Heart rate variability (HRV) analysis is widely used to investigate autonomous cardiac drive. This method requires periodogram measurement, which can be obtained by an electrocardiogram (ECG) or from a heart rate monitor (HRM), e.g. the Garmin 920 XT device. The purpose of this investigation was to assess the accuracy of RR time series measurements from a Garmin 920 XT HRM as compared to a standard ECG, and to verify whether the measurements thus obtained are suitable for HRV analysis. RR time series were collected simultaneously with an ECG (Powerlab system, AD Instruments, Castell Hill, Australia) and a Garmin XT 920 in 11 healthy subjects during three conditions, namely in the supine position, the standing position and during moderate exercise. In a first step, we compared RR time series obtained with both tools using the Bland and Altman method to obtain the limits of agreement in all three conditions. In a second step, we compared the results of HRV analysis between the ECG RR time series and Garmin 920 XT series. Results show that the accuracy of this system is in accordance with the literature in terms of the limits of agreement. In the supine position, bias was 0.01, - 2.24, + 2.26 ms; in the standing position, - 0.01, - 3.12, + 3.11 ms respectively, and during exercise, - 0.01, - 4.43 and + 4.40 ms. Regarding HRV analysis, we did not find any difference for HRV analysis in the supine position, but the standing and exercise conditions both showed small modifications.

This study compared changes in the energy time-profiles and related parameters in pole vaulting using three body models. Two-dimensional kinematics were collected from 20 trials (5.20-6.01 m) performed by 10 athletes during a competition. The linear and angular kinetic, potential, and mechanical energy time-profiles were obtained from three pole vaulter models composed of 12, 5, and 3 segments (M 12 , M 5 , and M 3 , respectively). The energy values of M 5 , compared to those of M 3 , were more similar to M 12 and appeared to be a good compromise between the decreased number of digitized points and the reliability of the energetic outcomes in pole vaulting.

This study compared changes in the energy time-profiles and related parameters in pole vaulting using three body models. Two-dimensional kinematics were collected from 20 trials (5.20-6.01 m) performed by 10 athletes during a competition. The linear and angular kinetic, potential, and mechanical energy time-profiles were obtained from three pole vaulter models composed of 12, 5, and 3 segments (M12, M5, and M3, respectively). The energy values of M5, compared to those of M3, were more similar to M12 and appeared to be a good compromise between the decreased number of digitized points and the reliability of the energetic outcomes in pole vaulting.