Acute physiological, biomechanical, and perceptual responses of runners wearing downward-curved carbon fiber insoles

In a randomized controlled cross-over study ten male runners (26.7 ± 4.9 years; recent 5-km time: 18:37 ± 1:07 min:s) performed an incremental treadmill test (ITT) and a 3-km time trial (3-km TT) on a treadmill while wearing either carbon fiber insoles with downwards curvature or insoles made of butyl rubber (control condition) in light road racing shoes (Saucony Fastwitch 9). Oxygen uptake, respiratory exchange ratio, heart rate, blood lactate concentration, stride frequency, stride length and time to exhaustion were assessed during ITT. After ITT, all runners rated their perceived exertion, perceived shoe comfort and perceived shoe performance. Running time, heart rate, blood lactate levels, stride frequency and stride length were recorded during, and shoe comfort and shoe performance after, the 3-km TT. All parameters obtained during or after the ITT did not differ between the two conditions [range: p = 0.188 to 0.948 (alpha value: 0.05); Cohen's d = 0.021 to 0.479] despite the rating of shoe comfort showing better scores for the control insoles (p = 0.001; d = -1.646). All parameters during and after the 3-km TT showed no differences (p = 0.200 to 1.000; d = 0.000 to 0.501) between both conditions except for shoe comfort showing better scores for control insoles (p = 0.017; d = -0.919). Running with carbon fiber insoles with downwards curvature did not change running performance or any submaximal or maximal physiological or biomechanical parameter and perceived exertion compared to control condition. Shoe comfort is impaired while running with carbon fiber insoles. Wearing carbon fiber insoles with downwards curvature during treadmill running is not beneficial when compared to running with control insoles.

Daytime fluctuations of endurance performance in young soccer players: a randomized cross-over trial

OBJECTIVES

Fluctuations of physical performance and biological responses during a repetitive daily 24-h cycle are known as circadian rhythms. These circadian rhythms can influence the optimal time of day for endurance performance and related parameters which can be crucial in a variety of sports disciplines. The current study aimed to evaluate the daytime variations in endurance running performance in a 3.000-m field run and endurance running performance, blood lactate levels, and heart rate in an incremental treadmill test in adolescent soccer players.

RESULTS

In this study, 15 adolescent male soccer players (age: 18.0 ± 0.6 years) performed a 3.000-m run and an incremental treadmill test at 7:00-8:00 a.m. and 7:00-8:00 p.m. in a randomized cross-over manner. No significant variations after a Bonferroni correction were evident in endurance running performance, perceived exertion, blood lactate levels, and heart rates between the morning and the evening. Here, the largest effect size was observed for maximal blood lactate concentration (9.15 ± 2.18 mmol/l vs. 10.64 ± 2.30 mmol/l, p = .110, ES = 0.67). Therefore, endurance running performance and physiological responses during a field-based 3.000-m run and a laboratory-based test in young male soccer players indicated no evidence for daytime variations.

Effects of High-Intensity Interval Training in School on the Physical Performance and Health of Children and Adolescents: A Systematic Review with Meta-Analysis

Background

Performance of high-intensity interval training (HIIT) by children and adolescents improves physical and health-related fitness, as well as cardiometabolic risk factors.

Objectives

To assess the impact of HIIT performed at school, i.e. both in connection with physical education (intra-PE) and extracurricular sports activities (extra-PE), on the physical fitness and health of children and adolescents.

Methods

PubMed and SPORTDiscus were searched systematically utilizing the following criteria for inclusion: (1) healthy children and adolescents (5–18 years old) of normal weight; (2) HIIT performed intra- and/or extra-PE for at least 5 days at an intensity ≥ 80% of maximal heart rate (HR_max) or peak oxygen uptake (VO_2peak) or as Functional HIIT; (3) comparison with a control (HIIT versus alternative interventions); and (4) pre- and post-analysis of parameters related to physical fitness and health. The outcomes with HIIT and the control interventions were compared utilizing Hedges’ g effect size (ES) and associated 95% confidence intervals.

Results

Eleven studies involving 707 participants who performed intra-PE and 388 participants extra-PE HIIT were included. In comparison with the control interventions, intra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 5.89 ± 5.67 (range 1.88–9.90); ES number of push-ups: 6.22 (range n.a.); ES number of sit-ups: 2.66 ± 2.02 (range 1.24–4.09)), as well as ES fasting glucose levels (− 2.68 (range n.a.)) more effectively, with large effect sizes. Extra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 1.81 (range n.a.); ES number of sit-ups: 2.60 (range n.a.)) to an even greater extent, again with large effect sizes. Neither form of HIIT was more beneficial for parameters related to cardiorespiratory fitness than the control interventions.

Conclusion

Compared to other forms of exercise (e.g. low-to-moderate-intensity running or walking), both intra- and extra-PE HIIT result in greater improvements in neuromuscular and anaerobic performance, as well as in fasting levels of glucose in school children.

Compensation or Displacement of Physical Activity in Children and Adolescents: A Systematic Review of Empirical Studies

Regular physical activity during childhood and adolescence is associated with health benefits. Consequently, numerous health promotion programs for children and adolescents emphasize the enhancement of physical activity. However, the ActivityStat hypothesis states that increases in physical activity in one domain are compensated for by decreasing physical activity in another domain. Currently, little is known about how physical activity varies in children and adolescents within intervals of one day or multiple days. This systematic review provides an overview of studies that analyzed changes in (overall) physical activity, which were assessed with objective measurements, or compensatory mechanisms caused by increases or decreases in physical activity in a specific domain in children and adolescents. A systematic search of electronic databases (PubMed, Scopus, Web of Science, SportDiscus) was performed with a priori defined inclusion criteria. Two independent researchers screened the literature and identified and rated the methodological quality of the studies. A total of 77 peer-reviewed articles were included that analyzed changes in overall physical activity with multiple methodological approaches resulting in compensation or displacement. Of 40,829 participants, 16,265 indicated compensation associated with physical activity. Subgroup analyses separated by study design, participants, measurement instrument, physical activity context, and intervention duration also showed mixed results toward an indication of compensation. Quality assessment of the included studies revealed that they were of high quality (mean = 0.866). This review provides inconclusive results about compensation in relation to physical activity. A trend toward increased compensation in interventional studies and in interventions of longer duration have been observed.

Kindergarten-Based Progressive Muscle Relaxation Training Enhances Attention and Executive Functioning in 5-6-year-old Children: A Randomized Controlled Trial

In the present study we assessed the impact of kindergarten-based progressive muscle relaxation (PMR) on attention and executive functioning of 5-6-year-old children. In this randomized-controlled trial, 52 children (26 female; 26 male; M age = 5.4, SD = 0.2 years) from two private Tunisian kindergartens were randomly assigned to experimental and control groups. Over 12 weeks, 18 children performed PMR in two 30-minute sessions/week, another 17 children performed generic physical education (PE) for two 30-minute sessions/week, and 17 children in a control group (CG) had no systematically guided physical activity and engaged in usual self-chosen activities like free play or artisanal activities during Kindergarten hours. Prior to (T0) and after (T1) the 12-week PMR intervention, all participants completed the Visuomotor Precision and Statue subtests of the Neuropsychological Evaluation Battery (NEPSY-2), the Teddy Bear Cancellation Test, and the Rey Simple Figure Test. While there were no significant group differences at T0, repeated measures analysis of variance revealed higher scores for the PMR group relative to both the PE and CG groups on measures of attention, visuomotor precision, memory, and motor inhibition. PMR provided an effective relaxation technique and enhanced attention and executive functioning of these 5-6-year-old children, with important implications for assisting learning and academic achievement among young children.

Repeated Sprint Training vs. Repeated High-Intensity Technique Training in Adolescent Taekwondo Athletes-A Randomized Controlled Trial

This study investigated the effects of 4-weeks repeated sprint (RST) vs. repeated high-intensity-technique training (RTT) on physical performance. Thirty-six adolescent taekwondo athletes (age: 16 ± 1 yrs) were randomly assigned to RST (10 × 35 m sprint, 10 s rest), RTT (10 × 6 s Bandal-tchagui, 10 s rest) and control (control group (CG): no additional training) groups. Additionally, to their regular training, RST and RTT trained 2×/week for 4 weeks. Training load (TL), monotony, and strain were calculated using the rating of perceived exertion scale. The progressive specific taekwondo (PSTT), 20 m multistage shuttle run (SRT_20m), 5 m shuttle run, agility T-test, taekwondo-specific agility (TSAT) and countermovement jump (CMJ) tests were performed before and after 4 weeks of training. Additionally, taekwondo athletes performed specific taekwondo exercises (i.e., repeated techniques for 10 s and 1 min). From week 1, mean TL increased continuously to week 4 and monotony and strain were higher at weeks 3 and 4 (p < 0.001). VO_2max calculated from SRT_20m and PSTT increased for RST and RTT in comparison to CG (p < 0.001). Agility performance during T-test and TSAT (p < 0.01) improved in RTT. The number of performed techniques during the 10 s specific exercise increased in RTT and RST (p < 0.01) for the dominant leg and in RTT for the non-dominant leg (p < 0.01). The number of techniques during the 1 min specific exercise was higher in RST and RTT compared to CG for the dominant leg (p < 0.001). Delta lactate at post-training was lower for RTT for both legs compared to RST and CG (p < 0.01). It is important to include a low-volume high-intensity training based on repeated sprint running or repeated technique in the training programs of adolescent taekwondo athletes.

Effects of Ramadan Observance on Dietary Intake and Body Composition of Adolescent Athletes: Systematic Review and Meta-Analysis

To evaluate the effects of Ramadan observance on dietary intake, body mass and body composition of adolescent athletes (design: systematic review and meta-analysis; data sources: PubMed and Web of Science; eligibility criteria for selecting studies: single-group, pre-post, with or without control-group studies, conducted in athletes aged <19 years, training at least 3 times/week, and published in any language before 12 February 2020). Studies assessing body mass and/or body composition and/or dietary intake were deemed eligible. The methodological quality was assessed using ‘QualSyst’. Of the twelve selected articles evaluating body mass and/or body composition, one was of strong quality and eleven were rated as moderate. Ten articles evaluated dietary intake; four were rated as strong and the remaining moderate in quality. Continuation of training during Ramadan did not change body mass from before to the first week (trivial effect size (ES) = −0.011, p = 0.899) or from before to the fourth week of Ramadan (trivial ES = 0.069, p = 0.277). Additionally, Ramadan observance did not change body fat content from before to the first week (trivial ES = −0.005, p = 0.947) and from before to the fourth week of Ramadan (trivial ES = -0.057, p = 0.947). Lean body mass remained unchanged from before to the fourth week of Ramadan (trivial ES = −0.025, p = 0.876). Dietary data showed the intake of energy (small ES = -0.272, p = 0.182), fat (trivial ES = 0.044, p = 0.842), protein (trivial ES = 0.069, p = 0.720), carbohydrate (trivial ES = 0.075, p = 0.606) and water (trivial ES = −0.115, p = 0.624) remained essentially unchanged during as compared to before Ramadan. Continued training of adolescent athletes at least three times/week during Ramadan observance has no effect on body mass, body composition or dietary intake.

Effect of Different Running Exercise Modalities on Post-Exercise Oxidative Stress Markers in Trained Athletes

The aim of this study was to examine the effect of running exercise modality on oxidative stress. Thirteen endurance athletes (age: 21.46 ± 0.66 years) performed three different running exercise modalities (Continuous running exercise (CR): continuous running exercise at 75% of VO2max for 25 min; intermittent running exercise #1 (15/15): intermittent running protocol, 15 s running at 75% of VO2max, 15 s passive recovery, performed for 50 min; intermittent running exercise #2 (30/30): intermittent running protocol, 30 s running at 75% of VO2max, 30 s passive recovery, performed for 50 min) in a randomized order. Blood samples were drawn at rest and immediately after each running exercise and assessed for malondialdehyde (MDA), advanced oxidation protein products (AOPP), superoxide dismutase(SOD), and glutathione peroxidase (GPX) activities. MDA increased by 55% following 30/30 exercise (p < 0.01), while it remained unchanged with CR and15/15 exercise. SOD increased after CR (+13.9%, p < 0.05), and also remained unchanged after 15/15 (p > 0.05) and decreased after 30/30 (-19.7% p < 0.05). GPX and AOPP did not change after exercise in all experimental sessions (p > 0.05). In conclusion, 30/30 intermittent running induced higher lipid damages than the 15/15 and CR exercise. 15/15 intermittent exercise promoted a better balance between free radicals production and antioxidant defense compared to continuous exercise and intermittent 30/30 exercise.

The Effects of Temporal Contiguity and Expertise on Acquisition of Tactical Movements

Various studies demonstrated that multimedia learning improves when text and pictures are presented contiguously in time rather than separately – the temporal contiguity effect. The present study investigated whether this advantage is restricted to only novice learners (novices) or also extends to more knowledgeable learners (expert), and whether it depends on the length of instructional segments. Learners with varied levels of expertise (experts vs. novices) learned about basketball game system in five different experimental conditions. In the first three conditions, an entire video clip and audio text were presented either at the same time or the video clip was presented before or after the entire audio (macro-step presentations). In the remaining two conditions, short segments of the video clip were presented before or after corresponding short segments of the audio (micro-step presentations). Overall, novice learners benefited more from the concurrent presentation (combination of learning and mental effort scores); in addition, and in the case of macro-step presentations novices performed better when the audio segment preceded the video clip segment. However, experts benefited more from the micro-step presentations, demonstrating an expertise reversal effect.

Effects of Ramadan Fasting on Recovery Following a Simulated Soccer Match in Professional Soccer Players: A Pilot Study

Objectives: Assessing the effects of Ramadan fasting on recovery following a soccer match simulation.

Methods: Eight elite soccer players (age: 21.0 ± 0.4 years) performed a modified Loughborough Intermittent Shuttle Test protocol (LIST_mod) on two occasions: 1 week before (BR) and during the fourth week of Ramadan (End-R). At BR and End-R, soccer players performed squat jump, countermovement jump, maximal voluntary contraction, and 20 m sprint, and creatine kinase, uric acid, and subjective ratings (feelings scale, quality of sleep, fatigue, muscle soreness and stress) were assessed at baseline and 0, 24, 48, and 72 h following LIST_mod.

Results: Following LIST_mod, performance in squat jump (48 and 72 h) (p < 0.05), countermovement jump (48 and 72 h), maximal voluntary contraction (0, 24, 48, and 72 h), and 20 m sprint (0 and 48 h) decreased significantly on both occasions. Decreases were higher at End-R than BR. Creatine kinase levels increased significantly at 24 and 48 h at BR and End-R (p < 0.05). Uric acid increased at 0 and 24 h only on BR. Muscle soreness increased throughout the recovery period at both occasions, with a higher level at End-R. Stress rating increased only at 0 h on End-R, while fatigue rating increased at 24 h at BR and at 0, 24, and 48 h at End-R.

Conclusion: Perturbations in physical performance and subjective ratings parameters were higher at the end of Ramadan. However, the results of this study showed that Ramadan fasting did not adversely affect the recovery following soccer match simulation in professional soccer players.

Classroom-Based Micro-Sessions of Functional High-Intensity Circuit Training Enhances Functional Strength but Not Cardiorespiratory Fitness in School Children-A Feasibility Study

The present study assessed the short-term effect of 6 min classroom-based micro-sessions of multi-joint functional high-intensity circuit training (FunctionalHIIT) performed by students during regular classes on parameters related to functional strength and cardiorespiratory fitness. In this randomized controlled 4-week study, 17 students (11 male; 6 female; age: 11.6 ± 0.2 years) performed 6 min of FunctionalHIIT (targeting >17 on the Borg scale) 4 days per week during regular school classes and 18 students (11 male; 7 female; age: 11.7 ± 0.3 years) served as control group (CG) without any additional in-class physical activity. The FunctionalHIIT group completed 86% of all planned sessions (mean duration: 6.0 ± 1.5 min) with a mean RPE of 17.3 ± 2.1. Body height, mass and BMI did not differ between the groups at baseline or between pre- and post-testing (p > 0.05; eta2 ≤ 0.218). The performances in lateral jumping (p < 0.000; part eta2 = 0.382; Δ% 4.6 ± 8.6), sit-ups (p < 0.000; part eta2 = 0.485; Δ% 3.1 ± 8.6) and 20-m sprints (p < 0.000; part eta2 = 0.691; Δ% 15.8 ± 5.4) improved in both groups with greater increase following FunctionalHIIT. No baseline differences and no interaction effects occurred in performance of 6 min run, flexibility, push-ups, balance, and long jump. Classroom-based FunctionalHIIT sessions, performed 4 days per week during 4 weeks did not improve variables related to aerobic endurance performance but enhanced certain parameters of functional strength in schoolchildren. As time is limited in the educational system of schools, FunctionalHIIT during regular school classes could offer a new perspective for increasing functional strength in schoolchildren.

Nap Opportunity During the Daytime Affects Performance and Perceived Exertion in 5-m Shuttle Run Test

Purpose

To compare the effect of different durations of nap opportunity during the daytime on repeated high-intensity short-duration performance and rating of perceived exertion (RPE).

Methods

Seventeen physically active men (age: 21.3 ± 3.4 years, height: 176.7 ± 5.9 cm, body mass: 71.8 ± 10.2 kg) performed a 5 m shuttle run test [to determine best distance (BD), total distance (TD), and fatigue index (FI)] under four conditions: a 25 min nap opportunity (N25), a 35 min nap opportunity (N35), a 45 min nap opportunity (N45), and control condition (no-nap) (N0). The sleep quality of each nap opportunity was evaluated using a scale ranging from 0 "no sleep" to 10 "uninterrupted, deep sleep throughout." The four conditions were performed in a random order. RPE was recorded after each repetition of the 5 m shuttle run test and the mean score was calculated.

Results

BD increased after N25 (+6%) and N45 (+9%) compared to N0 (p < 0.05) and was significantly higher after N45 compared to N35 (p < 0.05). Compared to N0, the three nap opportunity durations enhanced TD (p < 0.05) with greater enhancement after N45 compared to N25 (+8% vs. +3%) and N35 (+8% vs. +3%). For FI, no-significant differences were observed between the three nap opportunity durations and N0. The mean RPE score was significantly higher after N25 (+20%) and N0 (+19%) compared to N45 (p < 0.05). All participants were able to fall asleep during each nap condition with a sleep quality score of 6.9 ± 1.0, 7.0 ± 0.7, and 7.1 ± 0.8 for N25, N35, and N45.

Conclusion

A nap opportunity during the daytime was beneficial for physical performance and perceived exertion with the N45 being the most effective for improving performance and reducing fatigue during the 5 m shuttle run test. The implication of the present study is that athletes might benefit from a nap opportunity of 25, 35 or 45 min before practice or before a competition.

Short-term maximal performance, alertness, dietary intake, sleep pattern and mood states of physically active young men before, during and after Ramadan observance

Purpose

To assess changes in short-term maximal performance, alertness, dietary intake, sleep pattern and mood states of physically active young men before (BR), during and after Ramadan observance.

Methods

Twelve physically-active men (age: 21.9±2.4yrs, height:1.77±0.09m, body-mass: 72.6±7.8kg, exercising: ≥3h/week) performed the 5-jump and the digit-cancellation (alertness) tests 15-days BR, on the first (FR) and last 10-days of Ramadan (ER) and 10-days (AR10) and 20-days (AR20) after Ramadan. During each period, sleep pattern (Pittsburgh-Sleep-Quality-Index (PSQI)), mood states (Profile-of-Mood-States (POMS)) and dietary intake were recorded.

Results

No significant changes in the 5-jump, digit-cancellation test and POMS parameters appeared during and after Ramadan relative to BR. However, the PSQI total score was lower during FR compared to AR10 (p<0.001). Specifically, the subjective sleep quality was lower (i) at BR compared to FR (p<0.05), AR10 (p<0.01) and AR20 (p<0.01) and (ii) at ER and AR20 compared to FR (p<0.05). The sleep duration (i) increased at FR (p<0.05) and (ii) decreased at AR10 (p<0.01) and AR20 (p<0.05) compared to BR. Sleep disturbances were significantly greater (i) at BR compared to FR (p<0.01), ER (p<0.01), AR10 (p<0.05) and AR20 (p<0.05) and (ii) at AR10 and AR20 compared to FR and ER (p<0.05). In terms of diet, the fractional contribution of carbohydrate (%) was lower and the dietary fat content (g) was higher during ER than AR10 and AR20 (p<0.05). Further, the dietary protein (in %) was significantly lower during FR compared to BR (p<0.01), ER (p<0.05), AR10 (p<0.05) and AR20 (p<0.05).

Conclusion

Ramadan had no-adverse effects on the 5-jump performance, alertness, or mood states in physically active young men. However, the sleep duration was shorter and the sleep quality was improved following compared to during Ramadan. The fractional intake of fat also increased at the expense of carbohydrate during Ramadan, and the protein intake was lower at the beginning of Ramadan than before, at the end of and after Ramadan.

Verbal Encouragement and Between-Day Reliability During High-Intensity Functional Strength and Endurance Performance Testing

As verbal encouragement (VE) is used in high intensity functional exercise testing, this randomized controlled crossover study aimed at investigating whether VE affects high intensity functional strength and endurance performance testing. We further examined between-day variability of high intensity functional strength and endurance performance testing with and without VE. Nineteen experienced athletes (seven females and 12 males, age: 23.7 ± 4.3 years) performed a standardized one repetition maximum (1 RM) squat test and a 12-min high-intensity functional training (HIFT) workout [as many repetitions as possible (AMRAP)] on four different days over a 2-week period. Athletes randomly performed each test twice, either with VE or without (CON), with a minimum of 72 h rest between tests. Very good to excellent relative between-day reliability with slightly better values for strength testing (ICC: 0.99; CV: 3.5–4.1%) compared to endurance testing (ICC 0.87–0.95; CV: 3.9–7.3%) were observed. Interestingly, VE led to higher reliability during endurance testing. Mean squat strength depicted higher strength values with VE (107 ± 33 kg) compared to CON (105 ± 33 kg; p = 0.009, Cohen’s d: 0.06). AMRAP in the endurance test showed negligible differences between VE (182 ± 33 AMRAP) and CON (181 ± 35 AMRAP; p = 0.71, Cohen’s d: 0.03). In conclusion, the effects of VE do not notably exceed day-to-day variability during high intensity functional strength (CV: 3.5–4.1%) and endurance (CV: 3.9–7.3%) testing. However, high intensity functional strength and endurance testing with VE seems to be slightly more reliable, particularly during endurance testing.

12 Weeks of Kindergarten-Based Yoga Practice Increases Visual Attention, Visual-Motor Precision and Decreases Behavior of Inattention and Hyperactivity in 5-Year-Old Children

The present study assesses the impact of Kindergarten-based yoga on cognitive performance, visual-motor coordination, and behavior of inattention and hyperactivity in 5-year-old children. In this randomized controlled trial, 45 children (28 female; 17 male; 5.2 ± 0.4 years) participated. Over 12 weeks, 15 children performed Hatha-yoga twice a week for 30 min, another 15 children performed generic physical education (PE) twice a week for 30 min, and 15 children performed no kind of physical activities, serving as control group (CG). Prior to (T₀) and after 12 weeks (T₁), all participants completed Visual Attention and Visuomotor Precision subtests of Neuropsychological Evaluation Battery and teachers evaluated children’s behavior of inattention and hyperactivity with the Attention-Deficit/Hyperactivity Disorder (ADHD) Rating Scale-IV. At T₀, no significant differences between groups appeared. Repeated measures analysis of variance revealed that following Bonferroni–Holm corrections yoga, in comparison to PE and CG, had a significant positive impact on the development on behavior of inattention and hyperactivity. Further, yoga has a significant positive impact on completion times in two visumotor precision tasks in comparison to PE. Finally, results indicate a significant positive effect of yoga on visual attention scores in comparison to CG. 12 weeks of Kindergarten-based yoga improves selected visual attention and visual-motor precision parameters and decreases behavior of inattention and hyperactivity in 5-year-old children. Consequently, yoga represents a sufficient and cost-benefit effective exercise which could enhance cognitive and behavioral factors relevant for learning and academic achievement among young children.