Run Shorter Events After A Marathon

Maybe you've just completed your first marathon and are wondering what your next challenge should be? After giving yourself a well-earned rest, maybe you should consider training for a shorter distance such as a 3k, 5k, 10k or even half-marathon next time.

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Here are some shorter distance running options for you to consider after the marathon.  

Run shorter events after a won't lose your endurance

Marathoners often fear that by running shorter distances after a marathon they will lose their endurance through less mileage. This is not necessarily the case, provided that the reduction in running volume is met with an increase in running pace.  

How to estimate the correct speed to run

A sound method of estimating the speed that you should be running at when running shorter distances is by using the ten second rule working down from your own marathon finishing time time. The formula requires that  you increase the speed of running by ten seconds a mile as the race distance declines.  

Consider the following example based on a seven minutes/mile marathoner who finished in 3:03:24. If they were to run the events below, their pace would need to be as follows:  

Half marathon

6 mins, 50 secs


6 mins, 40 secs


6 mins, 30 secs


6 mins, 20 secs


Remember, these are just a guide. These estimations can be toughened up or extended to suit personal needs. The next stop when you want to run shorter distances after a marathon is to work out the approximate 400 metre times for track work.  

The above example will be:  

Half marathon

102.5 secs

per 400 metres


100 secs

per 400 metres


97.5 secs

per 400 metres


95 secs

per 400 metres


Again, using the table above, we can estimate our target times for the lesser distances:

Half marathon

88 mins, 50 secs


41 mins, 26 secs


20 mins, 11 secs (approx)


12 mins, 0 secs (approx)


How to use a heart rate monitor to judge speed

If you’re not too keen on track running, you can use a heart rate monitor with just as good effect.  

  • Half marathon pace will be 75 per cent of maximum heart rate (MHR)

  • 10k pace at 90 per cent MHR

  • 5k pace at 95 per cent MHR

  • 3k pace at 100 per cent MHR  

For the half marathon pace, the duration of effort will be for 10 minutes; for the 10k pace it will be for eight minutes; 5k will be six minutes, and 3k will be four minutes.  

After each effort, jog until the heart beat rate returns to 120 beats a minute. Build up from two efforts to at least four.  

If you have never run a ten mile race you can estimate your potential at the distance with the following formula:  

1. Divide your marathon time by three

2. Add five minutes to the calculation in 1

For example if your best marathon time is four hours, your ten mile potential will be 85 minutes; if three hours, it will be 65 minutes and for two and a half hours it will be 55 minutes.  

Note that the fastest-ever British marathoner, Steve Jones, with a time of 2:07:13, had a best of 46:49 for ten miles. Using the formula stated, this works out at 42 minutes plus five minutes; a total of 47 minutes!  

How to tackle shorter distances after running a marathon

Relative speed work for the marathoner who wants to run shorter races and are not accustomed to it should be tackled cautiously, with one session a week at the target race speed for a month; if the goal is 60 minutes for ten miles, start with either five miles in 30 minutes or six times one mile on a track or measured course with a 45 second rest, at race speed. Other sessions the same week can be 20 miles, 15 miles, and 13 miles.  

In the second month after you've run a marathon, two speed sessions a week can be done, one as stated and one faster at 10k pace. The maximum number of speed sessions in a week should not exceed three.  

At first, the recovery times after repetitions, where applicable, should be jogging half the distance of the repetition at the rate of 45 seconds per 100m. This should progress to jogging a quarter distance and even an eighth distance of the repetition if times are achieved. This particularly applies to 5k and 10k pace workouts where there is no opportunity for taking a breather. It’s one relentless mile after another, so you have to train for this. Good luck.  






4 x 1,500m at 3k speed

4 x 800m at 1,500m speed

Fast 10k


3 x 2k at 5k speed

4 x 1k at 3k speed

Fast 10k


25 x 400 at 10k speed

4 x 1600 at 5k speed

Steady 20k

10 miles

Fast 10k

Fast 5k

Fast 3k

Half marathon

Fast 10 miles

Fast 10k

7 x 800 at 5k speed

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