Eur. Phys. J. Plus (2025) 140: 1202
https://doi.org/10.1140/epjp/s13360-025-07140-z

Regular Article

Assessment of volume flow rate, real-time temperature, and CO₂ distribution in a sports club based on exercisers’ movement patterns with the approach of improving energy consumption

¹ College of Engineering, Department of Mechanical Engineering, Najran University, P.O Box 1988, King Abdulaziz Road, Najran, Saudi Arabia
² College of Engineering, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
³ Department of Civil Engineering, College of Engineering, Cihan University-Erbil, Erbil, Iraq
⁴ Department of Mechanical Engineering, College of Engineering and Computer Sciences, Jazan University, 45112, Jazan, Saudi Arabia
⁵ Physics Department, Faculty of Science, Islamic University of Madinah, P. O. Box: 170, Madinah 42351, Saudi Arabia
⁶ Faculty of Data Science and Information Technology, INTI International University, Persiaran Perdana BBN, Putra Nilai, 71800, Nilai, Malaysia
⁷ Independent Researcher, Mechanical Engineering, Doha, Qatar

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Received: 5 October 2025
Accepted: 29 November 2025
Published online: 13 December 2025

Abstract

This study investigates the real-time impact of varying exercise intensity and movement patterns on indoor air quality, thermal conditions, and ventilation demands in a fitness center. It focuses on the dynamic distribution of CO₂, temperature, and relative humidity in relation to metabolic activity and airflow efficiency. A controlled experimental setup with ten male athletes performing eight distinct exercise protocols was employed to quantify environmental responses. Despite growing awareness of indoor air quality in sports facilities, there remains a critical gap in real-time, spatially resolved data linking specific exercise intensities and sequences to CO₂ accumulation, thermal load, and humidity distribution. The study quantifies CO₂ generation per individual across a wide MET range (2.3–10.0) and validates these against established models. It also introduces spatial heat mapping to identify airflow-deficient zones, providing actionable insights for HVAC design. The results show that CO₂ concentrations increased by 58% during high-intensity exercises (Type 4, 10.0 METs) compared to baseline, peaking at 10:20 a.m. with a maximum indoor concentration rise of 40–50% above initial levels. A qualitative warming trend was observed during exercise, with a measured temperature increase of up to ~ 2.3 °C; however, as this value lies within the measurement uncertainty of the sensors, the precise magnitude should be interpreted with caution. The central sensor area reached 23.5 °C, while the western sensor location showed a 15% higher thermal retention. Relative humidity increased by 15–20%, with localized peaks of 78% in high-activity zones. Spatial analysis revealed that CO₂ at the west-corner sensor was about 25% higher than the room average and decayed more slowly after exercise, indicating a localized zone of weaker air mixing. Combined exercise sequences (Types 2–4) generated 33% higher CO₂ levels than isolated workouts, demonstrating a compounding metabolic effect. The required volumetric airflow rate peaked at 2000 m³/h for Type 4 exercises, representing an eightfold to 16-fold increase over sedentary ventilation needs (30.58 m³/h). Post-exercise, CO₂ levels decreased by 15–20% within 5 min due to infiltration, with faster recovery near ventilation points. These findings confirm that athlete movement patterns and exercise sequencing significantly influence indoor environmental quality, necessitating demand-controlled ventilation systems tailored to real-time metabolic load and spatial airflow dynamics.