You Didn’t Lose Fitness—You Lost Fuel
It’s April.
The structure you had in January is gone.
Meal prep is inconsistent.
Nutrition is now “flexible.”
But your training?
Still demanding.
And now your runs feel harder.
Your pace dropped.
Your legs feel heavy.
Your effort feels higher for the same output.
Most runners assume:
“I need to train harder.”
But that’s not the problem.
You’re not undertrained.
You’re under-fueled.
The Science: Why Carbs Drive Performance
Carbohydrates are converted into glucose and stored as glycogen in muscles and liver.
This glycogen is your primary energy source during:
- Moderate intensity running
- High-intensity efforts
- Long-duration sessions
When glycogen is available:
→ Energy production is efficient
→ Pace is sustainable
→ Fatigue is delayed
When glycogen is low:
→ Your body shifts to slower energy systems
→ Perceived effort increases
→ Performance declines
This relationship is well established in endurance physiology (Burke et al., 2011).
In simple terms:
No glycogen = no performance.
Why This Matters (Especially Now)
At the start of the year, most athletes are disciplined.
They:
- Plan meals
- Eat intentionally
- Support their training
By April?
Consistency drops.
But training load doesn’t.
That mismatch creates:
- Chronic fatigue
- Poor adaptation
- Performance plateaus
Female Athletes — This Is Critical
Female physiology adds another layer.
Low energy availability can affect:
- Hormonal balance
- Bone density
- Recovery capacity
(Mountjoy et al., 2018)
This is not about aesthetics.
It’s about function and performance.
Ignoring carbohydrates is not discipline.
It’s misalignment.
Practical Application: How to Use Carbs Correctly
1. Pre-Training = Priority Fuel
Before key sessions:
- Long runs
- Tempo
- Intervals
You need carbohydrates.
Simple guideline:
- 1–3 g/kg depending on intensity and timing
Examples:
- Oatmeal + fruit
- Toast + honey
- Rice-based meal
This fuels your session—not your cravings.
2. The Night Before Sets the Session
Glycogen is built over time.
If you have a long run tomorrow:
Your dinner matters.
Include:
- Lentils
- Rice
- Potatoes
You are not overeating.
You are pre-loading energy.
3. During Training (>90 Minutes)
Stored glycogen is not enough.
You must replenish.
Guideline:
- 30–60g carbs per hour
This maintains:
- Blood glucose
- Energy output
- Performance consistency
4. Post-Training: Be Strategic
Not every session requires high carb intake after.
Focus:
- Protein for recovery
- Carbs based on next session demand
If you train again soon → include carbs
If not → prioritize recovery balance
5. Stop Letting Trends Dictate Fueling
Low-carb trends don’t apply to performance athletes.
Your fueling should match:
- Training volume
- Intensity
- Frequency
Not social media.
Coaching Insight
I see this pattern constantly:
Athletes increase volume…
reduce carbs…
and expect progress.
That’s not discipline.
That’s contradiction.
Your body cannot produce output without input.
And when fueling is inconsistent, performance becomes inconsistent.
Key Takeaways
- Carbohydrates are essential for endurance performance
- Glycogen availability directly impacts energy and fatigue
- Under-fueling leads to plateaus and poor adaptation
- Pre-training and pre-long run fueling are critical
- Female athletes must prioritize energy availability
- Fueling should align with training—not trends
Closing
Performance is not built by pushing harder—it’s built by fueling correctly and executing with precision.
And when you align your training with what your body actually needs, progress stops being random.
It becomes predictable.
References
Burke, L. M., Hawley, J. A., Wong, S. H., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29(sup1), S17–S27. https://doi.org/10.1080/02640414.2011.585473
Mountjoy, M., Sundgot-Borgen, J., Burke, L., Ackerman, K. E., Blauwet, C., Constantini, N., Lebrun, C., Lundy, B., Melin, A., Meyer, N., Sherman, R., Tenforde, A., Klungland Torstveit, M., & Budgett, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine, 52(11), 687–697. https://doi.org/10.1136/bjsports-2018-099193
Sims, S. T. (2020). Roar: How to match your food and fitness to your unique female physiology for optimum performance, great health, and a strong, lean body for life. Rodale Books.