Presently, fitness centers have become extensively occupied spaces. These higher-activity-level spaces require different thermal comfort parameters than other indoor environments. Therefore, it is crucial to provide the comfort that users need during their physical exercise. Human body during exercise requires different thermal comfort conditions and higher fresh air supply rates than sedentary activities. The standards for fitness centers do not provide specialized thermal and spatial instructions for the fitness spaces. This thesis focuses on investigating the thermal and spatial conditions of exercise spaces. To determine ideal exercise space conditions, a thermal and flow analysis involving experiments and 3D simulations in a computer environment were employed. The study specifically examined spatial factors such as ceiling height, lateral and frontal distances between machines, and vent locations, along with thermal factors like inlet temperature and air velocity. A thirty-minute constant work rate exercise test at moderate intensity was conducted in a controlled climatic chamber with six participants. The experiment's conditions were replicated and verified in CFD software using the collected data. Then, computational models for various environmental and spatial scenarios for a five-person cycling class were generated. Employing the L9 orthogonal arrays method, nine spatial scenarios with three thermal operations were simulated. Optimal factor levels were determined based on thermal comfort conditions by predicted mean vote (PMV) around the thermal plumes. The findings indicated that a ceiling height of 5m, lateral and frontal distances of 1m and 0.5m between machines, and ventilation strategy with ceiling located inlets at a condition of 18°C and 0.2m·s-1 performed optimal results.