Half Marathon Training Plan: The 12-Week Plan I Wish I’d Had for My First 13.1

The first time I ran 16 km in training, I was so deep in oxygen debt that I sat on a curb and genuinely considered calling an Uber home. My legs were concrete. My vision narrowed. I had no half marathon training plan — just blind confidence and a calendar that said race day was 6 weeks away.

I know that feeling of doubt. You’ve signed up for 21.1 km, and now the distance feels impossible. Maybe your longest run is 8 km and you’re wondering how anyone doubles that. Maybe you’ve tried a plan before and got injured. I’ve been in both places. And I want you to know: you can do this — with the right structure.

The second time, I did it right. I followed a structured 12-week half marathon training plan built on periodization, ran my easy runs actually easy, fueled on every long run, and tapered properly. I crossed the finish line strong with gas in the tank — and I’ve run several halfs since. This guide is the complete plan I wish I’d had: week-by-week, evidence-based, and built for real runners.

📖 Table of Contents — Click to Expand

1. Am I Ready? Prerequisites
2. Training Principles
3. Workout Types Explained
4. The 12-Week Plan
5. Pace Calculator
6. Strength Training
7. Fueling Strategy
8. 8 Training Mistakes
9. Injury Prevention
10. The Taper
11. Race Day Execution
12. Post-Race Recovery
13. Essential Gear
14. Running Form
15. FAQ
16. The Bottom Line

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Am I Ready for a Half Marathon? Prerequisites That Matter

You need a base of at least 20 km per week for 6 weeks before starting this plan. I learned this the hard way — jumping into a 12-week plan without adequate base mileage is the primary reason first-time half marathoners end up injured. My first attempt started at 15 km/week, and my shins protested by week 3.

Minimum Requirements

• Running frequency: I recommend running at least 3 times per week consistently for 6+ weeks before starting
• Current long run: You should be able to run 8–10 km continuously at a comfortable, conversational pace
• Weekly mileage: Around 20–25 km/week — if you’re under this, spend 4–6 weeks building first with my beginner mileage guide
• No current injury: Training through an active injury only makes it worse. I’ve lost more time to pushed-through injuries than to any rest week

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The Training Principles Behind This Half Marathon Plan

Run 80% of your weekly mileage at easy conversational pace and only 20% at higher intensity. This is the single most important principle in my half marathon training plan, and the one I got completely wrong the first time. I ran every run at a “comfortably hard” pace that felt productive but accumulated fatigue faster than adaptation.

The 80/20 Rule: Why Easy Runs Are Non-Negotiable

Research on endurance training consistently shows that runners who follow a polarized approach develop better aerobic capacity and have lower injury rates than runners who chronically train in the gray zone. In practice: 4 out of 5 of your runs should be at a pace where you can hold a full conversation. If you’re breathing too hard to speak in complete sentences, you’re not in Zone 2 — see my Zone 2 training breakdown for heart rate benchmarks.

Progressive Overload and the 10% Rule

Your body adapts to training stress gradually. I cap my weekly volume increases at approximately 10% — and I build in a cutback week every 3–4 weeks to consolidate adaptation. The connective tissue adapts more slowly than cardiovascular fitness, which is how stress fractures happen when you increase mileage because you “feel fine.”

The Long Run: Cornerstone of Half Marathon Fitness

The weekly long run is the single most important workout in this half marathon training plan. It builds mitochondrial density, improves fat oxidation, and develops the mental tolerance for sustained effort. I always run my long runs at easy conversational pace — this is not a race simulation. Running it too fast switches the stimulus from aerobic base-building to fatigue accumulation.

Recovery Is Where Adaptation Happens

Training creates micro-damage. Adaptation — getting faster and more efficient — happens during recovery from that stress. Skipping rest days doesn’t accelerate adaptation; it delays it. My recovery science breakdown covers why rest is training.

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Understanding Your Workout Types

This plan uses seven distinct workout types, each targeting a specific energy system. Using the wrong intensity defeats the purpose. Here’s what each one means.

Workout	Effort	Pace Description	Purpose
Easy Run	RPE 4–5/10	Fully conversational — you could sing if forced to	Aerobic base and recovery
Long Run	RPE 4–5/10	Same as easy — if anything, slightly slower	Endurance, fat oxidation, glycogen management
Strides	RPE 7/10 for 20–30 sec	Controlled acceleration — smooth and fast, not a sprint	Neuromuscular activation, leg turnover
Tempo Run	RPE 7–8/10	“Comfortably hard” — short sentences only; 20–40 min	Lactate threshold, speed endurance
Intervals	RPE 8–9/10	Hard; no conversation; 400m–1200m repeats with jog recovery	VO2 max, speed development
Race Pace Run	RPE 7/10	Your target half marathon pace — practiced to feel familiar	Race simulation, pacing calibration
Cross-Training	Variable	Bike, swim, elliptical, yoga — non-impact aerobic work	Aerobic maintenance, reduced joint stress

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The Complete 12-Week Half Marathon Training Plan

Three phases — Base (weeks 1–4), Build (weeks 5–9), Peak/Taper (weeks 10–12) — from 26 to 41 km/week. Each week has 4 running days and 1–2 rest or cross-training days. Distances are approximate — adjust based on your starting fitness. If a week feels overwhelming, don’t worry — I’ve been there. Drop a mid-week run rather than the long run, and keep going.

Phase 1: Base Building (Weeks 1–4)

Focus: building consistency, establishing my easy run habit, and progressively increasing long run distance. All runs in this phase should be easy. No intensity work — I know it’s tempting, but save it.

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun	Total
1	Rest	Easy 5 km	Easy 6 km	Rest/XT	Easy 5 km	Long 10 km	Rest/Walk	~26 km
2	Rest	Easy 5 km + 4x strides	Easy 7 km	Rest/XT	Easy 6 km	Long 12 km	Rest	~30 km
3	Rest	Easy 6 km + 4x strides	Easy 8 km	Rest/XT	Easy 6 km	Long 13 km	Rest	~33 km
4 — Cutback	Rest	Easy 5 km	Easy 6 km	Rest/XT	Easy 5 km	Long 10 km	Rest	~26 km

Phase 2: Build and Speed Development (Weeks 5–9)

Focus: increasing my long run toward race distance, introducing one quality session per week, and adding race-pace work in weeks 8–9. This is where I started feeling like a real half-marathon runner.

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun	Total
5	Rest	Easy 6 km	Tempo 7 km (3 km at tempo)	Rest/XT	Easy 6 km	Long 14 km	Rest	~33 km
6	Rest	Easy 6 km + 4x strides	Intervals: 5x800m	Rest/XT	Easy 7 km	Long 16 km	Rest	~36 km
7	Rest	Easy 7 km	Tempo 8 km (4 km at tempo)	Rest/XT	Easy 6 km	Long 17 km	Rest	~38 km
8 — Cutback	Rest	Easy 6 km	Easy 7 km + 4x strides	Rest/XT	Easy 5 km	Long 13 km	Rest	~31 km
9	Rest	Easy 7 km	Intervals: 6x800m	Rest/XT	Easy 6 km	Long 19 km (4 km at race pace)	Rest	~40 km

Phase 3: Peak and Taper (Weeks 10–12)

Focus: peak long run in week 10, then strategic volume reduction. My taper follows the research: reduce volume by 30–40% while maintaining brief quality work to keep my nervous system sharp.

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun	Total
10 — Peak	Rest	Easy 7 km	Tempo 8 km (4 km at tempo)	Rest/XT	Easy 6 km	Long 19–20 km	Rest	~41 km
11 — Taper	Rest	Easy 6 km	Intervals: 4x800m	Rest/XT	Easy 5 km	Long 14 km	Rest	~30 km
12 — Race Week	Rest	Easy 5 km	Easy 4 km + 4x strides	Rest	Easy 3 km or Rest	Easy 15 min shakeout	RACE DAY	~20 km + race

Weekly Mileage Progression

Here’s how my plan ramps mileage — notice the cutback weeks at 4 and 8 that let your body absorb the training stress before building again.

Week	1	2	3	4↓	5	6	7	8↓	9	10★	11↓	12↓
km	26	30	33	26	33	36	38	31	40	41	30	20+race

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Half Marathon Pace Calculator: Know Your Target Splits

Know your target pace per km so you can execute a pacing plan from the gun. I write my target splits on my arm before every race because my mental math under fatigue is unreliable.

Goal Time	Pace/km	Pace/mile	5K Split	10K Split	15K Split
1:45:00	4:58/km	8:00/mi	24:52	49:44	1:14:36
2:00:00	5:41/km	9:09/mi	28:24	56:49	1:25:13
2:15:00	6:23/km	10:17/mi	31:57	1:03:54	1:35:52
2:30:00	7:06/km	11:26/mi	35:30	1:11:00	1:46:30
2:45:00	7:49/km	12:35/mi	39:03	1:18:06	1:57:09

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Strength Training for Half Marathon Runners

Two 20-minute strength sessions per week prevent the most common half marathon injuries. When I skipped strength work during my first training cycle, I developed IT band pain by week 7. Now I treat these sessions as non-negotiable as my long runs. I understand if lifting feels pointless when you just want to run — I felt the same way until the IT band forced me to stop running entirely for 3 weeks.

Exercise	Sets x Reps	Why It Matters
Single-leg squat / Bulgarian split squat	3 x 10 per side	Mimics running’s single-leg load; quad and glute strength
Hip thrust / glute bridge	3 x 12–15	Weak glutes = knee and hip problems. My most important exercise
Dead bug (core)	3 x 8 per side	Spinal stability; prevents energy leakage through trunk on long runs
Calf raise (single leg, slow eccentric)	3 x 15 per side	Achilles and calf resilience — critical at half marathon mileage
Lateral band walk	3 x 15 steps each way	Hip abductor strength; prevents IT band and knee issues
Copenhagen adductor plank	3 x 8 per side	Groin stability — often neglected, often injured

I schedule my strength sessions on easy run days — never the day before a quality session. For the full biomechanical framework, see my running form deep dive.

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Half Marathon Fueling Strategy: What I Eat During Training and Race Day

Start fueling at 30–40 minutes into any run over 60 minutes — waiting until depletion is too late. The half marathon sits in the glycogen-dependent zone: long enough that fuel depletion tanks your performance in the final 5 km. I learned this at mile 10 of my first training long run — the bonk that taught me everything.

During Training Runs

• Runs under 60 minutes: I don’t fuel. Water to thirst is plenty
• Runs 60–90 minutes: Water at key points. I take 1 gel at 45 minutes if the effort is moderate
• Runs over 90 minutes (from Week 5 onward): I target 30–60g carb per hour. One gel every 30–45 minutes, starting at 30–40 minutes — not when I feel hungry
• Practice everything: I never use a gel brand on race day that I haven’t tested on long runs. GI distress mid-race is almost always caused by unfamiliar products

My Race Day Fueling Timeline

Timing	What I Do
2.5–3 hours before	Oatmeal + banana + honey. ~70g carbs. No new foods.
30 min before start	Half a banana or small sports bar. Sip water — not chug.
Min 30–40 (km 5–7)	First gel. I take it even when I feel fine — absorption takes 15 minutes.
Min 65–70 (km 10–11)	Second gel. Caffeinated if I’ve trained with caffeine.
Throughout race	3–6 oz water every 15–20 min at aid stations. Drink to thirst.

For the complete evidence-based fueling framework including carb loading and electrolyte protocols, see my fueling and nutrition guide.

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8 Half Marathon Training Mistakes I Made (So You Don’t Have To)

These 8 mistakes cost me either injury, a bad race, or weeks of wasted training. I’ve watched friends repeat every one of them. Save yourself the pain — I wish someone had told me this before my first half.

Mistake	Why It Hurts	What I Do Instead
Running every run too fast	Accumulates fatigue without building aerobic base	I run 80% of my miles at conversational pace
Skipping cutback weeks	Connective tissue never catches up — leads to stress injuries	I reduce volume by 20–25% every 4th week
Ignoring strength training	Weak glutes and hips cause runner’s knee and IT band issues	Two 20-minute sessions per week, non-negotiable
No fueling on long runs	Bonking at mile 10. I learned this one personally	Gel at 30 min, then every 30–45 min on runs >60 min
New gear on race day	Blisters, chafing, GI distress from untested products	Everything I race in has been tested on at least 2 long runs
Going out too fast on race day	Feels amazing at mile 2, collapses at mile 10	First 5K: 30–45 sec/km slower than goal pace
Skipping rest days	Adaptation happens during recovery, not during runs	I take 2 full rest days per week minimum
Cramming missed runs	Running a skipped Tuesday on Wednesday creates micro-injury risk	Missed runs are gone — I never double up

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Injury Prevention: The 4 Most Common Half Marathon Training Injuries

Runner’s knee, shin splints, IT band syndrome, and plantar fasciitis cause over 80% of training injuries. I’ve dealt with two of these personally, and in both cases the root cause was doing too much too soon. If you’re feeling a nagging ache right now, I hear you — take the rest day. Future you will be grateful.

Injury	Primary Cause	Prevention	If It Happens
Runner’s knee	Too much mileage too fast; weak quads/glutes	Progress slowly; eccentric strength work; cadence improvement	Reduce mileage; ice; strengthen VMO; rehab before returning
Shin splints	Rapid mileage increase; hard surfaces; worn shoes	10% rule; replace shoes at 700–800 km; easy surfaces when possible	Rest 1–2 weeks minimum; calf strengthening; gradual return
IT Band Syndrome	Weak hip abductors; excessive downhill; volume spike	Lateral band walks; glute strength; avoid excessive downhill early	Rest; foam rolling glute medius; address hip weakness systematically
Plantar Fasciitis	Tight calves; sudden mileage increase; poor footwear	Calf stretching and strengthening; supportive shoes	Rest; night splints; aggressive calf stretching; orthotics if persistent

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The Taper: Why Doing Less Makes You Faster

Reduce volume by 30–40% in weeks 11–12 while keeping short intensity sessions for freshness. Taper madness is real. I get it every time — my legs feel heavy, my confidence drops, and every phantom twitch feels like an injury. It’s normal. This is what a taper feels like. It does not mean you’re losing fitness.

What’s Actually Happening During Taper

• Muscle fibers repair micro-damage accumulated over 10 weeks of training
• Glycogen stores replenish to maximum capacity
• Cardiovascular adaptations consolidate — your aerobic engine finalizes its upgrades
• Neural fatigue clears — your nervous system becomes fresh and reactive
• Inflammation from tissue stress resolves

My Taper Rules

• Reduce volume, not frequency: I keep running 4 days per week but shorten each run. Don’t stop entirely
• Keep some intensity: Short intervals (4x800m at race effort) maintain nervous system readiness without fatigue
• Don’t try new anything: New shoes, nutrition, or gear — race week is not the time for experiments
• Sleep more: I aim for 8–9 hours in the final week. Sleep is my most powerful recovery tool
• Don’t carb-overload aggressively: I shift meals toward simple carbs 2–3 days out, but I don’t eat until I’m bloated
• Ignore the heavy legs: The first 2 miles of a race after taper often feel stiff. Trust the training — by mile 3 you’ll feel like yourself

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Race Day Execution: Pacing Strategy and Logistics

Start 30–45 sec/km slower than goal pace for the first 5 km — this is the most important race decision. Race day is where first-timers most often undermine months of good training by going out too fast. Adrenaline and fresh taper legs make those early miles feel effortless. They are not. The debt comes due around mile 9–10.

Pacing Strategy: Even Splits

Segment	Approach	Why
km 0–5	30–45 sec/km SLOWER than goal	Allows warmup, manages adrenaline, preserves glycogen
km 5–15	Settle into goal race pace	Body is warmed up and calibrated — find your rhythm
km 15–18	Hold pace; don’t make moves yet	The hard section — focus on form and fueling, not pace gains
km 18–21.1	If you feel good, gradually increase effort	Finish strong — earned by conservative early pacing

My Race Day Timeline

Time Before Start	What I Do
3 hours	Wake up. Eat breakfast (oatmeal + banana + honey). Coffee.
75 minutes	Arrive at venue. Bag check. Bathroom queue — go twice.
30 minutes	Optional half banana. Pin bib. Gels in belt.
15 minutes	Easy 10-minute jog warmup + dynamic stretching.
5 minutes	Seed into corral. Start GPS watch. Deep breaths.

Running the Tangents

Race courses are measured along the shortest legal path. If I run the outer edge of every turn or weave around runners, I can add 200–400 meters to my total distance. I run the inside of every curve when possible. This optimization is free speed.

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Post-Race Recovery: My First 2 Weeks After the Half

Rest completely for 48 hours post-race, then return gradually over 2 weeks. After my first half, I tried to run 3 days later. My calves seized up at mile 1. A half marathon creates systemic fatigue that outlasts muscle soreness — immune response, hormonal disruption, and connective tissue stress all need time. If you’re feeling the post-race blues after crossing the finish line, that’s completely normal — the letdown after months of focused training is real and temporary.

Timeline	Activity	Notes
Day 1–2	Complete rest. Light walking only.	Elevate legs; prioritize sleep and eating well
Day 3–5	Easy 20–30 min walk or very gentle jog	Not a test run — gentle movement aids recovery
Week 2	Easy 20–40 min runs, 3x max	No pace targets, no hills. How you feel is the guide
Week 3–4	Return to normal easy training	No intervals until week 3 minimum

For the full recovery science including HRV monitoring and when it’s truly safe to return, see my post-run recovery protocol.

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Essential Gear for Half Marathon Training

Three non-negotiables: properly fitted running shoes, anti-chafe balm, and a way to carry fuel. You don’t need expensive gear — but you do need reliable, tested items that prevent the problems that derail training.

• Running shoes: The most important investment. I’ve trained in Brooks Ghost 17, ASICS Gel-Nimbus 26, and Saucony Ride 17 — all excellent for half marathon mileage. Get fitted at a specialty store and replace after 700–800 km. See my shoe selection guide for the complete framework
• Running socks: Technical wool or synthetic socks prevent blisters on long runs. Cotton kills. See my running socks breakdown for anti-blister options
• Anti-chafe balm: Non-negotiable for runs over 90 minutes. Thighs, underarms, and nipples. See my anti-chafe guide
• Running belt or vest: For carrying gels and water on long runs. I use a FlipBelt — race it in training, train in it for race
• GPS watch or app: A phone with a running app works fine for a first half. I use the COROS PACE 3 and Garmin Forerunner 265 — both track pace, heart rate, and cadence reliably. Nike Run Club is a solid free alternative
• Reflective gear: Essential for early morning or evening runs during autumn/winter training blocks

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Running Form for Half Marathon Distance

A cadence of 170–180 steps per minute reduces impact force and improves running economy. Poor form creates inefficiency that compounds over 21.1 km. These are the form elements I focus on.

• Cadence: I target 175 spm. Lower cadence means longer airtime and higher impact per step. My step rate optimization guide walks through measurement and gradual improvement
• Arm swing: Forward-backward, elbows at ~90°, hands relaxed. Crossing the midline wastes energy. See my arm swing mechanics guide
• Posture: I run tall with a slight forward lean from the ankles. When I’m tired in the final 5K, I focus on “standing tall” as my primary cue
• Breathing: Diaphragmatic breathing (belly, not chest) ensures maximum oxygen delivery. My breathing technique guide covers rhythmic patterns for different effort levels

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FAQ: Your Half Marathon Training Questions Answered

How many weeks do I need to train for a half marathon?

If you already run 3 times per week with a long run of 8–10 km, 12 weeks is enough. If you’re starting from near zero running fitness, plan for 20–24 weeks total: 8–10 weeks building your base, then 12 weeks of structured half marathon training. I’d always recommend erring on the side of more base-building — rushing into a plan is how injuries happen.

Should I run the full 21.1 km before race day?

No — and I never do. My longest training run peaks at 19–20 km, about two weeks before race day. Running the full distance in training creates excessive fatigue and recovery cost that undermines your taper. The physiological adaptation from a 19 km long run is almost identical to a 21 km run. Race-day adrenaline and fresh legs from taper will carry you the final 2 km.

What should I eat the morning of a half marathon?

A familiar, carb-rich breakfast 2.5–3 hours before the gun. My go-to is oatmeal with banana and honey — about 60–80 grams of carbohydrate. Other options: white rice with salt, toast with peanut butter, or a plain bagel. Avoid high-fat, high-fiber, or high-protein foods that slow digestion. The most important rule: never eat anything on race morning that you haven’t tested on a long run.

How do I prevent hitting the wall in a half marathon?

Three things prevent a mid-race collapse: (1) conservative pacing in the first 5 km — the most common wall cause is going out too fast; (2) fueling early and consistently — start gels at 30–40 minutes, not when you already feel depleted; (3) progressive long runs so your body is adapted to the duration. In my experience, every ‘wall’ in a half comes from pacing error or fueling failure, not fitness.

Can I do other exercise while training for a half marathon?

Yes — and I’d actually encourage it. Cycling, swimming, or elliptical 1–2 days per week maintains aerobic fitness with less impact than running. Strength training 2x per week is critical for injury prevention. The one thing to avoid: intense new activities that create heavy soreness mid-training block. A brutal HIIT class the day before your long run will compromise the most important workout of your week.

What pace should I run my easy runs at?

Easy runs should be truly easy — you should be able to hold a full conversation without gasping. For most beginners, that’s 1–2 minutes per km slower than your goal race pace. I know it feels frustratingly slow. That’s correct. If you’re breathing too hard to speak in complete sentences, you’re running too hard — slow down until you can speak in full sentences comfortably.

How do I know if I’m overtraining?

The warning signs I watch for: persistent fatigue that doesn’t improve with a rest day, elevated resting heart rate in the morning, irritability, disrupted sleep, frequent minor illnesses, and performance that gets worse despite training. If I notice 2–3 of these simultaneously, I take 3–5 days of complete rest. It’s always better to arrive at the start line slightly undertrained than injured or overtrained.

What’s a good first half marathon time?

For most first-timers, finishing is the goal — and that’s a perfectly valid target. Average first-half times are 2:15–2:30 for men and 2:30–2:45 for women, but these vary wildly by age, fitness background, and course difficulty. My first half was 2:22, and I was thrilled to finish upright. Focus on completing the distance with a strong final 5 km rather than chasing a specific time.

Should I use the run-walk method for my first half marathon?

Absolutely — and many experienced runners still use it. The Jeff Galloway run-walk method (e.g., run 4 minutes, walk 1 minute) is a legitimate strategy that reduces cumulative muscle fatigue and often produces faster finish times than running continuously at a pace that fades in the second half. I used run-walk intervals for my first half and it helped me finish strong.

How do I deal with taper madness?

Taper madness is the anxious, restless feeling you get when your mileage drops in weeks 11–12. Your legs feel heavy, you question whether you’ve trained enough, and every phantom twitch feels like an injury. This is completely normal — I get it every single time. The key is trusting that the fitness you built in weeks 1–9 is already there. Your job during taper is to let your body absorb that work, not add more stress.

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The Bottom Line

A first half marathon is one of the most rewarding goals I’ve ever set as a runner. It’s long enough to demand serious preparation, short enough to accomplish in 12 focused weeks with the right base, and meaningful enough that crossing the finish line — whatever your time — changes how you see your own capacity.

Stick to the easy-run discipline. Don’t skip the strength work. Practice your fueling on every long run from week 5 onward. Respect the taper. And on race day: start slow, stay patient in the middle, and earn the finish.

I bonked at mile 10 on my first attempt. I finished strong on my second. The difference wasn’t talent — it was having a plan and following it. This half marathon training plan is that plan. You’ve got this. Trust it.

Building your base? Start with my guide to first-time running distances. Already done a half and targeting a 10K PR? See my 10K training plan.

Updated May 2026