Eating for a Marathon: Eating Enough

One of the most common issues I see as sports nutritionist is athletes not eating enough. Strangely, it doesn’t seem to matter if they are trying to lose, gain or maintain their weight. And more often than not, it is completely inadvertent. Training increases but the athlete keeps eating the same amount as before. Or they follow the recommended portion sizes on packaging, which are for a 2000 kcal diet – when they are burning over 3000 kcal per day!

Not eating enough can lead to a syndrome known as Relative Energy Deficiency in Sport (RED-S) (previously known as the Female Athlete Triad). Symptoms include:

  • Irregular or missed periods in women and low testosterone in men
  • Decreased adaptation to training (you don’t progress) and decreased performance in competition, despite training harder than ever
  • Low mood and fatigue, despite getting enough sleep
  • Frequent injuries, particularly bone injuries like stress fractures
  • Frequent illnesses like colds and flu
  • Poor body composition – you can’t gain muscle mass or lose body fat

The second item on the list was of particular concern to me. My goals this year are all about performing well in the marathon – not losing body fat or looking a particular way. To set a new marathon PB, I needed to hit all my training targets. That meant I needed to eat enough to go hard in training, recover, and go hard again the next day. As my mileage and hours of training increased, so did the number of extra calories I had to consume. And it quickly became apparent just why so many of my athletes struggle to eat enough! Turns out, it can be hard to eat more than 3000kcal per day while sticking to healthy foods.

It was tempting to just add more treats to my diet. After all, junk foods – like cake or chips – taste so good because they are loaded with fat, salt and simple carbs (sugar, white flour, etc). This ramps up the calorie count. And I did sometimes have more cake or ice cream than I normally would. Problem is, these foods lack the protein, vitamins, minerals and antioxidants that speed up recovery. So you get the calories, but not much else in the way of nutrition.

Long run days, where I would burn over 1000 extra calories, were a particular challenge. After a bit of trial and error, I did find some meals that were both nutrient and calorie dense. For example, my typical breakfast before a long run is porridge made with gluten free oats, skim milk, a small chopped apple, ground flaxseed, raisins, pumpkin and sunflower seeds. Together with a large mug of tea with milk and sugar, that’s over 700Kcal and over 100g of carbs. And that fuel is a mix of both complex carbohydrates (oats), simple sugars (in the fruit) and healthy fats (from the seeds).

In the end, I used a variety of techniques to increase my calorie intake without resorting to a load of fat laden junk food. I increased the portion sizes of my usual healthy foods, which took some getting used to. In particularly, I needed enough complex carbohydrates to fuel training, like oats, sweet potatoes, quinoa, pasta, etc. If I had a particularly heavy training session, I would have a couple different carbohydrate sources in the same meal, such as butternut squash in a risotto, or a curry with both rice and naan bread. I also added more healthy fats to my diet, mostly from nuts, seeds and oily fish. And I did enjoy some higher calorie, higher fat foods like cheese (high in calcium and protein) and liver pate (high in iron, which is often low in runners).

In August I went for a second round of physiology testing, and it was all good news. My VO2 max had gone up by 6%, my lactate thresholds had shifted to higher speeds, and I was using more fats as fuel. Not to mention the new half marathon PB I also had in August. Eating enough to fuel proper hard training works!

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