At full ironman you have an additional 2 bags for the special needs tables. One for the bike and one for the run. Here you can store extra nutrition, or a top if you are planning to run late. However, you lose what you don't use - you can't go after the race to pick it up. ITO transition. Everything that can be attached to your bike stays with the bike. Helmet, sunnies etc stays in the transition bag which is hung on a hook in numerical order. DO NOT try and make you bag visible by putting on ribbons or stickers etc. They will take it off and you will not find your bag. In the past they had people decorating their bags in a similar way, person nr 1 grabbed the wrong bag and did not have the decency to go re-hang it. Person nr2 ran 21km barefoot. When you are on the run, your bags will be hung together with you wetsuit, cycling stuff etc in it.