Marathon Training Nutrition Math Tip #15

Are you ready for some marathon training nutrition math? Oh no, not math! There are a lot of numbers associated with running a marathon, including nutrition recommendations. Maybe you are of the same math mindset as Winston Churchill who stated:

“The human story does not always unfold like a mathematical calculation on the principle that two and two make four. Sometimes in life they make five or minus three; and sometimes the blackboard topples down in the middle of the sum and leaves the class in disorder and the teacher with a black eye.”

Since you don’t need disorder, make marathon training nutrition math simple with these suggestions (recent and common questions asked of me while on the trail):

  • How much fluid should I be drinking on a long run?
    Weigh yourself without clothes on a scale in the morning after going to the bathroom and before drinking anything. On your run, drink every two miles or so (similar to going through an aid station/water stop at the marathon). Weigh yourself without clothes after the run. If your weight is about the same then you drank enough. If you lost weight from sweating, you didn’t drink enough. If you gained weight, you drank too much. Do this a few times until you get a feel for the amount of fluid that works for you on a long run.


  • Should I be drinking these sports drinks that are loaded with sugar/carbs?
    Yes! Marathoners need carbs. Carbs in the form of these select sugars are best absorbed. The amount of carbs placed in the sports drinks are in the best concentration for absorption…the researchers and the companies did the marathon training nutrition math for you. You need the carbs, the fluid, the sodium and the potassium. Skip the math and just drink the stuff.


  • There seems to be a lot of sodium in the sports drinks. What gives?
    You need to replace the sodium that you sweat out during running, so the sports drinks are a convenient way to replace the sodium, again in a pre-determined proportion. In addition, a runner training for a marathon can usually eat more salty (sodium-rich) foods than the non-runner. So, unless you are under medical supervision for sodium as it impacts your blood pressure or a kidney condition, enjoy a sprinkle of salt on your foods and some sodium-rich snacks or meals. There is no need to do the sodium milligram math.

    Let me know if you need help with Medical Nutrition Therapy as it relates to your sodium intake.


  • How many calories does a person training for a marathon need?
    Calorie needs are quite varied, depending on your age, height, weight, gender, genetics, intensity, mileage, to name a few. But why count? If you are maintaining your weight, then you are eating and drinking enough calories for the extent of your activity. There are calculators to help with the marathon training nutrition math (coming up with a number of calories needed), but they are only estimates. Also, the time you spend keeping track of calories may be better spent doing the things runners tend to skip, such as stretching and strengthening. If you are not maintaining your weight, check out these ideas for weight gain or weight loss.

    If you absolutely LOVE math you are in luck. This website provides the most updated numerical recommendations for sports nutrition. Read through this website for marathon training math as needed, along with a ton of practical ideas, too.

    Marathon Training Nutrition Math Tip of the Day: Take a day off from numbers: label reading, weight scale, pace, mileage…and enjoy a day of math-free marathon training!

    Check out more marathon nutrition training blogs.

    Everyday is your day to succeed!