How to Train for Your First Half Marathon: A 16-Week Plan

A first half marathon is one of the most achievable meaningful distances in running. If you can comfortably run 5K (3.1 miles) at a conversational pace, you can complete a half marathon in 16 weeks with a sensible plan. This is that plan.

What you need to start

A reasonable starting fitness level: you can run 5K continuously at an easy, conversational pace. If you cannot do this yet, spend 4-6 weeks building up with a couch-to-5K type program before starting the half marathon plan.

A schedule that accommodates 3-4 runs per week, including one weekend long run. The long run is non-negotiable and typically takes 60-150 minutes depending on the week.

Reasonable running shoes. This does not mean expensive carbon-plate race shoes. A pair of cushioned trainers that fit, replaced every 300-500 miles, is sufficient. Go to a running specialty store and get fit if you have never done this before.

The overall structure

The plan is 16 weeks, divided into four 4-week blocks:

• Weeks 1-4 (Base): Build weekly volume gradually. Long run grows from 6 to 8 miles.
• Weeks 5-8 (Build): Introduce one light intensity session per week. Long run grows from 8 to 10 miles.
• Weeks 9-12 (Peak): Maintain or slightly grow volume, long run reaches 11-12 miles.
• Weeks 13-16 (Taper and race): Reduce volume, maintain intensity, race.

Weekly structure across all blocks: one long run, one easy run, one optional tempo/interval session, one or two rest or cross-training days.

The weekly template

Monday: Rest or easy cross-training

Full rest or 30-45 minutes of easy cross-training (cycling, swimming, walking). Not running. Full recovery from the weekend long run is the priority.

Tuesday: Easy run

20-40 minutes at conversational pace, depending on the week. This is a recovery run, not a workout. If you cannot speak in full sentences, you are running it too hard.

Wednesday: Rest or cross-training

Optional 30-40 minutes easy cross-training or full rest.

Thursday: Workout day

From week 5 onward, one structured session per week. Options:

• Tempo run: 15-30 minutes at comfortably hard pace (should feel like 7/10 effort — not all-out, but pushing), sandwiched by warm-up and cool-down.
• Intervals: Alternating hard and easy segments. A common workout is 6 x 3 minutes hard / 2 minutes easy, with warm-up and cool-down.
• Hill repeats: 6-8 repeats on a moderate hill, hard effort up, easy jog down.

If you are a first-time distance runner, tempo runs are the most important of the three for half marathon preparation. Intervals and hill repeats are supplementary.

Friday: Rest or very easy run

Full rest, or 20 minutes of very easy running if you feel recovered. No workouts the day before the long run.

Saturday: Optional short easy run

20-30 minutes very easy, or rest. This day is a cushion.

Sunday: Long run

The centerpiece of the week. Builds gradually across the 16 weeks:

• Week 1: 5 miles
• Week 2: 6 miles
• Week 3: 7 miles
• Week 4: 5 miles (cutback)
• Week 5: 7 miles
• Week 6: 8 miles
• Week 7: 9 miles
• Week 8: 6 miles (cutback)
• Week 9: 9 miles
• Week 10: 10 miles
• Week 11: 11 miles
• Week 12: 8 miles (cutback)
• Week 13: 12 miles (peak long run)
• Week 14: 9 miles
• Week 15: 6 miles
• Week 16: Race (13.1 miles)

Long runs should be run at conversational pace — slow enough that you can hold a conversation throughout. If you are running alone, the heart rate or perceived exertion should feel easy-to-moderate, never hard.

The biggest mistakes to avoid

Running easy runs too fast

The single most common mistake. Easy runs should feel easy. If your easy run is at 85% of your race pace, it is not easy — it is a moderate run and the fatigue accumulates across the week.

Rule of thumb: your easy pace should be 1-2 minutes per mile slower than your goal half marathon pace. If that feels embarrassingly slow, you are doing it right.

Skipping the long run

The long run is the single most important session of the week. Physiological adaptation to distance running — capillarization, glycogen storage, running-specific fatigue resistance — happens disproportionately during the long run. Skipping it because you are busy or tired compounds fast.

If you have to skip a session because of a busy week, skip the Tuesday easy run or the Thursday workout. Do not skip the long run.

Adding mileage too fast

The 10% rule is a reasonable heuristic: do not increase weekly mileage by more than 10% from the previous week. The plan above respects this. If you want to add runs beyond the plan, stay within the rule.

Injury rates in first-time half marathon training are primarily a function of mileage jumps and intensity spikes, not total mileage. A plan that builds gradually is the safest approach.

Racing the training runs

Training runs are not the race. Going hard on easy days, trying to hit a pace PR on a tempo workout, or racing your long run for no reason all erode the base the plan is trying to build. Save the hard effort for race day.

Neglecting strength work

Two short strength sessions per week — 20-30 minutes of squats, lunges, deadlifts, and core work — reduce injury risk substantially for first-time distance runners. You do not need a fancy program. Basic compound lifts at moderate loads, twice a week.

Race-day execution

Pace starting strategy: run the first three miles at conversational pace, even if you feel fresh. This is the hardest discipline of the race. Most first-timers blow up by going out too fast.

Fueling: For races under 90 minutes, water and electrolytes are usually enough. For races over 90 minutes (which most first half marathons will be), plan on one or two energy gels around miles 6-7 and 9-10. Practice this in training long runs; race day is the wrong time to try new fueling.

Gear: Wear what you have worn in training. Do not wear new shoes, new shorts, or a new sports bra on race day. The race is not the time to experiment.

Mindset: The race will get hard around mile 10. The training has prepared you for this. The last three miles are a matter of holding form and intention, not a matter of fitness you did not build.

After the race

Two weeks of very easy running or rest after the race. Your legs and endocrine system need recovery. Jumping back into training inside two weeks is how first-time racers end up injured.

After that, pick your next goal. A second half in 6 months, a full marathon in 9-12 months, or just a regular running practice. The base you built in 16 weeks persists and grows with continued running.