Carbs Aren't the Enemy: Why Active People Need Carbohydrates

I went through a hardcore low-carb phase. For six months, I ate under 50g of carbs daily, convinced I'd discovered the secret to leanness and health. My workouts suffered. My mood tanked. I had brain fog that wouldn't quit. But I stuck with it because carbs were "bad," right?

Eventually, I added carbs back in and felt like a different person in the gym. My lifts went up, my energy returned, and I wasn't constantly thinking about bread. Let me share what I learned.

The Great Carbohydrate Misunderstanding

Carbohydrates became the nutritional villain over the past two decades. Low-carb diets promised weight loss, better blood sugar control, and improved health. And for some people, reducing carbs can be helpful—especially sedentary individuals with insulin resistance.

But here's what got lost in the messaging: carbohydrates are the primary fuel for high-intensity exercise.

When you lift weights, sprint, or do anything explosive, your muscles run primarily on glycogen—stored carbohydrates. Low glycogen stores mean compromised performance, faster fatigue, and potentially impaired recovery.

The Science of Exercise Fuel

Your body has two main fuel systems:

1. Fat oxidation: Works great for low-intensity, long-duration activity
2. Glycolytic system: Uses carbohydrates for high-intensity work

During weight training, you're primarily using the glycolytic system. Your muscles need quick energy, and carbohydrates provide that. Fat oxidation is too slow to keep up with the energy demands of heavy lifting or intense intervals.

Research consistently shows that carbohydrate availability affects training performance. A study in the Journal of Strength and Conditioning Research found that low-carb diets reduced high-intensity exercise capacity and power output.

Low Carb vs. Performance

Can you build muscle on a low-carb diet? Yes, it's possible. Is it optimal? Probably not.

When you train with depleted glycogen:

• You fatigue faster during sets
• You can't sustain as much training volume
• Recovery between sets takes longer
• Overall work capacity decreases

Over time, less training volume likely means less muscle stimulus. The indirect effects matter as much as the direct ones.

How Many Carbs Do You Need?

It depends on your activity level and goals, but here are reasonable guidelines for active people:

Moderate training (3-4 days/week): 1.5-2.5g per pound of bodyweight
Intense training (5-6 days/week): 2-3g per pound
Athletes with high training volumes: 3+ grams per pound

For a 170-pound person training intensely: 340-510g of carbs daily.

Yes, that sounds like a lot if you're coming from a low-carb mindset. But it's what hard-training athletes actually need.

Carb Quality Matters

Saying "eat carbs" doesn't mean living on candy and white bread. The source of your carbohydrates affects energy levels, satiety, and overall health.

Prioritize:

• Whole grains (oats, rice, quinoa)
• Potatoes and sweet potatoes
• Fruits
• Legumes (beans, lentils)
• Vegetables

Limit (don't eliminate):

• Refined sugars
• Highly processed carbs
• Sugary drinks

The goal isn't perfection. Some simple carbs around workouts are fine. But most of your carbs should come from whole food sources.

Timing Your Carbs

While overall intake matters most, strategically placing more carbs around training can help:

Pre-workout (2-3 hours before): A solid meal with 40-100g carbs fuels your session

Post-workout: Carbs help replenish glycogen. Not urgent (you have 24+ hours), but a good practice

Training days vs. rest days: Some people prefer more carbs on training days, fewer on rest days. This works fine but isn't required.

What About Fat Loss?

Here's where it gets tricky. Low-carb diets can help with fat loss—but not because carbs are inherently fattening. They help because:

• Cutting carbs often reduces total calories
• Protein and fat are more satiating for many people
• Eliminating carbs removes many hyper-palatable processed foods

You can lose fat while eating carbs. What matters is a caloric deficit, not the specific macro ratios. Many successful dieters eat moderate to high carbs and get lean.

If cutting carbs helps you stick to a deficit, that's valid. But it's not the only way, and for intense training, maintaining carbs usually produces better results.

Signs You're Under-Eating Carbs

• Workouts feel harder than they should
• Strength or endurance declining
• Constant fatigue despite adequate sleep
• Poor recovery between sessions
• Mood swings or irritability
• Intense carb cravings

If you're experiencing these while training hard, try adding carbs before eliminating other variables.

My Current Approach

I eat around 250-350g of carbs daily, depending on training volume. Most comes from rice, oats, potatoes, and fruit. I don't track obsessively but ensure I'm eating carbs with every major meal.

My training quality is dramatically better than my low-carb days. I can push harder, recover faster, and actually enjoy my workouts.

The Bottom Line

Carbohydrates aren't the enemy—they're essential fuel for hard training. Low-carb might work for sedentary individuals or specific goals, but for most people lifting weights or doing intense exercise, adequate carbohydrates support better performance, recovery, and results. Don't let diet trends convince you to underfuel your training.