Descending can be hard work! Your quads can get very tired and on long runs the build up of fatigue from descents can be very dibilitating. If you are lucky, or choose a good line you might benefit from a scree descent. It is possible to loose height and move very quickly with minimal effort on good scree, but you will need to practise.
Good scree for descending is uniform and almost like gravel. It will flow down the hill as you move, but be aware in frosty weather wet scree can set hard and be quite unpleasant.
A confident approach allows you to relax and keep upright!. As the size of the stones increases the difficulty of descending also increases, and you are more likely to twist an ankle, fall over or bruise your shins and ankles.
If the scree is deep enough you can dig your heels in and take big steps, it;s great fun! But keep an eye out ahead, you could be travelling quite fast and If the scree thins you may end up in a tricky situation.
On steep "marginal" scree you can stand sideways and use your hand to stabilise you on the scree above - you really need tough gloves for this technique though!
Also your chosen scree chute will "run out" eventually so keep an eye out for parallel chutes that may be better, often you will find a traversing line (used by runners or goats/sheep) that will link into another chute.
You must also avoid blind drops - some great scree desents may finish in a big drop over a cliff, the stuff of nightmares!
Of course you need to avoid areas that may be sensitive in terms of flowers and plants.
The video below featured fell running legend Wendy Dodds on a great scree descent in the Costa Blanca. It has nearly 1,000 feet of descent in just a couple of minutes.
Wendy is co-auhor of Trail and Mountain Running a practical guide for runners designed to help those who are already running off road and wanting to improve their performance, to try longer or rougher terrain with confidence,