Speed is not the same as efficiency — a distinction that 18th-century Scottish physician John Brown spent his career arguing about medicine, and that quietly ruins most people's approach to fast training sessions. Brown's 'Brunonian' framework held that the body has a fixed 'excitability' that can be depleted or squandered; flood the system too fast, and you burn through the resource without converting it into adaptation. The insight has been largely retired from medicine, but the underlying logic maps cleanly onto what exercise physiologist Jaak Panksepp's neuroscience of arousal later confirmed: short training windows work not because they compress the same stimulus into less time, but because they operate in a distinct physiological register — higher neural drive, tighter motor unit recruitment, zero accumulated fatigue diluting the signal. The mistake most people make with brief workouts is treating them as truncated versions of longer ones: same exercise selection, same tempo, same rest, just fewer sets. That's not a short workout. It's an interrupted long one. The same logic applies to how you brief your staff and how you run a preflight — a five-minute interaction done with full intention is a different category of event than a twenty-minute meeting done at half-attention. Speed is a design choice, not a default.

When did you last design a short session from scratch — choosing every element specifically because it fits a tight window — rather than cutting an existing routine down?

Drawing from 18th-Century Scottish Medicine (Brunonian System) synthesized with Affective Neuroscience — John Brown (Elementa Medicinae, 1780) and Jaak Panksepp (Affective Neuroscience, 1998)