What Is Insulin and Why Is It Important for Athletes?
Insulin is a hormone produced by the pancreas whose main task is to transport glucose from the blood into cells. However, insulin is also the strongest anabolic hormone in the body — it promotes protein synthesis, glycogen storage and inhibits muscle breakdown.
📊 Glycemic Index and Glycemic Load
| Product Category | GI (glycemic index) | Examples | When to take? |
|---|---|---|---|
| Low GI (≤55) | Slow glucose release | Oats, buckwheat, lentils, apples, nuts | Daily, main meals |
| Medium GI (56-69) | Average speed | Basmati rice, bananas, whole-grain bread | 2-3 h before training |
| High GI (≥70) | Rapid glucose spike | White bread, white rice, mashed potatoes, glucose | Immediately after training |
🎯 Carbohydrate Timing Strategy (Nutrient Timing)
⏰ Before Training (1-2 h)
30-50 g of slow carbohydrates (oats, bread). The goal is to ensure a stable energy level without an insulin spike, which can cause hypoglycemia (“sugar crash”) during training.
🏋️ During training (if >90 min.)
30-60 g of fast carbohydrates per hour (sports drink, banana). Supports glycogen stores and prevents glucose levels from falling too low.
⚡ Immediately After Training (0-30 min.)
40-80 g of fast carbohydrates + 20-30 g of protein. This is the so-called “anabolic window” — insulin together with amino acids maximally promotes muscle recovery.
🌙 Evening / Rest Days
Reduce carbohydrates. High insulin levels in the evening can interfere with growth hormone secretion during sleep.
🔄 Increasing Insulin Sensitivity
Insulin sensitivity is the ability of cells to respond effectively to insulin. Higher sensitivity = less insulin is needed to transport the same amount of glucose. This is critically important for both health and body composition.
- Strength training: A single workout increases insulin sensitivity for up to 48 hours. Muscles “pump” glucose more efficiently after exercise.
- Walking after a meal: 10-15 min. of light walking after a meal reduces the glucose spike. One of the simplest and most effective habits.
- Intermittent fasting (IF): The 16/8 protocol can increase insulin sensitivity in 4-8 weeks.
- Sleep: One night with 4-5 hours of sleep reduces insulin sensitivity! Sleep deprivation is one of the main risk factors for insulin resistance.
- Fiber: Soluble fiber (oats, legumes, apples) slows glucose absorption and reduces the insulin response.
💊 Supplements for Insulin Sensitivity
| Supplement | Dose | Effect |
|---|---|---|
| Berberine | 500 mg 2-3x before meals | A powerful natural insulin sensitivity enhancer. Comparable in effectiveness to metformin. |
| Chromium (picolinate) | 200-400 mcg/day | An essential mineral for insulin signaling. Chromium deficiency worsens glycemic control. |
| Cinnamon (Ceylon) | 1-3 g/day (extract) | Mimics insulin action, slows gastric emptying after a meal. |
| Alpha-lipoic acid (ALA) | 300-600 mg before a carbohydrate meal | An antioxidant that increases GLUT4 receptor translocation — helps glucose enter muscles. |
| Magnesium | 300-400 mg/day | Magnesium deficiency is directly linked to insulin resistance. |
🛒 Recommended Products
⚠️ Signs That You Have Insulin Resistance
- Fatigue after meals: If you feel sleepy after a carbohydrate-rich meal — this is a classic sign of an insulin spike.
- Difficulty losing weight: High insulin levels block fat burning. The body is “locked” in storage mode.
- Constant hunger: Especially a craving for sweets and carbohydrates 1-2 hours after a meal.
- Dark patches on the skin (acanthosis nigricans): Dark, velvety skin areas on the neck and in the armpits — a serious sign of insulin resistance.
- Waist circumference: 🏋️ During training (if >88 cm is an indicator of increased risk.
❓ Frequently Asked Questions
How Many Carbohydrates Does an Athlete Need?
It depends on the sport and training volume. On average: 3-5 g/kg of body weight for moderately active athletes, 5-8 g/kg for those training intensively in endurance sports, 8-12 g/kg for elite endurance athletes before competitions. For strength athletes, 2-4 g/kg is sufficient.
Is the Keto Diet Suitable for Athletes?
The keto diet can work in endurance sports after 3-6 weeks of adaptation, but most strength and explosive power sports require carbohydrates for maximum performance. A hybrid approach (fewer carbohydrates on rest days, more on training days) is often optimal.
What Is the “Second Wind” and How Is It Related to Insulin?
“Second wind” in endurance sports is partly related to a drop in insulin levels and a shift to fat as the main energy source. When carbohydrate stores are depleted, the body increases fat oxidation.