Autism Spectrum Disorder (ASD) is a developmental condition that impacts a child's ability to communicate and interact socially, often accompanied by repetitive behaviors and unique patterns of activity. In addition to these core characteristics, children with ASD frequently exhibit lower levels of physical fitness and are at risk for a range of health concerns, including compromised cardiovascular health and reduced respiratory function. These physical limitations can contribute to broader health disparities and reduced quality of life. Regular physical activity is increasingly recognized as an important element in managing these challenges, offering benefits that extend beyond physical health to improve social skills, behavior, and overall well-being. However, understanding which types of physical activity can most effectively enhance cardiorespiratory fitness and respiratory performance in children with ASD remains a developing field. Examining the effects of structured exercise programs, such as circuit training, can provide valuable insights into optimizing fitness strategies that cater to the unique needs of children on the autism spectrum. The objective of study is to determine the effects of circuit aerobic training and circuit resistance training on cardiorespiratory fitness, cardiovascular responses, and peak expiratory flow rate in Autistic spectrum disorder children It is a randomized clinical trial. A consecutive sampling technique will be used to recruit the ASD children for the study. Then, they will be divided into two groups by simple random sampling through sealed opaque enveloped. Hand Grip Exercise will be given as baseline treatment. In group A patients will be given with circuit aerobic training while in group B patients will be given with circuit resistance training. The 6-minute walk test will be used to assess cardiorespiratory fitness (VO2 max), peak expiratory flow meter will be used to check peak expiratory flow rate (PEFR), and digital sphygmomanometer will be used to check cardiovascular response. Data will be entered and analyzed through SPSS version 21.