5 Phases of Endurance Training

January 22, 2014

For the past few months, I’ve been working on my marathon coaching certification. [My first test is this Sunday, and I’m excited to be one step closer to helping more runners accomplish their goals.] As I’ve been reading a number of running texts and doing a lot of studying on the more scientific and technical aspects of endurance sports, the importance of training cycles and the phases of endurance training has been on my mind.

Unless you’re working one-on-one with a personal coach or have been running for a long time, chances are that you may not be too familiar with the periodization – or progressive cycling of training – that is critical to help us peak at the right times and avoid injury. Even runners who do understand the basic phases of endurance training may not be paying close attention to how it dictates their weekly workouts (I know I certainly wasn’t when I first started running … and even last year I didn’t really understand how critical these cycles were to my success until I started training for Beach2Battleship). Have you ever found yourself incorporating too much speed too quickly/too early or not enough intensity when you should be focused on running faster than race pace? Confused altogether?

Without sending you back in a time machine to your high school anatomy/science class or letting your eyes glaze over too much, I want to share some basic guidelines around the phases that a solid long-distance training plan should take into account (for events longer than a 10K, with primary emphasis on half marathons, marathons and long distance triathlons). As with all things related to running and triathlon, there is not a one-size-fits-all approach or one right way to do everything. There are many different ways to structure training programs, and we also learn over time what works for us based on trial and error.

Today, I’m sharing some basic guidance about progressive training for you to think about as you successfully build your own training plans or work with a coach to do so. As my coaching certification process and journey continues, I will regularly share tips and guidance on the more technical aspects of running to help all of us focus on running as safely, efficiently and successfully as possible.

Basic Phases of Endurance Training

5 phases of endurance training on runladylike.com

1. Base Phase (4 weeks to 6 months, depending on fitness level)
The base phase should account for the longest portion of your training plan. This phase focuses on developing your aerobic conditioning and improving cardio and muscular endurance. The base phase includes easier running and strength training/cross training that gradually builds in duration, allowing all of our body’s systems to adapt to the activity and reduce the likelihood of injury. Base building is the key to successful long-distance training. Here are a few things to note about the base period of training:

  • How long should the base period be? For more experienced runners, it may comprise 4 to 8 weeks of the training cycle. For beginning runners, it may take 4 to 6 months. The key to determining how long this period should last is in your interpretation of how easy your running feels. You want to develop good running fitness and strength but not get bored or unmotivated with the lack of intensity. When you’ve reached that point, you’re ready to move on.
  • Training paces should be easy and aerobic. If you use a heart rate monitor, this phase should mostly be done at 70 to 75 percent of maximum heart rate or 70 percent of VO2 max (I’ll be talking more about heart rate training in the coming weeks).
  • Training volume should increase gradually (this applies to all phases) with no more than a 10% increase in mileage week over week. A good rule of thumb is that every third to fourth week, you should drop your weekly mileage by 25% to allow your body to rest and recover.
  • Strength training during the base phase should focus on total-body fitness and consist of lighter weights and higher reps. For example, multiple sets of 10 to 12 reps of exercises 2 to 3 days per week after runs or on non-running days can help build muscular strength.

According to Running Anatomy authors Joe Puleo and Dr. Patrick Milroy, “A training program that ignores or diminishes the importance of the base training component is a training program that ignores the tenets of exercise science. Without an extensive reliance on easy aerobic running, any performance enhancement training program is destined for failure.”

2. Build/Strength/Threshold Phase (4 to 8 weeks)
The build or threshold phase is typically 4 to 8 weeks of your training cycle (depending on the kind of race you are training for and your current fitness level) and introduces faster-paced training that gets the body used to running a comfortably hard pace that can be sustained for 5 to 6 miles before reaching exhaustion. This is the phase in which intervals and tempo runs begin to be introduced. This phase focuses on furthering your running performance by better developing your cardiothoracic systems and increasing your muscles’ ability to adapt to faster paced running. In other words, this phase will start to help improve your ability to huff and puff without getting too tired (improving your anaerobic conditioning). During this phase, you always want to alternate hard training days with easy ones. Additionally, strength training can be done twice per week and should focus on countering weaknesses and on functional exercises that directly correlate to running faster. Read more about strength training for runners here.

3. Peak/Speed Phase (2-3 weeks)
The peak phase of your training is a short period of time – typically 2 to 3 weeks – in which you are running at a high intensity. Several key workouts should be designed to be completed at your VO2 max (the rate at which you are running with the maximum amount of oxygen you can consume during exercise). These are paces that are much faster than your race pace, allowing your cardiovascular system to work at peak efficiency to deliver oxygen to your blood.

4. Taper (1-3 weeks)
The taper is the period in which we cut back on our miles to prepare our legs and body to be rested and recovered for race day. The purpose of the taper period is to maintain conditioning while simultaneously recovering. Energy stores will be maximized and muscles will repair and become rested. This is also a great time to focus on mentally preparing for an upcoming race – developing your mantras and positively preparing your mind. For those running a half marathon, 10 to 14 days is the typical taper period for a recreational runner, while a more competitive runner may only taper for 7 days. For those running a marathon, 14 to 21 days are typical for most recreational runners, while more serious athletes may only require a taper period of about 10 to 14 days.

At some point amidst all this training, you actually get to participate in your race. Woo hoo!

5. Recovery Phase (2 to 5 weeks)
The most often overlooked phase of many training plans is the recovery phase. It is critical to allow our bodies to properly recover after a race before dialing up too much intensity for our next race. This period can last between 2 to 5 weeks depending on the runner and is designed to address symptoms of low energy, soreness, muscle damage and depression that can sometimes come when a race is over. There are a variety of ways to approach the recovery phase. For some runners, engaging in a month of low intensity activities that incorporate new and fun workouts is optimal. For others getting ready to run another race, running easy for 2 weeks after a race and then slowing reintroducing speed work and strength training during the third week is ideal. The goal is to mentally and physically recover from a long training cycle and to focus on having fun.

Note: Although I am currently working on my marathon coaching certification through the North American Academy of Fitness Professionals, I am not yet a certified marathon coach, nor am I a medical professional. Before beginning any fitness training program, please consult your doctor. The information in this article is based on a variety of guidance from three primary texts: The NAAFP marathon coach manual, Running Anatomy by Joe Puleo and Dr. Patrick Milroy and Precision Heart Rate Training by Edmund R. Burke.

Here are some conversation starters to get us talking more about training. I want to hear from you!
Are you consistently incorporating these (or similar) phases of endurance training into your overall plan?
Do you have a personal coach helping you build your training plans? If not, where do you get your training guidance from? What areas of your training planning would you like to improve or understand more fully?


Ashley @ BrocBlog

Great to know thanks so much for sharing! I make training plans by just picking out my favorite parts of internet training plans and making them my own, I am definitely always looking to train more effectively and I had no idea how I should be breaking down speedwork until now, thanks!

Amber S.

I think the one area I need to focus on is the peak/speed phase. I just started trying to incorporate speed into my workouts once a week. I will be running my first ever half-marathon in May so in some way I feel like my main goal should just be to finish and feel good.Thoughts on this? On most sites I see people saying that for your first you shouldn’t have a time goal? I’ve built endurance in running by using a variation of Hal Higdon’s plans with a few of my own modifications. They’ve worked great for me to build a base.

jenn @ runnderlust

wahoo thanks for sharing this! I think a lot of people don’t realize how short the peak phase is and don’t anticipate what happens if you do not plan your peak right.


Thank you for this post! I read about periodization during ironman training ( I self coached) but it was so very confusing and I just didn’t take the time to figure it out and incorporate into my training. As a result I definitely think I was overtrained!

This post is also super encouraging since I have 5.5 weeks until my goal marathon and am just getting back into running after my ankle sprain but it’s good to know that the peak phase is only 2-3 weeks! I have time to peak and taper 🙂 I have a coach who probably knows all this bit to me it’s great to know to give me reassurance that all is not lost!

Laura @losingrace

Thanks for sharing, as much as I have read a ton about all of this, it is always nice to read again from another point of view. I do not have a coach, my plans I make from own experience and from the research that I do. It’s been trial and error but I am finally realizing what works for me and what doesn’t. I am much better than I used to be about phases of training. I used to neglect the most important one…the base. Now that I focus on strong base, the other phases come naturally.

Cyanne (RunStretchGo)

This is a super-helpful post. I’m definitely condensing this training cycle more than I should, but I’m adding several weeks of MAF Training to my base building to become more efficient. I’ve also added a really good fusion cross training class to my schedule several times a week. It’s all functional movements, so I can feel it working exactly where I need it!


I had to do this for my sprints/hurdles training – slightly different language, but same idea!

In my own running, I loosely do this kind of planning – but want to focus more on an overall plan. I do have a coach who has provided plans for my May half marathon. I do my own planning for 5K heavy seasons. Of course I have plans for my track team.

Kristin @ A Mom on the Run

I get most of my information from a friend of mine who has run over 50 marathons. My training plans typically come from books (Train Like a Mother) or the freebies online (Hal Higdon, FIRST).

They’re not working so well though, since I know I should be able to perform better than I do in races, particularly the marathon. I think part of my problem is pushing through mental barriers and convincing myself that I can hold a pace longer than I currently do.

Megan (Running Toward the Prize)

Thanks for this super informative post! I’m really excited for you to blog about heart rate training – I got my first heart rate monitor to try 🙂

Ali K. @ Hit the Ground Running

This is so useful!!! Thank you!!

When I train for my first marathon, I think I’ll need to tap your brain!!

Christine @ We Run Disney

Great post! I’ve never read the specifics of the various parts of a training cycle so this was very helpful!

Cassie @ Rural Running Redhead

I read Greg McMillan’s book and he talked a lot about these phases. Before, I always just followed a plan from a book or online and didn’t give enough thought to the phases. I still probably don’t do it quite right…maybe someday I’ll get a coach. 🙂


Cassie, It can definitely be confusing and takes work to master 🙂 I’ll be offering coaching services starting later this summer and will keep you posted about plans in case you’re interested in working together 🙂 xo


Great post! I follow training plans so they always include these phases, but it is helpful to understand why they are needed. I always have a hard time taking it slow in the build phase, but it is critical. Thanks again for the useful information!

Lacy @ Running Limit-less

This was such a great and informative post. I have never been great at finding the balance between these phases. Hopefully I will get there one day. Thanks for sharing and hope your certification is going well. You’ll be a great coach!

Leslie @ Triathlete Treats

I have almost always used periodization with triathlons. Most of the time it’s been from a coach or the Matt Fitzgerald book. For running I’m a little more lax when I’m training for a marathon which is probably why my marathons usually go a rye! 🙁


Matt Fitzgerald’s book is outstanding and he does a great job of not only explaining periodization, but also creating workouts that work on each of the cycles. His plans and book are what really helped me finally get a strong grasp on periodization last year. And I think it was also what has lead me to increase my speed so significantly from previous years. Keep up the great training for Ironman 🙂

Kristen L @ DYL

I have heard about periodization, but I appreciate your detailed insights into each phase. This was really helpful!

Training Update and #FFBURPEE Challenge

[…] The last three weeks have been filled with some pretty strong (and incredibly COLD) running. I’ve slowly built mileage since the last time I checked in with a training report HERE. And with the exception of some tightness after my track workout this past Wednesday, my hamstring has been a non-issue. I’ve built up to forty miles which finally feels solid to me. I’m going to take a “step-back” week this week and reduce my mileage back to the 30-35 ish range just to give my body a break before moving forward into higher mileage. Step back weeks are always a good idea, especially if you’re building towards a goal race. It can help prevent injury and burnout. And if you’re looking for guidelines on how to build mileage safely, Jesica over at rUnladylike.com just wrote a great post on the topic. You can find that article HERE. […]


This is a very important message for all runners and athletes of most sport. User friendly information highlighting the major principles needed to ensure continuous improvements in your sport.
From experience, I wouldn’t train any other way ever again. A suggested read of mine, Healthy Intelligent Training.