To win the national decathlon championship, in case you are thinking about doing that and wondering what to wear, you could do worse than begin with the kind of wardrobe Bill Toomey packed down to Los Angeles last week in two large, soft vinyl bags. The bags were nice and roomy because Toomey needed to get in his four extra sweat suits, his extra socks, extra T shirts, shorts and protective garments and eight pairs of track shoes variously studded with track-grabbing treads. He said he did not need a pair for each of the 10 events because he could double up on a couple, but just to be triply sure he had extra spikes for the shoes. He also had starting blocks, a pole for vaulting, a javelin for throwing and a 16-pound shot for putting. Then there was some stick spray for his hands so he would not drop the 16 pounds on his toe and some lighter fluid to activate the adhesive wrapping around the pole handle to keep him from shinnying down it on the way up. Finally, for a lively, lovelier him, there were vitamins, minerals and muscle-relaxant pills and prescription sun-glare contact lenses.