Mrs. Mina had prepared an "invigorating medicinal wine" that was clearly very effective, or rather, too effective.
After drinking the hot brandy, Sherlock visibly perked up, truly exhibiting the "excessive energy" he always talked about but seldom seemed to display.
Ordinarily, the Supervisory Bureau's Counselor restrained his behavior with his powerful rationality, and his occasional bouts of low blood sugar made him seem quite lazy and listless.
It was a paradoxical trait that made Sherlock's release of his surplus energy look rather awkward—like some sort of sudden fit of neurosis.
On Glass Island, Sherlock was somewhat of a celebrity, and many were familiar with his habits. He enjoyed intense intellectual labor such as brain-burning cases, and wouldn't shy away from intricate or dangerous investigations either.
But he had an aversion to physical exercise, as Sherlock believed that wasting energy meaninglessly was pointless.
