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.