Low sampling rates bias outcomes from the Wingate test.

The purpose of this work was to apply a simple method for acquisition of power output (PO) during the Wingate Anaerobic Test (WAnT) at a high sampling rate ( S(R)) and to compare the effect of lower S(R) on the measurements extracted from the PO. 26 male subjects underwent 2 WAnTs on a cycle ergometer. The reference PO was calculated at 30 Hz as a function of the linear velocity, the moment of inertia and the frictional load. The PO was sampled at 0.2, 0.5, 1, 2 and 5 Hz. Both the peak (16.03±2.22 W·kg (-1)) and mean PO (10.34±1.01 W·kg (-1)) presented lower relative values when the S(R) was lower. Peak PO was attenuated by 0.29-42.07% for decreasing sampling rates, resulting in different values for 0.2 and 1 Hz ( P<0.001). When the S(R) was 0.2 Hz, the time to peak was delayed by 53.81% ( P<0.001) and the fatigue index was attenuated by 22.12% ( P<0.001). In conclusion, due to the differences achieved here and the fact that the peak flywheel frequency is around 2.3 Hz, we strongly recommend that the PO be sampled at 5 Hz instead of 0.2 Hz in order to avoid biased errors and misunderstandings of the WAnT results.

Oxygen uptake, heart rate and energy expenditure during slideboard routines at different cadence.

AIM: Little is known about the physiological response during slideboard exercise (SE). The aim of the present study was to analyse the oxygen uptake (V.O2), the heart rate (HR) and the energy expenditure (EE) during a typical slideboard exercise session and investigate differences on these variables when performing the same choreography at two different cadences (130 e 145 beats per minute - bpm). METHODS: The sample comprised 13 female university students (21,77+/-0,97 years), apparently healthy and physically active, with past training in SE and mastering the technical levels 1 and 2. The subjects performed randomly exercise sessions at 130 bpm and 145 bpm. The ventilatory response was measured by an open air circuit system (COSMED K4b2, Rome, Italy) and HR was measured by a portable monitor (Polar Wireless Double Electrode, Kempele, Finland). HR and V.O2, during SE at 130 bpm, were 179.88+/-834 bpm and 37.95+/-3.71 mL/kg/min respectively. At 145 bpm SE mean values were 182.08+/-9.58 bpm and 39.67+/-3.82 mL/kg/min respectively. EE during 130 bpm exercise was 10.60+/-1.69 kcal/min and at 145 bpm was 10.90+/-1.36 kcal/min. No differences were found between 130 and 145 bpm in none of the variables. We conclude that slideboard exercise cardio respiratory response does not seem affected by the rhythm of execution. Moreover the EE associated with this type of exercise is above the literature reports for other types of group aerobic exercises.