physiology
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High-intensity interval session — 0 seconds

Follow a representative body through three short maximal efforts and the half hour around them.

Representative model
Change event
Representative whole-body physiology diagramActive organs become brighter as the timeline moves.

Interactive 3D is loading into this same frame contract.

Time elapsed

00:00:00
  • Before the first effort · 00:00:00
  • First effort complete · 00:00:30
  • Between the first and second effort · 00:04:30
  • Second effort complete · 00:05:00
  • Between the second and third effort · 00:09:00
  • Third effort complete · 00:09:30
  • Recovery underway · 00:20:00
  • Teaching window complete · 00:30:00
Happening now

The representative body is at rest; breathing, blood glucose and fuel mix are near their resting pattern.

Explore the mechanism The effort starts

Within the first seconds, muscle draws on stored phosphocreatine and breaks down glycogen quickly, because oxygen delivery has not yet had time to rise.

Evidence for this step

At the start of a maximal effort, working muscle typically draws on stored phosphocreatine and on rapid breakdown of muscle glycogen, because those pathways supply energy faster than oxygen delivery can rise. moderate · View sources

Time: 0 seconds. Milestone: Before the first effort. Active anatomy: Bloodstream, Liver. Metrics: Breathing rate: typically between 12 and 16 breaths/min; Blood glucose: typically between 75 and 95 mg/dL; Blood oxygen saturation: typically between 0.96 and 0.99 of 1
  • Whole-body context: 0%
  • Working skeletal muscle: 10%
  • Left lung: 12%
  • Right lung: 12%
  • Bloodstream: 15%
  • Liver: 15%