The beginning

I lined up at the park one morning for what I thought was a casual 5K. Sun filtering through the trees, other runners chatting quietly around me. Once I’d found my pace, someone next to me said, “Going for a 1:55 half-marathon in the fall.” I laughed and thought it sounded like a different game altogether. The remark stuck. Months later, it had become my own goal: break two hours at the half. A 1:55 over 13.1 miles takes more than raw speed. It takes trust in your training, attention to what your body needs, and learning to enjoy the longer stretches.

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The goal

Target: 13.1 miles (21.1 km) in 1 hour 55 minutes.

That’s an average of 8:38 per mile (or 5:22 per km). It’s challenging enough to feel like a real step up from a regular long run, but achievable once you’ve built the endurance, speed, and head to sustain it.

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Pre-requisites

Before starting, check the foundation:

• Current half-marathon or 10K time: 2:15 or under (half) or 45 min or under (10K). If you can comfortably hold 8:45–9:00 min/mile for 8 km, you’re ready.
• Weekly mileage: 15 to 25 miles (24 to 40 km) for at least the past 4 weeks.
• Consistency: at least 4 running days a week, including one longer run.
• Injury-free: no persistent aches that worsen with training.

If you’re not quite there, spend 2 to 4 weeks on easier runs and gradual mileage growth before the 10-week plan.

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How the plan works

Workout type	Purpose	Typical pace / effort
Easy run	Build aerobic base, support recovery	60–75% max HR, ~1 min slower than goal pace (≈9:45–10:00/mi)
Tempo run	Raise lactate threshold, hold “comfortably hard” effort	Goal pace + 20–30 s per mile (≈8:10–8:20/mi)
Interval	Develop speed and VO₂ max	5K–10K race pace (≈7:30–7:45/mi) with equal jog recovery
Long run	Build endurance, train fuel strategy	Easy pace, 1 to 2 min slower than goal pace (≈10:00–10:30/mi)
Recovery / rest	Allow adaptation, prevent over-training	Complete rest or light cross-training (cycling, swimming, yoga)
Cross-train	Strengthen supporting muscles, add variety	Low-impact activity, 30 to 45 min

The training follows a familiar shape: build for six to seven weeks, take a cut-back week, then spend the final two weeks tapering to arrive at the start line fully recovered.

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Weekly plan (10 weeks)

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun
1	Rest / light cross-train	Easy 4 mi (9:45–10:00)	Tempo 3 mi total (1 mi @ 8:15, 2 mi easy)	Easy 4 mi	Rest	Long 7 mi (10:15)	Easy 3 mi
2	Rest	Easy 4 mi	Intervals 5×800 m @ 7:35 with 400 m jog	Easy 4 mi	Rest	Long 8 mi (10:15)	Easy 3 mi
3	Rest	Easy 5 mi	Tempo 4 mi (2 mi @ 8:15)	Easy 5 mi	Rest	Long 9 mi (10:15)	Easy 3 mi
4	Rest	Easy 5 mi	Intervals 6×800 m @ 7:35	Easy 5 mi	Rest	Long 10 mi (10:15)	Easy 4 mi
5	Rest	Easy 5 mi	Tempo 5 mi (3 mi @ 8:15)	Easy 5 mi	Rest	Long 11 mi (10:20)	Easy 4 mi
6	Rest	Easy 5 mi	Intervals 5×1 km @ 7:30 with 400 m jog	Easy 5 mi	Rest	Long 12 mi (10:20)	Easy 4 mi
7	Rest	Easy 5 mi	Tempo 5 mi (3 mi @ 8:15)	Easy 5 mi	Rest	Long 9 mi (cut-back)	Easy 4 mi
8	Rest	Easy 5 mi	Intervals 4×1 mi @ 7:25 with 800 m jog	Easy 5 mi	Rest	Long 13 mi (10:20)	Easy 4 mi
9 (taper)	Rest	Easy 4 mi	Tempo 4 mi (2 mi @ 8:15)	Easy 4 mi	Rest	Long 8 mi (10:15)	Easy 3 mi
10 (race week)	Rest	Easy 3 mi	Race-pace 2 mi @ 8:38 (optional)	Rest	Light cross-train	Rest	Race day, half marathon (goal 1:55)

Easy runs can stay at conversational pace. Adjust mileage by 10% if you’re overly fatigued.

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Detailed workout descriptions

Easy run

• Start with 5 to 10 min of light jogging to warm up.
• Hold a pace where you could chat with a running partner. Heart rate stays in the aerobic zone.
• Finish with 5 min of easy jogging and a stretch.

Tempo run

• Warm up 10 min easy.
• 20 to 30 min “comfortably hard”. A few words, not a full sentence. Stick to the listed tempo pace.
• Cool down 10 min easy.
• New to tempo work? Start with 15 min and add time over the coming weeks.

Interval session

• 10 to 15 min easy jogging plus dynamic stretching.
• Run each repeat (800 m, 1 km, or 1 mi) at the target pace. A GPS watch or track helps.
• Recovery between efforts is jog or walk for roughly the same time you just ran hard (e.g. 400 m jog after 800 m).
• Cool down 10 min easy with a stretch.

Long run

• Start slow. The focus is time on feet, not pace.
• Every few miles, throw in a short 1 to 2 minute acceleration at goal half-marathon pace to get the legs used to it.
• Use these to test hydration and any race-day fuel.

Recovery / rest day

• Take the day completely off, or do something very light. A walk, yoga, or an easy bike. The body needs to repair.

Cross-training

• Whatever low-impact option you like: swimming, cycling, elliptical, or a short strength routine for core and legs.

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Notes and tips

• Progression: if a week is too hard, repeat the previous one. If it’s easy, add half a mile to a mile to your easy runs.
• Pacing tools: perceived effort, heart rate, or a GPS watch all work. Factor in weather, hills, and how you feel.
• Recovery: 7 to 9 hours of sleep, plenty of water, and protein-rich food within 30 minutes of finishing.
• Common mistakes:
  • Treating every run like a hard effort and skipping easy days.
  • Ignoring small aches. Address them with rest or a professional.
  • Expecting prescribed paces on new terrain. Terrain changes the math.
• Mental strategies: chop the long run into smaller segments, use a mantra, or run with a friend.
• Taper: the final two weeks are about polishing fitness, not building it. Cut mileage, keep the intensity, rest hard.

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FAQ

Q: I missed a key workout. Can I just do it later? A: Only if you’re still early in the week and it wasn’t your long run. Otherwise stick to the schedule.

Q: My paces feel off. How do I adjust? A: Use a recent race (5K, 10K, or half) to recalculate. If you’re consistently faster or slower across the board, shift all targets by 5 to 10 seconds per mile.

Q: I have mild shin splints. Should I keep training? A: Cut impact: cross-training, extra rest days, and calf and shin strengthening. See someone if it lingers more than a couple of days.

Q: Can I run on trails instead of roads? A: Yes. Technical terrain will slow you down. Hold the effort consistent and adjust distance to hit the same time.

Q: How much strength work should I add? A: Two 20 to 30 minute sessions a week (glutes, core, hamstrings) for running efficiency and injury prevention.

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Closing and workout suggestion

A 1:55 teaches you something new every step. Pushing through discomfort, reading your body’s signals, the satisfaction of steady training. Stick to the plan, stay flexible when you need to, and notice the small wins: a smoother tempo, a long run that felt easy, a stronger finishing kick.

Try this tempo session on a Tuesday:

1. Jog easy 10 min to warm up.
2. 3 × 5-minute efforts at 8:15/mi with 2-minute easy jogs between.
3. Cool down 10 min easy with a stretch.

Notice how your breathing settles into a rhythm and you’ll know you’re on the right track.

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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)