Sex Differences in Response to Low- Versus High-Volume Aerobic Exercise for Sport-Related Concussion: A Pilot Randomized Controlled Trial.

This was a pilot trial, so it was too small to prove which exercise volume is better. Only 5 females were in the low-volume group and 6 were in the high-volume group, so the female recovery finding rests on very few participants. Several participants were lost to follow-up or did not provide exercise data, so the actual dose received is uncertain. Participants and research assistants knew which exercise volume was assigned, so symptom reporting and adherence may have been influenced. The motivation and competence questionnaires were modified for this study, which may affect their accuracy. Orthostatic intolerance was not measured, so autonomic dysfunction such as POTS cannot be ruled out as a reason females stopped exercise. Results apply only to adolescent athletes with sport-related concussion within 10 days of injury, not to other ages or injury types. The trial compared only two fixed exercise volumes at 90% of the heart-rate threshold, not lower intensity or longer duration options.

The authors declared no relevant conflicts of interest. The supplied publication types indicate NIH extramural research support.

Do not conclude that high-volume aerobic exercise is harmful for females after concussion. The recovery difference was not proven, the study was a small pilot, and many participants did not provide complete exercise data.