Chasing 1:20: A 12‑Week Half‑Marathon Plan

It was a chilly Saturday morning, the kind where the breath forms tiny clouds and the streets are slick with the remnants of last night’s rain. I laced up my shoes, stared down the empty park loop, and thought about the last time I ran a half‑marathon—two hours and thirty minutes, a pace that felt like a gentle jog. That day, a friend whispered, “Imagine crossing the finish line in 1:20. What would that feel like?” The thought lingered, and over the next few weeks, every easy run became a conversation with that imagined finish line. If you’ve ever felt that tug—wondering whether you could shave 30 minutes off your half‑marathon—this plan is the roadmap for turning that curiosity into a concrete race time.

The Goal

Target: 13.1 miles (half‑marathon) in 1 hour 20 minutes

• Average pace required: 6:06 per mile (≈9:48 per km)
• What it demands:
  • Speed: Ability to sustain a sub‑6:10 pace for the majority of the race.
  • Endurance: A solid aerobic base that can comfortably handle 10‑12 miles at an easy effort.
  • Mindset: Consistent training, disciplined pacing, and the confidence to push through the inevitable fatigue around mile 9‑10.

Pre‑Requisites

Before you dive into the 12‑week schedule, make sure you meet these baseline criteria:

1. Current half‑marathon PB: 1:35:00 or faster OR you can comfortably run 10 miles at a steady 9:00 / mi pace.
2. Weekly mileage: At least 20–25 miles per week for the past month.
3. Injury‑free: No lingering aches that affect your form; be able to run three consecutive days without pain.
4. Time commitment: 5–6 days of running per week, plus optional cross‑training.

If you’re close but not quite there, add a 2‑week base‑building block (gradually increasing to 20‑25 miles/week) before starting.

How the Plan Works

The plan is built around four core workout types, each serving a specific purpose:

• Easy Runs (Zone 2): Build aerobic capacity and promote recovery. Keep heart‑rate at 60‑70 % of max, conversational pace.
• Tempo Runs: Sharpen lactate threshold. Run at a “comfortably hard” effort—about 80‑85 % of max HR, roughly 15‑20 seconds slower per mile than goal race pace.
• Intervals: Develop speed and running economy. Short, fast repeats with equal or slightly longer recovery.
• Long Runs: Extend endurance and teach the body to burn fat efficiently. Mostly Zone 2, with the last few miles at goal race pace in later weeks.

Pace Zones are expressed in minutes per mile (or km) but can be adapted to heart‑rate zones or perceived effort if you prefer.

Weekly Plan (12 Weeks)

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun
1	Rest	Easy 4 mi (Zone 2)	Tempo 3 mi @ 8:30 /mi	Easy 4 mi	Rest or cross‑train	Long 6 mi (Zone 2)	Rest
2	Rest	Easy 4 mi	Intervals 5×800 m @ 5:45 /mi, jog 400 m	Easy 4 mi	Rest or cross‑train	Long 7 mi	Rest
3	Rest	Easy 5 mi	Tempo 4 mi @ 8:20 /mi	Easy 5 mi	Rest or cross‑train	Long 8 mi (last 2 mi @ 7:30 /mi)	Rest
4	Rest	Easy 5 mi	Intervals 6×800 m @ 5:40 /mi, jog 400 m	Easy 5 mi	Rest or cross‑train	Long 9 mi	Rest
5	Rest	Easy 5 mi	Tempo 5 mi @ 8:10 /mi	Easy 5 mi	Rest or cross‑train	Long 10 mi (last 3 mi @ 7:15 /mi)	Rest
6	Rest	Easy 5 mi	Intervals 4×1200 m @ 5:35 /mi, jog 600 m	Easy 5 mi	Rest or cross‑train	Long 11 mi	Rest
7	Rest	Easy 6 mi	Tempo 5 mi @ 8:00 /mi	Easy 6 mi	Rest or cross‑train	Long 12 mi (last 4 mi @ 7:00 /mi)	Rest
8	Rest	Easy 6 mi	Intervals 5×1000 m @ 5:30 /mi, jog 500 m	Easy 6 mi	Rest or cross‑train	Long 13 mi (last 5 mi @ 6:55 /mi)	Rest
9	Rest	Easy 6 mi	Tempo 6 mi @ 7:55 /mi	Easy 6 mi	Rest or cross‑train	Long 14 mi (last 6 mi @ 6:50 /mi)	Rest
10	Rest	Easy 5 mi	Intervals 3×1600 m @ 5:25 /mi, jog 800 m	Easy 5 mi	Rest or cross‑train	Long 12 mi (steady Zone 2)	Rest
11	Rest	Easy 4 mi	Tempo 4 mi @ 7:45 /mi	Easy 4 mi	Rest or cross‑train	Long 10 mi (last 3 mi @ 6:45 /mi)	Rest
12	Rest	Easy 3 mi	Tempo 2 mi @ 8:00 /mi	Easy 3 mi	Rest	Race Day – 13.1 mi @ 6:06 /mi	Rest

Notes: Adjust mileage up or down by 10 % based on how you feel. If a specific day feels too hard, swap an easy run for a rest day.

Detailed Workout Descriptions

Easy Run (Zone 2)

• Purpose: Enhance aerobic base, promote blood flow, and aid recovery.
• How to Execute: Run at a pace where you can hold a full conversation. Monitor heart‑rate if you have a monitor; aim for 60‑70 % of max.

Tempo Run

• Purpose: Raise lactate threshold, making your goal race pace feel easier.
• How to Execute: After a 10‑minute warm‑up, run at a “comfortably hard” effort—just below the point where you start to accumulate noticeable lactic acid. For a 1:20 half‑marathon, this is roughly 8:00 /mi early in the plan, gradually moving toward 7:45 /mi.
• Cool‑down: 10 minutes easy jogging.

Interval Session

• Purpose: Boost VO₂ max and improve running economy.
• Structure: Example – 5×800 m fast repeats.
  1. Warm‑up: 10‑15 minutes easy.
  2. Repeats: Run 800 m at the prescribed fast pace (e.g., 5:45 /mi). Recover with a jog or walk for 400 m (or the same time as the repeat).
  3. Cool‑down: 10 minutes easy.
• Progression: As weeks advance, the distance of each repeat grows (800 m → 1200 m → 1600 m) while the pace sharpens slightly.

Long Run

• Purpose: Build endurance and teach the body to burn fat efficiently.
• How to Execute: Run at a comfortable Zone 2 pace. In weeks 5‑9, finish the last 20‑30 % of the run at a slightly faster pace (goal‑race‑pace or just a bit slower) to practice finishing strong.
• Hydration/Nutrition: Practice the fueling strategy you plan to use on race day (e.g., water, electrolyte drink, gels).

Cross‑Training / Rest

• Purpose: Allow muscles to recover while maintaining overall fitness.
• Options: Cycling, swimming, yoga, or a brisk walk. Keep intensity low to moderate.

Notes & Tips

• Progression is gradual: The plan adds roughly 1 mi to the long run each week and introduces faster paces in a stepwise fashion.
• Listen to your body: If you feel persistent soreness, cut back the mileage by 10‑20 % for a week and resume.
• Strength work: Two short sessions per week (bodyweight squats, lunges, planks) improve running economy and injury resistance.
• Sleep & nutrition: Aim for 7‑9 hours of sleep and a balanced diet rich in carbs, protein, and healthy fats.
• Pacing tools: Use a GPS watch, phone app, or perceived effort to stay in the right zones; avoid constantly checking the watch for every mile.
• Race‑day rehearsal: In week 11, try a “dress rehearsal” – run 10 mi at goal pace with the same breakfast and gear you plan to use.

FAQ

Q: What if I miss a workout? A: Skip the missed session and continue with the plan. If you miss a key quality workout (tempo or interval), replace a later easy run with that session, but don’t double‑up in one week.

Q: My paces feel too fast/slow. Should I adjust? A: Use the “talk test” for easy runs and “comfortably hard” for tempos. If you’re consistently over‑ or under‑performing, recalculate your zones based on a recent race time or a 5‑K time trial.

Q: I’m dealing with a minor niggle. Can I keep running? A: Apply the “pain‑vs‑discomfort” rule. Mild muscle soreness is okay; sharp or persistent pain warrants rest and possibly a visit to a physiotherapist.

Q: How much cross‑training is too much? A: Keep cross‑training sessions under 60 minutes and at low‑to‑moderate intensity. The goal is recovery, not additional fatigue.

Q: Should I do speed work on the track or the road? A: Both work. A track gives precise distances and easier pacing; road intervals can simulate race‑day terrain. Choose what feels most comfortable.

Closing & Workout Suggestion

The beauty of chasing a 1:20 half‑marathon is that every kilometer becomes a story—of early‑morning discipline, of learning to trust your legs, and of discovering that the finish line is as much a mental milestone as a physical one. Stick with the plan, respect your body’s signals, and celebrate the small victories along the way.

Starter Workout: If you’re eager to jump in, try the week‑1 “Tempo Intro” on a Tuesday:

• Warm‑up: 10 min easy jog.
• Main set: 3 mi at 8:30 /mi (just a touch faster than your usual easy pace).
• Cool‑down: 10 min easy jog.

Feel the rhythm, note how your breathing changes, and let that feeling guide you through the weeks ahead. Happy running!

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References

• 1/2 Marathon 12 Week Beginner | running Training Plan | TrainingPeaks (Blog)
• 1/2 Marathon 16 Week Beginner | running Training Plan | TrainingPeaks (Blog)