Youth sport participation can positively predict adult physical activity. In young adults, fitness gains help motivate exercise behaviors and enjoyment facilitates sport participation. CrossFit (CF), a high-intensity group-based exercise program that has recently surged in popularity, offers a competitive, community environment. PURPOSE: To determine if past youth sport experience differentially affected adherence to, fitness improvements from, and enjoyment of CF. METHODS: Data were from a 12-month program evaluation at a university CF gym with assessments at baseline, 2-, 6-, and 12-months. The 88 participants enrolled at baseline were ages 18-66 (M=30±11), 52.8% female, and 89.8% white; all but two had some college education. Participation was tracked over time. Strength was assessed at each time point through 1-rep max squat, press, and deadlift, which were summed for a “CrossFit Total” (CFT). At baseline and 6-months, participants rated how they felt at the moment about doing CF from 1=“I hate it” to 7=“I enjoy it.” At 2-months, participants indicated their past sport participation as none, through 8th grade, in grades 9-12, or both. Using SPSS, one-way ANOVAs with sport participation as the independent variable were used to examine between-group differences for each outcome variable. RESULTS: Fifteen participants (17%) dropped out of CF after baseline, eight (9.1%) after two-months, four (4.5%) after six-months, and six (6.8%) discontinued the study, but continued CF. Changes in CFT ranged from -20 to 146lb (M=33.8±45.1), and changes in enjoyment ranged from -1 to +3 (M=-0.1±0.7). Sports participation included none (n=17), through 8th grade (n=5), grades 9-12 (n=7), and both time periods (n=31). No significant differences were found between sport participation groups for length of adherence to CF, ƒ(3,53)=0.774, p=.51; change in CFT, ƒ(3,48)=1.235, p=.31; or change in CF enjoyment, ƒ(3,25)=1.922, p=.15. CONCLUSION: Unlike previous research, youth sport participation did not predict continued participation in CF, changes in strength or enjoyment. Although a group exercise program, CF also has aspects of sports (e.g., affiliation, challenge, competition) and thus may be able to address multiple exercise motivations, regardless of previous sport participation.