Lecture on Metabolic Health

Introduction

• Thank you to A4M for the invitation.
• Previous speaking engagement at Longevity Fest.
• Focus on three major lifestyle factors impacting metabolic health:
  • High-intensity interval training (HIIT)
  • Circadian timed eating
  • Sleep

High-Intensity Interval Training (HIIT)

Benefits

• Time-efficient way to improve:
  • Insulin sensitivity
  • Glucose homeostasis and transport
  • Mitochondrial function
  • Cardiorespiratory fitness
• Leads to decreased fat mass, improved body composition.

Research Findings

• Meta-analysis of 50 RCTs: HIIT outperforms moderate-intensity exercise in:
  • Decreasing insulin resistance
  • Improving HbA1c levels (blood glucose)
  • Lowering fasting blood glucose
• Systematic review: HIIT improves:
  • Blood pressure
  • HDL and triglycerides
  • Lowers oxidative stress
  • Enhances beta-cell function
• Increases PGC-1 alpha, a marker for mitochondrial biogenesis.

Mechanisms

• HIIT involves short bursts of intense exercise, causing muscle cells to use glucose and produce lactate.
• Lactate acts as an energy source and signaling molecule, improving glucose transport in muscles.
• Lactate-driven increase in glucose transporters lasts up to 48 hours post-exercise.

Optimal HIIT Conditions

• Duration: 8 weeks
• Frequency: At least 3 sessions/week
• Intervals: 60 seconds intense, 90 seconds recovery
• Improves body composition, with running and cycling having specific benefits.

Exercise Snacks

• Short bursts of exercise (1-2 minutes) throughout the day.
• Improve glucose regulation when done around meals.
• Associated with decreased all-cause mortality.

Circadian Timed Eating

Importance

• Align eating with circadian rhythms to optimize insulin sensitivity.
• Avoid late-night eating due to melatonin effects on insulin.

Research

• Meals given at different times show higher insulin sensitivity in the morning.
• Melatonin receptors on the pancreas influence insulin production.

Recommendations

• Stop eating 3 hours before natural bedtime.
• Avoid eating for an hour after waking.

Circadian Misalignment

• Can cause increased glucose and insulin production, decreased leptin levels.
• Time-restricted eating can help mitigate these effects.

Sleep and Metabolic Health

Effects of Sleep Restriction

• Mild sleep restriction (1-3 hours less) increases fasting insulin, decreases insulin sensitivity.
• Sleep debt can lead to glucose clearance issues similar to diabetes.

Optimal Sleep Duration

• 7-9 hours of sleep is associated with the lowest risk of type 2 diabetes.
• Less sleep increases risk for metabolic issues, such as elevated HbA1c.

Improving Sleep

• Good Sleep Hygiene:
  • Morning bright light exposure
  • Avoid blue light in the evening
  • Regular sleep schedule
  • Manage room temperature
• Sleep Extension and CBT-I:
  • Improve sleep quality and metabolic health.
  • Techniques include stimulus control and sleep restriction.

Conclusion

• Three key tools to improve metabolic health:
  • Vigorous intensity exercise (HIIT)
  • Circadian-aligned eating
  • Optimal sleep and sleep hygiene
• Exercise is a time-efficient way to enhance overall health.