I saw this German documentary in October 2007 at Le Giornate del Cinema Muto in Pordenone, Italy. The festival screened a print from a German collection (the FW Murnau archive in Wiesbaden) that had English intertitles.
According to the programme notes at Pordenone, in 1925 the failing German economy had forced a major decline in feature-film production (I hadn't noticed), and an attendant increase in documentary movies (again, I hadn't noticed), which were cheaper to produce. The programme notes also stated that this film was so popular upon its original release that it was re-released a year later in a new edition, with substantial new footage added and previous footage removed. I'm a bit surprised that it survived at all in its original version.
'The Way to Strength and Health: a film of modern body culture' is very much an artefact of the Naturist fad that swept Germany at this time. It was part of the same trend which helped the Nazis come to power, with their obsession for racial and physical purity and the beauty of the German countryside. This isn't a Nazi movie, but it comes directly out of the same school of thought which facilitated the rise of Nazism.
There's lots of footage of naked young bodies here, most of them German or at least (by Nazi definition) Aryan. I felt very uncomfortable watching these sequences, because I felt that they were somewhat dishonest. Audiences for this 1925 movie were fully-dressed and anonymous in the darkness, while watching adults (and teens) of both sexes who are naked, performing gymnastics and other physical rituals. I couldn't help wondering how much of this movie's original success was down to sexual prurience and voyeurism rather than a sincere interest in health and fitness. Lest I seem hypocritical, I freely admit that I felt very aroused indeed at the footage of the very sexy young Leni Riefenstahl in this movie.
At this late date, this movie's prime interest is historical. If you're interested in seeing naked bodies -- female or male, or both -- you can see far more attractive nudity on offer in other films. I'll rate this one just 2 out of 10.