ABSTRACT
A few studies have indicated that males and females respond differently to whole-body vibration (WBV) training. However, the existing insights are still insufficient and they cannot be transferred to sex-specific practice planning. To evaluate the effect of 5-week WBV training on neuromuscular [countermovement jump (CMJ), squat jump (SJ)] and cardiovascular [heart rate and blood pressure] data, taking into account sex-specific effects. This is a comparative experimental study including 96 healthy adults, divided into two groups: a WBV group (25 females and 24 males) and a control group (27 females and 20 males). The participants attended nine to ten training sessions (twice a week for 5 weeks), each lasting approximately 30 min. Both groups performed the same exercise routine on the vibration training device. For the WBV group, the training device was vibrating during the whole training session, including the breaks. For the control group, it was turned off. Maximum jump height (H, cm) and maximum relative power (MRP, kW/kg) were noted during CMJ and SJ performed on a force plate. Resting (sitting) heart rate (bpm) and blood pressure (mmHg) were measured twice, before and after the intervention. For each parameter, Δdata (= before - after) was calculated. Interactive effects of sex (2) vs group (2) vs session (2) were noted only in males and they only concerned ΔSJMPR and ΔCMJH: compared to the control group, the WBV group had better ΔSJMPR (1.39 ± 3.05 vs -2.69 ± 4.49 kW/kg, respectively) and ΔCMJH (0.50 ± 6.14 vs -4.42 ± 5.80 cm, respectively). No sex-specific effect of WBV on neuromuscular (CMJ and SJ) or cardiovascular (heart rate and blood pressure) data was found.
ABSTRACT
Paralympic Alpine Skiing comprises three main categories, namely Standing, Visually Impaired and Sitting, to one of which athletes get classified depending on their individual impairment of ability. An existing sport profile of alpine skiing for able-bodied athletes facilitates the physical preparation process of Standing and Visually Impaired athletes. However, very little is known about performance determinants as well as content and structure of the physical preparation of athletes with congenital or acquired spinal cord injury competing in the Sitting class. The objective of this study was to describe the metabolic demands of Paralympic Alpine Skiing Sitting class athletes using laboratory and field measurements. The study determined maximal oxygen uptake (VO2max), maximum heart rate (HRmax) and maximal blood lactate concentration ([La(-)]) as well as ventilatory thresholds in laboratory testing (n = 6) as well as on-snow in Slalom (SL) carried out in a ski dome, and Giant-Slalom (GS) on a natural slope. On-snow test variables are expressed normalized to laboratory maximum values (%VO2max, %HRmax). For SL, values reached ~30% VO2max and ~60% HRmax whereas GS values were slightly higher reaching ~50% VO2max and ~75% HRmax. Lactate concentration remained close to baseline values for SL and was slightly higher at ~3 mmol·L(-1) for GS. All athletes remained below their second ventilatory threshold and even skied for a long portion of runtime below their first ventilatory threshold. In general, measured metabolic values were lower than reported for able-bodied alpine skiers. However, despite the small and inhomogeneous sample covering all but one sit-skiing classes, strain of sit-skiing appears to be consistent throughout the five sit-skiing classes. Common measures of aerobic or anaerobic performance variables do not suggest further investigations in the field of metabolism for performance determinants in sit-skiing. Key pointsMetabolic demand and strain of Paralympic sit-skiing is different to able-bodied skiing.Measured parameters of VO2max and [La-] are lower in sit-skiers compared to able-bodies skiers.Equipment used for sit-skiing is suggested to absorb external forces to some degree, thereby lowering the strain.Implications for training focus (e.g. skiing higher volumes with a focus on technique) and the physical conditioning process (aerobic/ anaerobic capacity are suggested to be no performance determinants) may be derived.
ABSTRACT
Recent technical development focused on real-time heart rate monitoring instead of postexercise evaluation of recorded data. There are several systems on the market that allow direct and real-time monitoring of several individuals at the same time. The present study compared the systems of Polar, Acentas, Activio, and Suunto in a field test with twelve subjects regarding failure quota, operating distance, and ECG validity. Moreover, the installation and use of software and hardware were evaluated with a quality rating system. Chest belts were evaluated with a questionnaire, too. Overall the system of Acentas reached the best mark of all systems, but detailed results showed that every system has its advantages and disadvantages depending on using purpose, location, and weather. So this evaluation cannot recommend a single system but rather shows strength and weakness of all systems and additionally can be used for further system improvements.
