Speed Training
Speed training is intended to develop leg turnover and lactate tolerance, i.e. the ability to run at higher intensities and improve mechanical efficiency. For the speed training we will run short distances at a much higher pace, generally several sets of 800m to 1600m at about your 5km race pace, that is 10-15% faster than your marathon race pace. Speed Training is closely related to zone 3 and zone 5 runs described in Training Intensities - the Scientific Way.
Since the primary purpose is to increase strength as opposed to endurance, recovery periods between sets should be short so that you recover just enough but your body doesn't have the chance to get rid of all the lactate acid; The rule of thumb for speed training is to run only about 5mins at the fast pace; since we are training for a marathon we exceed this general rule; Runners training for shorter distance races will train shorter distances as well as shorten the recovery periods between intervals. We generally distinguish between intervals and repeats:
Intervals give you a recovery that is as long as the fast interval, it works out to be about 1/2 the distance of the fast interval at a very easy jogging pace. During the short recovery time your heart rate will only drop to a level that is more like your easy rate so that at the beginning of the next interval you will start with a higher base heart rate and hence reach your maximum heart rate much sooner.
Repetitions are at a slightly faster pace than intervals but allow for a full recovery between repeats. Repeats bear a higher risk for injury and are generally more useful in the preparation for shorter races.
We will only do intervals as part of the marathon preparation. Both types shouldn't really be mixed in the same training cycle unless you train a very high weekly mileage.
A Typical Speed Workout
A good warm-up jog before speed work is maybe even more important than before the hill training. For that we will typically do a 2km easy warm-up run.
The warm-up is followed by 5 strides to wake up your muscles. In a stride you slowly and continuously accelerate so that you reach approx 80-90% of your maximum speed at the end of a 100m straight, opening your stride as you get faster. Acceleration and decelaration should be smooth; it is not about reaching your top speed as quickly as possible.
The so called A-B-C drills help teach your legs to move in a more efficient way. A good two part training video can be found on YouTube: part 1 and part 2.
The basic training schedule for an interval workout would start with two intervals of 1mile each with 800m rest between the intervals and add one interval every week up to a maximum of 5x 1mile.
By changing the length of the intervals and adjusting the rest between intervals, or reducing the rest to be less than 50% of the interval length very different workouts can be created. Shorter intervals, e.g. 800m or 1200m are advisable for races of 5k to half marathon. Long intervals, i.e. 1600m, teach the half or full marathon runner to handle the inevitable build-up of lactate acids. The speed may need to be adjusted to acount for the length of the intervals. The pace for each interval should be hard but not at your limit, see the table below:
| goal time | 5:00 | 4:45 | 4:30 | 4:15 | 4:00 | 3:45 | 3:30 | 3:10 | 3:00 |
|---|---|---|---|---|---|---|---|---|---|
| min/km | 6:14 | 5:56 | 5:37 | 5:19 | 5:00 | 4:42 | 4:24 | 3:59 | 3:47 |
| min/mi | 9:58 | 9:30 | 8:59 | 8:30 | 8:00 | 7:31 | 7:02 | 6:22 | 6:03 |
| s/lap | 150 | 142 | 135 | 128 | 120 | 113 | 106 | 96 | 91 |
Speed work accumulates a lot of lactic acids hence a 2km cool down jog is mandatory to flush some of it about help speed up the recovery.
Stretch!