Hello Runner,
Welcome back to your weekly moment of endurance nutrition!
Happy Weekend!
How was your week?
My week was good!
I worked and trained a lot. I took care of some pending issues—you know, the ones we keep putting off—and I almost decided which running shoes to buy.
I'm happy the temperature in Barcelona is finally dropping. Going out early to run is wonderful! I've noticed that I'm sweating less than in previous weeks, and my training sessions are more productive.
I think I mentioned here that I signed up for my first half-marathon next year. And my training is already focused on the 21 km. Before, I used to run 8 or 10 km on the weekend, and now I run at least 15 km.
Just like every runner who starts training for longer distances, the body’s demands shift in subtle but powerful ways.
A 10K feels sharp and fast, fueled mostly by glycogen and pure determination. A half-marathon, though, is a different story—your metabolism, muscle recovery, and energy needs must adapt to sustain you over 21 kilometers.
Whether you're training to gain speed in the 10K or endurance in the half-marathon, nutrition and recovery are the two biggest factors that transform training into performance.
In this email, I explain how your metabolism changes between these distances (10K and 21K) and what that means for your nutrition and recovery strategy.
How Half-Marathon Training Works
Half-marathon training is about building endurance without sacrificing efficiency. Weekly training often includes:
Long runs (15–20+ km) that gradually extend your endurance.
Tempo sessions to improve lactate threshold (the pace you can hold without fading).
Easy recovery runs to build aerobic capacity without overtraining.
Metabolically, the key shift is that your body becomes more efficient at:
Using fat as fuel at submaximal paces (sparing glycogen).
Storing more glycogen in muscles and the liver.
Handling cumulative fatigue by repairing micro-tears in muscle fibers and replenishing glycogen repeatedly.
This is why nutrition is not just about race day—it’s about training your body to recover and adapt week after week.
INSIGHTS
Metabolic Differences – 10K vs Half-Marathon
Running a 10K
Fuel source: Almost entirely carbohydrate (glycogen).
Race time: Typically 40–70 minutes for most recreational runners, short enough that glycogen depletion isn’t a major risk.
Primary challenge: Running at a high intensity close to your VO₂ max, which burns glycogen quickly and produces lactate.
Recovery needs: Glycogen replenishment is important but not urgent if the overall diet is balanced. Muscle breakdown is moderate.
Training for a Half-Marathon
Fuel source: Mix of carbs + fat. Glycogen depletion is a real concern.
Race time: 90 minutes to 2.5+ hours, long enough that fueling mid-run is beneficial.
Primary challenge: Sustaining steady energy without “hitting the wall.” Training adaptations include more efficient fat oxidation and glycogen storage.
Recovery needs: Higher protein for muscle repair, strategic carbs to refill glycogen, and electrolyte replacement for hydration balance.
Why Nutrition Matters for Both
Think of training like building a house:
The workouts are the bricks.
Nutrition is the mortar. Without it, the bricks don’t hold together.
For a 10K, proper fueling:
Sharpens performance (better pacing, less mid-race fatigue).
Speeds up recovery so you can train harder, sooner.
For a half-marathon, proper fueling:
Prevents the dreaded late-race crash.
Ensures long training runs actually build endurance instead of breaking you down.
Improves consistency—because under-fueled runners often hit plateaus or injuries.
Bottom line: proper fueling isn’t optional. Combined with the right training, it will give you speed, resilience, pace, energy, and longevity.
Practical Nutrition & Recovery Tips
For 10K Runners
Before the Run:
Prioritize easy-to-digest carbs 2–3 hours before (oats, rice, toast, honey, jam, banana, etc).
Avoid heavy fats, fiber, or protein to reduce stomach issues.
Hydrate with 200-400ml of water 2-1 hours before
During the Run:
Water only (unless race exceeds 70–75 minutes, then consider a small gel).
After the Run:
Aim for a carb + protein combo within 1–2 hours. Examples:
Chocolate milk
Protein bar + a piece of fruit
Chicken + sweet potato and veggies
Prioritize protein (20–25g) to repair muscle.
Extra:
If you train several times a week, you should eat a certain amount of carbohydrates every day—not just on the days you run.
For Half-Marathon Runners
Before the Run:
Test pre-run meals in training: oatmeal + nut butter, bagel + + jam + almond butter, banana + cheese + honey + cinnamon
Focus on familiar, digestible carbs to maximize glycogen stores.
During the Run:
Use 30–60g carbs/hour after the first 60-75 minutes.
Example: 1 gel every 20–30 minutes, or sports drinks sipped throughout.
Hydrate with electrolytes (sodium helps prevent cramps and maintain balance).
After the Run:
Within 30–60 minutes: 2–3:1 carb-to-protein recovery snack.
Smoothie with banana + protein powder
Rice + salmon bowl
Greek yogurt with fruits and granola
Rehydrate: replace ~150% of the fluid lost (check sweat loss by weighing pre- vs post-run).
Weekly Nutrition Focus:
• Adequate iron (oxygen transport), calcium + vitamin D (bone health), and omega-3 fats (reduce inflammation).
Whether your goal is to shave minutes off a 10K or conquer your first half-marathon, the truth is this: your performance isn't based solely on training, but mainly on nutrition.
→ Train hard, eat smart, recover well, and you'll achieve your best running performance.
If you’re training right now, start experimenting with these fueling strategies on your long runs—your race day self will thank you.
Track of the week 🎧️
This week's Track of the Week it's a wonderful version of this Whitney Houston classic. I've always liked Felix Jaehn's remixes, and I think most of them are good to add to your running playlist!
I've chosen the track It’s Not Right But It’s Okay by Felix Jaehn, Whitney Houston
Any questions or something you would like to share, drop me an email
Wishing you a great weekend and week ahead!
Here’s to health and good runs⚡️
Ana Paula Alonso