Refine
Has Fulltext
- no (214) (remove)
Year of publication
Document Type
- Article (189)
- Review (15)
- Other (9)
- Monograph/Edited Volume (1)
Is part of the Bibliography
- yes (214)
Keywords
- football (15)
- athletic performance (13)
- resistance training (12)
- adolescents (10)
- balance (10)
- youth (10)
- strength training (9)
- stretch-shortening cycle (9)
- children (8)
- exercise (8)
- training (8)
- Exercise (7)
- electromyography (7)
- Gait (6)
- monitoring (6)
- performance (6)
- plyometric training (6)
- postural control (6)
- strength (6)
- training load (6)
- young athletes (6)
- Electromyography (5)
- Stretch-shortening cycle (5)
- injury risk (5)
- muscle strength (5)
- power (5)
- Aging (4)
- EMG (4)
- Ground reaction force (4)
- Resistance training (4)
- aging (4)
- elite athletes (4)
- gait (4)
- periodization (4)
- physical fitness (4)
- Balance (3)
- Power (3)
- Seniors (3)
- Walking (3)
- Youth (3)
- agility (3)
- change of direction (3)
- force (3)
- ground reaction force (3)
- injury (3)
- jumping (3)
- loading rate (3)
- movement (3)
- muscle power (3)
- physiology (3)
- postural stability (3)
- recovery (3)
- soccer (3)
- speed (3)
- sport-specific performance (3)
- striking combat sports (3)
- working memory (3)
- youth sports (3)
- Body composition (2)
- COVID-19 (2)
- Cognitive/motor interference (2)
- Crossover (2)
- Detraining (2)
- EEG (2)
- Fatigue (2)
- Jump height (2)
- Kampfsport (2)
- Muscle (2)
- Muscle power (2)
- Muscle strength (2)
- Performance (2)
- Physical fitness (2)
- Postural stability (2)
- Proactive/reactive balance (2)
- Single/dual tasking (2)
- Steady-state balance (2)
- Team sports (2)
- Trunk muscle strength (2)
- adolescent (2)
- apoptosis (2)
- attentional demand (2)
- biomechanics (2)
- cardiomyopathy (2)
- cardiorespiratory fitness (2)
- child (2)
- cognitive performance (2)
- cognitive-postural dual task (2)
- combat sport (2)
- cross-education (2)
- diabetes (2)
- drop jump (2)
- elderly (2)
- fatigue (2)
- gait analysis (2)
- global positioning system (2)
- ground reaction forces (2)
- hospitalization (2)
- human physical conditioning (2)
- inertial measurement unit (2)
- jumps (2)
- knee joint angle (2)
- maturity (2)
- miRNAs (2)
- modality compatibility (2)
- motor skills (2)
- muscle (2)
- musculoskeletal and neural physiological phenomena (2)
- oarsmen (2)
- on-water performance (2)
- overreaching (2)
- overtraining (2)
- peak height velocity (2)
- physical conditioning human (2)
- physical performance (2)
- plyometric exercise (2)
- plyometrics (2)
- postural sway (2)
- range of motion (2)
- rate of perceived exertion (2)
- rate of torque development (2)
- reliability (2)
- rolling averages (2)
- running (2)
- running mechanics (2)
- sensitivity (2)
- somatic variables (2)
- sportliche Leistung (2)
- sprint (2)
- sprints (2)
- talent (2)
- validity (2)
- weighted moving averages (2)
- youth athletes (2)
- youth soccer (2)
- ACWR (1)
- Acceleration (1)
- Acute Recovery and Stress Scale (ARSS) (1)
- Alpha-2 (1)
- Association (1)
- Attention (1)
- Balance Tests (1)
- Biomechanics (1)
- Bow leg (1)
- Cardiorespiratory endurance (1)
- Central activation (1)
- Children (1)
- Cognition motor (1)
- Cognitive enhancer (1)
- Cognitive fatigue (1)
- Cognitive interference (1)
- Cognitive skills (1)
- Cohort study (1)
- Computer Software (1)
- Conditioning activity (1)
- Core stability (1)
- Core strength (1)
- Countermovement jump (1)
- Cross-over fatigue (1)
- Crossover fatigue (1)
- DXA (1)
- Daily life (1)
- Dual tasks (1)
- EMOTIKON (1)
- EXERCISE (1)
- Elderly (1)
- Electric stimulation (1)
- Electroencephalography (EEG) (1)
- Electromyography (EMG) (1)
- Elite sports (1)
- Endocrine (1)
- Endurance (1)
- Executive function (1)
- Exercise therapy (1)
- Exertion (1)
- Exhaustion (1)
- Explosive force production (1)
- Fall risk (1)
- Fall risk assessment (1)
- Falls (1)
- Flat feet (1)
- Flexibility (1)
- Football (1)
- Footwear (1)
- Force (1)
- Force production (1)
- Frail elderly (1)
- Free moment (1)
- Functional magnetic resonance imaging (fMRI) (1)
- Gait biomechanics (1)
- Gait kinematics (1)
- Gait kinetics (1)
- Ginkgo biloba extract (1)
- Gym-based/home-based training (1)
- Health care (1)
- Healthy aging (1)
- ICA (1)
- Injury risk (1)
- Instability (1)
- Intensity Dose -response relationship (1)
- Isokinetic (1)
- Judo-specific pulling movement (1)
- Jugendliche (1)
- Jumping height (1)
- Kinder (1)
- Kindergarten (1)
- Kinematics (1)
- Knee valgus (1)
- Knee valgus motion (1)
- Lateral jumps (1)
- Linear mixed models (1)
- Linear regression analysis (1)
- Loading rate (1)
- MUSCLE (1)
- Maturation (1)
- Maximal isometric force (1)
- Maximal voluntary contraction (MVC) (1)
- Maximalkraft (1)
- Mental fatigue (1)
- Metabolism (1)
- Mild cognitive impairment (1)
- Mobility (1)
- Morote-seoi-nage (1)
- Motion (1)
- Motor function (1)
- Motor performance (1)
- Motor skills (1)
- Movement velocity (1)
- Multiple sclerosis (1)
- Muscle contraction (1)
- Muscle mass (1)
- Muscle torque (1)
- Neural inhibition (1)
- Oberflächenelektromyografie (1)
- OptoGait (1)
- Optojump system (1)
- Overhead athletes (1)
- Paediatrics (1)
- Parkinson's disease (1)
- Pediatric gait (1)
- Performance gains (1)
- Physical performance (1)
- Physiology (1)
- Plyometric exercise (1)
- Plyometrics (1)
- Post-activation potentiation (1)
- Postactivation potentiation (1)
- Postural Control (1)
- Postural balance (1)
- Postural control (1)
- Power training (1)
- Preventive therapy (1)
- Primary school (1)
- Principal component analysis (1)
- Quadriceps muscle (1)
- Quadriceps strength (1)
- Quarantine (1)
- RGB-D cameras (1)
- RPE (1)
- Reactive movement (1)
- Recovery (1)
- Reflex (1)
- Repeated sprint (1)
- Sars-CoV-2 (1)
- Scanning electron microscopy (1)
- Schnellkraft (1)
- Sensorimotor training (1)
- Short‐term effect (1)
- Shoulder (1)
- Skill (1)
- Speed (1)
- Sport-specific performance (1)
- Strength training (1)
- Stress (1)
- Stress levels (1)
- Sway (1)
- Swimming performance (1)
- Theraband training (1)
- Theta (1)
- Tiredness (1)
- Transcranial magnetic brain stimulation (TMS) (1)
- Velocity (1)
- Vertec device (1)
- WALKING (1)
- Walking speed (1)
- Widerstandstraining (1)
- Work ability (1)
- Young swimmers (1)
- Zebris (1)
- academy (1)
- activities (1)
- acute chronic workload ratio (1)
- adolescent athletes (1)
- aerobic exercise (1)
- aerobic metabolism (1)
- aerobic power (1)
- age (1)
- allometry (1)
- alpha-2 (1)
- ankles (1)
- annual training (1)
- anterior cruciate ligament (1)
- anthropometry (1)
- anxiety (1)
- assessment (1)
- athlete testing (1)
- athlete. (1)
- athletes (1)
- athletic (1)
- attention (1)
- balance strategy (1)
- balance training (1)
- ball speed (1)
- ballistic training (1)
- barbell velocity (1)
- biological age (1)
- biological maturation (1)
- blood (1)
- blood lactate; (1)
- blood sample (1)
- body density (1)
- body limbs (1)
- body shape (1)
- bone (1)
- boys (1)
- calcaneal eversion (1)
- canoe racing (1)
- causal mediation analysis (1)
- change of direction speed (1)
- change-of-direction speed (1)
- climbing (1)
- cognitive function (1)
- cognitive interference (1)
- cognitive skills (1)
- cognitive/muscular fatigue (1)
- combat sports (1)
- comparison of devices (1)
- concurrent training (1)
- conditioning activity (1)
- conditioning exercise (1)
- conditioning stimulus (1)
- congested calendar (1)
- core (1)
- core strength (1)
- data pipeline (1)
- deconditioning (1)
- depression (1)
- detraining (1)
- diabetes mellitus (1)
- diabetic (1)
- digital health (1)
- directed acyclic graphs (1)
- dominant limb (1)
- dose response (1)
- dose-response relation (1)
- dose-response relationship (1)
- dual task (1)
- dual-task costs (1)
- early sport specialization (1)
- eccentric-plyometric (1)
- electroencephalography (1)
- elite (1)
- elite sport (1)
- endurance (1)
- endurance performance (1)
- energetic systems (1)
- evaluation (1)
- exercise intervention (1)
- exercise prescription (1)
- exercise test (1)
- exercise training (1)
- exhaustion (1)
- explosive force production (1)
- external load (1)
- external training load (1)
- eyedness (1)
- fMRI (1)
- feet (1)
- field test (1)
- fitness (1)
- fitness tests (1)
- flat feet (1)
- flat foot (1)
- flexibility (1)
- footedness (1)
- footwear (1)
- free moment (1)
- function (1)
- functional performance (1)
- gait analysis algorithm (1)
- gait speed (1)
- gender (1)
- gender differences (1)
- girls (1)
- hamstring muscles (1)
- hearing loss (1)
- heart rate (1)
- hematocrit (1)
- high-intensity interval training (1)
- high-intensity-interval training (1)
- hip (1)
- hormones (1)
- human motion (1)
- immune system (1)
- impact loading (1)
- infection (1)
- injury prevention (1)
- intermittent sport (1)
- internal load (1)
- intervention (1)
- jump (1)
- jump height (1)
- jump height/power (1)
- jump performance (1)
- jump performances (1)
- jump training (1)
- jump/sprint exercises (1)
- jumping ability (1)
- kindergarten (1)
- kinetics (1)
- knee (1)
- knee flexion angle (1)
- knee osteoarthritis (1)
- knee valgus angle (1)
- knee valgus motion (1)
- knees (1)
- late childhood (1)
- latency (1)
- laterality (1)
- leg extensors (1)
- limb overuse conditions (1)
- linear sprint (1)
- load carriage (1)
- load-velocity (1)
- long-term (1)
- low-back-pain (1)
- lower limb mechanics (1)
- lower-extremity kinematics (1)
- martial arts (1)
- matched time (1)
- material fatigue (1)
- maturation (1)
- maximal isometric contraction (1)
- maximal isometric torque (1)
- maximum voluntary contraction (1)
- medial longitudinal arch (1)
- mental imagery (1)
- meta-analysis (1)
- methodological quality (1)
- mitochondrial adaptation (1)
- mobility disability (1)
- motion capture (1)
- motor-performance (1)
- muscle activation (1)
- muscle activity (1)
- muscle coactivation (1)
- muscle fitness (1)
- muscle metabolism (1)
- muscular endurance (1)
- muscular power (1)
- muscular strength (1)
- musculature (1)
- myofascial (1)
- neuromuscular rolling (1)
- non-dominant limb (1)
- of daily living (1)
- of-direction speed (1)
- optimal load (1)
- oxygen consumption (1)
- passive stretching (1)
- patients (1)
- peak torque (1)
- pelvic alignment (1)
- pervasive healthcare (1)
- physical activity (1)
- physical activity program (1)
- physical fitness expertise (1)
- physiological strain (1)
- postural balance (1)
- power training (1)
- preactivation (1)
- pressure (1)
- prevention (1)
- progression (1)
- proprioception (1)
- public dataset (1)
- race (1)
- race time (1)
- randomized controlled-trial (1)
- rate of force development (1)
- rating of perceived exertion (1)
- region/point elastic gym floor (1)
- relationship (1)
- relationships (1)
- responses (1)
- return-to-sport (1)
- rotation (1)
- rugby league players (1)
- running velocity (1)
- schedule (1)
- scholastic demands (1)
- school baseball players (1)
- sedentary (1)
- self massage (1)
- self-massage therapy (1)
- self-myofascial release (1)
- sensorimotor training (1)
- sensory input (1)
- sex-differences (1)
- shoe (1)
- short latency response (1)
- shoulder girdle (1)
- shoulder strength (1)
- skeletal joints (1)
- ski jumping (1)
- soccer players (1)
- specific assessment (1)
- specific strength training (1)
- specificity (1)
- spezifisches Krafttraining (1)
- sport profile (1)
- sports (1)
- sprinting (1)
- stability (1)
- standing position (1)
- static/dynamic postural control (1)
- stroke (1)
- structured (1)
- surface electromyography (1)
- taekwondo electronic scoring system (1)
- taekwondo-specific testing (1)
- task difficulty (1)
- tasks (1)
- team sport (1)
- tendon stiffness (1)
- test-retest reliability (1)
- therapy (1)
- theta (1)
- time (1)
- time-efficient exercise (1)
- torque (1)
- track and field (1)
- training adaptation (1)
- training intensity (1)
- training intervention (1)
- training specificity (1)
- twitch torque (1)
- unstable walkway (1)
- vertical jump height (1)
- vestibular (1)
- virus (1)
- virus infection (1)
- walking capacity (1)
- walking speed (1)
- water sports (1)
- weight lifting (1)
- weight loss (1)
- weight training (1)
- weightlifting (1)
- whole-body vibratoin (1)
- women (1)
- work (1)
- work-rate distribution (1)
- young (1)
- young adults (1)
- young soccer players (1)
- youth sport (1)
Institute
- Department Sport- und Gesundheitswissenschaften (116)
- Strukturbereich Kognitionswissenschaften (58)
- Extern (16)
- Department Psychologie (6)
- Humanwissenschaftliche Fakultät (6)
- Hasso-Plattner-Institut für Digital Engineering GmbH (3)
- Fakultät für Gesundheitswissenschaften (2)
- Fachgruppe Soziologie (1)
- Hasso-Plattner-Institut für Digital Engineering gGmbH (1)
Physical fitness of primary school children differs depending on their timing of school enrollment
(2023)
Previous research has shown that children who were enrolled to school according to the legal key date (i.e., keyage children, between eight and nine years in third grade) exhibited a linear physical fitness development in the ninth year of life. In contrast, children who were enrolled with a delay (i.e., older-than-keyage children [OTK], between nine and ten years in third grade) exhibited a lower physical fitness compared to what would be expected for their age. In these studies, cross-sectional age differences within third grade and timing of school enrollment were confounded. The present study investigated the longitudinal development of keyage and OTK children from third to fifth grade. This design also afforded a comparison of the two groups at the same average chronological age, that is a dissociation of the effects of timing of school enrollment and age. We tested six physical fitness components: cardiorespiratory endurance, coordination, speed, power of lower and upper limbs, and static balance. 1502 children (i.e., 1206 keyage and 296 OTK children) from 35 schools were tested in third, fourth, and fifth grade. Except for cardiorespiratory endurance, both groups developed from third to fourth and from fourth to fifth grade and keyage children outperformed OTK children at the average ages of 9.5 or 10.5 years. For cardiorespiratory endurance, there was no significant gain from fourth to fifth grade and keyage and OTK children did not differ significantly at 10.5 years of age. One reason for a delayed school enrollment could be that a child is (or is perceived as) biologically younger than their chronological age at the school entry examination, implying a negative correlation between chronological and biological age for OTK children. Indeed, a simple reflection of chronological age brought the developmental rate of the chronologically youngest OTK children in line with the developmental rate observed for keyage children, but did not eliminate all differences. The mapping of chronological and biological age of OTK children and other possible reasons for lower physical fitness of OTK children remain a task for future research.
BackgroundIn spring of 2020, the Sars-CoV-2 incidence rate increased rapidly in Germany and around the world. Throughout the next 2 years, schools were temporarily closed and social distancing measures were put in place to slow the spread of the Covid-19 virus. Did these social restrictions and temporary school lockdowns affect children's physical fitness? The EMOTIKON project annually tests the physical fitness of all third-graders in the Federal State of Brandenburg, Germany. The tests assess cardiorespiratory endurance (6-min-run test), coordination (star-run test), speed (20-m sprint test), lower (powerLOW, standing long jump test), and upper (powerUP, ball-push test) limbs muscle power, and static balance (one-legged stance test with eyes closed). A total of 125,893 children were tested in the falls from 2016 to 2022. Primary analyses focused on 98,510 keyage third-graders (i.e., school enrollment according to the legal key date, aged 8 to 9 years) from 515 schools. Secondary analyses included 27,383 older-than-keyage third-graders (i.e., OTK, delayed school enrollment or repetition of a grade, aged 9 to 10 years), who have been shown to exhibit lower physical fitness than expected for their age. Linear mixed models fitted pre-pandemic quadratic secular trends, and took into account differences between children and schools.ResultsThird-graders exhibited lower cardiorespiratory endurance, coordination, speed and powerUP in the Covid pandemic cohorts (2020-2022) compared to the pre-pandemic cohorts (2016-2019). Children's powerLOW and static balance were higher in the pandemic cohorts compared to the pre-pandemic cohorts. From 2020 to 2021, coordination, powerLOW and powerUP further declined. Evidence for some post-pandemic physical fitness catch-up was restricted to powerUP. Cohen's |ds| for comparisons of the pandemic cohorts 2020-2022 with pre-pandemic cohorts 2016-2019 ranged from 0.02 for powerLOW to 0.15 for coordination. Within the pandemic cohorts, keyage children exhibited developmental losses ranging from approximately 1 month for speed to 5 months for cardiorespiratory endurance. For powerLOW and static balance, the positive pandemic effects translate to developmental gains of 1 and 7 months, respectively. Pre-pandemic secular trends may account for some of the observed differences between pandemic and pre-pandemic cohorts, especially in powerLOW, powerUP and static balance. The pandemic further increased developmental delays of OTK children in cardiorespiratory endurance, powerUP and balance.ConclusionsThe Covid-19 pandemic was associated with declines in several physical fitness components in German third-graders. Pandemic effects are still visible in 2022. Health-related interventions should specifically target those physical fitness components that were negatively affected by the pandemic (cardiorespiratory endurance, coordination, speed).
DUO-GAIT
(2023)
In recent years, there has been a growing interest in developing and evaluating gait analysis algorithms based on inertial measurement unit (IMU) data, which has important implications, including sports, assessment of diseases, and rehabilitation. Multi-tasking and physical fatigue are two relevant aspects of daily life gait monitoring, but there is a lack of publicly available datasets to support the development and testing of methods using a mobile IMU setup. We present a dataset consisting of 6-minute walks under single- (only walking) and dual-task (walking while performing a cognitive task) conditions in unfatigued and fatigued states from sixteen healthy adults. Especially, nine IMUs were placed on the head, chest, lower back, wrists, legs, and feet to record under each of the above-mentioned conditions. The dataset also includes a rich set of spatio-temporal gait parameters that capture the aspects of pace, symmetry, and variability, as well as additional study-related information to support further analysis. This dataset can serve as a foundation for future research on gait monitoring in free-living environments.
Background: In terms of physiological and biomechanical characteristics, over-pronation of the feet has been associated with distinct muscle recruitment patterns and ground reaction forces during running.
Objective: The aim of this study was to evaluate the effects of running on sand vs. stable ground on ground-reaction-forces (GRFs) and electromyographic (EMG) activity of lower limb muscles in individuals with over-pronated feet (OPF) compared with healthy controls.
Methods: Thirty-three OPF individuals and 33 controls ran at preferred speed and in randomized-order over level-ground and sand. A force-plate was embedded in an 18-m runway to collect GRFs. Muscle activities were recorded using an EMG-system. Data were adjusted for surface-related differences in running speed.
Results: Running on sand resulted in lower speed compared with stable ground running (p < 0.001; d = 0.83). Results demonstrated that running on sand produced higher tibialis anterior activity (p = 0.024; d = 0.28). Also, findings indicated larger loading rates (p = 0.004; d = 0.72) and greater vastus medialis (p < 0.001; d = 0.89) and rectus femoris (p = 0.001; d = 0.61) activities in OPF individuals. Controls but not OPF showed significantly lower gluteus-medius activity (p = 0.022; d = 0.63) when running on sand.
Conclusion: Running on sand resulted in lower running speed and higher tibialis anterior activity during the loading phase. This may indicate alterations in neuromuscular demands in the distal part of the lower limbs when running on sand. In OPF individuals, higher loading rates together with greater quadriceps activity may constitute a proximal compensatory mechanism for distal surface instability.
This study aimed at examining the effects of nine weeks of sand-based plyometric jump training (PJT) combined with endurance running on either outdoor or treadmill surface on measures of physical fitness. Male participants (age, 20.1 +/- 1.7 years) were randomly assigned to a sand-based PJT combined with endurance running on outdoor surface (OT, n = 25) or treadmill surface (TT, n = 25). The endurance miming intervention comprised a mixed training method, i.e., long slow distance, tempo, and interval running drills. A control group was additionally included in this study (CG, n = 25). Participants in CG followed their regular physical activity as OT and TT but did not receive any specific intervention. Individuals were assessed for their 50-m linear sprint time, standing long jump (SLJ) distance, cardiorespiratory fitness (i.e., Cooper test), forced vital capacity (FVC), calf girth, and resting heart rate (RHR). A three (groups: OT, TT, CG) by two (time: pre, post) ANOVA for repeated measures was used to analyze the exercise-specific effects. In case of significant group-by-time interactions, Bonferroni adjusted paired (within-group) and independent (between-group comparisons at post) t-tests were used for post-hoc analyses. Significant group-by-time interactions were found for all dependent variables (p < 0.001 - 0.002, eta(2)(p) = 0.16 - 0.78). Group-specific post-hoc tests showed improvements for all variables after OT (p < 0.001, Hedges'g effect size [g] = 0.05 - 1.94) and TT (p < 0.001, g = 0.04 - 2.73), but not in the CG (p = 0.058 - 1.000, g = 0.00 - 0.34). Compared to CG, OT showed larger SLJ (p = 0.001), cardiorespiratory fitness (p = 0.004), FVC (p = 0.008), and RHR (p < 0.001) improvements. TT showed larger improvements in SLJ (p = 0.036), cardiorespiratory fitness (p < 0.001), and RHR (p < 0.001) compared with CG. Compared to OT, TT showed larger improvements for SLJ (p = 0.018). In conclusion, sand-based PJT combined with either OT or TT similarly improved most measures of physical fitness, with greater SLJ improvement after TT. Coaches may use both concurrent exercise regimes based on preferences and logistical constrains (e.g., weather; access to treadmill equipment).
Background:
Social isolation through quarantine represents an effective means to prevent COVID-19 infection. A negative side-effect of quarantine is low physical activity.
Research question:
What are the differences of running kinetics and muscle activities of recreational runners with a history of COVID-19 versus healthy controls?
Methods:
Forty men and women aged 20-30 years participated in this study and were divided into two experimental groups. Group 1 (age: 24.1 +/- 2.9) consisted of participants with a history of COVID-19 (COVID group) and group 2 (age: 24.2 +/- 2.7) of healthy age and sex-matched controls (controls). Both groups were tested for their running kinetics using a force plate and electromyographic activities (i.e., tibialis anterior [TA], gastrocnemius medialis [Gas-M], biceps femoris [BF], semitendinosus [ST], vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], gluteus medius [Glut-M]).
Results:
Results demonstrated higher peak vertical (p = 0.029; d=0.788) and medial (p = 0.004; d=1.119) ground reaction forces (GRFs) during push-off in COVID individuals compared with controls. Moreover, higher peak lateral GRFs were found during heel contact (p = 0.001; d=1.536) in the COVID group. COVID-19 individuals showed a shorter time-to-reach the peak vertical (p = 0.001; d=3.779) and posterior GRFs (p = 0.005; d=1.099) during heel contact. Moreover, the COVID group showed higher Gas-M (p = 0.007; d=1.109) and lower VM activity (p = 0.026; d=0.811) at heel contact.
Significance:
Different running kinetics and muscle activities were found in COVID-19 individuals versus healthy controls. Therefore, practitioners and therapists are advised to implement balance and/or strength training to improve lower limbs alignment and mediolateral control during dynamic movements in runners who recovered from COVID-19.
Associations between measures of physical fitness and cognitive performance in preschool children
(2022)
Background:
Given that recent studies report negative secular declines in physical fitness, associations between fitness and cognition in childhood are strongly discussed. The preschool age is characterized by high neuroplasticity which effects motor skill learning, physical fitness, and cognitive development. The aim of this study was to assess the relation of physical fitness and attention (including its individual dimensions (quantitative, qualitative)) as one domain of cognitive performance in preschool children. We hypothesized that fitness components which need precise coordination compared to simple fitness components are stronger related to attention.
Methods:
Physical fitness components like static balance (i.e., single-leg stance), muscle strength (i.e., handgrip strength), muscle power (i.e., standing long jump), and coordination (i.e., hopping on one leg) were assessed in 61 healthy children (mean age 4.5 +/- 0.6 years; girls n = 30). Attention was measured with the "Konzentrations-Handlungsverfahren fur Vorschulkinder" [concentration-action procedure for preschoolers]). Analyses were adjusted for age, body height, and body mass.
Results:
Results from single linear regression analysis revealed a significant (p < 0.05) association between physical fitness (composite score) and attention (composite score) (standardized ss = 0.40), showing a small to medium effect (F-2 = 0.14). Further, coordination had a significant relation with the composite score and the quantitative dimension of attention (standardized ss = 0.35; p < 0.01; standardized ss = - 0.33; p < 0.05). Coordination explained about 11% (composite score) and 9% (quantitative dimension) of the variance in the stepwise multiple regression model.
Conclusion:
The results indicate that performance in physical fitness, particularly coordination, is related to attention in preschool children. Thus, high performance in complex fitness components (i.e., hopping on one leg) tends to predict attention in preschool children. Further longitudinal studies should focus on the effectiveness of physical activity programs implementing coordination and complex exercises at preschool age to examine cause-effect relationships between physical fitness and attention precisely.
Background
The aim of this study was to analyze the shoulder functional profile (rotation range of motion [ROM] and strength), upper and lower body performance, and throwing speed of U13 versus U15 male handball players, and to establish the relationship between these measures of physical fitness and throwing speed.
Methods
One-hundred and nineteen young male handball players (under (U)-13 (U13) [n = 85]) and U15 [n = 34]) volunteered to participate in this study. The participating athletes had a mean background of sytematic handball training of 5.5 ± 2.8 years and they exercised on average 540 ± 10.1 min per week including sport-specific team handball training and strength and conditioning programs. Players were tested for passive shoulder range-of-motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, overhead medicine ball throw (OMB), hip isometric abductor (ABD) and adductor (ADD) strength, hip ROM, jumps (countermovement jump [CMJ] and triple leg-hop [3H] for distance), linear sprint test, modified 505 change-of-direction (COD) test and handball throwing speed (7 m [HT7] and 9 m [HT9]).
Results
U15 players outperformed U13 in upper (i.e., HT7 and HT9 speed, OMB, absolute IR and ER strength of the dominant and non-dominant sides; Cohen’s d: 0.76–2.13) and lower body (i.e., CMJ, 3H, 20-m sprint and COD, hip ABD and ADD; d: 0.70–2.33) performance measures. Regarding shoulder ROM outcomes, a lower IR ROM was found of the dominant side in the U15 group compared to the U13 and a higher ER ROM on both sides in U15 (d: 0.76–1.04). It seems that primarily anthropometric characteristics (i.e., body height, body mass) and upper body strength/power (OMB distance) are the most important factors that explain the throw speed variance in male handball players, particularly in U13.
Conclusions
Findings from this study imply that regular performance monitoring is important for performance development and for minimizing injury risk of the shoulder in both age categories of young male handball players. Besides measures of physical fitness, anthropometric data should be recorded because handball throwing performance is related to these measures.
Objective: To determine the effects of low- vs. high-intensity aerobic and resistance training on motor and cognitive function, brain activation, brain structure, and neurochemical markers of neuroplasticity and the association thereof in healthy young and older adults and in patients with multiple sclerosis, Parkinson's disease, and stroke. Design: Systematic review and robust variance estimation meta-analysis with meta-regression. Data sources: Systematic search of MEDLINE, Web of Science, and CINAHL databases. Results: Fifty studies with 60 intervention arms and 2283 in-analyses participants were included. Due to the low number of studies, the three patient groups were combined and analyzed as a single group. Overall, low- (g=0.19, p = 0.024) and high-intensity exercise (g=0.40, p = 0.001) improved neuroplasticity. Exercise intensity scaled with neuroplasticity only in healthy young adults but not in healthy older adults or patient groups. Exercise-induced improvements in neuroplasticity were associated with changes in motor but not cognitive outcomes. Conclusion: Exercise intensity is an important variable to dose and individualize the exercise stimulus for healthy young individuals but not necessarily for healthy older adults and neurological patients. This conclusion warrants caution because studies are needed that directly compare the effects of low- vs. high-intensity exercise on neuroplasticity to determine if such changes are mechanistically and incrementally linked to improved cognition and motor function.
Aims: High intensity interval training (HIIT) improves mitochondrial characteristics. This study compared the impact of two workload-matched high intensity interval training (HIIT) protocols with different work:recovery ratios on regulatory factors related to mitochondrial biogenesis in the soleus muscle of diabetic rats.
Materials and methods: Twenty-four Wistar rats were randomly divided into four equal-sized groups: non-diabetic control, diabetic control (DC), diabetic with long recovery exercise [4–5 × 2-min running at 80%–90% of the maximum speed reached with 2-min of recovery at 40% of the maximum speed reached (DHIIT1:1)], and diabetic with short recovery exercise (5–6 × 2-min running at 80%–90% of the maximum speed reached with 1-min of recovery at 30% of the maximum speed reached [DHIIT2:1]). Both HIIT protocols were completed five times/week for 4 weeks while maintaining equal running distances in each session.
Results: Gene and protein expressions of PGC-1α, p53, and citrate synthase of the muscles increased significantly following DHIIT1:1 and DHIIT2:1 compared to DC (p ˂ 0.05). Most parameters, except for PGC-1α protein (p = 0.597), were significantly higher in DHIIT2:1 than in DHIIT1:1 (p ˂ 0.05). Both DHIIT groups showed significant increases in maximum speed with larger increases in DHIIT2:1 compared with DHIIT1:1.
Conclusion: Our findings indicate that both HIIT protocols can potently up-regulate gene and protein expression of PGC-1α, p53, and CS. However, DHIIT2:1 has superior effects compared with DHIIT1:1 in improving mitochondrial adaptive responses in diabetic rats.
Background:
There is evidence that fully recovered COVID-19 patients usually resume physical exercise, but do not perform at the same intensity level performed prior to infection. The aim of this study was to evaluate the impact of COVID-19 infection and recovery as well as muscle fatigue on cardiorespiratory fitness and running biomechanics in female recreational runners.
Methods:
Twenty-eight females were divided into a group of hospitalized and recovered COVID-19 patients (COV, n = 14, at least 14 days following recovery) and a group of healthy age-matched controls (CTR, n = 14). Ground reaction forces from stepping on a force plate while barefoot overground running at 3.3 m/s was measured before and after a fatiguing protocol. The fatigue protocol consisted of incrementally increasing running speed until reaching a score of 13 on the 6-20 Borg scale, followed by steady-state running until exhaustion. The effects of group and fatigue were assessed for steady-state running duration, steady-state running speed, ground contact time, vertical instantaneous loading rate and peak propulsion force.
Results:
COV runners completed only 56% of the running time achieved by the CTR (p < 0.0001), and at a 26% slower steady-state running speed (p < 0.0001). There were fatigue-related reductions in loading rate (p = 0.004) without group differences. Increased ground contact time (p = 0.002) and reduced peak propulsion force (p = 0.005) were found for COV when compared to CTR.
Conclusion:
Our results suggest that female runners who recovered from COVID-19 showed compromised running endurance and altered running kinetics in the form of longer stance periods and weaker propulsion forces. More research is needed in this area using larger sample sizes to confirm our study findings.
Injuries in professional soccer are a significant concern for teams, and they are caused amongst others by high training load. This cohort study describes the relationship between workload parameters and the occurrence of non-contact injuries, during weeks with high and low workload in professional soccer players throughout the season. Twenty-one professional soccer players aged 28.3 ± 3.9 yrs. who competed in the Iranian Persian Gulf Pro League participated in this 48-week study. The external load was monitored using global positioning system (GPS, GPSPORTS Systems Pty Ltd) and the type of injury was documented daily by the team's medical staff. Odds ratio (OR) and relative risk (RR) were calculated for non-contact injuries for high- and low-load weeks according to acute (AW), chronic (CW), acute to chronic workload ratio (ACWR), and AW variation (Δ-Acute) values. By using Poisson distribution, the interval between previous and new injuries were estimated. Overall, 12 non-contact injuries occurred during high load and 9 during low load weeks. Based on the variables ACWR and Δ-AW, there was a significantly increased risk of sustaining non-contact injuries (p < 0.05) during high-load weeks for ACWR (OR: 4.67), and Δ-AW (OR: 4.07). Finally, the expected time between injuries was significantly shorter in high load weeks for ACWR [1.25 vs. 3.33, rate ratio time (RRT)] and Δ-AW (1.33 vs. 3.45, RRT) respectively, compared to low load weeks. The risk of sustaining injuries was significantly larger during high workload weeks for ACWR, and Δ-AW compared with low workload weeks. The observed high OR in high load weeks indicate that there is a significant relationship between workload and occurrence of non-contact injuries. The predicted time to new injuries is shorter in high load weeks compared to low load weeks. Therefore, the frequency of injuries is higher during high load weeks for ACWR and Δ-AW. ACWR and Δ-AW appear to be good indicators for estimating the injury risk, and the time interval between injuries.
This study aimed to investigate the effects of eight weeks of barefoot running exercise on sand versus control on measures of walking kinetics and muscle activities in individuals with diagnosed pronated feet. Sixty physically active male adults with pronated feet were randomly allocated into an intervention or a waiting control group. The intervention group conducted an 8-weeks progressive barefoot running exercise program on sand (e.g., short sprints) with three weekly sessions. Pre and post intervention, participants walked at a constant speed of 1.3 m/s +/- 5% on a 18 m walkway with a force plate embedded in the middle of the walkway. Results showed significant group-by-time interactions for peak impact vertical and lateral ground reaction forces. Training but not control resulted in significantly lower peak impact vertical and lateral ground reaction forces. Significant group-by-time interactions were observed for vastus lateralis activity during the loading phase. Training-induced increases were found for the vastus lateralis in the intervention but not in the control group. This study revealed that the applied exercise program is a suitable means to absorb ground reaction forces (e.g., lower impact vertical and lateral peaks) and increase activities of selected lower limb muscles (e.g., vastus lateralis) when walking on stable ground.
Background
The role of trunk muscle training (TMT) for physical fitness (e.g., muscle power) and sport-specific performance measures (e.g., swimming time) in athletic populations has been extensively examined over the last decades. However, a recent systematic review and meta-analysis on the effects of TMT on measures of physical fitness and sport-specific performance in young and adult athletes is lacking.
Objective
To aggregate the effects of TMT on measures of physical fitness and sport-specific performance in young and adult athletes and identify potential subject-related moderator variables (e.g., age, sex, expertise level) and training-related programming parameters (e.g., frequency, study length, session duration, and number of training sessions) for TMT effects.
Data Sources
A systematic literature search was conducted with PubMed, Web of Science, and SPORTDiscus, with no date restrictions, up to June 2021.
Study Eligibility Criteria
Only controlled trials with baseline and follow-up measures were included if they examined the effects of TMT on at least one measure of physical fitness (e.g., maximal muscle strength, change-of-direction speed (CODS)/agility, linear sprint speed) and sport-specific performance (e.g., throwing velocity, swimming time) in young or adult competitive athletes at a regional, national, or international level. The expertise level was classified as either elite (competing at national and/or international level) or regional (i.e., recreational and sub-elite).
Study Appraisal and Synthesis Methods
The methodological quality of TMT studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. A random-effects model was used to calculate weighted standardized mean differences (SMDs) between intervention and active control groups. Additionally, univariate sub-group analyses were independently computed for subject-related moderator variables and training-related programming parameters.
Results
Overall, 31 studies with 693 participants aged 11-37 years were eligible for inclusion. The methodological quality of the included studies was 5 on the PEDro scale. In terms of physical fitness, there were significant, small-to-large effects of TMT on maximal muscle strength (SMD = 0.39), local muscular endurance (SMD = 1.29), lower limb muscle power (SMD = 0.30), linear sprint speed (SMD = 0.66), and CODS/agility (SMD = 0.70). Furthermore, a significant and moderate TMT effect was found for sport-specific performance (SMD = 0.64). Univariate sub-group analyses for subject-related moderator variables revealed significant effects of age on CODS/agility (p = 0.04), with significantly large effects for children (SMD = 1.53, p = 0.002). Further, there was a significant effect of number of training sessions on muscle power and linear sprint speed (p <= 0.03), with significant, small-to-large effects of TMT for > 18 sessions compared to <= 18 sessions (0.45 <= SMD <= 0.84, p <= 0.003). Additionally, session duration significantly modulated TMT effects on linear sprint speed, CODS/agility, and sport-specific performance (p <= 0.05). TMT with session durations <= 30 min resulted in significant, large effects on linear sprint speed and CODS/agility (1.66 <= SMD <= 2.42, p <= 0.002), whereas session durations > 30 min resulted in significant, large effects on sport-specific performance (SMD = 1.22, p = 0.008).
Conclusions
Our findings indicate that TMT is an effective means to improve selected measures of physical fitness and sport-specific performance in young and adult athletes. <br /> Independent sub-group analyses suggest that TMT has the potential to improve CODS/agility, but only in children. Additionally, more (> 18) and/or shorter duration (<= 30 min) TMT sessions appear to be more effective for improving lower limb muscle power, linear sprint speed, and CODS/agility in young or adult competitive athletes.
The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., “ballistic” and “plyometric”). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1–2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24–48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research.
Purpose:
This study aimed to examine the effects of individualized-load power training (IPT) versus traditional moderate-load power training (TPT) on strength, power, jump performance, and body composition in elite young Nordic athletes.
Methods:
In a randomized crossover design, 10 young male athletes (ski jumpers, Nordic combined athletes) age 17.5 (0.6) years (biological maturity status: +3.5 y postpeak height velocity) who competed on a national or international level performed 5 weeks of IPT (4 x 5 repetitions at 49%-72% 1-repetiton maximum [RM]) and TPT (5 x 5 repetitions at 50%-60% 1-RM) in addition to their regular training. Testing before, between, and after both training blocks comprised the assessment of muscle strength (loaded back squat 3-RM), power (maximal loaded back squat power), jump performance (eg, drop-jump height, reactive strength index), and body composition (eg, skeletal muscle mass).
Results:
Significant, large-size main effects for time were found for muscle strength (P < .01; g = 2.7), reactive strength index (P = .03; g= 1.6), and drop jump height (P = .02; g= 1.9) irrespective of the training condition (IPT, TPT). No significant time-by-condition interactions were observed. For measures of body composition, no significant main effects of condition and time or time-by-condition interactions were found.
Conclusions:
Our findings demonstrate that short-term IPT and TPT at moderate loads in addition to regular training were equally effective in improving measures of muscle strength (loaded back squat 3-RM) and vertical jump performance (reactive strength index, drop jump, and height) in young Nordic athletes.
Physical fatigue (PF) negatively affects postural control, resulting in impaired balance performance in young and older adults. Similar effects on postural control can be observed for mental fatigue (MF) mainly in older adults. Controversial results exist for young adults. There is a void in the literature on the effects of fatigue on balance and cortical activity. Therefore, this study aimed to examine the acute effects of PF and MF on postural sway and cortical activity. Fifteen healthy young adults aged 28 ± 3 years participated in this study. MF and PF protocols comprising of an all-out repeated sit-to-stand task and a computer-based attention network test, respectively, were applied in random order. Pre and post fatigue, cortical activity and postural sway (i.e., center of pressure displacements [CoPd], velocity [CoPv], and CoP variability [CV CoPd, CV CoPv]) were tested during a challenging bipedal balance board task. Absolute spectral power was calculated for theta (4–7.5 Hz), alpha-2 (10.5–12.5 Hz), beta-1 (13–18 Hz), and beta-2 (18.5–25 Hz) in frontal, central, and parietal regions of interest (ROI) and baseline-normalized. Inference statistics revealed a significant time-by-fatigue interaction for CoPd (p = 0.009, d = 0.39, Δ 9.2%) and CoPv (p = 0.009, d = 0.36, Δ 9.2%), and a significant main effect of time for CoP variability (CV CoPd: p = 0.001, d = 0.84; CV CoPv: p = 0.05, d = 0.62). Post hoc analyses showed a significant increase in CoPd (p = 0.002, d = 1.03) and CoPv (p = 0.003, d = 1.03) following PF but not MF. For cortical activity, a significant time-by-fatigue interaction was found for relative alpha-2 power in parietal (p < 0.001, d = 0.06) areas. Post hoc tests indicated larger alpha-2 power increases after PF (p < 0.001, d = 1.69, Δ 3.9%) compared to MF (p = 0.001, d = 1.03, Δ 2.5%). In addition, changes in parietal alpha-2 power and measures of postural sway did not correlate significantly, irrespective of the applied fatigue protocol. No significant changes were found for the other frequency bands, irrespective of the fatigue protocol and ROI under investigation. Thus, the applied PF protocol resulted in increased postural sway (CoPd and CoPv) and CoP variability accompanied by enhanced alpha-2 power in the parietal ROI while MF led to increased CoP variability and alpha-2 power in our sample of young adults. Potential underlying cortical mechanisms responsible for the greater increase in parietal alpha-2 power after PF were discussed but could not be clearly identified as cause. Therefore, further future research is needed to decipher alternative interpretations.
Can compression garments reduce the deleterious effects of physical exercise on muscle strength?
(2022)
Background
The use of compression garments (CGs) during or after training and competition has gained popularity in the last few decades. However, the data concerning CGs' beneficial effects on muscle strength-related outcomes after physical exercise remain inconclusive.
Objective
The aim was to determine whether wearing CGs during or after physical exercise would facilitate the recovery of muscle strength-related outcomes.
Methods
A systematic literature search was conducted across five databases (PubMed, SPORTDiscus, Web of Science, Scopus, and EBSCOhost). Data from 19 randomized controlled trials (RCTs) including 350 healthy participants were extracted and meta-analytically computed. Weighted between-study standardized mean differences (SMDs) with respect to their standard errors (SEs) were aggregated and corrected for sample size to compute overall SMDs. The type of physical exercise, the body area and timing of CG application, and the time interval between the end of the exercise and subsequent testing were assessed.
Results
CGs produced no strength-sparing effects (SMD [95% confidence interval]) at the following time points (t) after physical exercise: immediately <= t < 24 h: - 0.02 (- 0.22 to 0.19), p = 0.87; 24 <= t < 48 h: - 0.00 (- 0.22 to 0.21), p = 0.98; 48 <= t < 72 h: - 0.03 (- 0.43 to 0.37), p = 0.87; 72 <= t < 96 h: 0.14 (- 0.21 to 0.49), p = 0.43; 96 h <= t: 0.26 (- 0.33 to 0.85), p = 0.38. The body area where the CG was applied had no strength-sparing effects. CGs revealed weak strength-sparing effects after plyometric exercise.
Conclusion
Meta-analytical evidence suggests that wearing a CG during or after training does not seem to facilitate the recovery of muscle strength following physical exercise. Practitioners, athletes, coaches, and trainers should reconsider the use of CG as a tool to reduce the effects of physical exercise on muscle strength.
The purpose of this study was to examine the test-retest reliability, and convergent and discriminative validity of a new taekwondo-specific change-of-direction (COD) speed test with striking techniques (TST) in elite taekwondo athletes. Twenty (10 males and 10 females) elite (athletes who compete at national level) and top-elite (athletes who compete at national and international level) taekwondo athletes with an average training background of 8.9 ± 1.3 years of systematic taekwondo training participated in this study. During the two-week test-retest period, various generic performance tests measuring COD speed, balance, speed, and jump performance were carried out during the first week and as a retest during the second week. Three TST trials were conducted with each athlete and the best trial was used for further analyses. The relevant performance measure derived from the TST was the time with striking penalty (TST-TSP). TST-TSP performances amounted to 10.57 ± 1.08 s for males and 11.74 ± 1.34 s for females. The reliability analysis of the TST performance was conducted after logarithmic transformation, in order to address the problem of heteroscedasticity. In both groups, the TST demonstrated a high relative test-retest reliability (intraclass correlation coefficients and 90% compatibility limits were 0.80 and 0.47 to 0.93, respectively). For absolute reliability, the TST’s typical error of measurement (TEM), 90% compatibility limits, and magnitudes were 4.6%, 3.4 to 7.7, for males, and 5.4%, 3.9 to 9.0, for females. The homogeneous sample of taekwondo athletes meant that the TST’s TEM exceeded the usual smallest important change (SIC) with 0.2 effect size in the two groups. The new test showed mostly very large correlations with linear sprint speed (r = 0.71 to 0.85) and dynamic balance (r = −0.71 and −0.74), large correlations with COD speed (r = 0.57 to 0.60) and vertical jump performance (r = −0.50 to −0.65), and moderate correlations with horizontal jump performance (r = −0.34 to −0.45) and static balance (r = −0.39 to −0.44). Top-elite athletes showed better TST performances than elite counterparts. Receiver operating characteristic analysis indicated that the TST effectively discriminated between top-elite and elite taekwondo athletes. In conclusion, the TST is a valid, and sensitive test to evaluate the COD speed with taekwondo specific skills, and reliable when considering ICC and TEM. Although the usefulness of the TST is questioned to detect small performance changes in the present population, the TST can detect moderate changes in taekwondo-specific COD speed.
Background: There is evidence that fully recovered COVID-19 patients usually resume physical exercise, but do not perform at the same intensity level performed prior to infection. The aim of this study was to evaluate the impact of COVID-19 infection and recovery as well as muscle fatigue on cardiorespiratory fitness and running biomechanics in female recreational runners.
Methods: Twenty-eight females were divided into a group of hospitalized and recovered COVID-19 patients (COV, n = 14, at least 14 days following recovery) and a group of healthy age-matched controls (CTR, n = 14). Ground reaction forces from stepping on a force plate while barefoot overground running at 3.3 m/s was measured before and after a fatiguing protocol. The fatigue protocol consisted of incrementally increasing running speed until reaching a score of 13 on the 6–20 Borg scale, followed by steady-state running until exhaustion. The effects of group and fatigue were assessed for steady-state running duration, steady-state running speed, ground contact time, vertical instantaneous loading rate and peak propulsion force.
Results: COV runners completed only 56% of the running time achieved by the CTR (p < 0.0001), and at a 26% slower steady-state running speed (p < 0.0001). There were fatigue-related reductions in loading rate (p = 0.004) without group differences. Increased ground contact time (p = 0.002) and reduced peak propulsion force (p = 0.005) were found for COV when compared to CTR.
Conclusion: Our results suggest that female runners who recovered from COVID-19 showed compromised running endurance and altered running kinetics in the form of longer stance periods and weaker propulsion forces. More research is needed in this area using larger sample sizes to confirm our study findings.