RW's Ultimate 16-week Marathon training plan for runners looking to run sub-3:45

A 3:45-hour marathon is approximately 8:35 per mile. However, it's likely you'll have to run more like 8:30 per mile on the day, once you factor in a bit of dodging and weaving. To break 3:45, you should eventually be capable of a sub-1:45 half-marathon (8:00 per mile) and sub-46:00 10K (7:30 per mile). Right now, you should be running at least 25 miles per week, and be able to run for 1:15 non-stop.

Rest/Cross-Train (XT) – Take a rest day, or do moderate cross-training with a no-impact activity such as yoga or swimming.

Tempo – Run easy for one mile to warm up. Then ease into the given pace for the distance show. Run easy for a mile to cool down. Tempo runs should feel challenging; on a scale of one to 10, your effort will feel like a seven or eight. You should be able to utter just a few words at a time. These runs train your body to sustain speed over distance.

Easy – Easy runs should be done 30 seconds to one minute per mile slower than your marathon goal pace.

Long run – Much like an easy run, this is a long, slow-distance run that will build your endurance. Run at an easy pace; you should be able to hold a conversation. This should be 30 seconds to one minute per mile slower than your goal pace.

Mile repeats – After a one-mile warm-up, run one mile at the given pace, then jog very slowly for half a mile to recover. Repeat cycles as directed. Cool down with one mile of easy running.

Marathon pace – This is the pace that you hope to maintain in the race. In this plan, that means 8:30 min per mile. Run one mile easy to warm up and one mile easy to cool down.

Work out what pace to do each of your runs at using our training pace calculator - just tell us a recent run time and we'll do the rest.

Very few runners will get to the end of their marathon training schedule without missing some runs due to illness, injury or life getting in the way. If you’ve missed four weeks or more, our best advice is to postpone your marathon, as it’s unlikely you’ll be able to get the time you want on race day having missed a month.

If you’ve missed two or three weeks, you should still have time to build up to your longest training runs, which are a key to race-day success. If you are coming back from injury, spend a week or two gradually increasing your training volume, using previous weeks on the training plan as a guide.

Week One (23M)

Mon 4M (miles) (38 mins) easy

Tue Rest

Wed 5M (48 mins) easy

Thu 3M (25 mins 30 secs) marathon pace

Fri Rest

Sat 3M (30 mins) easy

Sun 8M (75 mins) long

Week Two (29M)

Mon Rest

Tue 7M consisting of the following: 1M jog, then 3 x 1.5M (or 12 mins) tempo, with 400m (3-min) jog recoveries, then 1M jog to cool down

Wed 6M (58 mins) easy

Thu 4M of 1M jog, then 2M (approx 16 mins) temp, then 1M jog

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 10M (95 mins) long

Week Three (31M)

Mon Rest

Tue 7M of 1M jog, then 4 x 1M (or 7:30 mins) fast, with 400m (or 3-min) jog recoveries, then 1M jog

Wed 7M (70 mins) easy

Thu 4M (34 mins) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 10M (95 mins) long

Week Four (30M)

Mon Rest

Tue 6M consisting of the following: 1M jog, then 5 x 800m (or 4 mins) fast, with 200m (or 2-min) jog recoveries, then 1M jog

Wed 8M (80 mins) easy

Thu 1M jog, then 3M (25 mins 30 secs) marathon pace, then 1M jog

Fri Rest

Sat 3M (30 mins) easy

Sun 8M consisting of: 1M jog, then race 10K or 5M, then 1M jog. Aim for a sub-46:00 10K or sub-37:00 5-miler

Week Five (32M)

Mon Rest

Tue 6M consisting of: 1M jog, then 4M (or 35 mins) fartlek (3 mins fast, 2 mins slow), then 1M jog

Wed 6M (57 mins) easy

Thu 5M (42 mins 30secs) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 12M (1hr 55) long

Week Six (36M)

Mon Rest

Tue 6M 48 mins slow

Wed 7M (67 mins) easy

Thu 1M jog, then 4M (32 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 14M (2hrs 15) slow

Week Seven (40M)

Mon Rest

Tue 6M consisting of: 1M jog and strides, then 10 x 400 mins at 5K pace, with 200m ( or 1-min 30) jog recoveries, then 1M jog

Wed 8M (75 mins) easy

Thu 7M (59 mins 30 secs) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 16M (2hrs 30) long

Week Eight (35M)

Mon Rest

Tue 5M consisting of: of 1M jog and strides, then 12 x 200m at 1 mile pace, with 200m (or 1-min) jog recoveries, then 1M jog

Wed 7M (65 mins) easy

Thu 1M jog, then 3M (24 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy

Sun Race (ideally half-marathon) (15M inc warm up/ cool down). Aim for sub-1:50.

Note that the ‘approximate’ targets for training sessions are exactly that, especially on longer runs. By now, your training and racing should be giving you a clearer idea of your marathon (steady) and half-marathon (brisk) paces. Also, the times in the Tuesday speed sessions are alternatives to the distances, rather than targets. You should be running them as fast yet evenly as you can; roughly between 5K and 10K pace.

Week Nine (45M)

Mon Rest

Tue 7M consisting of: 1M jog and strides, then 10 x 2 mins uphill, jog back down. Then 1M jog at end of session

Wed 8M (75 mins) easy

Thu 9M (76 mins 30 secs) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 18M (approx 2hrs 35) long

Week Ten (39M)

Mon Rest

Tue 7M consisting of: 1M jog, then 3 x 1.5M (or 12 mins) tempo, with 400m (or 3-min) jog recoveries, then 1M jog

Wed 9M (85 mins) easy

Thu 1M jog, then 3M (24 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy

Sun Half-marathon. Aim for sub-1:45 (15M inc warm up and cool down)

Week Eleven (44M)

Mon Rest

Tue 1M jog, then 5M (or 50 mins) fartlek (3mins fast, 2mins slow), then 1M jog

Wed 6M (58 mins) slow

Thu 8M (68 mins) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 20M (3hrs 10) long

Week Twelve (44M)

Mon Rest

Tue 8M consisting of: 1M jog and strides, then 5 x 1M (or 8 mins) tempo with 200m (or 90 secs) jog recoveries, then 1M jog

Wed 7M (72 mins) easy

Thu 1M jog, then 3M (24 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 21M (3hrs 30) long

Week Thirteen (43M)

Mon Rest

Tue 7M consisting of: 1M jog and strides, then 10 x 2 miins uphill, jog back down. Then 1M jog at end of session.

Wed 7M (65 mins) easy

Thu 1M jog, then 4M (32 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 20M (3hrs 20) long

Week Fourteen (34M)

Mon Rest

Tue 6M consisting of: 1M jog, then 6 x 800m (or 4 mins) at 10K pace, with 100m (or 1-min) jog recoveries, then 1M jog

Wed 6M (58 mins) easy

Thu 7M (59 mins 30 secs) marathon pace

Fri Rest

Sat 3M (30 mins) easy or parkrun

Sun 12M (2 hrs) long

Week Fifteen (26M)

Mon Rest

Tue 5M of 1M jog, then 8 x 400m (or 90 secs) fast, with 200m (or 2-min) jog recoveries, then 1M jog

Wed 5M (48 mins) slow

Thu 1M jog, then 3M (24 mins) tempo, then 1M jog

Fri Rest

Sat 3M (30 mins) easy

Sun 8M (75 mins) long

Week Sixteen (35M inc race)

Mon Rest

Tue 4M consisting of: 1M jog, then 10 x 200m (or 45 secs) fat 5K pace, with 100m (or 30 secs) jog recoveries, then 1M jog

Wed 3M (30 mins) easy

Thu Rest

Fri Rest

Sat 2M (or 20 mins) easy

Sun Race day

If you don't think you can keep up with this marathon training plan, take a look at all of our marathon training schedules Everything you need to know about tempo runs.