Exercise Physiology Research in Germany 1700 to 1910
In 1719, Friedrich Hoffmann (1660-1742), a physician from Halle, obtained his doctoral degree with experimental investigations about the effects of physical exercise on the human cardiovascular system and on digestion. In 1796, the physician Christoph Wilhelm Hufeland (1762-1836) published a textbook about the significance of different types of physical exercise for human health and life expectancy (66).
In the 19th century, the physiologist Emil Dubois-Reymond (1818-1896) studied the role of gymnastics in the human body (21, 22). The physician and chemist Max von Pettenkofer (1818-1901) detected the existence of creatine in the skeletal muscle and described a strengthening of the circulatory system in connection with physical training (111).
The first ergometer in the present-day sense of the word was developed by the German physician Speck in 1883. When using this cranked ergometer, the test person was in the standing position (figure 4.1). The crank friction could be modified by pulling up a screw. Speck determined the resistance with weights hung on the crank. The number of revolutions could be determined by noting the number of turns of twine wound up around the crank axle. The exhaled air was collected in a double spirometer and the postexperimental air composition was determined, thus enabling conclusions to be drawn about the individual performance reaction (2, 125).
In 1887 the Viennese physician Friedrich Gaertner (1847-1917) presented a mechanically braked ergometer, based on Speck’s equipment that could measure the work performed in kilogram-meter. This device, called the ergostat, later went into standard production (112).
The first heyday of exercise physiology began with the veterinarian Nathan Zuntz (1847-1920) in Berlin (figure 4.2), who developed the first motor-driven treadmill in 1889 (figure 4.3). His work is described in chapter 1 (142).
Of substantial significance in the application of aspects of exercise physiology in medicine were Adolf Theophil Ferdinand Hueppe (1852-1938) and Ferdinand August Schmidt (1852-1929). In 1899 Hueppe wrote a fundamental work titled A Textbook of Hygiene that covered the whole of the exercise physiology discipline of those days. This was followed by the work titled Hygiene of Physical Exercises, published in 1911. In 1893 Schmidt published the book Physical Exercise According to the Exercise Value, which deals with an overview of suitable physical exercises for different ages (122, 123).
From 1904 to 1906 Kuelbs examined the influence of physical training on the internal organs, particularly the heart. He took two dogs from the same litter and trained one of them 5 times/wk for about 2 h on a treadmill, which he had taken over from Zuntz; the other dog had a normal, everyday life. After 1 yr both animals were killed and all internal organs were measured and examined. Although both dogs had more or less the same body weight, the heart of the dog trained on the treadmill was approximately 33% larger than that of the untrained dog. Similar differences were also manifest in the weights of the liver, kidneys, adrenal glands, spleen, and lungs (77).
Over the subsequent decades Arthur Mallwitz (1880-1968) became the most important promoter for German, and later international, sports medicine. He obtained his doctor’s degree at Halle University (Saale) in 1908 with what is presumed to be the first ever dissertation in sports medicine. In his dissertation, titled Maximum Performances With Special Consideration of Sports Done at the Olympic Games, Mallwitz considered, above all, the investigations of Hueppe and Schmidt as well as those of Zuntz and his school. In 1910 a comprehensive book about exercise physiology in connection with numerous kinds of sports was edited by Weissbein (141).
The first ergometer was developed by Speck in 1883. Gaertner produced it in series.
Hollmann W, Strueder HK, Predel HG, Tagarakis CVM. Spiroergometrie. Stuttgart, Schattauer, 2006.
Exercise Physiology Research in Germany 1911 to 1933
German Empire Committee for Scientific Research in Sport and Physical Exercise
The First Congress for Scientific Research in Sport and Physical Exercise took place in Oberhof, Germany, from September 20 to 23, 1912. The congress was conducted by the professor for internal medicine of the University Clinic Berlin CharitÃ©, Friedrich Kraus (1858-1936), and was chaired by Schmidt and Hueppe. Approximately 70 doctors participated (93). On September 21, 1912, the German Empire Committee for Scientific Research in Sport and Physical Exercise - the first national medical sport association worldwide - was founded under the chairmanship ofKraus, who was elected president.
Nathan Zuntz (1847-1920).
Reprinted, by permission, from W. Hollmann and K. Tittel, 2008, History of German sports medicine (Gera: Druckhaus Gera), 15.
The world’s first motorized treadmill, developed by Zuntz and Lehmann in 1889 in Berlin. This apparatus was shown in the international hygiene exhibition in Dresden in 1911.
Hollmann W, Strueder HK, Predel HG, Tagarakis CVM. Spiroergometry. Stuttgart, Schattauer, 2006.
Period From 1913 to 1924
In 1913, Arthur Mallwitz was appointed the first full-time sport physician worldwide by the Prussian State Gymnastics Institute. Mallwitz then took up his office under the official designation of sport physician (94).
At the same time the physician and chemist Otto Meyerhof (1884-1951) recognized the regulating relationship between respiration rate and the suppression of glycolysis in muscles. He demonstrated that the consumption of one molecule of oxygen prevents the formation of two molecules of lactate. Meyerhof’s findings supported the assumption that the enzymes fanning lactate also function aerobically but that the lactate formed is resynthesized to carbohydrate at the expense of the energy provided by respiration (98).
Hugo Wilhelm Knipping (1895-1984), physician and internist at Hamburg University, developed a gas metabolism apparatus for examination of humans at rest in 1924 and constructed a dynamo cranked ergometer in 1928. In 1929 he combined an enlarged gas metabolism apparatus for exercise examinations with the crank ergometer and designated the method as spiroergometry (73, 74). It was the genesis of precise and simple clinical exercise diagnostics. Engineering, however, was not able to construct the equipment to satisfy all technical requirements until 1949 (75, 76).
German Medical Association for the Promotion of Physical Exercise (1924-1933)
Because of the political confusion and economic difficulties after the finish of World War I in 1918, approximately 6 yr elapsed before research in sports medicine and thus exercise physiology was renewed in 1924. The founding of the German Physician Association for the Promotion of Physical Exercise in 1924 was the impetus for this.
In 1925 Max Rubner (1854-1932), director of the Robert Koch Institute in Berlin and an internationally recognized metabolism researcher, ascertained that the skeletal musculature in adults amounts to 43% of the total body mass and that the total musculoskeletal system inclusive of bones, heart, and lungs amounts to 61%. The greatest proportion of the musculature was allotted to the legs (56%) and the upper extremities (28%). The head and torso muscles contributed to 16% of the total body mass (120).
Approximately 3,200 kcal could meet the daily energy requirements for physical exercise for a 70 kg person whereas 2,600 calories was sufficient for simple office work. The metabolism of a farm worker during harvesting would require 4,300 kcal. The peak values of the daily calorie consumption for lumberjacks would amount to approximately 6,000 kcal for a 70 kg person. Long-distance racing cyclists, however, could reach a peak daily metabolic rate of 11,000 kcal. Rubner believed that the limiting factor for the uptake of calories in the human body was the intestinal system. A repeat of such great exertion over several days would inevitably lead to loss of body weight (119).
As early as 1925, Herbert Herxheimer (1894-1985) and others precisely described the psychic and physical effects of overtraining, including a decrease in maximal oxygen uptake, reduced appetite, tendency to sweat, shivering, jerky reflexes, and pronounced respiratory arrhythmia with a clear preponderance of the parasympathetic part. Obstipation and painful stomach spasms also could be observed. Herxheimer published all his sports medicine knowledge in his famous book in 1933.
Herxheimer also described the connection between heart size and distance running. He found an increase in the transverse diameters of the heart in the following ascending order: boxing, swimming, middle-distance running, long-distance running, marathon running, and long-distance skiing. Particularly large hearts would work with a large stroke volume. This would result in the corresponding bradycardia at rest. The blood pressure of endurance athletes would be low (39).
Ludwig Aschoff (1866-1942) in Freiburg ascertained that there is one physiological work hypertrophy of the heart muscle as an adaptation to increased muscular activity. The enlargement remains within moderate limits. Sport does not cause a pathological hypertrophy. If a conspicuous general hypertrophy of the heart exists, it is a matter of pathological circumstances (e.g., cardiac valve ailments, hypertony or glomerular-tubular cirrhosis of the kidney). It is impossible for sport to cause a fatality in an individual with a healthy heart. A muscular cardiac insufficiency is to be treated by taking it easy. Puberty is a dangerous period regarding possible functional damage of the heart through sport.
Another significant exercise physiologist of the 1920s was Richard Herbst (1893-1949) in KÃöenigsberg East Prussia. He conducted numerous experimental investigations on the behavior of maximum oxygen absorption in humans of different ages and in different training conditions. He published his findings in 1928, 4 yr after the first description of maximum oxygen uptake by Hill. According to Herbst (1928), endurance-trained subjects had a higher oxygen intake than did untrained subjects. Also, after reaching the maximum oxygen uptake value, ventilation could be increased still further. Herbst used the Douglas bag with the subsequent respiratory gas analysis method for runners and cyclists. Further, he examined running distances between 100 m and marathon using the Douglas bag and gas analysis. The values obtained at that time (e.g., marathon with an energy consumption of 3,050 kcal, 10 m sprint with an energy consumption of 50 kcal) agree with measurements made nowadays. Sustained running loads of more than 3 min were determined from the magnitude of the maximal oxygen uptake. Thus, these parameters were a measure of performance. The lung ventilation volume would still increase further after reaching the maximum oxygen absorption. Cardiac output is represented as the most important factor limiting physical performance (37).