Cardiorespiratory and Metabolic Responses to Daily Activities in Children: Examining Sex Differences and Weight Categories

Abstract

Aim: This study examined cardiorespiratory and metabolic responses to activities (supine rest, sitting, standing and walking) in children aged 6–12 years with normal weight, overweight and obesity, focusing on sex-specific differences. Overweight and obesity were categorised per World Health Organization criteria, emphasising their global health impact. Methods: Eighty-four children were classified by weight status and assessed for heart rate (HR), breathing frequency (BF), minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), resting energy expenditure (REE) and metabolic equivalents (METs) during each activity. Statistical analyses compared responses across weight and sex groups. Results: HR, BF and VE increased with activity intensity in all groups. Boys with overweight and boys with obesity had significantly higher HR than boys with normal weight, reflecting greater cardiac strain. VO2 and VCO2 were elevated in children with obesity, particularly girls, indicating increased metabolic demands. Boys with overweight and boys with obesity exhibited higher VE/VO2 and VE/VCO2 ratios during low-intensity activities, reflecting reduced ventilatory efficiency. Conclusion: Strategies targeting respiratory and metabolic efficiency, including muscle strengthening and endurance exercises, are crucial for mitigating obesity-related strain, particularly in girls. These findings highlight the need for tailored, sex-specific interventions to address obesity in children.