[The influence of negative air ions on the regulation of respiration and blood circulation under controlled physical stress, as well as on reaction time (author's transl)].

Ten healthy male test subjects (aged 29--35 years) were put on a bicycle ergometer twice for 10 minutes each time and had to perform work of 1 W/kg body-weight while being subjected to normal air and air enriched with negative ions. Using ergospirometry, a number of physiological indices for respiration, circulation, and the aerobic metabolism were recorded. In a further test, the reaction time of 14 test subjects (aged 23-55 years) was tested under the condition of normal breathing air and air enriched with negative ions. The intake of oxygen, which is a gross indicator for the entire aerobic metabolism, is not influenced by negative air ions. Given a constant environment, the presence or absence of ions does not have any effect. Sudden introduction or removal of negative air ions induces changes in control that tend to be of a negative nature: there is an increase in breathing frequency, breathing equivalent, and cardiac frequency at constant oxygen intake (p less than 0.025). In testing reaction time, only the sudden introduction of negative air ions produced a statistically significant effect, i.e. prolongation of reaction time. This effect, too, is of a more negative nature (p less than 0.05).