(And how it leads to faster running later.)

What's the most common mistake both beginner and experienced runners make?

It's not taking their base building phase seriously enough.

Whether you're training for your first 5K or gearing up for a half marathon or full marathon, skipping this essential phase increases your risk for common running injuries like runner’s knee, IT band syndrome, and Achilles tendonitis.

As a running physical therapist, I always start by understanding an athlete’s training history. The number one cause of injuries I see—especially during half and full marathon training—is training errors. This blog post will help you understand how to build a proper running base to avoid injury and create long-term running success.

New to running? Get my free 6-8 week run/walk training plan to help you build confidence as a beginner.

What is Base Building in Running?

Base building is a dedicated phase where you focus on gradually increasing your running mileage at an easy, conversational pace. It’s the foundation that supports your entire training cycle.

If your goal is to run a half marathon, marathon, or even an ultramarathon, you need this phase to improve your aerobic capacity—your body’s ability to generate energy over long periods of exercise. In contrast, anaerobic capacity fuels shorter, high-intensity bursts like sprints or intervals.

And remember: running is a high-impact sport. With every step, your body absorbs forces up to 2–3 times your body weight. That adds up quickly, especially if your body isn’t prepared.

Depending on your fitness level and running experience, your base building phase may last anywhere from 4 to 12 weeks. Think of it as giving your body a preview of what’s coming. Your mind might be ready for 10 miles next month—but your muscles, bones, and tendons need time to adapt.

Why Base Building Matters More Than You Think

When I treat beginner runners, I often notice a pattern: inconsistent training. A few long runs here and there, followed by several days off. This “clumped” approach is a fast track to overuse injuries like patellofemoral pain (runner’s knee) or shin splints.

Instead, aim for short, consistent runs throughout the week. It’s better to run 20–30 minutes three to four times per week than to only run twice for 60 minutes. Think of it like buttering toast—you want it spread evenly, not in thick clumps.

But this phase isn’t just about physical gains. Base building helps you create running habits and develop mental stamina. Establishing a routine takes time and intention. It’s the unglamorous work that builds discipline and helps you follow through when your training ramps up later.

How Base Building Leads to Faster Running Later

Many experienced runners want to know, “How do I run faster?”
The answer isn’t just speed workouts—it starts with a strong aerobic base.

During this phase, you’re increasing capillary density, building mitochondria (your body’s energy producers), and improving heart and lung efficiency. All of these are essential for sustainable endurance performance and for running faster later.

Think of speedwork as sharpening the stick. But base building is what gives that stick any strength to begin with.

I always remind my long-term coaching clients: training happens in seasons. You’ll have periods of hard interval training and goal-specific mileage, but these must be balanced with a season of base building and recovery. If you skip this phase, you risk burnout, injury, and stalled progress.

How to Build Your Base the Right Way

While every runner’s starting point is different, here are universal guidelines for building a strong running foundation:

• 🏃‍♀️ Follow the 10% rule – Don’t increase your weekly mileage by more than 10% to avoid overtraining.
  
  

• 🗣️ Run at conversational pace – If you can’t talk while running, you’re going too hard.
  
  

• ⏱️ Track by time, not distance – Running 25–30 minutes helps you focus on effort rather than pace or mileage.
  
  

• 🧘‍♂️ Incorporate strength and mobility – Base building is the perfect time to address muscle imbalances and running form issues.
  
  

• 📚 Need guidance? Check out The Runner’s Checklist Course for a step-by-step approach to improving your strength, mobility, and injury resilience.
  
  

Remember, it’s not about perfection—it’s about showing up with consistency and care.

Conclusion

Laying a strong foundation now helps you run faster, farther, and healthier later.
There’s nothing more frustrating than having to stop halfway through your training cycle due to a preventable injury.

By taking the time to build your base, you’re investing in your long-term running success.

If you're a beginner runner or returning after time off, I’d love to help you build your foundation. Send me an email to see how we can work together through one-on-one virtual coaching.

If you're an experienced runner but having recurring pain during your training blocks, you may benefit from my Return to Run Program. It's a three month instensive run and strength training plan personalized to you. 

And if this was helpful, don’t forget to subscribe to the blog for more evidence-based guidance on running, injury prevention, and training strategies.