Half Marathon Training Guide: Break Your Personal Record

Whether you’re a beginner or an intermediate runner aiming to eventually run a strong full marathon, this guide is for you.

Here, I’ll walk you through specific training methods to improve your half marathon time.

When I first got serious about running, I built my training around Jack Daniels’ Running Formula — and it helped me make significant progress.

But looking back after studying exercise physiology more deeply, I realized there was a lot I hadn’t fully understood just from reading the book.

By the end of this article, you’ll have a clear, science-backed understanding of what it takes to run your best half marathon — and you’ll know exactly where to focus your training efforts.

You’ll also learn concrete training methods proven to improve your half marathon performance.

Half Marathon Finish Time Distribution: Where Do You Stand?

If you’re reading this, you’re probably a runner who takes training seriously and wants to keep pushing toward higher goals.

To put half marathon performance in perspective, here’s data aggregated from six major JAAF-certified half marathons held in 2022.

Take a look at where your goal finish time falls. Running a half marathon in around 1:20 puts you in roughly the top 5% of all runners. Since breaking 3 hours in a full marathon also requires being in the top ~5%, a half marathon time around 1:20 is the rough equivalent of a sub-3 full marathon.

That said, reaching a high goal requires dedicating a meaningful portion of your daily time to running training. How quickly you get there depends on your athletic background and physical baseline — individual variation is real.

First Goals for Beginners: Finishing Under 2:00 to Sub-1:50

For many runners just starting out, the first half marathon goal is simply finishing under 2:00 — or eventually breaking 1:50 (110 minutes). The finish time data above shows that a large portion of finishers cluster around the 2-hour mark, making it a realistic and motivating target.

Goal Time	Monthly Mileage	Weekly Frequency
Finish under 2:00	37–62 miles (60–100km)	3–4 days/week
Sub-1:50 (110 min)	62–93 miles (100–150km)	4–5 days/week
Sub-1:40 (100 min)	93–124 miles (150–200km)	5+ days/week

The key is progression: nail the finish first, then work toward sub-1:50, then sub-1:40. This step-by-step approach minimizes injury risk while building sustainable fitness. In Daniels’ VDOT terms, a 1:50 finish corresponds to approximately VDOT 40–41, and a 1:40 finish to roughly VDOT 46–47 — useful reference points when setting your interval training paces.

A Training Framework That Works for Most Runners

Running training is highly individual, but there are frameworks that hold up for a wide range of runners.

For me, discovering Jack Daniels’ Running Formula was a turning point — my performance improved dramatically, and because the approach is designed to minimize injury risk, I got hurt far less often.

Another well-regarded system is Lydiard Running Training, the methodology used by Aoyama Gakuin University’s elite distance running team.

Both are substantial reads, but if you’re serious about continuing to improve over the long term, they’re worth reading at least once.

Monthly Mileage Targets for Half Marathon Training

There’s no single correct answer for how much you need to run to reach a given goal — the required training load varies widely from person to person.

From my own experience and that of runners I know, those running around 1:20 for a half marathon tend to be logging around 300km per month, on average. Training frequency is typically around 5 days per week.

When I ran my personal best of 1:12 for the half marathon, I was covering 400–500km per month.

Some runners reach their goals with less volume, but the required amount depends on your athletic history and individual makeup. The half marathon is long enough that weekly mileage needs to be taken seriously.

Balance your rate of improvement against your available training time, and gradually increase your volume from there.

Half Marathon Training: A 3-Phase Approach

Whether it’s a half marathon or any other race, I believe you need around six months of structured training to truly peak on race day.

If your target race is less than six months away when you read this, work through each phase but compress the timelines proportionally.

The key variable in structuring your training is the balance between intensity and volume. You need to stack training within the limits of what your body can recover from and adapt to.

Step 1 — Base Building Phase

The key priorities for the base building phase are as follows.

The base building phase is the period of your training cycle with the highest overall volume (total distance run).

Building volume here develops the injury resilience and recovery capacity you’ll need for the harder, higher-intensity training in Steps 2 and 3.

High training volume increases mitochondrial content (both number and size) in muscle tissue, raising your foundational aerobic capacity.

A review by Granata et al. (2018)※1 showed that mitochondrial content (quantity) responds to training volume, while mitochondrial respiratory function (quality) is regulated by intensity. This provides a clear physiological basis for the phased approach: build mitochondrial mass through volume in the base phase, then enhance their function through high-intensity work in the next phase.

The base phase is also the right time to incorporate speed work at paces far from race pace. As the race approaches, pure speed development becomes harder to fit in without compromising race readiness — so lay that groundwork now.

Here’s a sample training week for the base building phase when targeting a half marathon. If the distances and session lengths are too much for your current fitness, scale each session down proportionally.

The base building phase centers on moderate-to-threshold intensity running. Include strides regularly to stimulate fast-twitch fibers and prevent your top-end speed from slipping.

Strides operate at glycolytic intensity. Flat-ground strides are effective, but hill strides add an extra stimulus.

Include a long run once a week. Even for a half marathon, aim to reach around 120 minutes. In hot summer months, scale back to 90 minutes. Set the pace at moderate intensity.

Step 2 — Build Phase

The key priorities for the build phase are as follows.

The build phase is when high-intensity training enters the picture. To improve the function of the mitochondria you grew in the base phase, high-intensity work is essential.

Here’s a sample training week for the build phase.

VO2 max interval training is the centerpiece of the build phase. It bridges the aerobic capacity and raw speed built in the base phase to race-ready fitness.

Throughout the build phase, focus on maintaining — not extending — the aerobic capacity and raw speed from the base phase.

Moderate-intensity runs and long runs are your primary tools for preserving aerobic capacity. Think of it as keeping your mitochondrial mass intact while progressively upgrading their function.

Continue strides to maintain raw speed, but reduce frequency and reps compared to the base phase.

Step 3 — Race-Specific Phase

The race-specific phase is the final step before your target race. Key priorities for this period are as follows.

In this phase, shift toward training at or near your goal race pace.

Here’s a sample training week for the race-specific phase when targeting a half marathon.

Threshold pace corresponds to half marathon race pace. Repeatedly training at your target pace sharpens running economy (RE) at that specific effort level.

Running economy refers to how efficiently you use oxygen at a given speed. Bassett & Howley (2000)※2 showed that long-distance performance is determined by three factors — VO2 max, lactate threshold velocity, and running economy — and that a better RE means running faster even at the same VO2 max.

A review by Barnes & Kilding (2015)※3 identified accumulated aerobic training as the primary driver of running economy improvement.

Continue strides and long runs throughout this phase to maintain the fitness you’ve built over the previous months.

How to Set Your Training Paces with VDOT

Use the VDOT Calculator to determine your training paces based on your current personal best.

It calculates target paces appropriate for your current fitness level. For a detailed walkthrough of how to use it, see the article below.

How to Taper Before Your Half Marathon

Runners logging more than 200km per month can meaningfully boost race performance through proper tapering.

Tapering means reducing training volume in the weeks leading up to a race. Done well, it can lift your performance noticeably. A review by Mujika & Padilla (2003)※4 showed an average performance gain of around 3% — and up to approximately 6% — from effective tapering.

Meta-analysis by Bosquet et al. (2007)※5 found that beginning the taper two weeks (14 days) before the race is most effective, with a 40–60% reduction in training volume producing the best results. Simply running shorter distances and for less time is enough to see the benefit.

What you reduce is volume, not intensity — maintain your training pace throughout the taper. For a detailed guide to tapering, see the related article.

If your weekly mileage is low, there’s not much accumulated fatigue to clear — tapering isn’t necessary in that case.

Diet, Sleep, and Recovery: What to Do Off the Track

Beyond running itself, here are the three things I focus on in my daily life.

For nutrition, I aim for a balanced intake of carbohydrates, protein, and fat.

That said, I let myself eat what I enjoy. With the volume I run, I remind myself that “a little extra won’t hurt” — and I keep life stress-free around food.

For sleep, I make a conscious effort to get at least 7 hours a night. Many people feel too busy to sleep properly, but rest is just as important as training itself. Your body adapts and your fitness improves only after recovering from the stress you’ve placed on it.

Sleep deprivation has measurable effects on running performance. A meta-analysis of 45 studies (Kong et al., 2025※6) found that insufficient sleep significantly increases RPE (rate of perceived exertion) during exercise.

In other words: when you’re short on sleep, the same pace will feel noticeably harder than usual.

Self-care is also non-negotiable. To stay healthy and train consistently, I’ve made post-run stretching and foam roller work a daily habit.

This routine actually helped me recover from a hamstring pain near the attachment point at the top of the leg.

I weigh myself every morning. I recommend making it a daily habit.

Not to force weight loss — but to use body weight as a daily indicator of hydration and nutrition status. Asking “Am I properly hydrated? Am I eating enough?” is the real purpose. Weigh yourself at the same time each day so you can compare meaningfully. Right after waking up is ideal.

Body weight closely correlates with race performance — generally, lighter is faster. That said, don’t rush into aggressive weight loss. Underfueling on race day or increasing injury risk during training are real dangers worth avoiding.

A Final Note From My Own Training

The 3-phase approach outlined in this guide is what I used when I ran a personal best of 1:12:29 for the half marathon. While the specifics will vary based on your fitness level and available time, the underlying framework — build volume, raise intensity, sharpen race specificity — is sound for most recreational runners.

I hope this guide helps you find your path to a new half marathon personal record.

References

※1 Granata C, Jamnick NA, Bishop DJ (2018) “Training-Induced Changes in Mitochondrial Content and Respiratory Function in Human Skeletal Muscle” Sports Medicine

※2 Bassett DR, Howley ET (2000) “Limiting factors for maximum oxygen uptake and determinants of endurance performance” Medicine & Science in Sports & Exercise

※3 Barnes KR, Kilding AE (2015) “Strategies to improve running economy” Sports Medicine

※4 Mujika I, Padilla S (2003) “Scientific bases for precompetition tapering strategies” Medicine & Science in Sports & Exercise

※5 Bosquet L et al. (2007) “Effects of tapering on performance: a meta-analysis” Medicine & Science in Sports & Exercise

※6 Kong Z et al. (2025) “Effects of sleep deprivation on perceived exertion during exercise: a meta-analysis” Frontiers in Physiology