The purpose of this study was to examine the changes in technical and physical performance between the first and second half during official matches of Italian Serie A league. Further aim was to compare the technical and physical performance of the players of the more successful teams (ranked in the first 5 positions) with the players of the less successful teams (ranked in the last 5 positions) from the same league. A total of 416 individual games from 186 soccer players (27+/-4 years, 76+/-5kg, and 181+/-5cm) were analysed using a video match-analysis system. The match performance parameters analysed were: total distance covered (TD), high-intensity running distance (HIR), very high-intensity running distance (VHIR), total distance with the ball (TDB), high-intensity running distance with the ball (HIRB), and very high-intensity running distance with the ball (VHIRB). The number of skill involvements was also measured. The players from the more successful teams covered greater TDB and HIRB and also had more involvements with the ball, completed more short passes, successful short passes, tackles, dribbling, shots and shots on target compared to the less successful teams. A significant decline between the first and second half was found for both physical performance and some technical scores (involvements with the ball, short passes and successful short passes). This study showed a decline in technical and physical performance between the first and second half, and that both physical performance and technical skills were different between players from more successful and less successful teams.
2007. december 18., kedd
Sprint vs. Interval Training in Football
Int J Sports Med
The aim of this study was to compare the effects of high-intensity aerobic interval and repeated-sprint ability (RSA) training on aerobic and anaerobic physiological variables in male football players. Forty-two participants were randomly assigned to either the interval training group (ITG, 4 × 4 min running at 90 - 95 % of HRmax; n = 21) or repeated-sprint training group (RSG, 3 × 6 maximal shuttle sprints of 40 m; n = 21). The following outcomes were measured at baseline and after 7 weeks of training: maximum oxygen uptake, respiratory compensation point, football-specific endurance (Yo-Yo Intermittent Recovery Test, YYIRT), 10-m sprint time, jump height and power, and RSA. Significant group × time interaction was found for YYIRT with RSG showing greater improvement than ITG . Similarly, a significant interaction was found in RSA mean time with only the RSG group showing an improvement after training . No other group × time interactions were found. Significant pre-post changes were found for absolute and relative maximum oxygen uptake and respiratory compensation point These findings suggest that the RSA training protocol used in this study can be an effective training strategy for inducing aerobic and football-specific training adaptations.
2007. december 17., hétfő
The effect of the Ramadan fast on physical performance and dietary habits in adolescent soccer players
Eur J Appl Physiol. 2007 Dec 11;
The purpose of this study was to examine the effect of the Ramadan fast on performance capacities, dietary habits, and the daily behavioral patterns in adolescent (14-16-year-old) soccer players. Nineteen male players performed a series of fitness tests before and at the end of Ramadan fast. Caloric intake, physical activity pattern and sleep habits were evaluated during the week before the Ramadan fast and during the last week of the Ramadan fast. The fast resulted in a significant reduction in aerobic capacity (3,000 m run time) speed endurance (Sum 6 x 40 m run time) and jumping performance but had no significant effect on sprint performance or agility (4 x 10 m shuttle run time) Daily intense physical activity was significantly reduced during Ramadan. There were no significant differences in total caloric intake or total daily sleeping hours between Ramadan and a regular month. The results indicate that Ramadan fasting can lead to a significant decrease in athletic performance capacities. The decrease in performance does not necessarily relate to changes in caloric intake and sleeping hours during the fast.
2007. december 10., hétfő
Natural antiinflammatory agents for pain relief in athletes.
Neurosurg Focus. 2006 Oct 15;21(4):E11
Most athletes experience musculoskeletal injuries during their sports activity that require rest at a minimum, and occasionally injuries are severe enough to necessitate surgical repair. Neurosurgeons are often consulted for athletically sustained injuries and prescribe medications for the associated pain. The use of both over-the-counter and prescription nonsteroidal medications is frequently recommended, but recent safety concerns must now be considered. The authors discuss the biochemical pathways of nonsteroidal drugs and review the potentially serious side effects of these medications. They also review the use of natural supplements, which may be a safer, and often as effective, alternative treatment for pain relief.
Pain medications in the locker room: to dispense or not.
Curr Sports Med Rep. 2007 Dec;6(6):367-70
Sports medicine physicians often treat athletes who are in pain. Treatment may allow them to return to play more quickly. However, there is a lack of high-quality evidence to guide physicians. This article reviews over-the-counter and prescription medications that athletes with acute and chronic injuries can use via oral, topical, or injectable routes to control pain.
Effect of Hydrotherapy on Recovery from Fatigue
The present study investigated the effects of three hydrotherapy interventions on next day performance recovery following strenuous training. Twelve cyclists completed four experimental trials differing only in 14-min recovery intervention: cold water immersion (CWI), hot water immersion (HWI), contrast water therapy (CWT), or passive recovery (PAS). Each trial comprised five consecutive exercise days of 105-min duration, including 66 maximal effort sprints. Additionally, subjects performed a total of 9-min sustained effort (time trial - TT). After completing each exercise session, athletes performed one of four recovery interventions (randomly assigned to each trial). Performance (average power), core temperature, heart rate (HR), and rating of perceived exertion (RPE) were recorded throughout each session. Sprint (0.1 - 2.2 %) and TT (0.0 - 1.7 %) performance were enhanced across the five-day trial following CWI and CWT, when compared to HWI and PAS. Additionally, differences in rectal temperature were observed between interventions immediately and 15-min post-recovery; however, no significant differences were observed in HR or RPE regardless of day of trial/intervention. Overall, CWI and CWT appear to improve recovery from high-intensity cycling when compared to HWI and PAS, with athletes better able to maintain performance across a five-day period.
Early Motion for Achilles Tendon Ruptures: Is Surgery Important?
The American Journal of Sports Medicine 35:2033-2038 (2007)
Background: Comparisons of surgically and nonsurgically treated Achilles tendon ruptures have demonstrated that those treated with surgery allow earlier motion and tend to show superior results. However, early motion enhances tendon healing with or without surgery and may be the important factor in optimizing outcomes in patients with Achilles tendon rupture.
Hypothesis: There is no difference in the outcome of acute Achilles tendon rupture treated nonoperatively or operatively if controlled early motion is allowed as part of the rehabilitation program.
Study Design: Randomized, controlled clinical trial; Level of evidence, 1.
Methods: Patients with acute rupture of the Achilles tendon were randomized to surgery or no surgery, with both groups receiving early motion controlled in a removable orthosis, progressing to full weightbearing at 8 weeks from treatment. Both groups were followed prospectively for 12 months with measurements of range of motion, calf circumference, and the Musculoskeletal Functional Assessment Instrument (MFAI) outcome score; any reruptures and any complications were noted.
Results: Both groups were comparable for age and sex. There were no significant differences between the 2 groups in plantar flexion, dorsiflexion, calf circumference, or the MFAI scores measured at 2, 8, 12, 26, or 52 weeks. One patient in each group was noncompliant and required surgical rerepair of the tendon. There were no differences in complications and a similar low number of reruptures in both groups.
Conclusion: This study supports early motion as an acceptable form of rehabilitation in both surgically and nonsurgically treated patients with comparable functional results and a low rerupture rate. There appears to be no difference between the 2 groups, suggesting that controlled early motion is the important part of treatment of ruptured Achilles tendon.
Hypothesis: There is no difference in the outcome of acute Achilles tendon rupture treated nonoperatively or operatively if controlled early motion is allowed as part of the rehabilitation program.
Study Design: Randomized, controlled clinical trial; Level of evidence, 1.
Methods: Patients with acute rupture of the Achilles tendon were randomized to surgery or no surgery, with both groups receiving early motion controlled in a removable orthosis, progressing to full weightbearing at 8 weeks from treatment. Both groups were followed prospectively for 12 months with measurements of range of motion, calf circumference, and the Musculoskeletal Functional Assessment Instrument (MFAI) outcome score; any reruptures and any complications were noted.
Results: Both groups were comparable for age and sex. There were no significant differences between the 2 groups in plantar flexion, dorsiflexion, calf circumference, or the MFAI scores measured at 2, 8, 12, 26, or 52 weeks. One patient in each group was noncompliant and required surgical rerepair of the tendon. There were no differences in complications and a similar low number of reruptures in both groups.
Conclusion: This study supports early motion as an acceptable form of rehabilitation in both surgically and nonsurgically treated patients with comparable functional results and a low rerupture rate. There appears to be no difference between the 2 groups, suggesting that controlled early motion is the important part of treatment of ruptured Achilles tendon.
Fatigue and illness in athletes
Journal of Sports Sciences, Volume 25, Issue S1 December 2007 , pages S93-S102
Adequate nutrition before, during, and after training and competition is a key element to maintaining health. During both sprint and endurance exercise, the availability of glycogen is fundamental to performance and any deficit will lead to early fatigue. In addition, strategies to offset the negative effects of the products of metabolism are presented. Although nutritional strategies can attenuate the immunosuppressive effects of exercise, there remains a period of susceptibility to infection after a hard exercise session and when this is repeated without sufficient recovery an athlete can enter a period of "overtraining" during which performance deteriorates. The aetiology and identification of this state is not clear and some current ideas are discussed. Finally, gastrointestinal problems during running can negate any training benefits and we propose some suggestions to reduce this problem.
Adequate nutrition before, during, and after training and competition is a key element to maintaining health. During both sprint and endurance exercise, the availability of glycogen is fundamental to performance and any deficit will lead to early fatigue. In addition, strategies to offset the negative effects of the products of metabolism are presented. Although nutritional strategies can attenuate the immunosuppressive effects of exercise, there remains a period of susceptibility to infection after a hard exercise session and when this is repeated without sufficient recovery an athlete can enter a period of "overtraining" during which performance deteriorates. The aetiology and identification of this state is not clear and some current ideas are discussed. Finally, gastrointestinal problems during running can negate any training benefits and we propose some suggestions to reduce this problem.
Foot morphology and foot/ankle injury in indoor football.
J Sci Med Sport. 2007 Oct;10(5):311-9
While the pronated foot is implicated as a risk factor for sports injury in some studies, others suggest that a supinated foot posture increases the risk of overuse lower limb injuries. Athletes in a given sports discipline may tend to have a similar foot morphology, which varies from that observed elsewhere. Further, the foot morphology that is beneficial for performance in a sport may be detrimental with regard to injury. Intra- and inter-rater reliability of the Foot Posture Index (FPI-6) as a measure of foot morphology was determined (ICC (2,1) 0.88 and 0.69 respectively). Thereafter, in a prospective cohort study using the FPI-6, 76 adolescent male indoor football (Futsal) players were measured and followed monthly over one competition season. Coach-rated ability and reports of any overuse injuries at the ankle and/or foot over this period were obtained. A significant negative linear relationship was found between the mean FPI-6 scores and coach-rated ability (p=0.008), with supinated and under-pronated postures related to higher ability level. Overall, 33% of injuries at the ankle and/or foot were classified as overuse. Foot Posture Index scores of less than 2, indicating the supinated and under-pronated feet, were found to be associated with a significant increase in the risk of overuse injury (p=0.008). The greater rigidity of these foot types may assist adolescent, male, indoor football players to perform at a higher level in their sport. Unfortunately, these players are also more likely to sustain ankle and/or foot overuse injuries.
Serum cardiac troponin T, troponin I, plasma BNP and left ventricular mass index in professional football players.
J Sci Med Sport. 2007 Oct;10(5):291-6. Epub 2007 Feb 6.
Concentrations of cardiac troponins (cTn) in serum or plasma may be elevated in several disease states other than acute coronary syndromes. In heart failure and end stage renal disease, cardiac troponin T (cTnT) correlates positively with left ventricular mass index (LVMI). Exercise-induced elevation of cardiac troponins in well-trained athletes has been confirmed by several reports but the aetiology and clinical significance is unclear. In the present study, we measured baseline concentrations of cardiac markers and investigated whether or not serum cTnT is associated with left ventricular hypertrophy (LVH) in professional football players. METHODS: Twenty-three male professional football players with a mean age of 23 years (range 18-32) were studied. Echocardiography and blood sampling were carried out approx 24h after a training session. Serum cTnT, other cardiac markers and plasma brain natriuretic peptide (BNP) were compared with LVMI. RESULTS: cTnT was only detectable in one subject. The prevalence of elevated cardiac troponin I (cTnI), creatine kinase MB (CKMB) and creatine kinase was higher than for cTnT. cTnI concentrations were higher in football players than in controls. LVMI did not correlate with any of the cardiac markers. Plasma BNP concentrations were normal in all subjects. CONCLUSION: Serum cTnT concentrations were not elevated in healthy professional football players with LVH. This argues against the hypothesis that LVH per se may cause increased cTnT. The finding of higher cTnI in football players than in non-athletic controls should be confirmed and the aetiology elucidated.
A meta-analysis of the incidence of anterior cruciate ligament tears as a function of gender, sport, and a knee injury-reduction regimen.
Arthroscopy 2007 Dec;23(12):1320-1325.e6.
PURPOSE: The literature has shown that anterior cruciate ligament (ACL) tear rates vary by gender, by sport, and in response to injury-reduction training programs. However, there is no consensus as to the magnitudes of these tear rates or their variations as a function of these variables. For example, the female-male ACL tear ratio has been reported to be as high as 9:1. Our purpose was to apply meta-analysis to the entire applicable literature to generate accurate estimates of the true incidences of ACL tear as a function of gender, sport, and injury-reduction training. METHODS: A PubMed literature search was done to identify all studies dealing with ACL tear incidence. Bibliographic cross-referencing was done to identify additional articles. Meta-analytic principles were applied to generate ACL incidences as a function of gender, sport, and prior injury-reduction training. RESULTS: Female-male ACL tear incidences ratios were as follows: basketball, 3.5; soccer, 2.67; lacrosse, 1.18; and Alpine skiing, 1.0. The collegiate soccer tear rate was 0.32 for female subjects and 0.12 for male subjects. For basketball, the rates were 0.29 and 0.08, respectively. The rate for recreational Alpine skiers was 0.63, and that for experts was 0.03, with no gender variance. The two volleyball studies had no ACL tears. Training reduced the ACL tear incidence in soccer by 0.24 but did not reduce it at all in basketball. CONCLUSIONS: Female subjects had a roughly 3 times greater incidence of ACL tears in soccer and basketball versus male subjects. Injury-reduction programs were effective for soccer but not basketball. Recreational Alpine skiers had the highest incidences of ACL tear, whereas expert Alpine skiers had the lowest incidences. Volleyball may in fact be a low-risk sport rather than a high-risk sport. Alpine skiers and lacrosse players had no gender difference for ACL tear rate. Year-round female athletes who play soccer and basketball have an ACL tear rate of approximately 5%. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
PURPOSE: The literature has shown that anterior cruciate ligament (ACL) tear rates vary by gender, by sport, and in response to injury-reduction training programs. However, there is no consensus as to the magnitudes of these tear rates or their variations as a function of these variables. For example, the female-male ACL tear ratio has been reported to be as high as 9:1. Our purpose was to apply meta-analysis to the entire applicable literature to generate accurate estimates of the true incidences of ACL tear as a function of gender, sport, and injury-reduction training. METHODS: A PubMed literature search was done to identify all studies dealing with ACL tear incidence. Bibliographic cross-referencing was done to identify additional articles. Meta-analytic principles were applied to generate ACL incidences as a function of gender, sport, and prior injury-reduction training. RESULTS: Female-male ACL tear incidences ratios were as follows: basketball, 3.5; soccer, 2.67; lacrosse, 1.18; and Alpine skiing, 1.0. The collegiate soccer tear rate was 0.32 for female subjects and 0.12 for male subjects. For basketball, the rates were 0.29 and 0.08, respectively. The rate for recreational Alpine skiers was 0.63, and that for experts was 0.03, with no gender variance. The two volleyball studies had no ACL tears. Training reduced the ACL tear incidence in soccer by 0.24 but did not reduce it at all in basketball. CONCLUSIONS: Female subjects had a roughly 3 times greater incidence of ACL tears in soccer and basketball versus male subjects. Injury-reduction programs were effective for soccer but not basketball. Recreational Alpine skiers had the highest incidences of ACL tear, whereas expert Alpine skiers had the lowest incidences. Volleyball may in fact be a low-risk sport rather than a high-risk sport. Alpine skiers and lacrosse players had no gender difference for ACL tear rate. Year-round female athletes who play soccer and basketball have an ACL tear rate of approximately 5%. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
2007. december 6., csütörtök
Nutrition for travel
The training and competitive programmes of elite athletes incorporate travel schedules, often long journeys, across multiple time zones. In such cases, travel causes both transient fatigue and a malaise known as "jet-lag" that persists for some days. Jet-lag is due to the disturbance of the body's circadian rhythms: diurnal and performance rhythms are displaced, depending on the direction of travel and the number of time zones crossed in flight. Attention to diet and hydration is relevant during the flight and following disembarkation until adjustment to the new meridian is complete. The consequences of jet-lag on rhythms in digestion may be compounded if food preparation and hygiene are inadequate in training camps or competitive venues overseas. The irony of travel is that it often places athletes at a greater risk of failing to meet their specific nutrition goals or succumbing to illness, at a time when the demands or outcomes of performance are of greatest importance. In addition, gastrointestinal infections related to travelling are frequent among athletes. Fastidious planning and organization among the support staff is recommended before the journey to prevent any such problems arising. Equally, athletes often need special education initiatives to assist them to cope with the challenges of a new and unusual food supply, or altered access to food.
The use of dietary supplements by athletes
Journal of Sports Sciences Volume 25, Issue S1 December 2007 , pages S103 - S113
Many athletes use dietary supplements as part of their regular training or competition routine, including about 85% of elite track and field athletes. Supplements commonly used include vitamins, minerals, protein, creatine, and various "ergogenic" compounds. These supplements are often used without a full understanding or evaluation of the potential benefits and risks associated with their use, and without consultation with a sports nutrition professional. A few supplements may be helpful to athletes in specific circumstances, especially where food intake or food choice is restricted. Vitamin and mineral supplements should be used only when a food-based solution is not available. Sports drinks, energy bars, and protein - carbohydrate shakes may all be useful and convenient at specific times. There are well-documented roles for creatine, caffeine, and alkalinizing agents in enhancing performance in high-intensity exercise, although much of the evidence does not relate to specific athletic events. There are potential costs associated with all dietary supplements, including the risk of a positive doping result as a consequence of the presence of prohibited substances that are not declared on the label
Many athletes use dietary supplements as part of their regular training or competition routine, including about 85% of elite track and field athletes. Supplements commonly used include vitamins, minerals, protein, creatine, and various "ergogenic" compounds. These supplements are often used without a full understanding or evaluation of the potential benefits and risks associated with their use, and without consultation with a sports nutrition professional. A few supplements may be helpful to athletes in specific circumstances, especially where food intake or food choice is restricted. Vitamin and mineral supplements should be used only when a food-based solution is not available. Sports drinks, energy bars, and protein - carbohydrate shakes may all be useful and convenient at specific times. There are well-documented roles for creatine, caffeine, and alkalinizing agents in enhancing performance in high-intensity exercise, although much of the evidence does not relate to specific athletic events. There are potential costs associated with all dietary supplements, including the risk of a positive doping result as a consequence of the presence of prohibited substances that are not declared on the label
2007. december 5., szerda
Nutritional adequacy of different menu settings in elite Spanish adolescent soccer players
Int J Sport Nutr Exerc Metab. 2007 Oct;17(5):421-32
The article describes a study that evaluated the adequacy of 2 different menu settings in a group of elite adolescent Spanish soccer players. Five-day food intake was assessed on 2 occasions, while athletes were consuming a flexible "buffet-style" diet (B; n = 33) and a fixed "menu-style" diet (M; n = 29). For all principal meals of the day food weighing was performed, and snacks were recorded by self-report. M provided significantly higher total energy and carbohydrate intakes than B. Breakfast and snacks both provided more energy in M. Calories obtained from fat were excessive in both settings. Calcium and vitamin D were below recommendations in B but not in M. Fiber, magnesium, folate, vitamin A, and vitamin E intake fell below recommended values in both settings. M provided significantly greater quantities of magnesium and vitamins D and E. Both feeding options were far from optimal in satisfying current scientifically based recommendations for active adolescents.
The article describes a study that evaluated the adequacy of 2 different menu settings in a group of elite adolescent Spanish soccer players. Five-day food intake was assessed on 2 occasions, while athletes were consuming a flexible "buffet-style" diet (B; n = 33) and a fixed "menu-style" diet (M; n = 29). For all principal meals of the day food weighing was performed, and snacks were recorded by self-report. M provided significantly higher total energy and carbohydrate intakes than B. Breakfast and snacks both provided more energy in M. Calories obtained from fat were excessive in both settings. Calcium and vitamin D were below recommendations in B but not in M. Fiber, magnesium, folate, vitamin A, and vitamin E intake fell below recommended values in both settings. M provided significantly greater quantities of magnesium and vitamins D and E. Both feeding options were far from optimal in satisfying current scientifically based recommendations for active adolescents.
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