Half Marathon Training Plan to Improve Speed
Drop significant time at your next half marathon. This plan uses threshold intervals, race-pace long run segments, and a disciplined taper to unlock a faster 13.1.
The plan, week by week
Minutes per week. Tap a week.The half marathon rewards aerobic engine more than raw speed. The runners who struggle most are those who train like 5K runners, carrying too much intensity and not enough easy aerobic volume. Sustainable progression, quality long runs, and one threshold session per week is the formula that holds up across conditions. This plan is built for runners ready to go faster: the structure, pacing guidelines, and weekly progression are calibrated to your specific situation, not a generic template.
Speed sessions that actually help a half marathon
Getting faster at the half marathon is less about pure speed and more about holding a quick pace for longer. Short, fast intervals still have a place, but in smaller doses. A session every week or two of 1 km reps at around 10K pace keeps your legs quick and makes half marathon pace feel calmer. The main quality work is longer: 2 × 20 minutes at threshold, or 3 × 3 km at half marathon pace with a few minutes of steady jogging between. Weekly volume matters too. Many runners getting faster at this distance find a gradual rise in easy mileage does more than another hard session.
Testing your half marathon goal with a 10K race
A 10K race four to six weeks before a goal half marathon is one of the best ways to set a realistic race pace. A rough guide is that half marathon pace sits around 10 to 20 seconds per kilometre slower than your current 10K pace, depending on how much endurance you have built. If your long runs have been strong, expect to be at the faster end. Race the 10K properly, then use the result to set the pace for your remaining goal-pace sessions. Ease off for a few days before the 10K, and take two easy days afterwards so the block stays on track. Then keep building.
The physiology of getting faster
Speed improvement at recreational level comes from two places: increased VO2max (your aerobic ceiling) and improved lactate threshold (the pace you can sustain before fatigue accumulates). VO2max responds best to intervals run at hard effort (roughly 3–5K race pace) with short recovery. Threshold responds best to sustained tempo running at comfortably hard effort. This plan develops both systematically.
Running economy: the often-overlooked factor
Running economy — how much oxygen you use at a given pace — varies significantly between runners of equal fitness. Strides (short, controlled accelerations to near-sprint speed with full recovery) are one of the most effective and underused tools for improving economy. Two to three sets of strides, two to three times per week, gradually improve neuromuscular efficiency without adding meaningful stress.
Taper correctly to perform on race day
The taper is where the speed work pays off, but only if you do it correctly. Reducing volume by 30–40% in the final two weeks while maintaining intensity preserves fitness while allowing accumulated fatigue to clear. Running race-pace efforts of 60–90 seconds during the taper keeps the neuromuscular system primed. Cutting both volume and intensity in the taper leaves you flat on race day.
Training philosophy
The half marathon rewards aerobic engine more than raw speed. The runners who struggle most are those who train like 5K runners, carrying too much intensity and not enough easy aerobic volume. Sustainable progression, quality long runs, and one threshold session per week is the formula that holds up across conditions.
Questions
How many days per week does this half marathon plan require?
Most sessions in this plan run four to five days per week, including one quality session, a long run, and easy aerobic running. The plan is designed to be adjustable — with Daash, Claude can restructure it around your available days each week.
Do I need a GPS watch to follow this half marathon training plan?
A GPS watch or running app is helpful for tracking pace and distance, but not strictly required. Effort-based running (using a scale of 1–10 perceived exertion) works well for easy runs. For quality sessions where specific paces matter, a watch becomes more valuable.
What should I eat before a long run?
For runs under 60–75 minutes, eating beforehand is optional. For longer runs, a light carbohydrate-based meal two to three hours before the session — oats, toast with banana, or a rice-based option — provides fuel without gastrointestinal issues. Avoid high-fat, high-fibre, or unfamiliar foods on long run mornings.
How does Daash adapt the plan if I miss a session?
Daash sees missed sessions in your Garmin data. Tell Claude why — illness, fatigue, life — and it reworks the coming week: redistributing sessions, reducing volume if needed, or adjusting the next quality session, then updates the workouts on your watch.
Do I need to take gels or nutrition during training for a half marathon?
For long runs over 75–80 minutes, practising race nutrition is valuable. Train with the gels, chews, or drinks available at your target race so your gut is adapted before race day. Do not try a new nutrition product for the first time on race morning.