Aerobic Exercise Expedites Adolescent Athlete Concussion Recovery Time

John J. Leddy, MD

Individualized aerobic exercise regimens may be beneficial to adolescents recovering from concussion symptoms, according to new trial results.

A new study from investigators at the State University of New York at Buffalo found that adolescent athletes presenting with recent sports-related concussion (SRC) symptoms benefit more from subsymptom threshold aerobics than a controlled stretching regimen. The 20-minute daily regimen, designed to elevate patient heart rate, was associated with faster mean time to recovery in the young athletes.

Symptoms from SRC can remain for up to a month in 30% of concussed children and adolescents. As exercise has been associated with exacerbated symptoms in patients still recovering from their injury, a return to normal exercise tolerance is often the clinical determinant of an athlete’s recovery.

Previous standard-of-care regimens for SRC have been prescribed rest—an approach based on animal research and consensus guidelines, investigators, led by John J. Leddy, MD, of UBMD Orthopaedics and Sports Medicine at the university, noted.

“Studies are beginning to show, however, that there is no harm and there may even be benefit of self-selected moderate levels of physical activity or prescribed aerobic exercise for those with delayed recovery, which is defined as symptoms lasting more than 2 weeks in adults or more than 4 weeks in children and adolescents,” investigators wrote.

To assess an approach they called “diametrically opposed” to the current standard of care, Leddy and colleagues assessed 103 participants across 4 outpatient concussion management clinics, randomized 1:1 to either aerobic exercise (n= 52) or placebo-like stretching (n= 51). Participants were athletes aged 13-18, with 48 (46.6%) females. Participants had presented with SRC within 10 days of their random assignment to either regimen.

The regimens both consisted of about 20-minute daily activity, with aerobic exercise thresholds established by a baseline treadmill exercise test. Participants reported daily symptoms and exercise compliance via online entry. Recovery was defined as an symptomatic report, confirmed by a physician assessment. Recovery times were defined as either normal (<30 days) or delayed (≥30 days).

Participants across both patients groups reported similar age, sex, concussion history, time from injury, symptom severity score, physical examination, and in-trial physician assessment rates. Those to perform daily aerobic exercise recovered in a median 13 days (IQR: 10-18.5). Those who only stretched daily recovered in 17 days (IQR: 13-23; P = .009).

The aerobic exercise group also reported a lower incidence of delayed recovery than the control group (4% vs 14%; P = .08), though investigators indicated this rate was insignificant. They concluded that this was the first randomized, controlled trial to show an individualized threshold aerobic exercise plan leads to speedier recovery in adolescents with recent SRC.

“The results of this study should give clinicians confidence that moderate levels of physical activity, including prescribed subsymptom threshold aerobic exercise, after the first 48 hours following SRC can safely and significantly speed recovery,” investigators wrote.

In an editorial accompanying the study, Sara P.D. Chrisman, MD, MPH, of the Center for Child Health, Behavior and Development at Seattle Children’s Research Institute, noted how Leddy and colleagues led to a shift in discussion surrounding concussion care a decade ago. It was then the team had first published a study assessing subsymptom threshold aerobic exercise in individuals with concussion symptoms lasting more than a month.

“Over the next few years, additional research contributed to a body of evidence that exercise might be both effective and safe for treating patients with persistent concussive symptoms,” Chrisman wrote.

She expressed hope that, in this “new phase of concussion management,” goals regarding recovery rapidity can become better defined. As such, follow-up studies need to establish the limits of exercise treatment for concussions.

“When is the earliest exercise can be started safely post-concussion?” Chrisman prosed. “What intensity, frequency, and duration of exercise is required to elicit a given outcome? Is it possible for individuals to exercise too frequently or too intensely, and what are the risks if this occurs?”

Most importantly, clinicians need to understand whether post-concussion exercise is equally beneficial for all patients, Chrisman said—including those with mental health comorbidities purposefully excluded from Leddy’s trial.

“We look forward to following this line of research as it propels us toward continued improvement in the management of concussion,” she concluded.

The study, "Early Subthreshold Aerobic Exercise for Sport-Related Concussion," was published online in JAMA Pediatrics.