It is very easy when training for distance events to lose the ability to run fast in a relaxed way and with good form. By fast I mean at 400m race pace. The reason being that many distance runners never have the space in their program to dedicate a session a week to this sort of speed. Even if they do, often the athlete winds up injured from the faster work and becomes hesitant about making a commitment to something that may not provide gains that are worth the risk.
The solution is to integrate small manageable amounts of faster work & supplementary activities that will help "high speed ability" into the athletes program.
After or during continuos runs:
It is easy to do 4-6 x flying start 60m runs at 800m pace after each continuous run and then do a light warmdown. Do them with 2-3min rest in between. Focus on running smooth. As familiarity is developed it could be good to expand this to 5 x flying80m and finally 4 x flying 100m. All aiming to be running with good form at near to 800m or slightly above.
In all track session warmups.
A good warmup with be 1-2km of mixed warmup activity.
Then some sprinters drills.
Then some sprinters drills.
Then 3 x 60m where the athlete gently accelerates over 60m staying relaxed with a walk back recover or about 60-90s.
Then 4 x flying start 60m aiming to develop relaxation at near 400m average pace with 3-4min rests between.
Then stay active for about 10min before the start of the main session.
Athletes could increase the speed of the 60m efforts to the backstraight speed of a 400m before expanding the distance of the 400m pace efforts to perform 4 x flying80m starting at average 400m speed and increasing the speed before repeating the same process with 3 x flying100m. Once this is mastered the athlete wiull usually be in their competive season where they could replace the 3 x fly100m with 2 x fly150m at average 400m pace or phase them out.
Progress carefully with 400m back straight speed work as it involves athletes lifting up much higher off the ground and in many athletes who are not used to this will often cause considerable hamstring soreness. The way to avoid this is to make progress slowly and ensure good dynamic & static flexibility in the hips. Many athletes have very tight hip flexors and this can have many negative effects.
Bounding
Another area worth integrating somehow into the program is the use of alternate leg bounding.
An idea is to start off by doing alternate leg bounding with running up hill e.g. bound 20m then run 20m then bound 20m. This can be expanded to perform maybe up to 800m of bounding. This activity when done on grass is usually met by the athlete with sore glutes but no leg problems.
Next the athlete can introduce some bounding on a long jump runway into a pit. I have seen athletes develop large increases in leg power from just performing 5 lots of 4 bounds and a jump into a sandpit about once a week. Many good female middle distance athletes can do over 12.50m for this activity.
Progression can then be made throughout the year to bounding with shorter contact times. This means progressing to running start 4 bounds and a jump with 10m running start. Usually my group performed about 5 attempts.
Lastly athletes can perform speed bounding over 20m from a 10m running start. Athletes need to take as a few steps as possible over the 20m and also move that distance as quickly as possible. So both time and the the number of steps is recorded down to the nearest quarter step. A score can be calculated by multiplying the strides x the time to give a speed bound index score. The lower the score the better the athletes ability. It is essential in this activity that athletes contact the ground well underneath the body and not overstride. This will be as "reaching" in front and the athlete will be able to feel the jolting. Usually an athlete would perform about 4 attempts at speed bounding in a session.
It is possible to do a small amount of the above bounding activities after the warmup for any session. Initially this may impact on the qulaity of the main session but the athlete will get used to it. The main thing to emphasize is that more is not better - the athlete will develop steady gains by performing a small & manageable amount. Most athletes will find this bounding component great fun especially if it is measured carefully and personal bests are recorded and strived for.
A range of new e-books have been released at

regards
Steve Bennett