The Moment the Clock Started Ticking

It was a crisp Saturday morning. I was waiting at the curb for the bus, shoes still laced, when a kid sprinted past me, his tiny legs pumping like a metronome. He shouted, “I’m gonna beat my dad’s time!” and vanished down the street. In that instant I realized how many of us chase that invisible clock – not just to finish a race, but to finish it in a time that makes us proud.

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The Goal

A 1 hour 50 minute half marathon translates to an average pace of 5:12 per kilometer (or 8:21 per mile). Hitting that mark demands:

• Speed – the ability to hold a brisk tempo for at least 8–10 km.
• Endurance – a long run that comfortably exceeds 18 km.
• Mindset – confidence that you can stay disciplined for 21.1 km while the miles get tough.

If you can picture yourself running the second half of the race feeling strong, you’re ready to start.

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Pre‑Requisites

Requirement	Why it matters
Current Half‑Marathon PB ≤ 2:05‑2:10	Gives you a realistic safety net – you’re already within 5‑10% of the target.
Weekly mileage 15‑25 km (≈ 10‑15 miles) for at least 3 consecutive weeks	Ensures a solid aerobic base before adding intensity.
Comfortable 10 km time ≤ 55 min (≈ 5:30/km)	Indicates you have the speed needed for tempo work.
No lingering injuries	Training at this intensity will amplify any niggles.

If you meet most of these, the plan is a good fit. If you’re a little shy on one item, consider adding a 2‑week base phase before diving in.

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How the Plan Works

Workout Type	Purpose	Typical Pace / Effort
Easy Run	Builds aerobic volume while promoting recovery.	1:15–1:20 min/km (easy conversational pace).
Tempo Run	Improves lactate threshold – the pace you can sustain for long stretches.	5:20–5:30 min/km (comfortably hard, “just below race pace”).
Interval Session	Raises VO₂ max and leg speed.	4:45–5:00 min/km for the work interval, full recovery jog.
Long Run	Extends endurance and teaches the body to burn fat efficiently.	1:15–1:20 min/km (slow‑steady).
Recovery / Cross‑Train	Allows muscles to repair, reduces injury risk.	Light activity – cycling, swimming, yoga, or an easy 30‑min jog.

The plan is adaptive: if a week feels too hard, drop a kilometre from the long run or replace an interval day with an easy run. The key is to keep the overall structure – a mix of speed, threshold, and endurance – intact.

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Weekly Plan (10 Weeks)

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun
1	Rest	Interval – 5×800 m @ 4:45‑5:00/km, 400 m jog	Easy 5 km	Tempo – 4 km @ 5:20/km	Cross‑train 30 min	Long 12 km @ 1:20/km	Recovery 4 km easy
2	Rest	Interval – 6×800 m @ 4:45‑5:00/km, 400 m jog	Easy 6 km	Tempo – 5 km @ 5:20/km	Cross‑train 30 min	Long 14 km @ 1:20/km	Recovery 5 km easy
3	Rest	Hill Repeats – 6×90 s uphill @ 4:50/km, jog down	Easy 6 km	Tempo – 6 km @ 5:20/km	Cross‑train 30‑45 min	Long 16 km @ 1:20/km	Recovery 5 km easy
4	Rest	Interval – 5×1000 m @ 4:45‑5:00/km, 500 m jog	Easy 7 km	Tempo – 7 km @ 5:20/km	Cross‑train 30‑45 min	Long 12 km (cut‑back) @ 1:18‑1:20/km	Recovery 5 km easy
5	Rest	Interval – 4×1200 m @ 4:45/km, 600 m jog	Easy 7 km	Tempo – 8 km @ 5:15‑5:20/km	Cross‑train 45 min	Long 18 km @ 1:18/km	Recovery 6 km easy
6	Rest	Progression Run – 10 km, start @ 1:20/km, finish 5:30/km	Easy 5 km	Tempo – 9 km @ 5:15/km	Cross‑train 45 min	Long 20 km @ 1:18/km	Recovery 6 km easy
7	Rest	Interval – 5×1000 m @ 4:45/km, 500 m jog	Easy 8 km	Tempo – 10 km @ 5:15/km	Cross‑train 45 min	Long 16 km @ 1:17/km	Recovery 7 km easy
8	Rest	Hill Repeats – 8×90 s uphill @ 4:50/km, jog down	Easy 8 km	Tempo – 11 km @ 5:10‑5:15/km	Cross‑train 45‑60 min	Long 22 km @ 1:17/km	Recovery 7 km easy
9	Rest	Interval – 3×1600 m @ 4:45/km, 800 m jog	Easy 8 km	Tempo – 12 km @ 5:10/km	Cross‑train 45‑60 min	Long 18 km @ 1:16/km	Recovery 8 km easy
10 (Race Week)	Rest	Easy 5 km @ 1:20/km	Easy 5 km @ 1:20/km	Tempo – 6 km @ 5:10/km (optional)	Rest	Race Day – Half Marathon – aim for 5:12/km	Light jog 3 km or rest

All paces are guidelines – adjust based on how you feel that day.

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Detailed Workout Descriptions

Easy Run

• Goal: Keep heart rate in a low zone (≈ 60‑70% of max).
• How: Run at a pace where you can hold a conversation without gasping. Use a watch or perceived effort (2‑3/10).

Tempo Run

• Goal: Raise lactate threshold.
• How: Warm‑up 1‑2 km easy, then run the tempo portion at “comfortably hard.” You should be able to speak a few words at a time. Cool‑down 1‑2 km easy.

Interval Session

• Goal: Boost VO₂ max and running economy.
• How: After a 10‑minute warm‑up, run the prescribed distance (e.g., 800 m) at the target fast pace. Recover with a slow jog or walk equal to half the work time. Finish with a 10‑minute cool‑down.

Hill Repeats

• Goal: Build strength and improve running form.
• How: Find a 150‑200 m hill with ~5‑6% grade. Run uphill hard (focus on short, quick steps). Recover by jogging or walking back down.

Progression Run

• Goal: Teach the body to finish strong.
• How: Start at an easy pace and gradually increase speed every 2‑3 km, ending near race pace.

Long Run

• Goal: Expand aerobic base and teach fat utilization.
• How: Keep the pace relaxed, add 10‑15 seconds per km each week until the peak week. Hydrate and consider fueling after 90 minutes.

Recovery / Cross‑Training

• Goal: Promote blood flow without additional impact.
• How: Choose low‑impact activities (swim, bike, yoga) for 30‑60 minutes. If you prefer an extra jog, keep it under 5 km at an easy pace.

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Notes & Tips

1. Listen to your body – If you feel sharp pain, back off the intensity or replace the session with an easy run.
2. Pacing is personal – Use a recent race or a timed effort to calibrate your zones. Adjust the plan if the paces feel too easy or too hard.
3. Recovery matters – Prioritize sleep, nutrition (carb‑protein within 30 min post‑run), and hydration.
4. Progressive overload – The plan adds a little volume or speed each week, then drops back in week 4 (cut‑back) to let you adapt.
5. Mindset tricks – Break the race into 5‑km segments; celebrate each mini‑victory.
6. Flexibility – If you miss a day, shift it to a later day in the same week, but keep the total weekly mileage roughly the same.
7. Real‑time feedback – Use a watch or phone app that can give you instant pace and heart‑rate information; this helps you stay in the intended zone without over‑ or under‑doing it.

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Frequently Asked Questions

Q: I missed a Tuesday interval. What should I do? A: If you still have a hard day left in the week, replace the missed interval with a shorter version (e.g., 3×800 m) and keep the rest of the schedule intact.

Q: My current half‑marathon PB is 2:12. Can I still try this plan? A: Yes, but add a 2‑week base phase focusing on consistent 15‑20 km weekly mileage before starting week 1.

Q: How do I adjust paces for hot weather? A: Slow your easy runs by 10‑15 seconds per km and keep interval work slightly slower than the target pace; the goal is to maintain effort, not exact speed.

Q: I’m dealing with a slight shin splint. Should I keep training? A: Switch the hard day to cross‑training, reduce mileage by 20‑30%, and add extra stretching/foam‑rolling. If pain persists, see a professional.

Q: Can I swap a Saturday long run for a Sunday long run? A: Absolutely – the only requirement is that you keep a recovery day after the long run.

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Closing & First Workout Suggestion

The magic of chasing a 1:50 half marathon isn’t just the finish line; it’s the countless sunrise jogs, the post‑run coffee with friends, and the confidence that builds mile after mile. Stick with the plan, honor your body’s signals, and remember that consistency beats perfection every time.

Ready to start? Try the Week 1 Interval today:

• Warm‑up: 10 min easy jog
• 5 × 800 m at 4:50 min/km (≈ 1:34 per lap on a 400 m track)
• Recovery: 400 m jog between each repeat
• Cool‑down: 10 min easy jog

Mark the time, feel the rhythm, and let the journey begin. Happy training!

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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)