Context: Cognitive and physical rest are commonly utilized when managing a sport-related concussion (SRC); however, emerging research now suggests that excessive rest may negatively impact recovery. Despite current research recommendations, athletic trainers (ATs) may be behind in implementing this emerging research into clinical practice. Objective: To assess college ATs’ perceptions and implementation of an emerging SRC management approach (cognitive and physical rest and activity). Design: Cross-sectional study. Setting: Survey. Participants: A total of 122 (11.8%) ATs (53.3% female; 10.8 [9.8] y experience; 8.7 [6.9] SRCs managed annually) responded to the survey, which was randomly distributed to 1000 members of the National Athletic Trainers’ Association, as well as 31 additional ATs from varying universities. Main Outcome Measures: A 5-point Likert scale assessed the ATs’ perceptions and clinical practices as they relate to specific athlete behaviors (ie, texting, sleeping). The ATs were asked about their willingness to incorporate physical activity into clinical practice. Results: Playing video games (95.9%) and practicing (93.4%) were the activities most perceived to extend SRC recovery. However, sleeping more than usual (7.4%) and increased time in a dark environment (11.5%) were viewed as less likely to extend recovery. ATs restricted practicing (98.4%) and working out (91.8%) for athletes with SRC, while sleeping more than usual (6.6%) and increased time in a dark environment (13.1%) were less restricted. About 71% of the ATs would implement light physical activity for athletes with a symptom score of 1 to 5, 31% with scores of 6 to 10, and 15% with scores of 11 to 20. About 43%, 74%, and 97% believe that light, moderate, and vigorous physical activity, while symptomatic, will extend recovery, respectively. Conclusions: The ATs were receptive to including light physical activity into their SRC management, although only in certain situations. However, most ATs’ beliefs and clinical practices did not completely align with emerging research recommendations for the management of SRCs.