69 research outputs found
Analysis of anaerobic power in club level young rowers
Aim: To date, assessment of the anaerobic components to determine performance in rowers is not part of standard evaluation or monitoring set for training. The aim of this study was to evaluate the relation between anaerobic power output and ergometer rowing performance over 2000 meters, in a group of 14 -17 years old rowers (n = 11).
Methods: Each subject performed, in three separate days, two “all-out” tests, over 20 and 60 seconds, and a 2000 meters trial, using a Concept II rowing ergometer. Mean power values over 20 sec (W20) and 60 sec (W60) were measured and compared with the time to perform the 2000 m trial (t2000).
Results: Statistical analysis showed high and significant correlation between 2000 meters performance (6.90 ± 0.1 min) and anaerobic power over 20 sec (479.5 ± 93.90 watts; r = 0.941, P = 0.00002) and 60 sec (435.5 ± 64.60 watts; r = 0.964, P = 0.000002).
Conclusions: The data of our study confirm that parameters of anaerobic power strongly affect the performance and that the determination of these variables by testing on rowing ergometer can be an useful tool for planning and monitoring of training in young rowers
Effects of training on plasmatic cortisol and testosterone in football female referees
none6Antonella Muscella; Giulia My; Selmi Okba; Daniele Zangla; Antonino Bianco; Santo MarsiglianteMuscella, Antonella; My, Giulia; Okba, Selmi; Zangla, Daniele; Bianco, Antonino; Marsigliante, Sant
Relationship Between Heart Rate Recovery After Exercise and Maximal Oxygen Uptake in Sedentary Patients with Type 2 Diabetes
AIMS: Heart rate recovery after exercise (HRR) is an estimate of autonomic modulation of the heart, and has been
shown to be inversely associated with type 2 diabetes. Type 2 diabetes is associated with decreased maximal
oxygen consumption (VO2max). Aim of our study was to assess the relationship between HRR and VO2max in
sedentary patients with type 2 diabetes.
METHODS: Maximal exercise testing to determine VO2max (ml ∙ Kg-1 ∙ min-1) was performed in 16 sedentary
patients with type 2 diabetes (DP) and in 16 age-matched sedentary healthy controls (HS). HRR (bpm) 2 min after
cessation of the exercise was recorded. Simple linear regression was used to assess the relations between HRR
and VO2max.
RESULTS: VO2max and HRR were significantly lower in DP compared to HS (P = 0.002 and P = 0.008
respectively). A correlation between HRR and VO2max has been found, stronger in DP (r = 0.672, P = 0.004) than
HS (r = 0.620, P = 0.01).
CONCLUSIONS: Our study suggests that regular physical activity aimed to improve the levels of VO2max in
subjects with diabetes may improve the HRR and reduce the risk of cardiovascular events
Visuospatial attention lateralization in volleyball players and in rowers.
In the present study, differences in visuospatial attention lateralization were evaluated in athletes engaged in open-compared to closed-skill sports and sedentary nonathletes. 23 volleyball players (open skill; Italian national level and regional level), 10 rowers (closed skill, Italian national level), and 23 sedentary participants responded to a computerized line-length judgment task. Five lines, differing in the length of their right and left segments, were randomly presented; the respondent made a forced-choice decision about the respective length of the two segments. Volleyball players responded significantly faster; those at the higher competitive level were also more accurate, making a statistically significantly lower number of leftward errors as compared with rowers and controls. If such responses are due to training rather than self-selection of ability, then the results may suggest the possibility of changing the distribution of visuospatial attention by training in open-skill sports
Effects of Exercise on the Airways
In the last ten years, the effects of exercise on bronchial epithelial cells and inflammatory
cells in the airways have been studied in detail, and such new information has been
combined with previous knowledge on bronchial reactivity and asthma evoked by exercise
in asthmatic patients and athletes. The resulting picture is very complex, and the potential
clinical consequences are often contradictory, suggesting the opportunity to define different
phenotypes of exercise-associated airway changes (Lee & Anderson, 1985; Haahtela et al.,
2008; Moreira et al., 2011a).
Studies in asthmatic athletes in the 90\u2019 had began to explore the possibility that airway
inflammation might be involved in exercise-associated respiratory symptoms. However,
studies in non-asthmatic athletes also found increased number of inflammatory cells not
only at rest, but also after strenuous endurance exercise (Bonsignore et al., 2001). It was
therefore hypothesized that endurance exercise may physiologically cause influx of
inflammatory cells into the airways, associated with low or absent inflammatory activation
(Bonsignore et al., 2003a). Subsequent studies in athletes and animal models have extended
these finding, but the mechanisms of inflammatory cell recruitment into the airways and the
tight control of inflammatory activation physiologically associated with exercise remain
poorly understood.
Exercise is a known cause of bronchoconstriction in asthmatic patients (Cabral et al., 1999)
and athletes (Parsons & Mastronarde, 2005). A large number of asthmatic elite athletes
participate to international top-level competitions, and guidelines regarding management of
asthmatic athletes (Fitch et al., 2008) and rules on the use of anti-asthmatic drugs have been
issued (World Anti-Doping Agency, WADA, Oct. 18 2010 report). However, exercise is a
powerful physiologic stimulus for bronchodilatation, and some reports underlined that
exercise training may actually downmodulate bronchial reactivity in normal subjects
(Scichilone et al., 2005, 2010), asthmatic children (Bonsignore et al., 2008) and animal models
of asthma (Hewitt et al., 2010).
This chapter will summarize the changes induced by acute exercise and training in
bronchial reactivity and airway cells in both humans and animal models. It will also discuss
the changing paradigm regarding the impact of physical activity in patients with bronchial
asthma, and the new perspectives of exercise-based rehabilitation in patients with
respiratory diseases such as chronic obstructive pulmonary disease (COPD)
Is karate effective in improving postural control?
Background: Performing complex motor skills, such as the ones performed by karate athletes, requires a great sense of balance.
Because the posturo-kinetic performance seems to be improved by sport practice, especially by sports involving a
lot of posturokinetic activities, the aim of this review was to critically analyse the scientific literature in order to
appraise whether any positive correlation between karate and improved postural control is scientifically supported.
Material/Methods: The online search engines Scirus and Medline were used for generating the data. A comprehensive literature search
was conducted based on the following keywords: “karate”, “postural control” and “body sway”. Results were collected
and filtered manually.
Results: Four articles were identified related to karate practice and postural control, covering a period between 1998 and
2009. Although different experimental approaches were used to investigate this concept, overall the results of these
studies confirm the effectiveness of karate in improving postural control.
Conclusions: Practicing karate seems to elicit long term improvements in postural control. However, a much deeper approach
to this fighting sport, which would take into account its technical specificities (e.g. kata & kumite), is required in
order to increase our understanding of the posture-kinetic impact of this relatively unexplored sport activity
Relationship between heart rate variability and repeated sprint exercise in young soccer players
Aim: The sport of soccer is characterized by neuromuscular performance resulting in short bursts interspersed by brief recovery periods over an extended period of time. Several studies suggest that the cardiac autonomic nervous system (ANS) assessed by heart rate variability (HRV) may provide useful information regarding the functional adaptations to training stimulus. Although HRV has often been associated with aerobic power and cardiovascular fitness, the influence of sympathovagal balance on neuromuscular performance in young athletes is not well assessed.
The aim of this study was to assess the influence of the autonomic system on the performance of repeated sprints, involving predominantly muscular power and anaerobic metabolism, in young soccer players.
Method: Twelve young soccer players, selected for the Sicilian Regional Representative of the Italian Football Federation, mean age 15 years, were recruited. Resting HRV was measured and indices of power spectral analysis (ratio LF/HF) were calculated to evaluate the sympathovagal balance. To assess the state of physical fitness of subjects, VO2max was determined by maximal graded treadmill test. Finally, the athletes performed 10 maximal all-out 6-sec cycling sprints (RS), interspersed with 30-sec of passive recovery, to measure the peak power (PP) represented by the highest value recorded during a single sprint, and the average of the values of maximum power (AP) recorded during all sprints.
Results: On the basis of their VO2max (56.22 ± 3.93 ml/Kg/min), all subjects showed good levels of physical fitness. HRV index (LF/HF = 1.31 ± 0.74) showed an inverse correlation with PP (14.05 ± 0.89 W/Kg; r = -0.709, P = 0.01), and with AP (12.82 ± 0.88 W/Kg; r = -0.606, P = 0.04).
Conclusion: Our study shows that a low ratio LF/HF, which reflects a parasympathetic predominance in the ANS balance, is associated with a better anaerobic contribution to performance resulting in higher values of PP and AP during brief repeated maximal cycling sprints. The assessment of resting HRV before exercise may be useful for performance monitoring of young soccer players
Physical exercise and prevention of falls. Effects of a Pilates training method compared with a general physical activity program. A randomized controlled trial
Abstract
Introduction: Falls are the leading cause of injury-related mortality and morbidity in the elderly. Physical activity plays a key role in the prevention of falls and stimulates postural control. The aim of this study was to compare a general physical activity program for the elderly with a Pilates program to evaluate the effects on balance and on reducing the risk of falling.
Materials and Methods: Forty-six subjects were enrolled in this study, but only 41 were included in the study. The subjects were divided into 2 groups: Pilates group (P-G) and a group following a nonspecific program of physical activity (Pa-G). Each subject underwent the hand grip test, Berg balance scale test, and posturographic analysis.
Results: Spearman correlation coefficient showed correlations between the following parameters: BBS versus hand grip test (r = 0.68); BBS versus ellipse surface area (r=0.75). There were significant differences between groups after the exercise program: both groups showed an improvement in performance but the P-G recorded significantly better results than the Pa-G.
Discussion and conclusions: This study confirmed that physical activity improves both balance and strength. However, our data show that Pilates has a greater effect on these physical abilities than a general physical activity program
Predicting the 2000-m rowing ergometer performance from anthropometric, maximal oxygen uptake and 60-s mean power variables in national level young rowers
Many studies reported various relationships between 2000-m rowing performance and anthropometric as well as metabolic variables, however, little is known about 60-s mean power in elite youth athletes. The aim of this study was to develop different regression models to predict 2000-m rowing indoor performance time (t2000)using anthropometric variables, maximal oxygen uptake (VO2max) and mean power established during a 60-s all-out test (W60) in national elite youth rowers. Fifteen youth male Italian rowers (age: 15.7 \ub1 2.0 years; body height: 176.0 \ub1 8.0 cm; body mass: 71.2 \ub1 10.0 kg) performed an incremental maximal test, a 60-s all-out test and a 2000-m race simulation using a Concept2 rowing ergometer to assess VO2max, W60and t2000, respectively. The relationships of all variables with t2000 were investigated through Pearson\u2019s correlation. Multiple regression analyses were used to verify the best prediction model of 2000-m indoor rowing performance. The reliability of these models was expressed by R2 and the standard error of estimate. The results showed that t2000 was significantly correlated with all the examined variables, except for VO2max/body mass and age, and exhibited the significantly highest relationship with W60 (r = -0.943). The combination of anthropometric, VO2max and W60 variables was found to be the most reliable equation to predict t2000 (R2 = 0.94, SEE = 6.4). W60 measure should be considered when monitoring the rower\u2019s capability to perform high-intensity phases, important during the race\u2019s fast start and end. Not requiring expensive equipment and long duration, a 60-s all-out test could be considered a valuable tool for predicting 2000-m performance of elite youth rowers
Comparison of Postural Features and Muscle Strength between Children with Idiopathic Short Stature and Healthy Peers in Relation to Physical Exercise
Previous research has reported that children with idiopathic short stature (ISS) showed
functional and cognitive impairments. The purpose of this study was to compare muscle strength
and body posture between children with ISS treated with growth hormone (GH) and healthy peers
(healthy children, HC), and to analyze whether these parameters were affected by physical exercise.
Eighteen children for the ISS group (mean age: 10.96 ± 1.68 years) and 26 children for the HC group
(mean age: 10.19 ± 1.06 years) were recruited for the study. All participants performed the following
assessments: handgrip and Sargent test for the muscle strength evaluation; baropodometric and
stabilometric test for the posturographic measures. Data were analyzed with analysis of covariance
(ANCOVA) using height and weight as covariate. Groups were then stratified into active and
inactive and independent t-tests were used to determine differences between variables. Significance
level was set to p < 0.05. Our results showed a significantly lower performance for both hands (p <
0.01) and a greater difference of plantar loading distribution between feet in the ISS compared to
the HC groups (p < 0.01). In relation to physical exercise, the HC active group showed the highest
handgrip strength values for both hands among the analyzed groups and, moreover, handgrip
strength of both ISS active and inactive groups was significantly lower than corresponding CH peers
for both hands. Although ISS and HC inactive groups reported an unequal plantar loading
distribution between feet (p < 0.05), this asymmetry was not present in both ISS and HC active
groups. We assume that GH therapy integrated with physical exercise in young patients with ISS
could be suggested to increase muscle strength and body posture improving their quality of life
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