Eight sprints of 20 seconds, each followed by a full minute of walking. The warmup and cooldown run two minutes apiece — sprinting cold is asking for a pulled hamstring — and the session totals 13:40.
The lopsided ratio is deliberate. True top-speed running, riding, or rowing can’t be repeated on short rest — quality collapses and you end up doing tempo work instead. Three parts recovery to one part work keeps every rep genuinely fast. Take this to a track or hill, or onto a bike or rower, and once eight quality reps come easily, open the preset in the editor and shorten the walks.
Even work and rest. Ten rounds of 0:30 hard, 0:30 easy. A reliable cardio base session for any movement.
Six rounds of 1:00 hard with 0:30 active recovery. Sustained efforts for engine-building.