THE MARATHON IS a very challenging blend of endurance, strength, and speed. As such, marathon training should incorporate all three of these components into a training plan.
That said, you should begin your training by focusing on building your mileage before you mix in speedwork.
For the first two to three months, increase your weekly mileage and lengthen your long runs to expand your aerobic endurance base. Weekly mileage increases are done in small increments – most commonly a 10 to 20 percent increase in total weekly volume. Staying within this recommended range minimises your risk of injury while building mileage. Often this increment can be accomplished by increasing your weekly long run by a couple of Ks.
Increase weekly mileage for three to four weeks, then plan a “cut back” week. Cutting back means dropping your mileage volume by about 30 percent for recovery purposes. This build and recovery cycle should help provide adequate recovery throughout your training. During this phase of your training, you can include some speedwork once a week by incorporating some tempo runs on one of your shorter weekday runs. Tempo runs refer to runs that are slightly faster than your goal marathon race pace, and this should comprise no more than 20 percent of your total weekly mileage.
After 12 weeks of training, you can begin to include more formal speedwork if you choose. But remember, speedwork, especially for your first marathon, should be done at a controlled speed. Set a pre-designated pace or interval time for your workouts. This time can be based on recent 5K/10K times or your predicted goal marathon time.
The intention is to develop some speed along with your endurance, so you want speed workouts to be run at a pace you can maintain for the entire duration of the workout, not an all out sprint that you cannot maintain. For example, get on the track for some sharpening workouts at a controlled pace for the remainder of your training until you begin to taper.
Suggested speed workouts:
1) Run two sets of 6 x 400 at 5K pace; jog a 200 for recovery. Take 4 minutes recovery between sets.
2) Run 6-8 x 800 at 10K pace; jog a 200 for recovery.
3) Kilometre Repeats: 4 x 1 kilometre at 45 to 60 seconds faster than your goal race pace. Take 3 minutes recovery between kilometre repeats. Do these on the road, not the track.
Suggested guidelines for speed work:
1) For kilometre repeats, use 45 to 60 seconds per K faster than your goal marathon race pace.
2) Use a consistent pace. No more than a 5-second variance in kilometre repeats or intervals.
3) Track workouts should be no longer than 8 total kilometres. For longer workouts, use the road.
4) Do kilometre repeats or 800s during or after higher mileage weeks
5) Do the 400s workout following shorter or cut back mileage weeks