Want to join us live for our next KN Insights? RSVP for free HERE.
Pre-Workout Nutrition: Fast or Fuel?
Should you eat before a workout or go in on an empty stomach? It’s one of the most common questions we get. In this blog, we break down the science behind fasted versus fueled workouts and help you decide what works best for your body, goals, and routine. Spoiler: food might be your secret weapon for better performance and faster results.
What Is a Fasted Workout? ⏱️
A workout is considered “fasted” if it’s been 8+ hours since your last meal. Most often, this happens when you exercise first thing in the morning before breakfast. A 6 PM workout after skipping lunch or eating too little during the day could also count as under-fueled, even if it’s not technically fasted.
Why Fueling Matters ⚡
Here’s why having something in your system before exercise can make a big difference:
Increased Endurance: Carbs provide quick energy, helping you power through longer workouts.
Improved Performance: With more energy available, you can lift more, run harder, or push through more sets.
Faster Recovery: Starting your workout with fuel can reduce post-workout soreness and speed up recovery.
Preserve Muscle Mass: Without carbs, your body may start breaking down muscle tissue for energy.
“Even if weight loss is your goal, fueling before a workout helps you push harder — and burn more.” -Samantha Cutrona, MS, RD
The Downsides of Fasted Workouts
While fasted training might sound appealing, it comes with several drawbacks:
Higher Perceived Effort: Everything feels harder. You might think you’re pushing yourself more than you actually are.
Reduced Workout Quality: Lack of energy = lower intensity and fewer results.
Muscle Breakdown Risk: Your body may break down muscle to get fuel.
No Guaranteed Fat Loss: Using fat as fuel doesn’t mean you’re losing body fat. Fat loss still comes from a caloric deficit.
Are There Any Benefits to Fasted Training?
Yes — but they’re situational:
Low-Intensity Workouts: Short walks or light mobility sessions may not require fuel.
GI Sensitivities: If food causes digestive issues, a small snack or fasted workout may be better.
Personal Preference: Some people simply feel better training fasted. But 9 out of 10 times, fueling wins.
What Should You Eat Before a Workout? 🌾
Carbohydrates are the body’s preferred fuel source. When we eat carbs, they break down into glucose, which provides immediate energy. The higher the workout intensity, the more your body relies on carbs.
Types of Carbs
Simple Carbs = Quick to digest; best 30-60 mins before workout
Complex Carbs = Contain fiber, digest slower; best 2-3 hours before workout
Example: Banana = simple carb (good 30 mins before); Oatmeal = complex carb (best 2+ hours before)
When should you eat before a workout? ⏰
2-3 hours
Balanced meals with carbs, protein & fat
Balanced Meal Ideas:
Oatmeal + berries + Greek yogurt
Grilled chicken + roasted potatoes + broccoli
1 hour
Light carbs with low fiber
30 mins
Simple carbs like fruit or fruit pouches
30-60 Minutes Before: Simple Snack Ideas
Squeeze pouch (kids fruit pouches work great!)
1 banana or apple
Dried fruit (small serving)
Rice cakes or pretzels
Fruit snacks
Keep it light: Simple, low-fiber carbs digest quickly and prevent GI discomfort.
Customizing Pre Workout Fuel to Your Schedule & Intensity ⚖️
Morning workouts? Opt for easy, small simple carbs like dried fruit, applesauce, or squeezable pouches.
Evening workouts with hunger? Combine two carb options to feel satisfied — fruit + granola bar, for example.
GI issues? Avoid fibrous or high-fat foods right before training (no peanut butter + banana combos, sorry!).
Q&A Highlights
Q: What if I’m hungry before a nighttime workout?
A: Choose 2 simple carb options to feel more full. Volume helps without overloading calories.
Q: Should I eat a lighter dinner after?
A: Depends on your goals. If weight loss isn’t a concern, eat normally. If it is, lighten an earlier meal instead so dinner still meets your recovery needs.
Q: What if I forget to eat ahead of time?
A: Keep shelf-stable options like fruit pouches or dried fruit in your bag for easy, on-the-go energy.
Fasted workouts might sound trendy, but most people perform and recover better when they fuel beforehand. Prioritize simple carbs before your workout — especially if you’re training at high intensity or with performance goals in mind.
Questions?
You can message us in the chat here or book your free nutrition evaluation with Sam Cutrona, MS, RD here. And don’t forget—our nutrition webinars happen monthly on Mondays. Sign up for our email list to be notified of the next one!