Exercise following a sport induced concussion.

OBJECTIVE To determine if an athlete's capacity to perform exercise is impaired following concussion and whether this would be reflected by an altered heart rate response. METHODS Of the 14 concussed athletes, nine missed playing time as a direct result of their concussion and five did not. The concussed athletes performed an exercise protocol on a cycle ergometer within 72 hours of being asymptomatic at rest and a second test at 5 days following the previous assessment. Matched controls (n = 14) were tested using the same time line. The exercise protocol consisted of a 2 minute warm up, 10 minute, low-moderate intensity, steady state exercise session, and a high intensity interval protocol. The interval protocol consisted of a 40 second high intensity bout, followed by a 40 second rest period. This protocol continued until the participant had reached volitional fatigue. RESULTS The number of exercise bouts completed was not significantly different from their matched controls. However, concussed athletes who missed playing time had a significantly higher heart rate during the steady state exercise session. During this same period, they also exhibited a greater rise in heart rate over time. CONCLUSION These findings indicate that exercise capacity is unaffected in concussed athletes who are asymptomatic at rest. However, their heart rate response to submaximal exercise is increased.