It's November. Your spring race is months away. Plenty of time to start training, right?
Well… maybe.
If you've registered for a spring half marathon or marathon, you might be thinking that January is when the real work begins.
And for some runners, that's perfectly reasonable.
But for others, waiting until January could mean starting a training plan without the running foundation needed to complete it successfully.
The question isn't just when your training plan starts. It's whether you're ready for it when it does.
Let's talk about how much time you actually need to prepare for a spring race, what you should be doing now, and why building a foundation before your official training block can make such a difference.
How Many Weeks Do You Need to Train for a Half Marathon or Marathon?
There's no single training timeline that works for everyone, but there are some useful starting points.
For runners who already have a consistent running routine, I generally recommend:
Half marathon: 12–16 weeks of structured, race-specific training.
Marathon: 16–20 weeks of structured, race-specific training.
These aren't hard rules. They're planning guidelines.
An experienced runner maintaining 40–50 km per week may need a different preparation period than someone currently running twice a week for a total of 10 km.
And a runner aiming simply to finish their first half marathon will have different training demands than someone chasing a significant personal best.
Your current fitness, running history, goals, and available training time all matter.
But here's where things get interesting.
Those 12–20 weeks shouldn't necessarily be your first 12–20 weeks of running.
The Part Runners Often Forget: Base Building
Imagine signing up for a marathon and finding a 16-week training plan online.
Week one includes four runs, a speed session, and a 14 km long run.
Looks reasonable enough.
Except you've only been running twice a week, and your longest recent run was 6 km.
That's a pretty big jump.
A training plan might be well designed, but that doesn't mean it's appropriate for your starting point.
This is where base building comes in.
Base building is the period before your more structured race-specific training begins. The focus is on developing the consistency and physical capacity needed to handle the training ahead.
Depending on the runner, this might involve gradually increasing weekly running frequency, developing comfortable aerobic endurance, establishing a manageable long run, and incorporating regular strength training.
It doesn't necessarily involve complicated workouts.
In fact, much of this running should be relatively easy.
The goal isn't to be race-ready before your training plan starts. It's to be ready to train.
What Should You Be Doing in November and December?
If you're planning a spring race, these next couple of months can be incredibly valuable.
And no, that doesn't mean you need to start running 25 km every Sunday.
For many runners, November and December are a good opportunity to establish a consistent routine without the pressure of an approaching race.
Depending on your current fitness, that might mean running three or four times per week, gradually extending one run, and incorporating strength training.
If you're already running consistently, this period can help you maintain your aerobic fitness and address areas you've neglected during previous training cycles.
If you're returning from a break, your focus may simply be on rebuilding consistency.
And if you're completely new to running, you may need a longer preparation period before beginning a conventional half-marathon or marathon plan.
There's no requirement to make every week more challenging than the last.
A well-designed base-building phase should include appropriate progression, recovery, and flexibility.
When Should You Actually Start Your Spring Training Block?
Let's put those training timelines into perspective.
For a race in early May, a 16-week training block begins in approximately mid-January. A 20-week block begins around mid-December.
For an early-March half marathon, a 12-week block begins around early December, while a 16-week block begins around mid-November.
Here's a rough guide:
Target raceTypical training startEarly March half marathonMid-November to early DecemberLate April half marathonEarly January to early FebruaryEarly May half marathonMid-January to early FebruaryEarly May marathonMid-December to mid-January
These are approximate timelines, not fixed requirements.
If your running foundation isn't established yet, you may need to begin preparing earlier.
And if you've maintained a strong base throughout the fall, you may be able to transition into race-specific training without a lengthy buildup.
The key is to work backward from race day while also looking honestly at where you're starting.
What If You're Starting From Scratch?
If you're not currently running consistently, don't panic.
But be realistic.
Going from very little running to completing a half marathon or marathon takes time.
Your cardiovascular fitness may improve relatively quickly, but your muscles, tendons, and bones also need time to adapt to the repeated demands of running.
Trying to rush that process can increase your risk of developing problems along the way.
For a new runner considering a spring half marathon, the first priority may be establishing the ability to run consistently several times per week.
That could mean starting with a run-walk program and gradually building duration before introducing more demanding sessions.
For someone considering their first marathon with little recent running experience, a later race may be a more appropriate goal.
And that's not a failure.
Choosing a realistic timeline is part of preparing well.
Do You Need Speedwork During Base Building?
Not necessarily.
If you're currently running inconsistently, adding intervals probably isn't your biggest priority.
You may benefit more from establishing regular easy running and gradually increasing the amount of training you can tolerate.
For experienced runners, some controlled faster running, strides, or hills may fit into a base-building phase.
But the goal isn't to make every run harder.
It's to develop a foundation that allows you to handle more race-specific training later.
And remember, easy running isn't wasted training.
It's an important part of developing aerobic endurance.
Don't Forget Strength Training
One of the advantages of preparing early is having time to establish a strength-training routine before your running volume increases.
Strength training can support running performance and help develop the physical capacity needed for training.
For many runners, two well-planned sessions per week can be a reasonable starting point.
These might include exercises targeting the calves, quadriceps, hamstrings, glutes, and trunk, with progressive loading appropriate to the individual.
You don't need an elaborate gym routine.
But establishing strength training now can be easier than trying to introduce it for the first time during your highest-mileage marathon weeks.
And if you have a history of recurring running injuries, this is also a useful time to address specific strength or capacity limitations.
What If You're Already Running Regularly?
Maybe you've just completed a fall half marathon or marathon.
Or perhaps you've maintained consistent weekly mileage throughout the year.
Do you still need a base-building phase?
Not necessarily in the same way as a newer runner.
If you already have a solid aerobic foundation, your preparation might focus on maintaining consistency, recovering from your previous race, developing strength, or gradually adjusting your training toward your next goal.
You don't need to start from zero every time you begin a new training cycle.
But you also don't need to maintain peak marathon training volume all year.
There's value in having periods when training is less demanding.
The goal is to arrive at your next training block healthy, consistent, and ready for the work ahead.
What About the Holidays?
Let's address the obvious.
December isn't exactly known for predictable schedules.
Between holiday gatherings, travel, work commitments, and family obligations, maintaining a perfect training routine can be challenging.
And that's okay.
Base building doesn't require perfection.
If your schedule is busy, prioritize consistency over trying to squeeze in every possible kilometre.
Three manageable runs that fit into your week may be more useful than planning five and repeatedly missing them.
You can also use cross-training when appropriate, but remember that cycling, rowing, and other activities don't completely replace the specific physical demands of running.
The important thing is to build a routine you can sustain.
Because consistency over months matters much more than one perfect training week.
How Do You Know If You're Ready for a Training Plan?
Before starting a structured half-marathon or marathon program, ask yourself:
Have I been running consistently for several weeks or months?
Can I comfortably complete the running frequency expected in the early weeks of the plan?
Is the plan's starting mileage reasonably close to what I'm currently doing?
Can I complete the early long runs without making a dramatic jump in distance?
Am I managing any existing injuries or recurring pain?
Does the training schedule realistically fit into my life?
You don't need to have everything figured out.
But if the first week of your training plan already looks like a major challenge, that may be a sign you need more preparation before beginning it.
A training plan should build on your current fitness, not assume fitness you haven't developed yet.
Where a Running Coach Can Help
One of the most common questions runners ask is, "When should I start training for my race?"
But the more useful question is often, "What should I be doing between now and then?"
That's where individualized coaching can be particularly valuable.
A coach can look at your current running volume, training history, injury history, available schedule, and race goals to determine whether you're ready for structured race training or would benefit from a base-building phase first.
And when the race-specific training begins, your program can progress from the foundation you've already established.
Rather than forcing your life and fitness into a generic 16-week schedule, the training can be built around you.
At Nth° Running, that's exactly the approach I take: thoughtful progression, individualized training, and helping runners understand why they're doing what they're doing.
The Bottom Line
If you're planning a spring half marathon or marathon, don't just circle the date when your training plan begins.
Think about what needs to happen before that.
For some runners, January is a perfectly reasonable time to begin structured training.
For others, the most important work starts now.
You don't need to be running your peak mileage in November.
You don't need to be doing marathon-pace workouts in December.
And you definitely don't need to panic because your race is still months away.
But you do need a realistic plan for getting from where you are today to where you want to be on race day.
Your spring race might be months away. Your preparation doesn't necessarily have to wait.
Interested in building a plan for your spring race? Explore personalized running coaching at nthdegreerunning.com.
— Nth° Running
