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Purpose: Simulated competition as a training tool has a relevant role in enhancement of exercise intensity, motivation and physical enjoyment. Including a competitive component into the agility training could represent another way to improve agility performance significantly more. The aim of this study was to assess the effect of agility training performed in the form of competitive exercising on agility performance. Methods: Twenty-two athletes were randomly assigned to an experimental or a control group. Both groups completed the same eight-week agility training, but only the experimental group performed exercises in the form of head-to-head competition. Prior to and after the training, agility time in the Agility Dual test (performed in pairs in the form of head-to-head competition) and Agility Single test (performed individually) was measured. In addition, simple and two-choice reaction time and speed of step initiation were also assessed. Results: A significant group × time interaction effect was observed for agility time in the Agility Dual test only (p = 0.002). This effect occurred in favor of experimental group (18%, p < 0.01). No further significant interactions were detected. Conclusions: Competitive agility training led to significant improvement of agility time under competitive conditions only. This training does not contribute to more pronounced improvements of other reaction and speed abilities.

The molecular clockwork of the rat suprachiasmatic nucleus, the site of the circadian clock, is affected by the photoperiod (Sumova et al., 2003). The aim of the present study was [...]

The SCN as a site of the circadian clock itself exhibits rhythmicity. A molecular clockwork responsible for the rhythmicity consists of clock genes and their negative and positive transcriptional-translational feedback [...]

BACKGROUND: Aging-related deterioration of the lower limb muscle strength could highly influence the functional performance of elderly individuals. OBJECTIVE: To investigate how advancing age impacts the lower limb muscle strength and consequently affects the balance and walking performance. METHODS: Twenty-seven community-dwelling elderly females underwent isokinetic ankle dorsi/plantar flexion (ADF/APF), inversion/eversion (AIN/AEV), knee flexion/extension (KFL/KEX), hip flexion/extension (HFL/HEX), and abduction/adduction (HAB/HAD) tests, the six-minute walk test, open-eyed biped balance test on foam rubber and the performance-oriented mobility assessment (POMA). RESULTS: The Pearson's product-moment correlation coefficients demonstrated that advancing age negatively influenced the relative work and moment produced in all the muscle groups, the POMA score (r = - 0.51), walking speed (r = - 0.62), and the vertical (r = 0.55) and anteroposterior (r = 0.54) postural sway velocities. The peak moment and work values of AINs and APFs; KFLs and KEXs; and HABs, HFLs, and HEXs showed a significantly positive correlation with the walking speed (α ⩽ 0.05). CONCLUSION: The strength of HFLs, HEXs and HABs, as the important contributors to the walking performance, underwent attenuation as the age increased, consequently resulting in impairments of stepping profiles of elderly females. Elderly females are needed to be trained to reach the optimum levels of lower limb muscular strength to overcome premature incapacitation and have control over their independence in daily activities. [ABSTRACT FROM AUTHOR]

Previous studies reported a significant association between postural control and lower-limb strength of several muscle groups, however, they were focused especially on knee muscles and ankle plantar and dorsal flexors. The aim of the present study is to examine the correlation between the muscle strength of ankle invertors, evertors, plantar flexors, and dorsal flexors and the control of bipedal stance in young and older adults. Thirty one young (aged 22.8 ± 2.6 years) and thirty one older adults (aged 70.5 ± 7.2 years) voluntarily participated in this study. Ankle muscle strength was evaluated by an isokinetic dynamometer. Normalized peak torque and work were averaged for four repetitions and for both lower limbs. The control of bipedal stance was evaluated by the sample entropy derived from an accelerometer placed on the lumbar spine while the subject stood on a foam pad with eyes open. Results showed significant age-related differences in ankle muscle strength and sample entropy in medial-lateral direction. More interestingly, the correlation between ankle muscle strength and the sample entropy was significantly different between young and older adults. Indeed, no significant correlation was observed in the younger adults. Conversely, in the older adults, the work of the ankle evertors positively correlated with sample entropy in the medial-lateral direction during bipedal stance (r = 0.36), whereas the peak torque and work of the dorsal flexors were significantly correlated with sample entropy in the anterior-posterior direction during bipedal stance (r = 0.44 for both variables). In the young adults, results suggest that, standing on foam with eyes open is a relatively easy postural task that does not require the full ankle muscle strength capacity. Taken together, the present findings suggest that older adults have a different association between ankle muscle strength and the sample entropy during bipedal stance. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the postural stability in children with asthma using balance tests under conditions of a comfortable foot placement and with a foot placement provoking instability.Methods: A group of 10 school children from 8 to 10 years old with mild intermittent asthma and 10 healthy children of the same age range performed four balance tests in a randomized order: preferred stance, adjusted stance, and tandem stance each under both conditions of eyes opened (EO) and eyes closed (EC), as well as a one-legged stance with eyes-opened conditions. To determine postural stability, the center of pressure (CoP) movement was recorded. Basic stabilographic parameters were calculated: CoP velocity in the anterior–posterior direction, CoP velocity in the medial–lateral direction, and the total CoP velocity.Results: Statistically significant differences between the groups were found only for the one-legged stance. Significantly greater anterior–posterior CoP velocity (p = 0.05) and total CoP velocity (p = 0.03) were found in children with asthma when standing on the preferred foot. A significantly greater medial–lateral velocity (p = 0.02) was also found in the non-preferred foot of children with asthma.Conclusions: We can conclude that standing on one leg might be an appropriate test with which to identify balance differences between young children with mild intermittent asthma and healthy children. [ABSTRACT FROM AUTHOR]

Objective: Postural control is a complex skill based on the interaction of dynamic sensorimotor processes. This study assessed the effect of lateral perturbations on postural re-stabilization regarding lower limb preference., Methods: A group of 14 physically active individuals (9 male, 5 female) randomly underwent postural perturbations in lateral-left and lateral-right directions at a velocity of 0.2 m.s-1 and a platform shift of 6 cm. Perturbation to the preferred limb side (PS) was noted when the contralateral body movement was primarily controlled by the preferred limb and perturbation to the non-preferred limb side (NS) was noted when the contralateral body movement was primarily controlled by the non-preferred (stabilizing) limb. Prior to, during and after the perturbation centre of pressure (CoP) was registered using a computerized motor driven FiTRO Dynamic Posturography System based on force plate (Fitro Sway Check) with a sampling rate of 100 Hz. The basic stabilographic parameters of peak displacement (Peak 1), peak-to-peak displacement (Peak 2), time to peak displacement (Time 1), time to peak-to-peak displacement (Time 2) and re-stabilization time (Time 3) were analyzed., Results: Results showed significantly larger Time 3 on PS than on NS (2.81 ± 1.32 s and 1.73 ± 1.10 s; p=0.02). However, there were no significant differences in other parameters between PS and NS., Conclusion: It may be concluded that the observed shorter re-stabilization time at NS was due to the stabilization role of the non-preferred limb.

Damp dwellings represent suitable conditions for extended indoor moulds. A cellulolytic micromycete Stachybotrys chartarum (Ehrenb.) Hughes is considered to be a tertiary colonizer of surfaces in affected buildings. Known adverse health effects of S. chartarum result from its toxins--trichothecenes or atranones, as well as spirolactams. Mechanism of their potential pathological effects on the respiratory tract has not yet been sufficiently clarified. The cytotoxic effects of complex chloroform-extractable endo- (in biomass) and exometabolites (in cultivation medium) of an indoor S. chartarum isolate of an atranone chemotype, grown on a liquid medium with yeast extract and sucrose at 25 degrees C for 14 d, on lung tissue were evaluated in the 3-day experiment. For the purpose, 4 mg of toxicants were intratracheally instilled in 200 g Wistar male rats. A trichothecene mycotoxin diacetoxyscirpenol was used as the positive control. Bronchoalveolar lavage (BAL) parameters--viability and phagocytic activity of alveolar macrophages (AM), activity of lactate dehydrogenase, acid phosphatase and cathepsin D in cell-free BAL fluid (BALF), as well as in BAL cells, were measured. Acute exposure to the metabolites caused statistically significant changes, indicating lung tissue injury in the experimental animals. Decreased AM viability and increased activity of lysosomal enzyme cathepsin D in BAL cells after fungal exometabolite exposure were the most impressive. As toxic principles were found predominantly in the growth medium, toxins were more likely responsible for lung cell damage than e.g. fungal cell wall components. S. chartarum toxic metabolites can contribute to the ill health of occupants of mouldy building after inhalation of contaminated aerosol.