Coach’s Corner: Six Pointers for Marathon Improvers

David Chalfen, experienced Level 4 Coach and former England Athletics Coach Mentor, provides six pointers for marathon improvers: key areas to consider to focus your training and improve your time.

marathon improvers


Here are a six key pointers for autumn (or indeed any) marathons. These are not intended to be exhaustive or definitive, but they are marathon-specific. So they probably aren’t the best ways to do hard training efforts if your target distances are half marathon or shorter, though they aren’t “wrong” for those distances either.

This advice is aimed at “improvers” – those who have done at least one marathon and are aiming for something in the 2.40 to sub 4.00 range next time out. (People running much quicker than 2.40 will—to varying degrees—use some of these ideas, but they probably won’t be the main group reading this particular article.)

1. Focus on Training for the Last Third of the Marathon

One of your main objectives in marathon training will be to shift your focus to maintaining pace over a longer distance.

Assuming you have built a decent 5k/10k base about three to four months pre-marathon, the overall shift is to build your readiness for the 26.2 miles, and specifically for the last third of the distance.

Ideally you want the pace in the last third of the race to be very close to the pace in the first third.

That’s easy to write and to hope for, often less straightforward to achieve on the road. But the following points will help you work towards achieving it.

2. Plan Your Longest Run

How far should your longest run be? There really is no “right” number on this. You can read and ask around at the highest level of the sport (and I have done this!) and you won’t get a consensus. And indeed, for the same runner, the best option may evolve over time.

Generally the quicker you are, the more likely you are to be trying longer runs closer to the full marathon distance. Linked to this, the quicker you are, the more likely that you are seeking smaller margins of improvement, and thus may be more willing to try slightly different options from what you have used before.

For those targeting sub-3 hours, a couple of runs at about the target “time on feet” is usually good, but at about 110 to 115% of target marathon pace (MP). This will get you about 23 miles.

For 3.30 and slower, 20-21 miles is perhaps the better balance, perhaps slightly closer to MP. These longer runs for those with less history at doing them seem to increase the risk of a stress fracture as well as other ill-effects of inadequate recovery.

Think in terms of:

  • Timing the two longest runs about four to seven weeks before the race, and not in consecutive weeks.
  • Typically racing a half marathon race in similar time frame. However, increasingly I believe that for the quicker, more experienced runners, the half marathon is actually less essential and won’t be particularly more indicative than will a 10k. By this I mean that the energy system balance for 10k and half marathon for runners at the faster club levels is pretty similar – whereas for the step up from half marathon to the full 26.2, it’s more notably different.
  • Trying an 18-to-20 miler at MP, or maybe 1 or 2% slower (but not quicker!) than target MP, in this window. But do respect the recovery from this. It’s a major physical effort, and most runners will typically need five days recovery before trying anything fast after this effort.

If possible try to do at least two of the longer runs on terrain similar to that of the target marathon, and at (or very close to) the time of day of the race start.

3. Include Long Efforts With Varying Pace

Long efforts with varying pace are probably the most significant specific sessions alongside the long runs.

Put simply, these are mid-long runs with alternating blocks of running at paces a bit quicker and a bit slower than MP. These are particularly effective for finessing the effectiveness at which you combine fat and carb utilisation, whilst also fine tuning your pace judgement.

What pace should you run these at? The difference between the two pacing levels should be about 35 to 40 seconds per mile. The faster you are, the narrower the gap is likely to be. You can structure around this in various ways, but think in terms of alternating blocks between about five and nine minutes each.

What distance should they cover? You should be covering at least 10 or 11 miles to make the run challenging, with maximum distance of about 14 to 15 miles, beyond which it blurs with the longer runs at around MP, and becomes almost unmanageable at the desired pace.

Over an eight week period you might progress from five sets of (1 mile at 10 mile pace/1 mile at MP + 15 seconds per mile) to seven sets of (1 mile at 10 mile pace/1 mile at MP + 15 secs per mile) + final 1 mile at MP.

Be sensible about working these in with the long runs so you don’t do two mammoth efforts two or three days apart. The maths of these tough efforts tends to show that, if using a fast flat route, you will be covering a half marathon only about three to four minutes slower than your PB, and doing so in a fartlek kind of way – so it’s not easy. Give yourself recovery time.

4. Try Practising Marathon Pace After Some Intervals

These mixed sessions bring the benefits of faster running with those of running at MP.

Simplistically, the faster reps in the first part of the session start to deplete your carbs because of the intensity. In the second part of the session you are then running at MP with reduced carbs to dip into. This makes a great event-specific training session, simulating what happens in the marathon.

So a session might be 8 x 800 metres (or 8 x 3 mins at 5k race pace) with a 90 second jog recovery, after which you head into 5 or 6 miles at MP.

Some points to consider for this session:

  • The precise details of the intervals aren’t a huge deal in this marathon build up session, but you want to make it fast enough to incur some fatigue but not so fast that you are overly anaerobic (as you won’t be running anaerobically in a marathon).
  • Therefore 3k to 10k pace is appropriate, and it is also fine to mix these in a single session.
  • The MP section should be as even-paced as possible. The first couple of miles should feel quite comfortable, but the last mile should feel pretty tough.

5. Be Flexible With Your Weekly Structure

Don’t be too hung up about sticking to a pattern of two hard sessions plus one long run every single week.

When you start marathon training, you may already be comfortable with a long run of up to about 15 miles and one rep session at about 5k race pace, in which case you will probably want and have capacity for an additional harder session as well. But once you build up to a long run of 20-21 miles plus a midweek mid-long effort including anaerobic threshold to MP, then it can be overload to add an extra faster session every week.

Linked to this, if you are a regular at club session on Tuesdays and you do a long hard run on Sundays, don’t feel that you have to do the club session on Tuesday. You may well benefit from a further day’s recovery and could run the faster stuff solo.

So if you have weeks where the standout sessions are a long run and one tough midweek session, and the rest of the running is simply recovery pace between these two, then that’s fine. You are training to race a marathon, not primarily to have a busy training diary.

6. Build a Realistic Understanding of Marathon Pace

I believe a big part of marathon training, in addition to the essential physiological stimulus and adaptations, is gradually getting an accurate and realistic perception of what your marathon pace should be.

If you are training effectively and consistently you ought to have relatively tight time bands to aim for, which should be much more precise than the 15 minute ranges often used. So for example someone aiming realistically for a 3.10 marathon, that is 7.15 per mile, should be able to gauge that 7.00 – which is 3.03/3.04 pace, just isn’t quite achievable this time round.

I hope these suggestions will be useful, and good luck in your training and race.

David Chalfen has been in the sport as runner and coach for almost 40 years. He is a Level 4 Coach, worked as an England Athletics Area Coach Mentor in Endurance from 2009 to 2014 and his book Improve Your Marathon and Half Marathon Running is on England Athletics recommended reading list for runners and coaches, and is available from The Flying Runner bookshop. He coaches a wide range of runners from national/international level through to more recreational level with a focus on 5k to marathon, and can be contacted via his website runcoach1to1.com.

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