Iron & Ferritin: Why They Matter for Marathon Runners
Have you been feeling unusually fatigued during your training runs? Struggling to hit your usual paces or experiencing longer recovery times? Low iron or ferritin levels could be the underlying cause.
Iron is a key component of hemoglobin, the protein in red blood cells that carries oxygen from your lungs to your muscles. Ferritin, on the other hand, is a storage protein that reflects your body's iron reserves. For endurance athletes like marathoners, maintaining adequate ferritin levels is essential for sustained energy, performance, and recovery.
Signs of Low Iron/Ferritin in Runners:
- Persistent fatigue despite adequate rest
- Decreased endurance and shortness of breath during workouts
- Pale skin and frequent dizziness
- Increased heart rate or feeling of "heavy legs"
- Poor recovery and frequent injuries
If you resonate with any of these symptoms, it might be time to check your ferritin levels.
Tips for Optimizing Iron Intake:
- Combine Heme and Non-Heme Sources – Heme iron (from animal products) is more readily absorbed, but pairing it with non-heme sources (plant-based iron) can help improve overall intake. Example: Add ground beef to a spinach salad to boost iron absorption.
- Pair with Vitamin C – Consuming vitamin C-rich foods (bell peppers, oranges, strawberries) with iron-rich meals enhances absorption. Example:have a glass of OJ with your steak or when taking your iron supplement.
- Avoid Inhibitors Around Meals – Coffee, tea, dairy, and high-calcium foods can hinder iron absorption. Try to consume them separately from iron-rich meals or supplements
- Consider Timing of Iron Supplementation – If dietary intake isn't enough, iron supplements may be necessary, but they should be taken on an empty stomach or with vitamin C for better absorption.
Best Dietary Sources of Iron:
Heme Iron (Highly Absorbable):
- Red meat (beef, lamb)
- Poultry (chicken, turkey)
- Fish (salmon, tuna)
- Organ meats (liver)
Non-Heme Iron (Plant-Based Sources):
- Legumes (lentils, chickpeas, beans)
- Tofu and tempeh
- Dark leafy greens (spinach, kale)
- Nuts and seeds (pumpkin seeds, cashews)
- Fortified cereals and grains
Struggling with Low Ferritin? A Dietitian Can Help.
As a marathon runner, your iron needs are higher than the average person. A Registered Dietitian can help you:
Assess your dietary intake and create a fueling strategy that supports training Recommend iron-rich meal plans and appropriate supplementation if necessary Monitor your ferritin levels and help you optimize recovery and performance Tailor an iron strategy that fits your training cycle and lifestyle
If you’ve been struggling to increase your ferritin levels OR have never had your iron tested, now is the time to take action.
Book an Intro Call with a Dietitian & Run Coach Today! Let’s ensure you’re fueling properly for your best marathon yet!
Get More In-Depth With A Nutrition Consultation
Don’t hesitate to reach out if you’d like personalized recommendations or need help troubleshooting your post-workout nutrition plan!
Grace Thomas, MDN, RDN, LDPerformance Dietitian, Personal Trainer, Speed/Agility CoachGracesGrit Nutrition & Fitness Solutions LLC