Fuel-Your-Fit Challenge Week 1: The Best Carbs for Cardio Workouts

Thanks to the superstardom of ultra-low-carb diets like keto and a resurgence in strength-training workouts, carbs and cardio haven't been winning many popularity contests lately. But just because they're not ‌en vogue‌ doesn't mean they're not important.

In fact, carbs and cardio are a match made in healthy-living heaven, which is why we're starting with this perfect pairing for the first week of our January Fuel-Your-Fit Challenge.

‌Psst‌ — new to the challenge? Click here to get all the details on the four-week program, which pairs different types of workouts with the optimal nutrients to "fuel your fit."

Click here for a printer-friendly version of this week's plan!

Think of your body as a car and carb-rich foods as the fuel it needs to power through a race — or a cross-country road trip.

"Carbs are a quick energy source for the body," Maryann Walsh, RD, tells LIVESTRONG.com.

Your body converts the carbohydrates you eat into glycogen (a form of glucose that's stored in your muscles and liver) and then taps into this energy supply when it's needed to perform physical activity.

The type of carbs you eat determines how quickly that energy peaks. High-quality, complex carbs like whole grains take longer to digest than simple, refined carbs like white breads, pasta and rice. That's because complex carbs are made up of longer chains of molecules and get broken down by the body more slowly, leading to more sustained energy instead of a quick spike and crash, Walsh says.

The easiest way to identify complex carbs in the grocery store is to look for "whole grain" in products' ingredient lists; on the flip side, to avoid simple carbs, steer clear of foods that have words that end in "-ose" (aka added sugar) in their ingredient lists.

Walsh's go-to choices for pre-cardio eats are overnight oats with Greek yogurt (for some muscle-fueling protein) or whole-grain toast with no-added-sugar peanut butter (for protein and healthy fat). But if neither of those options appeal to you, don't worry! There are plenty of other ways to get your complex carb on.

Generally, most adults should get between 45 and 65 percent of their daily calories from carbohydrates, according to the U.S. Department of Health and Human Services' (HHS) Dietary Guidelines for Americans; however, there may be a "sweet spot:" Getting between 50 and 55 percent of daily calories from carbs was linked to the lowest risk of dying over a 25-year study period in August 2018 research published in ‌The Lancet‌.

So if you eat 2,000 calories a day, you need between 900 and 1,300 of those calories to come from carbs. And because 1 gram of carbohydrates provides 4 calories, that translates to eating 225 to 325 grams of carbs daily. Here's what the daily carb breakdown looks like for different daily calorie goals:

After you're fueled up and ready to go, it's time to work. "Cardio simply means that you are doing rhythmic activity to raise your heart rate," Meg Takacs, running coach and creator of the #RunWithMeg app, tells LIVESTRONG.com.

Cardio requires you to move multiple large muscles repeatedly, which gets your heart rate high and burns calories, according to the Mayo Clinic.

Your heart rate reveals how hard you're working during exercise. The more strenuous the exercise, the higher your heart rate. It's important to know what your target heart rate should be for cardio training as well as successful weight loss and management: For moderate-intensity cardio, you want to aim for about 50 to 70 percent of your maximum heart rate, and for high-intensity activity you want to aim for about 70 to 85 percent of your maximum heart rate, according to the American Heart Association.

Cardio exercise also bolsters your immune system and even boosts your mood.

"I approach running from a mental health perspective, which is what I think running is best for," Takacs says. "Sure, there are other physical benefits like increased lung capacity, a stronger heart and reducing your risk for health conditions like diabetes, high cholesterol and high blood pressure, but the mental side of running is truly amazing."

But you don't ‌have‌ to run. There are plenty of cardio options to choose from:

• ‌Hiking‌ is great for people who enjoy being outdoors and can get outside easily. It's also good for older adults because walking isn't as hard on the joints as other forms of cardio. That said, don't dawdle — if your goal is to lose weight or build endurance, you'll need to pick up the pace.
• ‌Indoor or outdoor cycling‌ is best for people who have access to a bicycle or cycling class, as well as people who have joint issues, as cycling puts less stress on your back, hips, knees and ankles than other cardio workouts.
• ‌Swimming‌ is an excellent full-body workout option for people who have access to a pool and is another great low-impact exercise option for people with joint trouble.
• ‌Rowing‌ is a great workout for the arms and legs but also engages the core.
• ‌Dancing‌ is ideal for people who love music and would prefer to take their workout outside of the gym. It's a total-body workout that gives you the benefits of cardio and helps with coordination.
• ‌Playing sports‌ can help you stay accountable if you like a group workout and enjoy some mental strategizing.
• ‌Climbing stairs‌ is an accessible lower-body and core workout for anyone who lives in a building with steps or has access to a stepmill machine.
  
• ‌Kickboxing‌ can help you let go of stress; the punching bag is a great outlet. With so much jumping involved, it might not be best for someone with knee issues, though.
• ‌Body-weight drills‌ like jumping jacks, high knees and butt kicks are ideal for people who like to mix things up. They're also great for people who enjoy HIIT cardio.
• ‌Running or jogging‌ is a great option for people who like being outdoors or enjoy a treadmill workout. But running, wherever you do it, is a higher-impact cardio choice, so if you have joint issues, an elliptical or a bike might be more your speed.

Although this week's challenge is to do three cardio workouts for at least 30 minutes each, it's good to note the HHS' Physical Activity Guidelines for Americans: The recommendation is ‌at least‌ 150 minutes of moderate-intensity cardio or 75 minutes of vigorous cardio each week, which means you might want to increase the number, duration and/or intensity of your cardio workouts this week.

But also don't push yourself too hard too fast — listen to your body and do what's best for your personal fitness needs.

• ‌Start slowly.‌ True beginners will benefit most by starting at a slow speed regardless of their cardio workout, Takacs says. This gets your body acclimated to the impact and builds an aerobic foundation.
• ‌Push your pace.‌ A leisurely stroll on the treadmill or half-hearted elliptical session isn't going to do much for you. You don't need to be sprinting the entire time, but you do need to push yourself enough to get your heart rate up to at least 50 percent of your maximum.
• ‌Mix it up.‌ To prevent boredom, burnout and injury, Takacs recommends varying your workouts. For runners, that might mean incorporating sprints, treadmill intervals, slow-and-easy runs, average-pace runs and long runs into your routine. Experiment with similarly varied paces and workouts with other types of cardio, too.