Adolf Karl Hubert Koch (9 April 1897, in Berlin^[1] – 2 July 1970) was a German educationalist and sports instructor, best known for founding a progressive gymnastics movement emphasizing natural movement and physical freedom. A prominent advocate of Freikörperkultur (free body culture), a social movement promoting nudity to foster health and body positivity, Koch's work was also integral to the broader Lebensreform movement, which aimed to renew society through a return to nature, simplicity, and holistic well-being.^[2]

Koch's father, Karl Koch, was a trained carpenter and firefighter, and the family, including a younger sister, adhered to the Protestant faith. Koch spent his early years in what is now Kreuzberg, Berlin. He began his education in 1902 and attended a Volksschule starting in 1903, graduating in 1911. Following this, Koch enrolled in a preparatory school in Kyritz to train as a teacher. In 1914, however, he interrupted his studies to voluntarily join the Imperial German Army during the First World War. As a trained combat medic and soldier, Koch sought an escape from the rigid structure of his teacher training. He distinguished himself in his military service, earning favorable evaluations and receiving a high-level decoration.

At the end of the First World War, Koch returned to Berlin and resumed his teacher training in the spring of 1919, completing it in the autumn of 1920 with the first state examination. In parallel, he pursued studies in pedagogy and medicine at the Royal Friedrich Wilhelm University (Königlichen Friedrich-Wilhelms-Universität), focussing on 'hygiene.' Among the lectures he attended was Fritz Albert Lipmann's course on 'physiology of women.' Lipmann, who would later win the Nobel Prize in Physiology or Medicine in 1953, significantly influenced Koch, who frequently referenced him in his own lectures.

Before 1919, Koch had no involvement with the Freikörperkultur (free body culture) movement, which had developed in Germany during the early 20th century. His interest in naturism emerged during his studies in hygiene. He explored Freikörperkultur literature such as Die Schönheit (The Beauty), and attended cabarets featuring nude dancing. He was particularly captivated by the elegance and expressiveness of dancer Della de Waal, which left a lasting impression on him.

In September 1920, immediately after completing his teacher training, Koch began working at a Volksschule in the proletarian section of Berlin-Kreuzberg as the class teacher of the 4th girls' class. He sought to implement his reformist ideas of a 'new upbringing' and actively participated in the Association of Resolute School Reformers [de] (Bund Entschiedener Schulreformer) until 1923. His reforms emphasized the connection between mind and body, advocating for comprehensive physical education, which he felt was neglected due to its reliance on monotonous and repetitive gymnastics (see also physical culture). As part of his efforts, Koch addressed widespread neglect of personal hygiene, famously highlighting the irregular bathing habits of the time:

It is a common habit to wash only your hands and face every day, but your feet only twice a week, and your whole body only every eight to fourteen days. Not to mention bathing.

— Adolf Koch

To promote health, Koch championed daily personal hygiene and dental care, which were not yet widespread practices at the time. He introduced simple yet effective measures, beginning with daily fingernail cleaning and appointing a 'cleaning commissioner' from among the students to inspect their peers' hands and nails. A week later, he implemented dental care routines. These efforts were highly successful, fostering a cleaner, healthier, and happier student community.

In 1921, Koch began gymnastics training at the Anna Müller-Herrmann [de] 'School for Physical Education and Movement Development' (Schule für Körpererziehung und Bewegungsbildung) in Berlin-Charlottenburg. This period coincided with the rise of expressive dance, which sought to convey emotions and moods through movement. Koch explored various gymnastics methods, including those developed by Bess Mensendieck, Rudolf Bode, Émile Jaques-Dalcroze, Dora Menzler [de], and the anthroposophical Loheland gymnastics [de]. He particularly favored Dora Menzler's approach, believing it combined the strengths of multiple systems.

Koch advocated for unclothed physical education, considering it essential for accurately observing and understanding the human body. This concept aligned with the educational vision of Anna Müller-Herrmann and Dora Menzler, who supported his philosophy. As an educator, Koch utilized nudity as a pedagogical tool to integrate physical and cultural studies, fostering the ideal of an 'athletic intellectual' and promoting gender integration.^[3]

...the most precise observation of that infinitely rich interplay of muscle and joint function and skeletal form, on the constant perception of any changes in the structure and function and expression of the body. It is inconceivable how the gymnast can find his way around the unusually complicated structure of the human body if he is not given the opportunity of constant observation of detail, as is the case with the doctor and the artist.

— Anna Müller-Herrmann, The question of clothing in physical education (Die Bekleidungsfrage in der Körpererziehung).

Koch sought to develop a modern general physical and posture school (Körper- und Haltungsschule) that integrated open-style dance gymnastics inspired by Mary Wigman. With support from Anna Müller-Herrmann, he designed exercises specifically tailored to children. For younger students, the emphasis was on joy, playfulness, and imagination, while for older students, the focus shifted to gravity- and momentum-based work exercises.

A proponent of coeducational practice, which was not the norm in Germany at that time, Koch advocated for boys and girls to practice together, stating that this approach also fostered mutual respect for the bodies of the opposite sex and encouraged an understanding that nudity, in itself, carries no inherent sexual connotation. At the Kreuzberg school, however, he was unable to implement his envisioned gymnastics program; instead, nude bathing occasionally occurred in lakes during class excursions.

At the end of the 1920/21 school year, Koch had to leave the Kreuzberg school in Berlin. He was transferred under the accusation that he had inappropriately touched a girl on her abdomen during a regular class. Koch, who was medically trained, acknowledged touching the student on her abdomen but clarified that it was a medical examination for suspected appendicitis. The student was later taken to the hospital for this condition. Despite this explanation, Koch was reassigned as a disciplinary measure to a school in East Berlin, where he worked with children who were, in part, regarded as difficult to educate.

Following his transfer to a new school, Koch became acquainted with the Freikörperkultur (free body culture) social movement, which had been active in Berlin since shortly after 1900. Some parents of the school's pupils had formed a 'friendship society' focused on physical fitness in their leisure time, operating informally without formal statutes. Their children organized their own group, the 'Sun Land Youth Guild' (Jugendgilde Sonnenland). Recognizing an opportunity to implement his reformist gymnastics methods, Koch joined the association. Meetings were held every Saturday at the youth center (Jugendheim) on Mariannenufer 1a, where boys and girls, initially aged 10 to 13, practiced nude gymnastics in the presence of their parents.

By late 1922, Koch introduced his gymnastics exercises into regular school lessons, with students initially wearing swimming trunks. In 1923, he completed his training as a gymnastics teacher. The school's rector, Ruthe, commended Koch as 'particularly suitable for gymnastics lessons.' Koch was determined to make nudity a fundamental element of the exercises, viewing it as essential to his educational philosophy. Unable to incorporate this approach during regular school hours, Koch turned to the parents of his students for support.

In June 1923, this collaboration resulted in the formation of the 'Parents Groups for Free Physical Culture' (Elterngruppen für Freie Körperkultur). Participating parents were required to follow basic hygiene guidelines, which remained a central focus of Koch's teachings. The school's classrooms and auditorium were repurposed as practice spaces outside of regular hours; however, growing interest soon surpassed the available capacity. The term Freie Körperkultur (Free Physical Culture) first appeared in this context and was commonly abbreviated to Freikörperkultur (Free Body Culture), serving as a term in German-speaking regions to describe all unclothed recreational activities. Throughout his life, Koch favored the term Freie Körperkultur, emphasizing the 'free' (freie) aspect of physical culture.

Koch sought to incorporate his 'new' form of gymnastics, closely aligned with his vision of a natural lifestyle, into the school curriculum with the support of parents. However, controversy arose when a visitor to the school publicly condemned 'nude dancing' within a state institution. In response, school authorities prohibited Koch from conducting further nude exercises.^[3] Undeterred by this setback, Koch resigned from public school service and founded the Institute for Free Body Culture (Institut für Freikörperkultur).

In 1924, Koch established the private remedial Physical Culture School Adolf Koch (Körperkulturschule Adolf Koch), which eventually grew to encompass thirteen schools across Weimar Germany. The school program extended beyond gymnastics, incorporating hydrotherapy, high-intensity heliotherapy, medical examinations and care, discussions on various topics, and further education. The institution's management included prominent figures, such as the physician and sexologist Magnus Hirschfeld. Koch's approach was distinctive in that he did not merely create a nudist organization but founded a nudist school focused on education and well-being.^[3]

Documentary footage from Koch's schools depicts families, adults, children, and young people engaging in activities such as dancing, jumping, and hopping nude under Koch's guidance. He described the process as fostering a natural connection between physical movement and emotional expression, emphasizing the importance of freedom and body awareness in education:

For example, if at the beginning of a session, I let the boys and girls run freely—first in a line, then forwards and backwards, then crisscrossing—it may seem of little purpose. However, for each individual, it is a playful reorientation in space, with and around others, awakening the sense of touch and creating moments of joy through surprises and turns within just a few minutes. A fixed structure for our gymnastics sessions cannot be determined, as there are no rigid exercise patterns. Fun and joy in movement are always the focus. Of course, these relaxed gymnastics sessions can also be conducted in the open outdoors [nature].

— Adolf Koch

Koch's schools represented a major advancement in the German Freikörperkultur (free body culture) movement of the time. In Berlin, his school at Friedrichstraße 218 operated alongside several Freikörperkultur associations established around 1900. The school hosted nude swimming and gymnastics sessions at the communal swimming hall Stadtbad Mitte (Berlin) [de]. Additionally, Koch managed an expansive site in Selchow, which included sports fields, playgrounds, a lake, and barracks.

In November 1929, Koch's Berlin school hosted the first 'International Conference on Free Body Culture,' attracting 200 delegates from 23 countries, including France, the United Kingdom, Austria, and Switzerland.^[3] In addition to this achievement, Koch oversaw an active publishing program and served as the editor of the nudist journal Körperbildung Nacktkultur (Physical Education Nude Culture) from 1928 to 1932. Unlike other Freikörperkultur magazines of the time, this journal uniquely focused on presenting nudism as an indoor, classroom-based activity.^[3]

By 1930, Koch had established schools in Berlin, Breslau, Barmen-Elberfeld (Wuppertal), Hamburg, Ludwigshafen, and Mannheim, with a combined enrollment of 60,000 students.^[3] Attended by men, women, and children, these institutions had gained the support of prominent Social Democratic parliamentarians, educators, sociologists, and physicians.^[2] That same year, Koch noted that total membership in all German Freikörperkultur organizations had exceeded three million.^[3] His schools also offered four-year teaching certificates accredited by the German government, further solidifying their role in shaping modern physical education.^[3]

The successes of Koch's schools were achieved despite significant challenges. Several judicial proceedings were brought against him by individuals with strict moral views, yet none resulted in convictions or the closure of his schools. Although these legal battles demanded considerable time and energy, they also elevated Koch's public profile. A far more profound setback occurred in 1933 when the National Socialists rose to power.^[3] Koch's institutes were forcibly closed, in part because he refused to dismiss his Jewish employees voluntarily. His writings were deemed 'forbidden and un-German' and were publicly burned during the infamous Nazi book burnings.

Despite these challenges, Koch persisted in his work, openly defying the Nazi regime. Operating illegally, he founded two new institutes under different names and actively assisted many Jews and other victims of Nazi persecution. During the Second World War, Koch was conscripted for military service, where he served as head of sports for the rehabilitation of wounded soldiers and the follow-up care of disabled individuals at Castle Marquardt [de], near Berlin.

After 1945, Koch focused on rebuilding his institute, which was soon recognized by the Senate of Berlin as an 'open school facility' (Freie Schuleinrichtung). In 1946, he founded the Adolf Koch Institute (Adolf-Koch-Institut) for physical culture in Hasenheide, Berlin-Neukölln. Koch's second wife, Irmgard (born 26 July 1923), played a key role in managing the institute and also contributed as a gymnastics instructor.

In 1964, the German Association for Free Body Culture (DFK) formally distanced itself from Koch, citing concerns over his assertive public relations efforts.^[3] During the Adenauer era, the DFK frequently succumbed to public pressure, as naturism was still viewed by some as potentially harmful to young people and morally questionable.

Koch passed away on 2 July 1970. His wife, Irmgard, carried forward the promotion of Freikörperkultur gymnastics, traveling extensively to countries such as Switzerland and Hungary. In addition to teaching gymnastics until 2003, she also gave lectures on health and nutrition. That same year, she retired from the institute and relocated to Sanitz near Bad Doberan on the Baltic Sea coast to live with her daughter. Irmgard Koch passed away there on 10 August 2009.^[4]

In 1951, Koch's Berlin institute was succeeded by the 'Family Sport Association Adolf Koch' (Familien-Sport-Verein Adolf Koch e.V.), which remains active to this day.

Koch is regarded as a pioneer of nude culture, embodying the international and humanistic currents of the Freikörperkultur movement. In its early stages, influenced by a fashion trend of the late imperial era, this social movement was partially shaped by misinterpreted Darwinian concepts. However, Koch emerged from a socialist tradition rather than the 'Völkisch' (ethnic) strand of the Freikörperkultur. Through his magazine Wir sind nackt und nennen uns Du! (We are naked and call each other thou! [you]), Koch championed ideals rooted in the Age of Enlightenment. He became a leading advocate for egalitarian principles, emphasizing the communal and egalitarian essence of undressed group activities.

• Körperbildung und Nacktkultur (Physical education and nude culture), Leipzig 1924
• Nacktheit, Körperkultur und Erziehung. Ein Gymnastikbuch (Nudity, physical culture and upbringing. A gymnastics book), Leipzig 1929
• Körperkultur und Erziehung (Physical culture and education), Berlin 1950

• Physical culture
• Body culture studies

• Krüger, A.; Krüger, F.; Treptau, S. (2002). "Nudism in Nazi Germany: Indecent Behaviour or Physical Culture for the Well-being of the Nation". The International Journal of the History of Sport. 19 (4): 33–54. doi:10.1080/714001799. ISSN 0952-3367. S2CID 145116232.
• Jefferies, Matthew (2006). "'For a genuine and noble nakedness'? German naturism in the Third Reich". German History. 24 (1): 62–84. doi:10.1191/0266355406gh363oa.
• Williams, John Alexander (2007). Turning to Nature in Germany: Hiking, Nudism, and Conservation, 1900-1940. Stanford University Press. ISBN 978-0-8047-0015-3.
• Spender, Stephen (1994). World Within World. St. Martin's Press. ISBN 9780312113582.

• Familien-Sport-Verein Adolf Koch e.V. (Family Sport Association Adolf Koch)