Advanced skiing in Les Arcs
Head to the Aiguille Rouge cable car and the genuinely challenging skiing to be found on the Varet glacier, high above Arcs 2000. 
Varet glacier
Up here you'll find the longest run in resort, a breathtaking black that goes all the way down to Villaroger - 7km long and over 2,000m of vertical drop. The initial drop-in at the top is pretty steep, and following windy conditions can be very sheer. If you don't fancy it in those conditions, follow Arandelières 2 as it wends its way down the upper section; both runs converge on the Glacier du Varet, which is broad, open, steep and largely north-facing. 
The black and red runs and the bounteous off-piste possibilities in the Aiguille Rouge area will keep even the most energetic skier or snowboarder entertained. However, to make the most of the terrain up here a mountain guide is recommended as the area is glaciated and there are also some expansive cliff faces to be avoided.
If speed is your thing then the Aiguille Rouge-Varet area is also home to Les Arcs "Kilometre Lancé" or "Flying Kilometre" piste. Whilst you can't do this piste unsupervised, it is possible to put yourself against the clock through the Les Arcs Club des Sports, who can also provide you with all the necessary safety equipment. You will often see the pro-speed skiers in their futuristic space suits training on this piste, attaining speeds of over 200km/h.
Ecureuils 
Over the other side is this black run with the steepest section at the bottom. An ideal 'starter' run, the more difficult mogul part can be avoided by taking a steep, but still significantly easier, turn towards Plan Peisey. 
Fond Blanc 
The perfect finisher black run, as it's short, sharp and sweet. Running straight off the ridge you can pick up some serious speed before joining a blue run above the snowpark. 
Red runs in Les Arcs
Some great red runs to consider are Belette, Myrtille and Malgovert. 
Belette can be very fast, literally dropping off the Traversée (blue), starting very steep then levelling off gradually. The lower section ends with a gradient increase that gives an additional boost. 
Myrtilles is a tree run down the Vallandry that is fast and wide with sweeping corners and consistent gradient. 
Malgovert off the Comborciere chair is one the piste-bashers leave well alone, and consequently includes a number of obstacles. After an initial flat (snowboarders beware), the piste traces a rather eccentric route down to the Mont Blanc blue run and Arc 1600. When visibility is poor we'd recommend avoiding this run, as its twists and turns are easily missed. 
Cachette
Over in Arc 1600 it's surprisingly steep, broad and thus invites carving enthusiasts. 
Aigle cuts through the woods above Vallandry ending at the Grizzly lift. A favourite run of ours, it's never too steep or too flat, the piste is wide and the trees aid visibility in flat light. The pisteurs also ensure the slope remains in tip top condition even late in the season. 
Those of you with springs in your legs will no doubt love pounding the bumps of the Dou de l'Homme piste, or perhaps explore the fabulous off-piste through the Nancroix forest.