Stronger brace for bed loft?

[Darl Bundren]

I am building a loft to support a twin sized mattress, and I have a design question: Which type of bracing would be stronger? Shorter diagonal pieces from each leg to the mattress platform, or long pieces that parallel the mattress platform halfway or so down running from leg to leg? I was leaning towards using the long, horizontal pieces so I could later affix shelving to them if Sonny Boy wanted more storage.

Thanks as always.

[Alan Schwabacher]

Triangles are rigid, but rectangles can squash. Diagonal pieces help much more.