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  • Nicole Rubenstein, MS, RD, CSSD, CDE

It’s not ONLY about macros...particularly for athletes

Updated: Dec 21, 2021

Nutrient timing is key

Counting macros, aka macronutrients, is very popular on social media and I’ve been seeing more and more people taking an interest in doing this. As a dietitian, I feel ambivalent about this. People want to learn more about what they are putting into their bodies. They are paying close attention to portion sizes and the nutrient content of foods. However, they may not be paying close attention to nutrient timing and digestibility of foods, and this could be a game-ender if you’re an athlete. I’ll talk more about why this is true.

Before we get into nutrient timing and digestibility, here is a brief summary of counting macros for those not familiar with it.

What is counting macros? Tailoring your diet to meet protein, carbohydrate and fat gram goals.

How do you do it? Meal plan in advance to ensure you are meeting these goals OR track your food intake throughout the day to ensure that you meet your goals. Time consuming, right?!?!

How do you figure out your macro goals? You could find 100 answers for this on the internet, but which one is right? As a Certified Specialist in Sports Dietetics, I base my recommendations on science. Percentages are meaningless! Macronutrient goals should not be determined by a percentage. These goals will be different for every person based on their exercise training regimen, performance, and body composition goals. We start with calculating protein goals, which can range from 1-2 grams of protein/kg body weight/day. Then carbohydrate goals, which can range from 2-10 grams of carbohydrate/kg body weight/day. These are huge ranges because an Olympic Nordic skier will have very different goals than a bodybuilder, and different goals than an overweight individual who just started exercising to lose weight. Once protein and carb goals are calculated, we figure out calorie goals, tweak protein and carb goals if necessary and the remainder becomes the fat goal.

So why is it not all about macros? Here are 10 reasons to support that nutrient timing and food choice is just as important (if not more important) than counting your macros:

1) Carbohydrate intake during exercise needs to be consumed in the right amount, at the right time to properly fuel high intensity, long-duration exercise. In general, for most types of exercise, carbs need to be quick to breakdown to they don’t upset the stomach and they can provide immediate fuel. Carbohydrates higher in fructose may cause more GI upset. General recommendations for carb intake during exercise range from 30-60 grams per hour. However, long endurance events, especially when performed at high intensity can require up to 90 grams of carbs per hour. Training the stomach to tolerate such an amount is beyond the scope of this article, but will be addressed in a future article.

2) Meals within ~2 hours of the start of exercise should be low enough in fat and fiber, as to not delay stomach emptying. No one wants to feel food in their stomach or feelings of reflux during exercise.

3) Some people may need to avoid high glycemic carbohydrates within 30-60 minutes of the start of exercise to avoid hypoglycemia during the beginning exercise

4) Low glycemic carbohydrates are a great choice for ~3 hours before the start of exercise, as these provide a slower release of glucose into your blood.

5) The correct amount of protein intake before and after exercise can help reduce muscle breakdown and increase muscle synthesis. About 0.25-0.4 g protein/kg body weight at each meal is likely to give you the best results with building muscle.

6) Starting low to moderate intensity cardio exercise in a fasted state may be beneficial, depending on your fitness and body composition goals. Those looking to lose fat, or wanting to enhance fat oxidation may benefit from this.

7) Carbohydrates that are high in FODMAPs may cause more GI upset in certain individuals. FODMAP stands for Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. Visit this website for more information on FODMAPS,

8) Fluid intake is an extremely important factor for athletes. Starting a workout in a dehydrated state will increase your heart rate, reduce plasma volume, and reduce aerobic endurance. Therefore, staying on top of your hydration status is key. Many athletes need to measure their sweat rate to determine how to properly hydrate during exercise. Visit this website for an easy to use sweat rate calculator,

9) Does it matter if your protein comes from animal or plant-based sources? Animal protein foods have a slightly higher leucine content, which is important for muscle protein synthesis. Therefore, if you follow a strictly plant-based diet and are looking to build muscle, your protein requirements will likely be higher than your animal-eating counterpart.

10) Vegetables and legumes are an important part of the diet for many reasons. However, an athlete may have a hard time figuring out when to consume these foods, as they are high in fiber and could cause stomach upset during exercise if consumed too close to commencement. They are also very filling and some athletes have a hard time fitting in all of the protein and carbohydrate foods that they need for training, so vegetables can fall by the wayside. Time your intake of these nourishing foods far away from exercise. For example, if you exercise from 3-6 PM, consume these high fiber foods for your evening meal after training, at breakfast, or for a mid-AM snack.

The right combination of meeting your protein and carbohydrate goals, appropriate nutrient timing, and consideration of the gastrointestinal implications of various food choices are all part of the formula for proper fueling of athletes. Stay tuned for more sport nutrition tips and comment below with topics that you would like to learn more about.

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