Nice postcard, the first Turnerbund example that I've seen or really looked at, I think? At first I thought it was produced a little later - the brownshirts would have loved this imagery. The type-font the artist created is a stylized runic alphabet, something one would expect from the SS, nicht? The saying sounds like some of those stern "Hitler-quote" cards that were fairly common at the time. This one boldly states, "The Last Victory Lies in the Sword." ... pretty heavy stuff for a gymnastics organization. Here, I'd say the sword has just cut through the binding Allied chain that was meant to crush the German spirit after WWI.
Great sunwheel-swastika, too. It reminds you of the outstanding Luftwaffe sword pommel design. There's a great Turnerbund tinnie that's a large, heavy depiction of their unique sunwheel - it's a very nice unit for those who like a good tinnie, still fairly inexpensive, too.
I think it's a great illustration, you can really feel the power and jubilant force in that painting. I'd think that by 1926 the Allied yoke was becoming just about unbearable for many Germans, especially any towns, industries or areas that were still under direct supervision for repaying the war-debt, and what a debt it was!
