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Association between match physical activity and neuromuscular characteristics in youth football
No full textBACKGROUND: The aim of this study was to examine the associations between maximal and submaximal neuromuscular field tests, match
physical activity levels and biological maturation in youth football players.
METHODS: Sixty-four football players from under 14 to under 17 age groups were assessed. Players performed a repeated-sprint ability test,
counter movement jump, 10-m, and 30-m sprint test, as well as an assessment of peripheral muscle function following a multi-stage incremental
(i.e., four intensity levels) change of direction test (COD). Knee extensors peak-torque (PTmax) and the decrement of torque values (dec) were
considered as COD outcomes. Physical match activities were tracked by GPS technology, while rate of perceived exertion (RPE) was assessed
using the CR10 Börg Scale. Pearson’s correlations (90% confidence interval) were used to examine the relationships.
RESULTS: Small associations were found between field tests and match activities. The relationships increased from small to moderate for some
tests when match data with RPE>5 were considered. The largest associations were found between distance covered <-2.5m·s-2 and both COD
PTmax and dec when RPE>5.
CONCLUSIONS: The results of the present study provide further evidence of a small-to-moderate association between muscular performance
and match work-rate in young football players. Although physical and physiological evaluations fail to precisely estimate the quantity of physical
activities performed during matches, it is suggested that they can be utilized to monitor the training effect over time in young football players
Quantitative elastosonography of the myotendinous junction normal behavior and correlation with a standard measurement system during functional tests
No full textAbstract
OBJECTIVES:
In recent years, an increasing need to use imaging to assess normal and adaptive muscle function, in addition to its anatomy and structure, has emerged. We evaluated the myotendinous junction's elastosonographic behavior in light of the most recent literature on its physiologic behavior. The elastosonographic studies were compared with the results obtained from a standard measurement system to ensure a correlation with maximal muscle contraction.
METHODS:
Nineteen male professional soccer players were assessed during functional tests. The participants performed 5 repetitions at 60°/s to assess muscle strength and 3 repetitions at 30°/s to assess the maximum force peak of thigh muscles. The participants were monitored by a strength-power measurement system and an ultrasound machine equipped with multifrequency (18-6-MHz) linear array transducers.
RESULTS:
The 19 soccer players were aged between 19 and 34 years (mean age, 28 years). For the right rectus femoris, the results of the elastosonographic studies showed a mean elasticity value ± SD of 30.75% ± 10.05% with the muscle relaxed and a value of 13.75% ± 8.44% during contraction (mean decrease, 17.00% ± 11.71%). Elasticity values were 36.48% ± 8.39% before contraction and 8.77% ± 6.55% during contraction of the left rectus femoris muscle (mean decrease, 27.71% ± 11.95%). For 30° eccentric contraction of the left leg, correlation with the standard measurement system showed Pearson r values of -0.53 and -0.51 when comparing force peak and mean work, respectively, with elasticity values.
CONCLUSIONS:
Our study shows that strain elastosonographic quantification of muscle elasticity seems to match the expected physiologic and biomechanical behavior of the myotendinous junction
Effects of Exhaustive Exercise on Adiponectin and High-Molecular-Weight Oligomer Levels in Male Amateur Athletes
Full text link: Physical activity promotes metabolic health and prevents lifestyle-related diseases. Adiponectin is specifically produced by adipose tissue and comes in three forms, differing in terms of weight: trimers (LMW), hexamers (MMW), and high-molecular-weight (HMW) oligomers. The oligomers are associated with the beneficial effects of adiponectin. In this study, we aimed to investigate the impact of a single bout of exhaustive exercise on adiponectin expression in 25 male amateur athletes, divided into two groups, one comprising young adults (YAs) (n = 15), and the other comprising middle-aged adults (MAs) (n = 10). Body fat was estimated through skinfold thickness. Adiponectin levels were assessed at baseline and at 15 min and 24 h post-exercise, while HMW oligomer levels were evaluated at baseline and at 24 h post-exercise. We observed a significant increase in total adiponectin at both 15 min and 24 h after exercise, with there being a more evident effect among the YA subjects. HMW oligomers also increased significantly after exercise both in the total sample and among the YA subjects, but this was not the case in the MA subjects. The increase in adiponectin levels was significantly associated with Powerpeak. Furthermore, a significant inverse correlation was found between basal adiponectin and VO2peak and Powerpeak. In conclusion, a single bout of exhaustive exercise can rapidly and significantly enhance the basal circulating adiponectin concentration, which seems to be negatively associated with maximal aerobic capacity
Alpha-amylase serum levels in professional soccer players are not related with physical fitness
No full textBACKGORUND: Recent evidence has showed that serum or salivary values of α-amylase predict endurance running performance. In this study we investigate whether serum α-amylase concentration may be associated with training status during a competitive season and after a detraining period in professional soccer players. METHODS: The study population consisted in 15 male professional soccer players from an Italian major league team (age [mean±SD] 27±5 years, weight 76.9±4.1 kg, height 1.82±0.05 m). Serum α-amylase levels were measured 3 times during the last part of a competitive season (January, March and May) and just before preseason training (July). RESULTS: Metabolic and cardiovascular fitness of soccer players was improved during the last part of the season. The levels of α-amylase did not change significantly throughout the study period (χ2=7.331, P=0.062), nor they were found to be associated with variation of physical fitness and training status. CONCLUSIONS: The α-amylase fluctuations throughout a competitive season and after vacation time were meaningless in professional soccer players. No significant associations with physical fitness variations could be observed. These results suggest that α-amylase concentration may be a useful parameter for identifying individual inclination to endurance exercise, but not for predicting actual training status
Hs-cTnT levels in professional soccer players throughout a season: No evidence of sustained cardiac damage
No full textHs-cTnT levels in professional soccer players throughout a season: No evidence of sustained cardiac damag
Morning Priming Exercise Strategy to Enhance Afternoon Performance in Young Elite Soccer Players.
Full text linkPURPOSE: To compare the effects of different modalities of morning priming exercise on afternoon physical performance with the associated hormonal and psychophysiological responses in young soccer players. METHODS: In a randomized counterbalanced crossover design, 12 young soccer players completed 3 different morning conditions on 3 different days: repeated-sprint running (6 × 40 m), easy exercise (4 × 12 fast half squats, 6 speed ladder drills, and 20-m sprints), and control (no exercise). Blood testosterone and cortisol concentrations were assessed upon arrival (approximately 8:30AM) and approximately 5 hours and 30 minutes later. Body temperature, self-reported mood, quadriceps neuromuscular function (maximal voluntary contraction, voluntary activation, rate of torque development, and twitch contractile properties), jump, and sprint performance were evaluated twice per day, while rating of perceived exertion, motivation, and the Yo-Yo Intermittent Recovery level 2 (IR2) tests were assessed once per day. RESULTS: Compared with the control, repeated-sprint running induced a possible positive effect on testosterone (+11.6%) but a possible to very likely negative effect on twitch contractile properties (-13.0%), jump height (-1.4%), and Yo-Yo IR2 (-7.1%). On the other hand, easy exercise had an unclear effect on testosterone (-3.3%), resulted in lower self-reported fatigue (-31.0%) and cortisol (-12.9%), and had a possible positive effect on the rate of torque development (+4.3%) and Yo-Yo IR2 (+6.5%) compared with the control. CONCLUSIONS: Players' testosterone levels were positively influenced by repeated-sprint running, but this did not translate into better physical function, as both muscular and endurance performance were reduced. Easy exercise seemed to be suitable to optimize the physical performance and psychophysiological state of young soccer players
Association between match physical activity and neuromuscular characteristics in youth football
No full textBackground: The aim of this study was to examine the associations between maximal and submaximal neuromuscular field tests, match physical activity levels and biological maturation in youth football players. Methods: Sixty-four football players from under 14 to under 17 age groups were assessed. Players performed a repeated-sprint ability test, counter movement jump, 10-m, and 30-m sprint test, as well as an assessment of peripheral muscle function following a multi-stage incremental (i.e., four intensity levels) change of direction test (COD). Knee extensors peak-torque (PTmax) and the decrement of torque values (dec) were considered as COD outcomes. Physical match activities were tracked by GPS technology, while rate of perceived exertion (RPE) was assessed using the CR10 Börg Scale. Pearson's correlations (90% confidence interval) were used to examine the relationships. Results: Small associations were found between field tests and match activities. The relationships increased from small to moderate for some tests when match data with RPE>5 were considered. The largest associations were found between distance covered 5. Conclusions: The results of the present study provide further evidence of a small-to-moderate association between muscular performance and match work-rate in young football players. Although physical and physiological evaluations fail to precisely estimate the quantity of physical activities performed during matches, it is suggested that they can be utilized to monitor the training effect over time in young football players
Physical demands during 3×3 international male and female basketball games are partially impacted by competition phase but not game outcome
Full text linkDespite the increased popularity and number of international competitions for 3 × 3 basketball, the precise physical demands of this sport are not well described. Therefore, this study aimed to quantify the physical demands of 3 × 3 basketball games according to game outcome and competition phase. Following an observational design, video footage from 27 games were analysed from 104 international 3 × 3 basketball players (n = 52 male and n = 52 female players) belonging to 26 national teams (n = 13 male and n = 13 female teams) during the 2019 FIBA 3 × 3 World Cup. Manual frame-by-frame time-motion analyses were conducted to determine the relative frequency (n · min−1) and duration (% of live playing time) for several physical demand variables to make comparisons according to game outcome (win vs. loss) and competition phase (group games vs. finals games). Linear mixed models for repeated measures and effect size analyses revealed non-significant, trivial-small differences in physical demands between games that were won and lost. Regarding competition phase, male players completed more high-intensity activity (sprinting, high-intensity specific movements, and jumping) but spent a greater proportion of playing time jumping and performing recovery activities (standing/ walking) during finals games than group games (P < 0.05, small), while female players performed more lowintensity activity (jogging and low-intensity specific movements) during group games than finals games (P < 0.05, small). These findings indicate that the physical capabilities of male and female 3 × 3 basketball players may not be the determining factor for team success in games and players can mostly maintain activity outputs across phases of tournament play conducted at the highest international standard
Despite association, the acute:chronic work load ratio does not predict non-contact injury in elite footballers
Full text linkPurpose: To examine association and prediction of load-based markers (rate of perceived exertion) with non-contact injuries.Materials and methods: Thirty-four elite Italian football players (age 26 5 y, height 182 5 cm, body mass 78 +/- 4 kg) participated in a 3-seasons prospective study. Markers examined were: RPE, exposure, weekly load, week-to-week load change, cumulative 2, 3, 4 WL, acute:chronic 1:2 (acute:chronic2), 1:3 (acute:chronic3) and 1:4 (acute:chronic4) WL ratios. After checking multicollinearity between markers, a Generalized Estimating Equation analysis was used to examine association with a non-contact injury in the subsequent week. The associated markers were split into four groups based on 15th, 50th, 85th percentile to compare injury risk (IR) in different zones. Prediction was examined with receiver operating characteristic curve, area under the curve (AUC) and Youden index.Results: IR increased when acute:chronic2 of 1.00-1.20, >1.20 were compared to <0.81 (odds ratio (OR), 90% confidence interval (CI): 1.6, 0.79-3.29; 2.2, 1.03-4.74). IR increased when comparing acute:chronic3 of 1.01-1.23, >1.23 vs. <0.80 (OR, 90% CI: 1.9, 0.9-3.8; 2.5, 1.2-5.4). IR increased when comparing acute:chronic4 of 0.78-1.02, 1.02-1.26, >1.26 vs. <0.78 (OR, 90% CI: 2.4, 1.4-3.9; 3.3, 1.6-6.6; 3.5, 1.7-7.4). The AUC 0.60 for all markers and Youden Index (close to 0) showed poor prediction.Conclusion: Acute:chronic markers showed association however with poor prediction ability
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