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Preparing for a marathon takes more than just following a training plan. As I wrote about in my previous blog, there are other factors that make a difference come race day. But what sometimes gets overlooked (and has the potential to catapult you the next level) is your nutrition. Yup, believe it or not - what you eat throughout your training, and especially on race day, can greatly impact your personal marathon goals. “But where do I even begin?” you might be thinking? Well, don’t worry - Dr. Rob is here to help you avoid common marathon training nutrition mistakes. Let’s dive in to learn some helpful tips, shall we?


In my opinion, two of the most important factors determining performance on race day are training and nutrition. Most endurance athletes spend countless hours per week planning, training, and preparing their running sessions. But how much actual time do those athletes spend on nutrition? More times than not, the answer is not enough.

I’m constantly reminding my clients not to take their nutrition for granted, warning them that neglecting their diet could jeopardize all the hours and days of their hard training. But here’s the good news - with just a few modifications to your diet, any athlete can ensure they are 100% prepped and ready to go. See below for my top 4 tips:


While training, and especially on race day, you want to make sure you are maintaining a normal blood sugar level without too much fluctuation. Remember, when your blood sugar dips, so too will your energy. And when you hope to run 26.2 miles, you can't afford to give out midway — you’ll need enough gas in your tank to take you to the end.

In addition to eating before your workouts, you should be fueling throughout your long workouts. You're likely to burn through your breakfast calories within an hour or so, so I recommend that my clients eat BEFORE they feel hungry. Depending on your size, you should aim to consume a small snack or meal an hour to keep your body working at its peak. This should be something that you know is good on your stomach but light enough that it won't come back up on you while you are training. Stick to more complex carbohydrates with small amounts of proteins and fats thrown in. This can include a banana with peanut butter, pasta, or rice.

What does a mid-training snack look like? You need carbs for fuel — gels, sports drinks, power bars

or dried fruit all do the trick. But what kinds of food you eat depends on what your body can tolerate, so explore different options during your training to learn what foods will work specifically for you during the long run (including race day). For example, many energy gels are known to give digestion problems due to the high levels of maltodextrin and the sharp

fluctuations of glucose levels in the body. The “runs” after a race is a well-known issue for people who have taken certain energy gels during a race. I have certainly experienced this myself on many occasions while trying different and new products over the years. So, experiment BEFORE the big day to see what works best for you!