5 Mistakes First-Time Marathoners Make (Avoid These!)
Training for your first marathon is exciting. It is also a little overwhelming. With so much advice online, it is easy to miss the simple things that make the biggest difference on race day.
To help you feel confident at the start line, here are five of the most common first-time marathon mistakes, plus practical fixes you can start using this week.
Mistake #1: Starting Too Fast (Because It Feels Easy)
Mistake #1: Starting Too Fast (Because It Feels Easy)The first miles of a marathon can feel effortless. Crowds are cheering, adrenaline is high, and your legs feel fresh. This is exactly why many first-time marathoners go out too fast and pay for it later.
Why it hurts:
Going out fast spikes effort early, burns through glycogen sooner, and can lead to cramps, nausea, or a painful slowdown in the final 10K.
How to avoid it:
- Pick a realistic goal pace based on recent long runs or a tune-up race (10K, half marathon).
- Run the first 2 to 4 miles slightly slower than goal pace.
- Use a “negative split” mindset: finish stronger than you start.
- If pace groups are available, start with the group that matches your conservative goal.
Quick rule: If mile 3 feels “hard,” you are running the wrong pace for 26.2.
Mistake #2: Ignoring Fueling Until It Is Too Late
Mistake #2: Ignoring Fueling Until It Is Too LateMany beginners treat fueling like an emergency plan instead of a strategy. The marathon is long enough that even well-trained runners will struggle without calories.
Why it hurts:
Your body stores limited glycogen. When it runs low, energy drops fast. That is the “wall” many runners talk about.
How to avoid it:
- Practice fueling during long runs, not just on race day.
- Aim for 30 to 60 grams of carbs per hour (some runners can handle more with practice).
- Start fueling early, usually around 30 to 45 minutes into the run.
- Test different options (gels, chews, sports drink) to find what your stomach tolerates.
Simple plan to start with:
1 gel every 30 to 40 minutes, plus water as needed (adjust based on your body and conditions).
Mistake #3: Treating Hydration Like a Contest
Mistake #3: Treating Hydration Like a ContestIn warm or humid conditions, hydration matters. In cool weather, it still matters. The mistake is assuming “more is always better” or “I can just tough it out.”
Why it hurts:
Too little fluid can lead to fatigue, dizziness, and cramping. Too much plain water can dilute sodium levels and cause serious issues.
How to avoid it:
- Use thirst as a guide, but have a plan.
- Include electrolytes (sports drink or electrolyte tabs), especially if you sweat heavily.
- Learn your sweat rate on long runs (how much weight you lose per hour in similar weather).
- Take small sips consistently instead of chugging occasionally.
Austin tip: If your race-day forecast is warm, practice hydration and electrolytes in similar conditions during training. Heat changes everything.
Mistake #4: Skipping Strength Training and Then Getting Injured
Mistake #4: Skipping Strength Training and Then Getting InjuredRunning builds endurance, but it does not automatically build the strength and stability that protect your joints when fatigue sets in.
Why it hurts:
As the miles add up, form can break down. Weak hips, glutes, and core can contribute to knee pain, shin splints, IT band issues, or plantar fasciitis.
How to avoid it:
Add 2 short strength sessions per week. Keep it simple and consistent:
- Squats or goblet squats
- Lunges or split squats
- Deadlifts (or Romanian deadlifts with light weights)
- Calf raises
- Glute bridges or hip thrusts
- Planks and side planks
Minimum effective routine:
20 minutes, twice a week, done year-round.
Mistake #5: Not Respecting the Taper (or Overthinking It)
Mistake #5: Not Respecting the Taper (or Overthinking It)The taper is the last stretch of training where you reduce volume so your body can recover and show up rested. Many first-timers panic when mileage drops. They add “extra” workouts to feel ready, or they change everything at the last minute.
Why it hurts:
You cannot gain fitness in the final week, but you can accumulate fatigue. New shoes, new gels, or a last-second hard workout can turn race day into a struggle.
How to avoid it:
- Trust your training. The taper is part of the plan.
- Keep some intensity (short, controlled efforts), but reduce overall mileage.
- Prioritize sleep, hydration, and consistent meals.
- Avoid trying anything new in the final 10 to 14 days.
Remember: You want to feel a little “itchy” to run on race morning. That is a good sign.
Quick Race-Day Checklist for First-Time Marathoners
- Start slower than you think you should
- Begin fueling early and fuel consistently
- Drink small amounts regularly, include electrolytes
- Stick to familiar gear and nutrition
- Focus on effort, not just pace, if conditions change
Frequently Asked Questions
How long should I train for my first marathon?
Most first-time marathon training plans run 12 to 20 weeks, depending on your base mileage and running history. Longer is often safer if you are new to running.
What is the biggest mistake first-time marathoners make?
Starting too fast is one of the most common. It feels great early, then becomes costly late in the race.
When should I take my first gel during a marathon?
Many runners do best starting 30 to 45 minutes into the race, then continuing every 30 to 40 minutes. Practice in training to confirm what works for you.
Should I walk during my first marathon?
A planned run-walk strategy can be effective for first-timers, especially to manage pacing, fueling, and fatigue. If you use it, practice it in long runs.
Your first marathon does not need to be perfect. It just needs to be prepared. If you avoid these five mistakes and stick with a simple plan, you will give yourself the best chance to finish strong and actually enjoy the experience.
Ready for race day in Austin?
Check out our race weekend info, course details, and runner resources here:
1) Run by effort, not pace
2) Time your runs to avoid the worst heat
3) Hydrate smarter (and do not skip electrolytes)
4) Dress like it is summer (because it is)
5) Use cooling strategies that actually work
6) Know the warning signs and respect them
7) Adjust your training week so it still adds up
8) Fuel your long runs like race day
