Metabolic Switch Fasting Protocol
Extend the overnight fast, monitor your response, and fuel demanding training.
- Difficulty
- Moderate
- Time to result
- ~weeks to results
- Steps
- 5
- Confidence
- 94%
Patrick frames intermittent fasting as two related mechanisms: a practical way to reduce calorie intake and an extended period in which the body shifts from stored liver glycogen toward greater fat use and ketone production. Her own pattern is roughly a 16-hour fast with an eight-hour eating window, usually extending the overnight fast into the morning. She sometimes pairs that state with moderate aerobic training but distinguishes a short run from a long endurance session that needs fuel. The protocol therefore starts gradually, protects total nutrient and protein intake, and uses how the person feels and performs as a decision signal. Women doing high-volume training need particular care because a severe energy deficit can disrupt reproductive hormones and menstrual function. This is a personal-practice framework discussed in the episode, not a universal medical recommendation.
Origin
Patrick explains the protocol through her own morning fasting and fasted aerobic-training routine. Extracted from The Diary of a CEO.
Core principles
- 01Extending the overnight fast can make calorie reduction simpler for some people.
- 02The timing of glycogen depletion varies with diet and physical activity.
- 03Short aerobic sessions and long endurance sessions have different fueling needs.
- 04Subjective tolerance matters, especially for women training at high volume.
- 05A fasting window must still contain enough nutrition and protein overall.
How to run it
- 1
Extend the overnight fast
Begin by delaying the first meal rather than forcing an abrupt, extreme fast. Patrick says the metabolic switch often begins after roughly 10 to 12 hours, while emphasizing that timing varies.
Pro tip Treat the clock as an estimate because prior food intake and activity alter glycogen depletion.
- 2
Set a sustainable window
Choose an eating window that can be repeated without compromising nutrition. Patrick describes a 16:8 pattern as her own practice, not as a requirement for everyone.
Pro tip Use consistency and tolerability rather than a longer-is-always-better target.
- 3
Protect meal quality
Use the meals inside the window to obtain adequate nutrients and protein. Skipping a meal should not become chronic under-fueling.
Pro tip Plan protein before compressing the eating window.
Watch out Calorie restriction without enough protein can contribute to muscle loss.
- 4
Match fasting to training
Reserve fasted training for sessions that are short enough and comfortable enough to complete well. Fuel long, intense, or high-volume endurance work rather than treating fasting as a test of discipline.
Pro tip Patrick contrasts a roughly three-mile run with a ten-mile run that she would fuel.
Watch out Poor performance or feeling terrible is a signal to eat, not to push through.
- 5
Monitor recovery signals
Watch energy, training quality, recovery, and—where relevant—menstrual regularity. Modify the eating window or add fuel if those signals worsen.
Pro tip Judge the protocol by several weeks of function, not one unusually good or bad morning.
Watch out Loss of menstrual periods can signal inadequate energy availability and warrants medical attention.
In the wild
Patrick says she commonly extends her overnight fast into the morning, eats within an eight-hour window, and performs some shorter aerobic sessions while fasted. She would not use the same approach for a ten-mile run because the longer effort requires fuel.
→ The example defines fasting as a context-sensitive routine rather than a rule applied to every workout.
Common mistakes
Assuming twelve hours is universal
Patrick explicitly says glycogen depletion varies with food composition and physical activity.
Fasting through a demanding session
Long or high-volume exercise can require fuel even when short fasted sessions feel fine.
Ignoring under-fueling signals
Feeling terrible, poor recovery, or menstrual disruption are reasons to change course rather than extend the fast.
Is it for you?
Best for
Healthy adults who prefer time-restricted eating to calorie counting and can monitor training and recovery.
Not ideal for
Pregnancy, eating disorders, under-fueling, menstrual disruption, elite training loads, or medical conditions without professional guidance.
From the episode
Anti-Aging Expert: Stop Touching Receipts Immediately! The Fast Way To Shrink Visceral Fat