Identification of Affective- and Social-Reinforcement Functions of Driven Exercise: Evidence From Three Samples

Driven exercise is a transdiagnostic maladaptive behavior, especially common in eating disorders (ED); however, its maintenance mechanisms remain poorly understood. To address this gap, we examined the applicability of previously empirically-derived and validated reinforcement function models in explaining driven exercise maintenance in studies varying across developmental stages and clinical presentations (Study 1: N=279 adolescents/adults oversampled for EDs; Study 2: N=118 adolescent/adult inpatients with severe EDs; Study 3: N=52 adults oversampled for athletes and/or EDs). Results supported the utility of a four-function model (automatic positive/negative reinforcement [APR/ANR; increase/decrease negative affect], social positive/negative reinforcement [SPR/SNR; engage in/avoid interpersonal situations]) in explaining driven exercise. APR was most frequently endorsed, followed by ANR, SNR, and SPR in all studies. APR correlated with last-month driven exercise episodes across studies; associations between other functions and ED psychopathology varied between studies. Further, results suggested a separate control function could be considered in samples with more severe EDs.