Day 39 of 100 Days Muscle Resistance Workout Challenge
Focus Topic: During Workout Fueling. Explore what your body needs for longer workouts — water, light carbs, or electrolyte drinks.
Learning Material
Most people think fueling matters only before and after a workout, but what you do during your session can make or break your performance. Whether you’re running, cycling, lifting, or doing a long strength circuit, your muscles are constantly burning glycogen, electrolytes, and fluids. If you don’t refuel during long sessions, your energy dips, your focus fades, and fatigue sets in earlier than necessary.
Learning to fuel while moving is a science of timing, balance, and listening to your body. The goal is not to eat a lot, but to provide small, steady energy and hydration so your performance stays strong to the end.
Key Insight
1. What Happens Inside Your Body During a Workout
When you train, your muscles rely on glycogen (stored carbohydrates) for quick energy. After 45–60 minutes of moderate-to-intense effort, these stores begin to be depleted. Your body then shifts to using fat for energy, which is a slower process. That’s when you start to feel heavy, dizzy, or unfocused, what athletes call “hitting the wall.”
To prevent that, you need small doses of energy, usually water, electrolytes, and simple carbs, to keep your glycogen levels from dropping too low.
Key Insight 1: During exercise, your brain and muscles compete for glucose. When glycogen is low, both performance and focus decline.
2. Water and Electrolytes: Your Internal Cooling System
Sweating is your body’s built-in cooling system, but it comes at a cost: you lose water and electrolytes like sodium, potassium, and magnesium. These are essential for muscle contractions and nerve communication.
If you’ve ever felt your muscles suddenly tighten or cramp during a workout, it’s often not from lack of strength, but an electrolyte imbalance.
How to balance it:
- Under 45 minutes: Water alone is fine.
- 45–75 minutes: Add electrolytes (a pinch of salt or a low-sugar electrolyte mix).
- 90+ minutes: Include carbs and electrolytes (sports drinks or energy gels).
Scientific note: Individualized hydration plans improve performance outcomes for collegiate athletes (2018). This randomized crossover study found that athletes following a prescription hydration plan, tailored to their sweat & sodium loss, showed statistically significant improvements in anaerobic power, attention/awareness, and heart rate recovery compared with an ad lib hydration group1.
Key Insight 2: Hydration without electrolytes is like refilling your car with water instead of fuel. It looks full, but it can’t run properly.
3. Carbohydrates During Training: The Steady Fire
Simple carbs, such as glucose, fructose, or maltodextrin, are fast energy sources that keep your glycogen levels stable. During longer workouts, consuming 30–60 grams of carbs per hour can delay fatigue and preserve strength.
Best sources:
- Sports drinks or coconut water
- Energy gels or chews
- Half a banana or small handful of raisins
The goal isn’t to eat a full meal, but it’s to top off your tank just enough to keep your energy steady.
Real-world example
Professional cyclists fuel strategically every 20 minutes, not because they’re hungry, but because they know the body performs better when glucose is continuously available.
Key Insight 3: The best athletes don’t wait for exhaustion; they prevent it by fueling early and consistently.
Metaphor: The Campfire Effect
Imagine your body’s energy like a campfire. Carbs are the kindling that lights quickly and burns hot; fats are the logs that burn long and steady. During a workout, you need a few sparks of kindling (carbs) to keep the fire bright. Without them, even the best-built fire fades too early.
Your job during exercise is to keep that fire alive, not too much, not too little.
My Reflection
Now I understand why sports drinks and water are always available at running events; they’re not just for comfort but for maintaining hydration and electrolyte balance during endurance activity. I normally don’t drink or eat anything before my cardio sessions since I work out first thing in the morning. My body has adapted well to this routine, and I rarely feel any issues. However, when I exercise later in the day, I make sure to eat something light beforehand to keep my energy levels steady.
This week, my muscle mass increased, but so did my overall weight. I suspect that’s partly from the chicken meals I had over the past couple of days. My plan for the coming week is to return to a slight weight-loss mode, focusing on cleaner meals and more hydration to help flush out excess sodium from eating out at work.
Today is an active rest day, which works well since I had to go into the office. I still want to move, but in a way that allows my body to recover. This weekend, I’ll need to adjust my workout intensity, as I haven’t felt much muscle soreness lately, a sign that my body has adapted to the current routine.
Biometric data
Change in Weight from Day 1: -2.0 lb.
Skeletal Muscle: 39.10%
Muscle Mass: 94.6 lb.
Adjustment Ideas (Strategic Adjustments)
- Fuel Smart: Bring a small electrolyte or sports drink for any workout longer than 45 minutes. Keep portions light but regular.
- Plan Hydration Timing: Sip water every 15–20 minutes rather than waiting until you feel thirsty.
- Experiment with Carbs: Test which mid-workout carb source feels best, fruit, gel, or drink, and adjust your fueling strategy accordingly.
Note
- David Ayotte and Michael P. Corcoran, “Individualized Hydration Plans Improve Performance Outcomes for Collegiate Athletes Engaging in In-Season Training,” Journal of the International Society of Sports Nutrition 15, no. 1 (2018): 27, https://doi.org/10.1186/s12970-018-0230-2. ↩︎