es were conducted using SAS software, version 9.3 (SAS Institute Inc); all tests conducted were 2-sided, with P  < .05 indicating statistical significance. Final statistical analyses were completed on August 11, 2018. Figure. Kaplan-Meier Curves for the Cumulative Risk of Cardiovascular Disease Outcome in 5 Push-up Categories. Open in a new tab Push-up categories are by numbers of push-ups performed during baseline examination. Results Study Population A total of 1562 eligible firefighters underwent baseline examination between February 2, 2000, and November 12, 2007, and were included in the initial retrospective cohort. Mean (SD) age at baseline for all participants was 39.6 (9.2) years and the mean (SD) BMI was 28.7 (4.3). Table 1 shows the baseline characteristics of the 1104 participants for whom push-up information was available stratified by push-up capacity at baseline examination. As summarized in Table 1 , push-up capacity was found to be significantly inversely associated with most of the baseline risk factor variables that we examined (age, P  < .001; BMI, P  < .001; systolic blood pressure, P  < .001; diastolic blood pressure, P  < .001; total cholesterol level, P  = .02; low-density lipoprotein cholesterol level, P  = .04; triglycerides, P  < .001; glucose level, P  < .001; and smoking status, P  < .001), although it was significantly positively associated with the estimated V̇ o 2 max ( P  < .001). The baseline characteristics of firefighters without push-up data were similar and not statistically different from those who completed the push-up capacity evaluation on all markers of CVD risk. Table 1. Descriptive Characteristics of Study Participants With Available Push-up Data Stratified by Number of Push-ups Performed During Baseline Examination. Variable All Participants 0-10 Push-ups 11-20 Push-ups 21-30 Push-ups 31-40 Push-ups ≥41 Push-ups P Value a No. Mean (SD) No. Mean (SD) No. Mean (SD) No. Mean (SD) No. Mean (SD) No.