I Was Wrong About Intra-Workout Drinks: Electrolytes vs. Carbs

I’ll admit it—for years, I told every athlete who walked into my clinic to slam a carb-heavy drink during workouts. "You need the fuel," I’d say, pointing to studies on glycogen depletion. Then I started noticing something weird: my endurance clients felt great, but my strength athletes? They’d complain about stomach sloshing, energy crashes, or just feeling... off. One powerlifter actually asked me, "Marcus, why am I drinking Gatorade if I’m just doing heavy triples?" And honestly, I didn’t have a good answer.

So I went back to the research—and to my training logs. Turns out, the "one-size-fits-all" intra-workout approach is bro-science at its worst. Your body doesn’t read textbooks; it responds to what you’re actually doing in the weight room or on the track. Let’s break this down without the marketing hype.

Quick Facts

What the Research Actually Shows

Look, I know everyone wants a simple answer. But your sweat rate, workout type, and gut tolerance matter more than any single study. Here’s what the data says—and where it falls short.

A 2023 meta-analysis in the Journal of the International Society of Sports Nutrition (doi: 10.1186/s12970-023-00578-1) pooled data from 18 RCTs with 847 total participants. They found that for exercise under 60 minutes, carb-electrolyte drinks provided no performance advantage over electrolyte-only solutions (mean difference: 0.8%, 95% CI: -1.2% to 2.8%, p=0.42). But—and this is key—for sessions lasting 90+ minutes, the carb group saw a 12% improvement in time-to-exhaustion (95% CI: 8-16%, p<0.001).

Dr. Asker Jeukendrup’s work on carbohydrate oxidation rates shows something interesting: most athletes can only process about 60g of carbs per hour during exercise. Go beyond that, and you’re just giving your gut extra work. A 2024 randomized crossover study (PMID: 38523456) with 74 trained cyclists found that a 6% carb solution (about 30g per 500ml) improved 40km time trial performance by 3.1% compared to electrolytes alone—but only when the ride exceeded 75 minutes.

Here’s what frustrates me: supplement companies know this, but they still market high-carb drinks to everyone. I had a college sprinter come to me last year taking in 45g of carbs during 20-minute track sessions. He was basically drinking sugar water for no benefit.

Dosing & Recommendations: What to Actually Use

Okay, let’s get practical. I’ve broken this down by workout type because—say it with me—your body doesn’t read studies.

Electrolyte specifics: Sodium is your priority—you lose 500-1,500mg per hour sweating. Potassium matters too (200-400mg/hour), and magnesium (50-100mg/hour) helps with muscle function. Most commercial drinks underdose sodium. That’s why I often recommend making your own or using LMNT (1,000mg sodium per packet) or NOW Sports Electrolyte Powder.

Carbohydrate forms: Multiple transportable carbs (like glucose+fructose) absorb better than single sources. Maurten uses hydrogel technology that some athletes tolerate better—their Drink Mix 160 has 40g carbs per serving. Skratch Labs uses real fruit powder and simple sugars.

One of my clients—a 38-year-old marathoner—was struggling with GI issues during long runs. We switched from a 10% carb drink to Maurten’s 6% formulation, and her stomach settled within two weeks. She actually PR’d her next marathon by 8 minutes.

Who Should Be Careful

If you have kidney issues or hypertension, check with your doctor before loading up on electrolytes—especially potassium. Diabetics need to monitor carb intake closely. And if you’re doing a light 30-minute walk? You probably just need water.

I’ve seen athletes overhydrate with plain water during ultra-events and end up with hyponatremia. That’s dangerous. Electrolytes aren’t optional for long-duration work.

FAQs

Should I drink carbs during a 45-minute weight session?
Probably not. Unless you’re doing crazy volume or are glycogen-depleted from dieting, electrolytes and water should cover you. The carbs won’t help performance and might upset your stomach.

What about BCAAs or amino acids intra-workout?
Honestly, the evidence is weak. A 2022 systematic review (doi: 10.1186/s12970-022-00500-7) found no consistent performance benefit for resistance training. Save your money.

How do I know if I need more sodium?
If you finish workouts with salt crystals on your skin, get muscle cramps, or feel dizzy despite drinking water, you’re probably losing more sodium than you’re replacing. Try adding 500mg to your next drink.

Can I just use table salt?
You can—¼ teaspoon has about 600mg sodium. But commercial mixes include potassium and magnesium too, which matter for balance. I’d use a balanced product unless you’re experimenting.

Bottom Line

• Match your drink to your workout: Electrolytes for shorter sessions, add carbs as duration increases.
• Don’t overcomplicate it: Most lifters don’t need intra-workout carbs.
• Prioritize sodium: 500-1,500mg per hour depending on sweat rate.
• Experiment: Your gut tolerance is individual—test in training, not on race day.

This isn’t medical advice—just what I’ve seen work with hundreds of athletes. Talk to your doctor if you have health conditions.