Each participant was asked to sit on a chair, roll up one sleeve, and relax for five minutes, so that the measurements were made at rest. Subsequently, they underwent an electrocardiogram and spirometry to verify normal results. A second stage consisted of serial measurement of vital signs, including heart rate, systolic blood pressure, diastolic blood pressure, tympanic temperature, total hemoglobin, perfusion index, and baseline lactic acid levels.
Blood pressure and heart rate were measured with the use of oscillometric sphygmomanometry (Schiller BP 200 Plus; Schiller, Baar, Switzerland). For measuring tympanic temperature we used a Braun Thermoscan Pro 6000 (Welch Allyn, Inc., New York, USA) with ExacTemp™ technology. Total hemoglobin values and perfusion index were monitored with a multiparameter monitor Pronto 7 (Masimo, California, USA), software version b99e80000004ef796 (2.2.15), and sensor revised version a83f90f0000c53f2. For the determination of lactic acid levels we used an Accutrend Plus meter (Roche Diagnostics, Mannheim, Germany), with a measurement range of 0.8-21.7 mmol/L.
Blood pressure and heart rate were measured with the use of oscillometric sphygmomanometry (Schiller BP 200 Plus; Schiller, Baar, Switzerland). For measuring tympanic temperature we used a Braun Thermoscan Pro 6000 (Welch Allyn, Inc., New York, USA) with ExacTemp™ technology. Total hemoglobin values and perfusion index were monitored with a multiparameter monitor Pronto 7 (Masimo, California, USA), software version b99e80000004ef796 (2.2.15), and sensor revised version a83f90f0000c53f2. For the determination of lactic acid levels we used an Accutrend Plus meter (Roche Diagnostics, Mannheim, Germany), with a measurement range of 0.8-21.7 mmol/L.