Objective·To explore the correlation between body compositions and cardiovascular fitness(CRF)in patients with coronary heart disease(CHD).Methods·The CHD patients(CHD group)who underwent elective percutaneous coronary intervention treatment at Renji Hospital,Shanghai Jiao Tong University School of Medicine from October 2022 to June 2023 as well as healthy people(control group)were selected.All the participants completed cardiopulmonary exercise testing(CPET)to determine CRF and bioelectrical impedance analysis(BIA)to determine body compositions on the same day.Results·A total of 191 patients with coronary heart disease and 188 healthy individuals were included.There was no statistically significant difference in baseline characteristics between the two groups.Compared with the control group,the CRF indicators of the CHD group were significantly reduced(all P<0.05).In terms of body composition indicators,the trunk muscle mass(TMM)of the CHD group was significantly lower than that of the control group(P<0.01),and the trunk fat mass(TFM)was significantly higher than that of the control group(P<0.01).Correlation analysis showed that TMM(R=0.538),lower limbs muscle mass(LMM)(R=0.754),and lower limbs fat mass(LFM)(R=0.593)were positively correlated with peak oxygen uptake per kilogram of bodyweight(VO2peak/kg)in the CHD group(all P<0.01),while TFM(R=-0.563)was negatively correlated with VO2peak/kg(P<0.01).There was no statistically significant correlation between other body composition indicators and VO2peak/kg.According to VO2peak/kg,the CHD patients were divided into low CRF group,medium CRF group,and high CRF group.The results showed that there were statistically significant differences in LMM,TMM,LFM,and TFM among the three groups of patients(all P<0.05).Multiple linear regression analysis suggested that age,gender,TMM,TFM,LMM,and LFM were related factors of VO2peak/kg in the patients with CHD.The VO2peak/kg of CHD patients increased with the increase of TMM,LMM,and LFM and the decrease of age and TFM;the female patients had lower VO2peak/kg compared to the males.Conclusion·The CRF of CHD patients is significantly lower than that of the healthy population,with higher TFM and lower TMM;in the CHD patients,CRF is negatively correlated with TFM and positively correlated with TMM,LMM,and LFM.