A fast isn't one long timer - it's six distinct metabolic stages, each with its own physiology and its own best use of the time. FastFlow maps your live biometrics onto these stages so you always know where you are and what to do.
Digesting; insulin high, glucose is fuel. The easy setup stage.
Insulin falls; your body burns stored glycogen - mostly overnight.
The metabolic switch; first ketones and a passing hunger wave.
Ketosis; fat is primary fuel and mental clarity peaks.
Autophagy ramps up; conserve energy and stay gentle.
Deep autophagy and regeneration; rest is the work.
Connect your Garmin or Apple Watch and FastFlow shows the stage you're in right now - driven by your real heart rate, HRV, Body Battery and stress.
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