Pain acceptance, measured by the chronic pain acceptance questionnaire (CPAQ), is related to exercise adherence for those with arthritis. The CPAQ measure has 20 items comprising two subscales -- pain willingness and activities engagement about pursuing “valued daily activities” despite pain. However, exercise is not specified as a valued activity and respondents may be considering other activities raising generalizability and strength of prediction concerns.Accordingly, a modified CPAQ solely for exercise (CPAQ-E) was developed to heighten salience to pursuit of exercise in the face of pain. An exercising sample with arthritis (N=98) completed the CPAQ-E at baseline and exercise 2 weeks later. Exploratory factor analysis of the CPAQ-E was performed using Mplus. Regression was used to predict exercise.Analysis revealed a two-factor, 14 item model with good psychometric properties reflecting pain willingness and activities engagement subscales (χ2=85.695, df=64, p<.037; RMSEA=.055; CFI=.967; TLI=.954). Both subscales and the total score positively predicted future weekly exercise bouts (range ps from <.05 to <.001). Activities engagement predicted future weekly exercise volume (p<.05).This study offers preliminary support for the factorial and predictive validity of the CPAQ-E among exercising individuals with arthritis.This measure could help researchers increase the specificity and sensitivity of pain acceptance responses to exercising among individuals with arthritis. A more sensitive measure might help clinicians interpret patient responses to exercise for pain self-management.