The running speed at a defined net lactate increase thus produces an increasing prediction accuracy with increasing distance. A parallel curve of the identity straight lines with the straight lines of regression indicates the independence of at least a second independent performance determining factor.
Most of the competition time during the mass start stages was spent at intensities near the LT. Compared with power output, heart rate measurement underestimated the time spent at intensity zones 1 and 3, and overestimated the time spent in zone 2.
The aim of this study was to evaluate the demands of riding a "Grand Tour" by monitoring both heart rate and power output in 15 professional cyclists. SRM power output profiles (SRM Trainingsystem, Jülich, Germany) were collected during 148 mass start stages during the 2005 Tour de France and analyzed to establish average power, heart rate (HR) and cadence produced in different terrain categories (flat [FLT]; semi-mountainous [SMT]; mountainous [MT]). The maximal mean power (MMP) for progressively longer durations was quantified. Average HR was similar between FLT (133 +/- 10 bpm) and SMT (134 +/- 8 bpm) but higher during MT (140 +/- 3 bpm). Average power output revealed a similar trend (FLT 218 +/- 21 W [3.1 +/- 0.3 W/kg], SMT 228 +/- 22 W [3.3 +/- 0.3 W/kg], and MT 234 +/- 13 W [3.3 +/- 0.2 W/kg]). Cadence during MT was approximately 6 - 7 rpm lower (81 +/- 15 rpm) compared to FLT or SMT. During MT stages, the MMP for 1800 sec. was highest (394 W vs. 342 W) but the MMP 15 was lower (836 W vs. 895 W) compared to FLT. The data document comprehensively the power output demands during the Tour de France.
The results of this study confirm the minimal, recommended donation intervals (56 days for men) as adequate when, for the first time, judged upon by tHb as a direct marker of hematologic recovery.
Haemoglobin mass is a main determinant of maximal oxygen uptake. Blood doping aims at increasing this variable. Limits for haematocrit and haemoglobin concentration are used as indicators of blood doping. However, these variables are measures of concentration, do not represent total haemoglobin mass and are altered by vascular volumes shifts. Direct estimation of haemoglobin mass could improve blood tests. It is unknown if physical exercise alters haemoglobin mass. The purpose of this study was to investigate the reaction of haemoglobin mass and other vascular compartments to heavy exercise in athletes. Haemoglobin mass and vascular compartments were evaluated using the optimised CO rebreathing method in 7 elite cyclists during a stage race. Simultaneously, haemoglobin concentration and haematocrit were analysed. Haemoglobin mass (pre-race 958 +/- 123 g, end race 948 +/- 106 g) and red cell volume did not change significantly over the study period, while plasma volume and blood volume tended to increase. Haematocrit (pre-race 44.1 +/- 2.5 %, end race 40.9 +/- 1.59 %) and haemoglobin concentration (pre race 15.8 +/- 0.9 g/dl, end race 14.7 +/- 0.7 g/dl) decreased. During the study, a plasma volume expansion as adaptation to prolonged exercise occurred. Haemoglobin concentration and haematocrit decreased accordingly, whereas haemoglobin mass remained stable. Haemoglobin mass might therefore be a suitable screening tool for blood manipulations.
Hb mass determination with the optimized CO-rebreathing method has sufficient precision to detect the absolute differences in Hb mass induced by blood withdrawal and autologous reinfusion. Thus, it may be suited to screen for artificially induced alterations in Hb mass.
The aim of this study was to determine possible influences, including data processing and sport-specific demands, on the validity of acceleration measures by an inertial measurement unit (IMU) in indoor environments. IMU outputs were compared to a three-dimensional (3D) motion analysis (MA) system and processed with two sensor fusion algorithms (Kalman filter, KF; Complementary filter, CF) at temporal resolutions of 100, 10, and 5 Hz. Athletes performed six team sport-specific movements whilst wearing a single IMU. Mean and peak acceleration magnitudes were analyzed. Over all trials (n = 1093), KF data overestimated MA resultant acceleration by 0.42 ± 0.31 m∙s−2 for mean and 4.18 ± 3.68 m∙s−2 for peak values, while CF processing showed errors of up to 0.57 ± 0.41 m∙s−2 and −2.31 ± 2.25 m∙s−2, respectively. Resampling to 5 Hz decreased the absolute error by about 14% for mean and 56% for peak values. Still, higher acceleration magnitudes led to a large increase in error. These results indicate that IMUs can be used for assessing accelerations in indoor team sports with acceptable means. Application of a CF and resampling to 5 Hz is recommended. High-acceleration magnitudes impair validity to a large degree and should be interpreted with caution.
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