A concussion should be treated with prolonged complete physical and mental rest until every symptom disappears.

Rest seemed like the safest possible prescription after a concussion. If exertion could worsen headache, dizziness, or cognitive symptoms—and a second head impact posed obvious danger—then eliminating physical exercise, schoolwork, screens, reading, and other stimulation until symptoms vanished appeared cautious. This sometimes hardened into “cocooning”: days or longer in a dark, quiet environment.

The evidence did not support indefinite inactivity. Trials comparing prolonged strict rest with shorter rest followed by graded activity found no recovery advantage and, in some cases, more symptoms and slower return to normal life. Rehabilitation research also showed that carefully controlled aerobic activity can be useful once the brief acute-rest period has passed. Guidance consequently shifted toward relative rather than complete rest, followed by progressive activity that stays below a level that substantially worsens symptoms.

The correction is not permission to ignore a concussion. Immediate removal from collision risk remains essential, and return to school, exercise, and especially contact sport should proceed in stages guided by symptoms and appropriate clinical advice.