Insulin 101: What Every Endurance Athlete Needs to Know

The Athlete's Compass

In this insightful episode, hosts Paul Warloski, Dr. Paul Laursen, and Marjaana Rakai break down the crucial topic of insulin sensitivity and resistance—a metabolic issue that affects not just people with diabetes but endurance athletes too. They explore how insulin works in the body, how chronic exposure to sugar can lead to insulin resistance, and why even fit athletes can suffer from poor metabolic health. Drawing from personal experience, science, and practical tips, they discuss how dietary choices, strength training, stress, and lifestyle all shape our insulin response. Importantly, they offer actionable advice for athletes who want to optimize performance, avoid midsection weight gain, and stay metabolically healthy as they age.

Key Takeaways

• Insulin is essential for moving glucose into muscle and fat cells but becomes problematic when chronically elevated.
• Advanced Glycation End Products (AGEs) from persistent high glucose contribute to aging and health decline.
• You can't outrun a bad diet—even fit athletes can become metabolically unhealthy with excessive sugar intake.
• Insulin sensitivity declines with age, high stress, or sugar-heavy diets, but can be reversed.
• Strength training and endurance training increase insulin sensitivity by increasing muscle mass and GLUT4 activity.
• Common signs of insulin resistance: stubborn fat, reduced performance, fatigue, poor sleep, and high blood pressure.
• Fasted training and reducing sugar can restore insulin sensitivity and boost fat metabolism.
• Lifestyle plays a huge role: stress and processed foods drive insulin resistance, especially in aging athletes.

• Paul Warloski - Endurance, Strength Training, Yoga
• Marjaana Rakai - Tired Mom Runs - Where fitness meets motherhood.