a respiratory snorkel. HR was measured from RR intervals (CardioSwim, Freelap). Data were time aligned and 1-âs interpolated. Exercise VO2 was the average ...
Schuller T., Hoffmann U., Iglesias X., Chaverri D., Rodríguez F.A. Concurrent validity of a new model for estimating peak oxygen uptake based on post-‐exercise measurements and heart rate kinetics in swimming. In Mason B. (editor), Proceedings of the XIIth International Symposium for Biomechanics and Medicine in Swimming. Canberra: Australian Institute of Sport, 2014. pp. 506-‐511.
CONCURRENT VALIDITY OF A NEW MODEL FOR ESTIMATING PEAK OXYGEN UPTAKE BASED ON POST-‐EXERCISE MEASUREMENTS AND HEART RATE KINETICS IN SWIMMING Schuller T.1, Hoffmann U.1, Iglesias X.2, Chaverri D.2, Rodríguez F. A.2 1
Institut für Physiologie und Anatomie, Deutsche Sporthochschule Köln, Germany INEFC-‐Barcelona Sport Sciences Research Group, Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Spain ABSTRACT Introduction. We aimed to assess the validity of a mathematical model based on heart rate (HR) and post-‐exercise VO2 measurements for estimating peak VO2 at the end of a swimming exercise. Its physiological rationale relies on the assumption that during the immediate recovery the systolic volume and the arterio-‐venous O2 difference remain practically constant for a certain period. According to Fick’s principle, this leaves HR as the main parameter for changes in VO2 . Method. 34 elite swimmers performed 3x200 m at increasing sub-‐maximal speeds, followed by a maximal 200 m swim. VO2 was measured breath-‐by-‐breath using a portable gas analyser (K4 b2, Cosmed) connected to the swimmer by a respiratory snorkel. HR was measured from RR intervals (CardioSwim, Freelap). Data were time aligned and 1-‐s interpolated. Exercise VO2 was the average of the last 20 s during the swim [VO2 (end)], and recovery VO2 was the post-‐ exercise first 20 s average [VO2 (0-‐20)]. The model calculates a virtual VO2 at time (t) of recovery [vVO2 (t)], using the quotient between the peak HR during the last 10 s of the swim [HR(0)] and the 1-‐s interpolated value at (t) [(HR(t)], multiplied by the 1-‐s interpolated VO2 value at (t) [VO2 (t)], resulting in: vVO2 (t) = HR(0) / HR(t) ·∙ VO2 (t). Average vVO2 values were calculated for different time intervals and compared to measured exercise VO2 values (RM-‐ANOVA, post-‐hoc Tukey, *p< 0.05). Mean differences (mean ∆) and Pearson’s coefficient of determination (R2) were also calculated. Results. Peak VO2 at the last 20 s during exercise (3547± SD 692 ml·∙min-‐1) was different from VO2 (0-‐20) (3431 ± 685) (mean diff. -‐116, 3.3%, p= 0.001). All virtual VO2 values were highly correlated with (R2 = 0.86 to 0.96, p
