Aerobic Base Training Plan for Runners: 20-40 Miles per Week [16 Weeks]

The Aerobic Base Training Plan (20 to 40 miles per week, 32 to 64 km) is a 16-week base building plan for experienced runners that develops deep aerobic endurance and durability through higher volume easy mileage before race specific training.Whether you're preparing for a race or simply looking to boost your endurance, this plan is the perfect pathway to help you achieve your goals while maintaining balance in your training.

Plan at a glance:

• Length: 16 weeks
• Weekly volume: builds from 20 to 40 miles per week (32 to 64 km)
• Best for: experienced runners building toward higher training loads or longer races
• 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 currently run 20 miles (32 km) per week comfortably without overtaxing your body.
• You want to progressively increase your weekly mileage to 40 miles (64 km) in a safe, controlled manner.
• You're focused on easy-effort running to build aerobic capacity, endurance, and overall fitness.
• You seek a flexible plan with mileage, kilometers, and time-based options that adapt to your schedule and fitness level.

What’s Included:

• 16-Week Progressive Training Schedule: This plan includes equivalent schedules in miles, kilometers, and time-based formats, making it easy to track and adjust your progress as you work up to 40 miles per week.
• Easy Effort Focus: The majority of runs in this plan are easy-effort runs designed to build endurance and prevent injury. You’ll learn how to monitor your heart rate and perceived effort, helping you stay in your true easy zone.
• Long Run Development: Weekly long runs are key to increasing endurance, with a steady increase in distance that helps you build mileage comfortably and efficiently.
• Uphill Sprints and Strides: These additional workouts at the end of easy runs will help you develop strength, power, and running efficiency, ensuring a well-rounded base.

Additional Resources:

• Dynamic Warm-Ups & Cool-Downs: Follow video-guided routines for preparing your body for runs and aiding recovery afterward.
• Hydration & Fueling Tips: Essential guidance on staying hydrated and fueling for long runs, especially in various weather conditions.
• Strength Training Suggestions: Incorporate optional core and lower-body strength training sessions to reduce injury risk and improve performance as you increase mileage.

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.  The plan contains an option to run 3-4 days a week or 4-5 days a week.

Why Choose This Plan?

The Base-Building 20 to 40 Miles Per Week Plan is the ideal choice for runners looking to safely and progressively increase their weekly mileage while focusing on easy-effort running. The plan offers flexibility, expert guidance, and a well-rounded approach to building a strong aerobic foundation. Ready to elevate your running? Start building your base today!

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.