An index for breathlessness and leg fatigue

The features of perceived symptoms causing discontinuation of strenuous exercise have been scarcely studied. The aim was to characterize the two main symptoms causing the discontinuation of heavy work in healthy persons as well as describe the growth of symptoms during exercise. Breathlessness (b) and leg fatigue (l) were assessed using the Borg CR10 Scale® and the Borg CR100 (centiMax) Scale®, during a standardized exercise test in 38 healthy subjects (24–71 years). The b/l‐relationships were calculated for terminal perceptions (ERIb/l), and the growth of symptoms determined by power functions for the whole test, as well as by growth response indexes (GRI). This latter index was constructed as a ratio between power levels corresponding to a very strong and a moderate perception. In the majority (71%) of the test subjects, leg fatigue was the dominant symptom at the conclusion of exercise (P