Athletes training for an autumn marathon will be at a critical stage of their preparation right now. Most will be targeting a half marathon a few weeks out from their marathon as part of their final preparations. They may use their half marathon time to project their potential marathon time. For athletes who are not familiar with their lactate threshold and not training at the appropriate intensity, this could lure the athlete into a false sense of security that could potentially end in disappointment.
Your best effort over 13.1 miles does not tell you how efficient you are over at a projected intensity over 26.2 miles unless you have trained yourself to develop that efficiency. There is also the mechanical efficiency factor, which we covered, in our previous blog. As we know, inefficient movement comes with a high metabolic cost. But we can train ourselves to reduce that metabolic cost.
Like setting out on a long car journey, we can only go so far with a limited fuel supply. Our bodies are the same. We can only run so far at a given intensity with our limited energy stores. This poses a big challenge for marathon runners covering the distance from as little as just over 2 hours to over 4 hours. We must train ourselves to be better at utilizing fat stores and sparing our limited glycogen stores for as long as possible. This can be achieved by training to develop and enhance our aerobic capabilities.
Take for example a runner who has done a half marathon in 73 minutes and is targeting 2 hours 36 minutes for the marathon. They need to maintain 6 minutes per mile for 26.2 miles. But how are they training themselves to do that? If the typical key workouts in those final 4-6 weeks are at 5.00 per mile pace or faster, and long runs (18-22 miles) at 8 minutes per mile pace; have they developed that steady-state efficiency (mechanically and metabolically) to maintain 6 minutes per mile for the full marathon?
The runner, in this case, may get away with some lack of efficiency over a half marathon, but small deficits can magnify over the full marathon distance. The runner should focus on the pace between his half marathon and target marathon pace for key workouts in order to build that marathon steady-state potential. A lactate step test of 6 x 1 mile or 2km intervals progressing by 15 seconds per mile, would tell us the lactate threshold and where the specific focus of the training should be.
There is much debate as to how fast the long runs should be. The best approach is to first build a good volume at a slower pace at perhaps 80-85% marathon pace. Getting up to 18-20 miles eight weeks out from the race day would provide a good platform. From there, only a handful of runs over 20 miles need to be done at intensities between 85-95% marathon pace. There is no need to go beyond 24 miles for the long run. An accumulation of runs between 18-22 miles over a 3-month period will be enough to prepare for a 26.2-mile race. There is also no need to do these runs too close to marathon pace, as they can be quite taxing.
For key workouts, rather than trying to get faster, it would be more beneficial to extend out the volume of intervals, fartlek and a steady-state tempo run at 95-110% marathon pace. You should be covering close to half the marathon distance in intervals/fartlek workouts and steady tempo runs at those intensities. For the 2.36 (6.00 per mile) marathon runner, sessions such as 7 x 3km at 5.30 per mile, 4 x 5km at 5.45 per mile, or 15-25km runs at 6.00-6.15 per mile would suffice. These are just examples and not a training prescription! Like everything else, it depends on the athlete and their individual specific needs.
The broad principles outlined above should apply to any athlete (male or female) of any level, whether they are trying to run 2.15 or break 4 hours. You need to focus on an intensity window specific to your marathon potential and current fitness status. A lactate test will help guide that process and can also provide a useful monitoring tool on key workouts. Training at the right intensity will enable you to be ‘fuel-efficient’ over 26 miles. We want to develop good fat-burning potential at marathon pace through aerobic mechanisms for as long as possible. This can be enhanced by doing some medium distance runs in the morning pre-breakfast when in a fasted state. We can also challenge our aerobic system adaptations further through extended hill workouts and altitude training.
It is important to train the right training components and mechanisms to support the ability to run at the highest sustained effort for 26.2 miles. We must focus in on an intensity window (85%-110%) specific to the marathon. An optimum amount of that type of work over those final 6-10 weeks on top of a good aerobic base and shorter racing season over 5kms up to half marathon; will prepare you physically for the demands of a marathon. You also need to be mentally prepared and have confidence in the work you have done!
In the next blog, we will discuss training load monitoring and recovery strategies.