Aerobic Base Training Plan for Runners: 5-20 Miles per Week [16 Weeks]

The Aerobic Base Training Plan (5 to 20 miles per week, 8 to 32 km) is a 16-week base building plan for newer and returning runners that grows your weekly mileage gradually with easy, consistent running before any race training. Whether you're a beginner or returning after a break, this plan is perfect for you.

Plan at a glance

• Length: 16 weeks
• Weekly volume: builds from 5 to 20 miles per week (8 to 32 km)
• Includes: easy runs, a weekly long run, recovery days
• Formats: miles, kilometers, or time-based
• Best used before: a speed block or race plan

This Plan is for You If:

• You can currently complete a 2-mile run or run/walk without feeling overtaxed.
• You're looking to safely increase your weekly mileage from 5 to 20 miles (8 to 32 km).
• You want a flexible and progressive plan that allows you to build your endurance at a steady pace.
• You want to improve your aerobic capacity and overall fitness.

What’s Included:

• Flexible 16-Week Training Schedule: Provided in both miles and kilometers, this plan is designed to be flexible. It allows you to adjust your schedule based on your needs, while focusing on building up to 20 miles per week.
• Easy Effort Emphasis: This plan focuses on easy effort running, the foundation for endurance building. Most of your runs will be in the easy effort zone, allowing your body to adapt and improve its ability to run longer without fatigue.
• Run-Walk Intervals: Ideal for runners looking to gradually build their endurance, you can incorporate run-walk intervals to stay within your easy effort zone.
• Progressive Long Runs: Each week culminates with a long run, designed to help you gradually increase your distance while maintaining a comfortable, easy pace.

Additional Resources:

• Dynamic Warm-Ups & Cool-Downs: Learn effective routines to prepare your body for running and to promote recovery post-run.
• Hydration & Fueling Guidance: Tailored advice on how to stay hydrated and fuel your runs, especially for those over 30 minutes in duration.
• Optional Strength Training Recommendations: Suggestions for incorporating strength workouts to improve running form and reduce injury risk.

FAQ

Q1. What is base building in running?

Base building is a training phase focused on easy, consistent mileage to develop your aerobic engine before race specific work. It improves endurance, efficiency, and injury resistance.

Q2. How long should a base building phase last?

Most base phases run 12 to 16 weeks. These plans are 16 weeks with gradual weekly mileage increases, long runs, and recovery days.

Q3. Which base building plan should I choose?

Choose the mileage band that matches your current weekly volume: 5 to 20, 10 to 25, 15 to 30, 20 to 40, or 30 to 50 miles per week (8 to 32, 16 to 40, 24 to 48, 32 to 64, or 48 to 80 km).

Q4. Do I need speedwork during base building?

No. Base building is almost entirely easy effort. Save speedwork for a dedicated speed block or a race specific plan.

Q5. How many days a week will I run?

Each plan includes easy runs, a weekly long run, and recovery days, in miles, kilometers, or time based formats.

Why Choose This Plan?

The Base-Building 5 to 20 Miles Per Week Plan is the perfect way to establish a strong aerobic foundation that will support more advanced training in the future. Whether you're working toward your first race or simply want to improve your endurance, this plan offers the structure, flexibility, and expert guidance you need to succeed. Emphasizing recovery and easy effort running, it ensures you're prepared to handle longer distances while minimizing the risk of injury.

Build your base, and get ready for the next level of your running journey!

Written by Coach Nick a USATF and RRCA certified Running Coach with 9 years experience and CEO of Running Explained. Every Running Explained plan is built on the same structure, science, and strategy Coach Nick uses with his 1:1 coaching athletes, and is trusted by thousands of runners training for everything from their first 5k to a Boston qualifier. Have a question about this plan? Book a 30-minute call with Coach Nick, or explore 1:1 coaching at runningexplained.com.