MACROS 101 Spartan Challenge: Week #3 — Carb Intake + Intra-Workout Fueling

MACROS 101 Spartan Challenge: Week #3 — Carb Intake + Intra-Workout Fueling

We're primed to hack it on the race course after a helluva long year. Are you? Sure, true to your unstoppable grit, determination, and perseverance, you've done your best to stay OCR-ready while sheltering at home. But with Spartan races back in full swing, it's time to clean up your nutrition program and ditch poor pandemic habits once and for all. In partnership with Renaissance Periodization, we created this four-part MACROS 101 series to optimize your nutrition so you can get faster, stronger, and prevent injury. Download the free nutrition plan and keep an eye out for healthy recipes rolling out all month. We've got you covered for your most EPIC return to racing ever. AROO!

Carbs have it rough. Of course, just like fats, there’s the “good” kind, and the “bad” kind. But when we’re talking about leveraging non-processed, whole foods rich in carbohydrates to fuel tough workouts, we’re actually talking about improving energy levels for optimized performance. 

Next up in our Macros 101 series for week #3, with Renaissance Periodization, we’re handing the spotlight to carbohydrates—because strategic carb use boosts your muscle and brain function during exercise, and improves recovery. 

“Carbs have quite the bad rap,” says Dr. Alex Harrison, CSCS, USATF-3, USAW-1, USAT-1 and RP coach. “It probably stems from their direct mechanistic connection to stimulating insulin and some pretty bold claims about increased carbohydrates, specifically sugar consumption, correlating with obesity.” Turns out, he says, unless you’re eating mostly crappy carbs and nothing else, that’s not really causative—especially for weightlifting endurance athletes. “You have to take diets very extreme in the direction of carbs-only for a eucaloric diet [a diet that is in caloric balance without surplus or deficit] to cause blood sugar regulation issues. Endurance athletes, especially Spartans who lift, don’t really have to worry about this.” 

Why? The human body burns through glycogen during exercise and lowers blood glucose levels as a result. GLUT4, a transport protein, activates during workouts and works to suck glucose from the bloodstream into working muscles for up to 30 minutes post sweat session, Harrison says. In other words, thanks to GLUT4 during exercise, “muscle cells get to vacuum up all the sugar in the blood,” he says. “This prevents sugar from circulating your bloodstream and causing inflammation, insulin spikes or [sticking around] until the liver turns it into fat.” This is why it’s quite common for elite endurance athletes to consume hundreds of grams of sugar in a single day, regularly, and skate by without blood sugar issues.

What Spartan Racers do have to worry about, however, is intra-workout fueling: smart carb intake to supercharge power during intense, long training sessions and racing. 

Related: MACROS 101 Spartan Challenge: Week #1 — Protein Primer + Calorie Balance

Complex vs. Simple Carbs & Why Glycemic Index Matters

Complex carbs means there are more carbohydrate subunits strung together into a larger molecule, Harrison says, like most whole foods. Simple carbs, on the other hand, generally refer to monosaccharides and disaccharides, like raw sugar. “The mistake that everyone makes is to think that because it’s a long-stranded, complex carb, it will behave in your gut and bloodstream like a simple carb,” he says. “In general, most complex carbs are slower to digest than most simple carbs, but there is a lot of crossover.” 

To optimize carb intake, you need to know how quickly it will hit your bloodstream, a.k.a how fast your body will be able to use it. To do this, Harrison recommends getting familiar with glycemic index (GI). GI is a number from 0-100 assigned to a particular food (i.e. pure glucose is 100), representing the relative rise in blood glucose two hours after eating that food. 

“Higher on the GI scale and you get a faster increase in blood glucose [read: energy] than lower GI carb sources,” Harrison says. “Turns out that some common complex carbs hit quite fast, and some common simple carbs hit slowly when consumed in isolation, or in foods where they are commonly found (like fructose in fruit, for example).” 

Fruit, though high in fructose, is also high in fiber placing it lower on the GI scale. When digested, fruit poses no risk to blood sugar regulation, but it also takes a while to hit the bloodstream, so it wouldn’t be ideal for workouts where immediate energy is a must. “Right before and after workouts, it's probably best to go with more moderate fiber choices to limit the risk of gastrointestinal distress, especially while running,” Harrison says. 

Related: MACROS 101 Spartan Challenge: Week #2 — Why (+ When) Athletes Need Healthy Fats

What is Intra-Workout Fueling? 

macro meal plan carbs

Intra-workout fueling is just what it sounds like: consuming calories to support high-energy demands during exercise, replenishing what's burned throughout the workout so you can go harder, longer and faster. The goal? To make every mile and rep count. In short: it’s crucial to know what kind of carbohydrates you need to properly fuel your workouts before, during and after. 

As a rule of thumb, Harrison recommends eating quicker carbs (55 or higher on the GI scale) 20 minutes before you train, and during training, for rapid digestion, absorption and faster-acting energy. Think: most gels, crackers, non-fat gummy candy, cereals and white bread with jam.

When you’re not training, slower carbs are generally a better call. “More nutrient dense carbs have more fiber, vitamins and minerals, and they result in more even energy throughout the day,” Harrison says. Think: rolled or steel cut oats, barley, quinoa, rice, and carb-rich veggies like carrots, peas and corn. “All of these are wiser choices for filling, satiating and blood-sugar-leveling carbs, when you're far from workout time.”

When You Should Fuel During Workouts 

Each individual athlete’s carb intake will be slightly different. But RP’s Table of Intra-Workout Carb Needs per hour of training will help you establish a baseline of grams necessary to fuel your muscles and avoid the fatigue wall. “For pure performance, hitting the recommended amounts in the table, on a per-hour basis, definitely sets folks up for better training performance within the well-fueled session, as well as for chronic training adaptations over the course of the training phase,” says Harrison. 

Undershoot these numbers, and your performance may plummet due to muscular fatigue, lack of energy, decreased power output, GI distress, brain fog and other issues. Bottom line: “Fuel early, fuel often, fuel aggressively,” Harrison says. “Liquid fueling options are the most efficient and effective by far. Gels plus water are also acceptable.”

If you target carb consumption over 60 grams/hour, pay attention to your sugar ratios. Harrison says not to exceed 60 grams/hour of glucose unless you are sure your gut can tolerate it without issue. “It’s usually a recipe for gut cramps for less experienced folks who try to do the full 90-120 grams/hour using purely maltodextrin or dextrose.” 

Related: MACROS 101 Spartan Challenge: Week #4 — Fruits, Veggies & Micros Decoded

Include Intra-Workout Fueling In...

1. Exercise Over 30 Minutes

Yes, it sounds like a short period. But Harrison says he always has an intra-workout beverage on hand, especially when training indoors on stationary cardio machines. “It might not enhance performance for that specific session but it kickstarts the recovery faster than having nothing during training and then solid food afterward,” he says. 

2. Outdoor Training Sessions, Period

Sunshine zaps electrolytes when you’re sweating like crazy, trying to keep up on hydration and fuel. Occasionally, Harrison will have clients go as long as 75 minutes without consuming anything, but that’s only for logistical reasons. In a perfect world, athletes consume carbs to replenish glycogen stores on runs 45 minutes or longer to optimize performance. “If it’s a logistical headache, I’ll push for at minimum carrying something small for 60 minutes and up.” You don’t want your stomach to be completely empty on runs over 75 minutes. 

Related: Whoever Said Bread = Bad Was Full Of It. Try this Healthy Strawberry Bread Recipe

3. Starting Lines and Warm Ups 

“A commonly missed opportunity for fueling runs is after the warm-up and at the starting line of a major race,” says Harrison. When you get your body moving with a dynamic warm up, your gastrointestinal tract activates. “If you’re not taking advantage of that by consuming fluids, carbs and sodium in the final few minutes pre race, you’re missing out on much more optimal hydration and fueling.” Dehydration further slows your gut’s ability to absorb its contents, which is detrimental in the long haul. 

BONUS PRO TIP:  For more info like this to support your endurance training from RP, Harrison recommends to check out The RP Diet for Endurance.

Week #3 Goal: Intra-Fuel to Sustain Tougher, Longer Workouts, Cut Back on Processed Carbs

Week Three To-Do:

Now that we’re clear on carbs, here’s your homework for Macros 101 week #3. In addition to increased protein consumption and healthy fats from weeks 1 and 2, all you have to do this week is to start playing with your intra-workout fueling during longer sessions to discern what’s right for you. Also, help your future self out and cut garbage carbs keeping it to whole foods and smart drinks.


The Best Nutrient-Rich Guacamole Recipe to Fuel Up Your OCR Training

Leeks You'll Love: Try this Tasty Veggie & Chicken Broth Recipe

The Most Epic Side Dish EVER: Oven-Baked Crispy Green Beans

Burgers Just Got Better. (WAY Better.) Try Our Spartan-Approved Skillet Recipe

Feeling Under the Weather? Beat Colds with This Chicken Noodle Soup Recipe

Need More Fat In Your Diet? Add This Basil Oil To Just About Anything

Fuel Your Workouts with a Thai Twist on Coconut Pasta

Amp up your fitness and wellness routine NOW. Click here to find a Spartan race close to you!