurance can be attributed to several factors, including decreased muscle strength, poor aerobic capacity, and increased energy expenditure during daily activities 1.

Children with cerebral palsy (CP) are often presented with reduced physical fitness and endurance levels and frequently experience limitations in their ability to engage in physical activities, which can further exacerbate their health issues and overall quality of life 2.

Aerobic exercise, defined as any sustained physical activity that elevates heart rate and promotes cardiovascular fitness, enhances cardiopulmonary endurance in various populations, including those with disabilities. For individuals with CP, engaging in regular aerobic exercise can lead to improvements in several key areas: increased oxygen uptake, enhanced muscle efficiency, and improved overall physical fitness. These benefits are crucial, as individuals with CP are at a higher risk for developing secondary health issues, such as obesity, cardiovascular diseases, and decreased quality of life due to sedentary behaviour 3.

Research indicates that structured aerobic training can significantly improve the aerobic capacity of children and adolescents with CP. Studies have demonstrated that such training not only enhances cardiopulmonary endurance but also positively impacts walking speed, functional mobility, and overall physical activity levels. Furthermore, aerobic exercise can help mitigate the effects of Deconditioning that often accompany inactivity, thereby breaking the cycle of disability and promoting a more active lifestyle 4.

Incorporating aerobic exercise into rehabilitation programs for individuals with CP is essential for fostering long-term health benefits. By improving cardiopulmonary endurance, aerobic training can enhance the ability to perform daily activities, increase participation in recreational and social activities, and ultimately contribute to a better quality of life. As such, understanding the role of aerobic exercise in this population is vital for developing effective interventions that support their physical and emotional well-being 5.

Children with CP have a decreased level of daily physical activity in comparison with their healthy peers 6. They need to train almost 2.5 hours a day to reach the same level of daily physical activity as their healthy peers 7.

Many children, adolescents, and adults with cerebral palsy have reduced cardiopulmonary endurance (the capacity of the body to perform physical activity that depends mainly on the aerobic or oxygen-requiring energy systems), muscle strength, and habitual physical activity participation 8, 9, 10, 11, 12, 13, 14, 15. Reduced cardiopulmonary endurance and muscular weakness both pose significant risks for negative health outcomes and early, cardiovascular- and all-cause mortality 16, 17, 18, 19. People with CP have lower levels of health-related fitness (muscle strength and cardio-respiratory

endurance) and reduced levels of physical activity, they are at higher risk for developing metabolic and cardiovascular diseases.

Aerobic fitness may be defined as the ability to deliver oxygen to the muscles to generate energy during exercise 20. It is any activity that increases the heart rate or proposes to increase heart rate to exact physiological change. The benefits of aerobic exercise for people with disabilities include increased cardiovascular capacity and endurance, weight management and lower blood lipid levels, preservation of bone mass and overall maintenance of function 21.

The study explores the effects of aerobic exercise on improving cardio-respiratory endurance in children with cerebral palsy (CP). This study aims to determine the potential benefits of aerobic training on various parameters, including walking speed, distance covered in a 6-minute walk test, heart rate, and energy expenditure index. The primary objective of this research is to assess the effectiveness of a structured aerobic exercise program when combined with conventional physiotherapy. The authors hypothesized that the combined training group would exhibit better improvements in the outcomes than the conventional training.

The study employed a two-group experimental pre-test post-test design to evaluate the effects of aerobic exercise on cardio-respiratory endurance in children with cerebral palsy (CP). A total of 32 children, aged 4 to 14 years, diagnosed with CP at Gross Motor Function Classification System (GMFCS) levels I and II, were recruited from the private clinics of Bhubaneswar Odisha. Participants were selected based on specific inclusion and exclusion criteria, ensuring they had normal or near-normal cognitive function and the ability to walk continuously for six minutes. Children of both genders aged between 4-14 years were included in the study. Similarly, any form of orthopedic or neurosurgery and botulinum toxin injection in the past six months were excluded from the study. Additionally, any form

of respiratory or cardiac causes that would affect regular physical activity and children with any intellectual problems are also excluded from the participation.

The intervention lasted six weeks, during which both groups received conventional physiotherapy. The experimental group additionally participated in structured aerobic exercises five days a week. Key outcome measures included the 6-minute walk test (6MWT), walking speed, heart rate, and energy expenditure index (EEI), which were assessed before and after the intervention.

A two-group experimental pre-test & post-test study design was used.

A total of 32 children were recruited from local clinics from Bhubaneswar according to the inclusion and exclusion criteria.

6 weeks.

The study was conducted according to the declaration of Helsinski for experiment in human subjects. A written and informed consent was obtained from all the participants prior to the inclusion in the study.

By convenience sampling, the subjects were selected from the CP population according to the inclusion and exclusion criteria and were randomly assigned to 2 different treatment groups after getting the consent from the parents/caregivers.

Children diagnosed with cerebral palsy (Spastic Hemiplegic/Dieplegic/Triplegic/Tetraplegic) with GMFCS level I & II of either sex are aged between 4-14 years with normal or near normal cognitive function with the ability to walk continuously at the best for 6 minutes.

No orthopaedic or neurosurgery should have been done and botulinum toxin injection should not have been administered within last 6 months. Any cardiac or respiratory conditions should be excluded that could negatively affect the proposed training. The subject should be free of intellectual problems that can influence their participation.

6 minute walk test (6MWT), Walking speed calculated on the basis of 6MWD, heart rate, Energy expenditure index (EEI).

After meeting the inclusion and exclusion criteria through an assessment performa, informed consent was taken from the parents/caregivers of the subjects and then were randomly allocated to either of the two groups. 32 children (Spastic Hemiplegic/Dieplegic/Triplegic/Tetraplegic) met the criteria; 16 were allocated to the experimental group (mean age of 9.44 ± 2. 851; 7 females and 9 males) and 16 were allocated in the conventional group (mean age of 8.56 ± 3.444; 9 females and 7 males) using the block randomisation method. Two blinded raters performed the randomization and the outcome assessment.

All the participants underwent an initial baseline assessment of heart rate, distance covered in a 6-minute walk test, walking speed calculated based on 6MWD & energy expenditure index. Both the groups received conventional physiotherapy. The experimental group, in addition, received Aerobic exercises. The intervention period was 6 weeks, 5 days/week. After completion of 6 weeks, all participants received a follow up assessment.

The children are trained for 21 minutes in the 1st & 2nd week, 30 minutes in the 3rd & 4th week and 45 minutes in the 5th & 6th week (excluding warm-up and cool-down sessions); 5 days a week for 6 weeks, which means the intensity & duration was gradually increased over time. The training consisted of a form of circuit training with three workstations (Figure 1).

Warm up period consisted of stretching exercises, AROM exercises of all joints and free walking on a flat surface.

There were three stations-

The cool down period consisted of breathing exercises and stretching exercises.

There was a period of 2 minutes rest before moving on to the next station. A group consists of a maximum of 4 children. The therapist was always along with the children to instruct, guide & encourage them. During the 6 weeks of the study period, the children continued with their normal therapy program.

Statistical analysis was performed using SPSS version 23.0. The dependent variables were analyzed using repeated measures ANOVA. There was one between factors (groups) with two levels (groups: aerobic exercises and conventional therapy alone) and one within factors (time) with two levels (pre-test and post-test). All pair wise post-hoc comparisons were analyzed using a 0.05 level of significance.