Sub-2-hour half marathon training plan: 12 weeks at 9:09 a mile

Breaking 2 hours in the half marathon comes down to one number: 9:09 per mile, held for 13.1 miles. This 12-week sub-2-hour half marathon training plan builds the endurance to hold it and the speed to make it feel controlled, with every training pace worked out from that goal.

Who this plan is for

This plan is for runners who have a base and a realistic shot at 2:00. Before you start, you should:

• be running four days a week, about 18 to 20 miles in total, with a long run of 6 to 7 miles;
• have a recent race that puts 2:00 within reach (see the table below);
• be free of injury.

If you are not there yet, start with our half marathon training plan for beginners, finish a half, and come back. If you have a health condition or have been inactive for a while, check with your doctor before adding speed work.

Is sub-2 realistic for you?

The most useful way to check is to compare a recent race at another distance. Most race time predictors are based on Riegel's formula, published in American Scientist in 1981:

predicted time = known time × (new distance ÷ known distance)^1.06

The exponent is a "fatigue factor": how much you slow down as the distance grows. Riegel cited 1.08 for elite runners and 1.05 to 1.06 for male recreational runners aged 40 to 70. A 2016 study of 2,303 recreational runners, using an exponent of 1.07, found the formula predicted times reasonably well for races up to a half marathon. It was much less reliable for the full marathon, where its predictions were 10 minutes or more too fast for about half of the runners.

Working backward from 2:00:00 for 21.0975 km with an exponent of 1.06:

So if you ran a 10K in about 54 minutes or a 5K in about 26 minutes recently, your fitness already says sub-2 is in range, and this plan is about turning that into a half marathon result. A 55:00 10K predicts 2:01:21: close enough that 12 weeks of focused training may well bridge it. To turn any 10K result into a per-mile pace, use the 10K pace chart.

If your best half marathon is around 2:10, going under 2:00 means cutting about 7.7% off your time (running about 8.3% faster). That is ambitious for one training block. It is much more realistic if your shorter races predict close to 2:00 and the 2:10 was a first half, a hot day or a poorly paced race. Treat any prediction as a guide, not a promise: the same study found that factors such as age, sex, body mass index and training were linked to how fast people ran.

Your sub-2-hour half marathon paces

A half marathon is 13.1094 miles (21.0975 km). Two hours is 7,200 seconds:

• 7,200 ÷ 13.1094 = 549.2 seconds per mile = 9:09.2 per mile
• 7,200 ÷ 21.0975 = 341.3 seconds per kilometer = 5:41 per km

Even 9:09 miles add up to 1:59:57 at the finish, which is cutting it fine. Most runners cover a little more than the certified distance because of weaving and wide turns, and GPS watches often read long. At 9:09.2 a mile, 13.2 miles takes 2:00:50; to finish 13.2 miles in 2:00 you need 9:05 per mile. That is why this plan uses 9:05 to 9:09 as goal pace. Our half marathon pace chart has the splits for other finish times.

Every training pace in the plan comes from the goal:

The easy range is a rule of thumb, not a target. What matters is the effort: on easy days you should be able to hold a conversation, which matches the CDC's talk test for moderate intensity. On a hot or hilly day, easy may be slower than 11:09, and that's fine. The 5K and 10K paces use the 1.06 exponent; with exponents from 1.05 to 1.08 the 5K-equivalent pace ranges from 8:09 to 8:31, which is why the interval range is a range.

The 12-week sub-2 half marathon plan

Four runs a week. Distances are in miles. On interval and tempo days the total in brackets is approximate and includes a warm-up and cool-down of about a mile each, plus the recovery jogs. Interval recoveries are a 2-minute easy jog. Rest or cross-train on the other three days, and keep at least one full rest day.

Half-mile reps at 8:15 to 8:30 pace take 4:08 to 4:15; three-quarter-mile reps take 6:11 to 6:23. Strides are about 20 seconds of relaxed, fast running with a full walk or jog back.

How the plan works

Most running stays easy

Two of your four runs are easy: the Saturday run and the long run, apart from the goal-pace finishes in weeks 6, 9 and 10. In Stephen Seiler's review of how successful endurance athletes train, studies of nationally and internationally competitive athletes keep finding about 80% of sessions at low intensity and about 20% dominated by hard work. Those athletes train 10 to 13 times a week; on four runs a week, two quality days are a bigger share, so everything else (the Saturday run, warm-ups, cool-downs, recovery jogs and most of the long run) has to stay truly easy. The easy miles build the aerobic base and let you run the quality sessions properly. If your easy runs creep toward 9:30, slow them down.

Two quality sessions, each with a job

Intervals at 5K-equivalent pace make 9:09 feel slower by comparison. Run every rep at the same pace; if the last one is much slower than the first, you started too fast.

Tempo runs at 8:45 to 9:00 teach you to hold a pace a little quicker than race pace when you are tired. From week 6, some Thursdays switch to goal-pace runs, and the long runs in weeks 6, 9 and 10 finish at goal pace. That is the most race-specific training in the plan: 9:05 to 9:09 on tired legs.

Mileage rises gradually, with easier weeks

Weekly volume goes from 20 to a peak of 31 miles in week 9, with lighter weeks in 4 and 8. Most weeks add only a mile or two, and after each lighter week the mileage resumes just above where it was before it (24.5 to 26 miles, then 28 to 31), not from the lower number. In a study of 874 new runners, those who increased weekly distance by more than 30% had a higher rate of some distance-related overuse injuries than those who added less than 10%, although the difference was not statistically significant. Keep increases modest and don't make up a missed week by doubling the next one.

A two-week taper

Weeks 11 and 12 cut your running sharply but keep some pace work. A meta-analysis of tapering in competitive athletes found the best results came from a taper of about two weeks with volume cut by 41% to 60% while intensity and frequency stayed the same. Here, the two taper weeks (21.5 miles, then 9 plus the race) average about half the volume of week 10, and you still run on your usual days with short bits at goal pace. Cleveland Clinic's marathon advice is similar: cut mileage by 25% to 50% two weeks out, then in half again in the final week.

Running the race

A common way to miss sub-2 is to run the first few miles too fast and pay for it after mile 9.

• Miles 1 to 3: start at about 9:12. It will feel too easy. You give up only about 8 seconds against even pace, and you keep something in reserve for the last 3 miles.
• Miles 4 to 10: settle into about 9:06.
• Mile 10 to the finish: if you feel good, press to 9:00 or a little faster. This is where the goal-pace finishes of your long runs pay off.

Run that way and you cross the line in about 1:59:17. Check your time at the official mile markers rather than trusting the pace on your watch: the extra distance you cover weaving around people is already in those splits. At an even 9:09.2 a mile you would pass 5 miles at 45:46, 10 miles at 1:31:32 and 13 miles at 1:59:00. If you are at or a few seconds under 1:31:32 at the 10-mile marker, you are on track. Pace groups are useful if your race has a 2:00 group, but run your own race if the group goes out too fast.

Fueling matters at this distance, too: practice your race-morning breakfast and any gels on the long runs. Our guide to what to eat before a half marathon covers the night before and race morning. For context on where 2:00 sits, see the average half marathon time.

If you feel sharp pain, or pain that changes how you run, stop the session. A missed workout costs you nothing; running through an injury can cost you the race. See a doctor or physical therapist if it doesn't settle.