Frank Horwill



  • These articles were first published many year's ago and whilst some are as relevant today as they were when new, many are now mostly of historical interest as modern research and coaching methods have superseded them.

Twelve Things You Should Know about Marathon Training

By Frank Horwill

  1. More people run in the London Marathon than in the 1,500m for the whole of Europe in one year. The marathon is the most run event, it’s also the worst trained for. A survey of city marathons revealed that half of the competitors ran only 26 miles in total in a week. That’s about 4½ miles a day for six days. They then expect to run reasonably well, 26 miles in one day!

    However, there are those who believe it is necessary to run four times the distance in training in one week (104 miles), usually at one pace. Such people who average 7 minutes/mile in their excursions believe that on the day some magic will enable them to run at 6 minutes/mile.

  2. The marathon is 99 per cent aerobic. This means that all predominantly aerobic running should be exercised: a) Jogging (100%) for recovery b) Target marathon pace (99%) c) Half marathon pace (99%) d) 10k pace (90%) e) 5k pace (80%) f) 3k pace (60%). The percentage of the VO2 max utilised in these speeds in order is: a) 60% b) 70% c) 80% d) 90% e) 95% f) 100%. The difference in speed for each distance is approximately 15 seconds a mile for the experienced and 10 seconds for the novice. Thus, a 2hr 37min 12sec marathoner (6 minutes/mile), would expect to run the half marathon at 5min 45 second/mile, the 10k at 5min 30 second/mile, the 5k at 5min 15 second/mile and the 3k at 5 minute/mile.

  3. There are two fairly reliable ways of assessing one’s potential in the marathon: 1) Five times the 10k time minus 10 minutes. 2) Twice the half marathon time plus 6½ minutes. Thus a 30 mins/10k runner can expect to run 5 x 30mins = 150mins minus 10mins = 140mins (2hr 20min). Women tend to convert their 10k times better than men. This has been investigated and is due to a better reserve of fat which cannot be seen.

  4. If one’s potential works out at 7 minute/mile, that speed must be rehearsed. A major problem with many marathoners is that they run long and slow (22 miles), then short and fast (10 miles), but do not rehearse the target pace. The result is that in the race they are often confused, either running too slow or too fast. The starting point with marathon pace is a third of the distance, about 9 miles, in this example this will be in 63 minutes. When this distance can be comfortably handled, it should be increased by mile increments to two-thirds of the distance (18 miles).

  5. If the 10k reveals one’s potential, that speed must be used in training in order to improve it. Part of the process of improving one’s 10k time is to train at 5k and 3k speeds.

  6. Training at marathon pace, half-marathon pace and 10k pace etc is severe. After such days the body needs to replenish glycogen stores and minerals lost in sweat. Some runners can handle this with a 35 minute slow run following a severe day, others require two days of recovery. It’s vitally important to find out how much recovery you require.

  7. One of the great concerns of all novice marathoners is the question of lasting the distance. Research helps here. Twice the marathon distance in total in a week is considered the minimum to handle the distance, i.e. 52 miles a week. Better is three times the distance – 78 miles a week. However, this fear of the distance can be greatly allayed by running for the same duration as the target time but much slower. This has been referred to as, “time on the legs”. If the target time is 3 hours, build up to running for that time even if it’s a minute a mile slower.

  8. All the great physiologists agree that fast aerobic running should last from 3 to 10 minute spells. Thus, a good session at half-marathon speed can be 6 x 10 minutes with 30 second recovery periods. A meaningful 10k session is 6 x 1,600m on the track or miles on the road with 45sec rest after each rep. A good 5k pace work out can be 4 x 1,500m with 60sec rest. And a golden 3k speed session can be 5 x 800m with 90sec rest.

  9. Replacing fuel in the body before and after training is of major importance. Greater physical output comes from eating moderate sized meals every 4 hours. This might be at 8am, midday, 4pm and 8pm. The most important meal of the day is breakfast.

  10. The body’s main fuel is carbohydrates. There are two types: 1) high glycaemic and 2) low glycaemic. The first causes insulin bursts and glucose is in the bloodstream within 15 minutes of consumption. This is a good thing to take immediately after training when glucose levels are low and includes: glucose drink, honey, bananas and raisins. Low glycaemic carbs do not cause insulin bursts and after digestion the glycogen in them is stored in the liver. Glycogen is not stored all round the clock, it’s preferentially stored in the first four hours after training. Foods to be consumed include: drinks containing fructose, soya beans, kidney beans, lentils, sweet potatoes, apples, oranges, whole wheat spaghetti, oats, brown rice, buckwheat pancakes, whole wheat bread. A sound routine is to take 225g (8oz) of glucose polymers via a drink immediately after training. Sip a 5 – 10% carb rehydration drink during training. Take 100g of complex carbs 3 hours before training. A good investment is to buy Enduro Load from a health food or chemist shop.

  11. Costill discovered from muscle biopsies on marathoners before the Boston Marathon, that many were suffering from miniscule muscle cell damage which was worse after the race. This is no way to start and finish a marathon. The process of tapering does many things. The body, used to mileage, will store glycogen from habit. If the volume is reduced by a third with three weeks to go, and a further third with two weeks left, with only a third of normal training in the final week, a good reserve of glycogen will be built up. The tapering process also improves glycogen storage in the legs and alters the blood status for the better. Research reveals that better performances come from the final week (one-third) being run faster than normal. It’s important to conserve glycogen in the race by running the first half at 51 percent of the target time and the next half at 49 per cent. The first mile and 10k must be judged carefully.

  12. Here is a blue-print schedule for an athlete wishing to run a 3 hour 3min 24sec marathon (7 minute/mile). Times for faster or slower targets can be worked out from the figures given earlier.

    • Day 1 – Build up to run for 3 hours at 8 minute/mile (22 miles). Start with 1 hour and add 10 min per cycle.
    • Day 2 – 35 min recovery run (5)
    • Day 3 – Half-marathon pace – Run 10 miles at 6min 45 second/mile (10)
    • Day 4 – 35 min recovery run (5)
    • Day 5 – Marathon rehearsal pace – Run 9 miles in 63 min. Add a mile when comfortable up to 18 miles (9 – 18)
    • Day 6 – Rest or swim a mile or cycle 16 miles
    • Day 7 – 10k pace – Build up to 6 x 1,600m in 6 min 30 sec with 45 sec rest (6)
    • Day 8 – 35 min recovery run (5)
    • Day 9 – 3k pace – 5 x 800m in 3 min with 90 sec recovery (3)
    • Day 10 – 35 min recovery run (5)
    • Day 11 – 5k pace – 4 x 1,500m in sub 6minn with 90sec rest (4)
    • Day 12 – 35 min recovery run (5)
    • Day 13 – Start cycle again

    The warm up before the faster sessions has not been included in the brackets, this will add a further 10 miles to the cycle.

    The decision to train twice a day needs careful consideration. This should be avoided on Days 1, 3, 5, 7, 9 and 11 as these days are severe. If another 35 min recovery run is done on days 2, 4, 8, 10 and 12, this should be ten hours after the first run.

    The aim with the fast sessions listed is to improve the average times of the reps.

    A variable pace work out can be alternated with the 5k session on day 11. This is a golden session which works wonders with fitness levels. The athlete runs 400m at best 5k pace, in this example it’s 94 sec. This is immediately followed by 400m at marathon pace, in this case it’s 105 sec, the process continues like this (94 – 105) until 10k in total is run (25 laps). Should the pace falter after, say 10 laps, the athlete should walk a lap recovery and start again until the 10k target is reached.