Half Marathon Training Plan for Beginners (12-Week Guide)

Prerequisites: Are You Ready?

This half marathon training plan assumes you can comfortably run 5 km without stopping before week 1 begins. If you cannot yet do this, complete an 8-week 5K training plan first, then return here. Entering a 12-week half marathon programme without adequate base fitness is the primary cause of overuse injury and dropout among first-time half marathon runners.

The plan runs 4 days per week across three training phases:

• Phase 1 — Base (Weeks 1–4): Build aerobic base; long run extends from 8 km to 14 km
• Phase 2 — Build (Weeks 5–9): Introduce one tempo run per week; long run extends to 18 km
• Phase 3 — Peak & Taper (Weeks 10–12): Long run peaks at 19 km, then taper volume 40% for race week

Before you begin, set your target pace using the Running Pace Calculator. A realistic beginner half marathon finish time is 2:00–2:45 (pace 5:41–7:49 min/km). All easy runs should be at a conversational pace — comfortable enough to speak in full sentences.

12-Week Beginner Half Marathon Training Plan

Abbreviations: E = easy run · T = tempo run · LR = long run · Rest = full rest · km = kilometres

↓ = recovery week. Easy runs at conversational pace. Tempo runs at comfortably hard effort (~target half marathon pace minus 15–20 sec/km). All sessions include 5-min warm-up walk.

Plan structure based on: Knechtle B, Nikolaidis PT. "Physiology and pathophysiology in ultra-marathon running." Front Physiol. 2018;9:634. PubMed ↗

Types of Runs in This Plan

Easy Run (E)

The foundation of every week. Easy runs are done at a fully conversational pace — 65–75% of maximum heart rate. They build your aerobic base, promote fat oxidation, and allow recovery between harder sessions. Most beginners run their easy runs too fast. If you cannot hold a full conversation, slow down. Use the Heart Rate Calculator to find your Zone 2 target.

Tempo Run (T)

Tempo runs are done at a comfortably hard effort — approximately your target half marathon pace, or 80–85% of maximum heart rate. You should be able to speak only in short phrases. Tempo running improves your lactate threshold, which directly raises the pace you can sustain on race day. The tempo portions within the listed distances are typically 20–25 minutes at tempo effort, bookended by easy warm-up and cool-down kilometres.

Long Run (LR)

The most important session of the week. Long runs are always done at easy effort — the same conversational pace as your easy runs. The purpose is to increase time on feet, build glycogen storage capacity, and strengthen tendons and ligaments progressively. Do not run your long runs at race pace; the adaptation stimulus comes from duration, not speed.

Race Day Pacing Strategy

For a beginner half marathon, the most common mistake is starting too fast. Adrenaline and crowd energy make the first 3–4 km feel effortless — but if you go out 20–30 seconds per km faster than sustainable pace, you will pay heavily in kilometres 16–21. Aim for an even split or a slight negative split (second 10 km faster than the first).

Use the Running Pace Calculator to convert your goal finish time to a per-kilometre pace, and memorise that pace. Run the first kilometre deliberately at or slightly slower than this pace. By kilometre 3 you should feel relaxed and in control — that is the correct feeling.

Fuelling for a Half Marathon

Unlike a 5K, a half marathon requires active fuelling for most runners. Glycogen stores are adequate for approximately 90 minutes of running at moderate intensity. For a finish time over 1:45, take one gel or equivalent carbohydrate source (30–45 g) at approximately kilometres 8–10. Practise with your exact race-day gel during your long training runs — GI distress from an untested product on race day is common and avoidable.

Drink water at every aid station (one cup, approximately 150–200 ml). You do not need sports drinks for a half marathon unless the race is held in high heat and humidity.