Training on F1 track, wearing extremely expensive footwear (10)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

SPA (F1 track) + DRILL (training) contained by [wearing] E{xpensiv}E [extremely]. Google informs me that the Belgian Formula 1 Grand Prix is held on the Circuit de Spa-Francorchamps, but  fortunately I didn’t need to know that to spot the answer.