Muscle damage,inflammation, and recovery interventions during a 3-day basketball tournament

Abstract

Cold water immersion and compression garments are now popular strategies for post-exercise recovery. However, little information exists on the effectiveness of these strategies to minimize muscle damage, or any impact they may have on biomarker clearance after team sport competition. The main aim of this study was to investigate the time course of muscle damage markers and inflammatory cytokines during basketball tournament play. We also wished to examine if cold water immersion and compression recovery strategies ameliorate any post-game increases of these biomarkers, compared with traditional refuelling and stretching routines.

Male basketball players (age 19.1 years, s=2.1; height 1.91 m, s=0.09; body mass 87.9 kg, s=15.1) were asked to compete in a three-day tournament playing one game each day. Players were assigned to one of three recovery treatments: carbohydrate+stretching (control, n=9), cold-water immersion at 11°C for 5×1 min (n=10); or full-leg compression at 18 mmHg for ～18 h (n=10). Players received their treatment after each game on three consecutive days. Venous blood samples were assayed before the tournament and at 10 min, 6 h, and 24 h after each game for concentrations of the muscle damage markers fatty-acid binding protein (FABP), creatine kinase, and myoglobin; interleukin-6 (IL-6) and interleukin-10 (IL-10) were also assayed. Inferences were based on log-transformed concentrations.

Post-game increases in damage markers were clear and very large for FABP after the cold water immersion (3.81 ×/÷ 1.19, factor mean ×/÷ factor s), compression (3.93 ×/÷ 1.46), and control (4.04 ×/÷ 1.19) treatments. Increases in myoglobin were also clear and very large after the cold water immersion (3.50 ×/÷ 1.35), compression (3.66 ×/÷ 1.48), and control (4.09 ×/÷ 1.18) treatments. Increases in creatine kinase were clear but small after the cold water immersion (1.30 ×/÷ 1.03), compression (1.25 ×/÷ 1.39), and control (1.42 ×/÷ 1.15) treatments, with small or unclear differences between treatments. There were clear moderate to large post-game increases in IL-6 for cold water immersion (2.75 ×/÷ 1.37), compression (3.43 ×/÷ 1.52), and control (3.47 ×/÷ 1.49). Increases in IL-10 were clear and moderate for cold water immersion (1.75 ×/÷ 1.43), but clear and large after the compression (2.46 ×/÷ 1.79) and control (2.32 ×/÷ 1.41) treatments. Small decreases in IL-6 and IL-10 were observed with cold water immersion compared with the compression and control treatments, with unclear effects between treatments over the tournament. There was no clear benefit from any recovery treatment post-game, as the differences between treatments for all biomarker measures were small or unclear. Pre- to post-tournament increases in FABP, myoglobin, and creatine kinase were clearly small to moderate. There were also small to moderate differences between cold water immersion and the compression (0.85 ×/÷ 1.21) and control (0.76 ×/÷ 1.26) treatments for the post-tournament measures compared with pre-tournament. Pre- to post-tournament changes for IL-6 and IL-10 were unclear, as were the differences between treatments for both cytokines.

Tournament basketball play elicits modest elevations of muscle damage markers, suggesting disruption of myocyte membranes in well-trained players. The magnitude of increase in muscle damage markers and inflammatory cytokines post-game ranged from small for creatine kinase, to large for IL-6 and IL-10, to very large for FABP and myoglobin. Cold water immersion had a small to moderate effect in decreasing FABP and myoglobin concentrations after a basketball tournament compared with the compression and control treatments.     

周期训练中不同水平男子皮艇运动员血浆内皮素的变化

观察了20名不同水平男子皮艇运动员在一个周期训练中血浆内皮素(ET)的变化.结果提示:高水平男子皮艇运动员血浆ET水平与运动训练持续的时间及运动负荷成正相关,说明长时间、大强度训练能有效增加高水平运动员血浆ET的含量,运动员的心脏内分泌功能对周期训练适应性强,具有良好的心力储备和泵血功能,然而也不排除运动员有心脏功能的损伤.     

Influence of recovery intensity on time spent at maximal oxygen uptake during an intermittent session in young,endurance-trained athletes

Abstract

In this study, we examined the effects of three recovery intensities on time spent at a high percentage of maximal oxygen uptake (t90[Vdot]O_2max) during a short intermittent session. Eight endurance-trained male adolescents (16 ± 1 years) performed four field tests until exhaustion: a graded test to determine maximal oxygen uptake ([Vdot]O_2max; 57.4 ± 6.1 ml · min^?1 · kg^?1) and maximal aerobic velocity (17.9 ± 0.4 km · h^?1), and three intermittent exercises consisting of repeat 30-s runs at 105% of maximal aerobic velocity alternating with 30 s active recovery at 50% (IE₅₀), 67% (IE₆₇), and 84% (IE₈₄) of maximal aerobic velocity. In absolute values, mean t90[Vdot]O_2max was not significantly different between IE₅₀ and IE₆₇, but both values were significantly longer compared with IE₈₄. When expressed in relative values (as a percentage of time to exhaustion), mean t90[Vdot]O_2max was significantly higher during IE₆₇ than during IE₅₀. Our results show that both 50% and 67% of maximal aerobic velocity of active recovery induced extensive solicitation of the cardiorespiratory system. Our results suggest that the choice of recovery intensity depends on the exercise objective.     

Interval running with self-selected recovery: Physiology,performance, and perception

This study (1) compared the physiological responses and performance during a high-intensity interval training (HIIT) session incorporating externally regulated (ER) and self-selected (SS) recovery periods and (2) examined the psychophysiological cues underpinning SS recovery durations. Following an incremental maximal exercise test to determine maximal aerobic speed (MAS), 14 recreationally active males completed 2 HIIT sessions on a non-motorised treadmill. Participants performed 12?×?30?s running intervals at a target intensity of 105% MAS interspersed with 30?s (ER) or SS recovery periods. During SS, participants were instructed to provide themselves with sufficient recovery to complete all 12 efforts at the required intensity. A semi-structured interview was undertaken following the completion of SS. Mean recovery duration was longer during SS (51?±?15?s) compared to ER (30?±?0?s; p?d?=?1.46?±?0.46). Between-interval heart rate recovery was higher (SS: 19?±?9?b?min^?1; ER: 8?±?5?b?min^?1; p?d?=?1.43?±?0.43) and absolute time ≥90% maximal heart rate (HR_max) was lower (SS: 335?±?193?s; ER: 433?±?147?s; p?=?.075; d?=?0.52?±?0.39) during SS compared to ER. Relative time ≥105% MAS was greater during SS (90?±?6%) compared to ER (74?±?20%; p?d?=?0.87?±?0.40). Different sources of afferent information underpinned decision-making during SS. The extended durations of recovery during SS resulted in a reduced time ≥90% HR_max but enhanced time ≥105% MAS, compared with ER exercise. Differences in the afferent cue utilisation of participants likely explain the large levels of inter-individual variability observed.     

射箭运动员在不同训练时期血液氨基酸变化的研究

目的：观察射箭运动员在不同运动负荷状态时的血液氨基酸的变化。方法：用高效液相法测定射箭运动员冬训期间不同的训练时期血液中四种氨基酸——门冬氨酸（Asp）、谷氨酸（Glu）、甘氨酸（（Gly）和r-氨基丁酸（GABA）的含量。结果：在进行中等强度训练期和大强度训练期运动后1h血浆中谷氨酸的血浆浓度明显升高（P〈0．01）。而在大强度训练期后明显下降,甚至低于安静值;门冬氨酸在中等强度训练后血浆浓度也升高（P〈0．05）,在疲劳期则呈下降趋势,但仍高于安静值;在进行中等强度训练期和大强度训练期运动1h后血浆中r-氨基丁酸、甘氨酸均上升。大强度训练期明显升高,与训练前期安静值相比有显著意义（P〈0．01）。结论：射箭运动员在长时间大强度大运动量训练后,血液中的氨基酸会发生变化,中枢疲劳可能从血浆氨基酸的变化反映出来。     

6周递增负荷训练对大鼠骨骼肌IGF-I及血清GH、IGF-I水平影响的研究

生长激素(GH)、胰岛素样生长因子I(IGF-I)都是了解GH-IGF轴变化的主要指标.IGF不仅是内分泌因子,还能在组织局部起作用.通过对6周递增负荷跑台练习的大鼠进行研究,结果显示:运动后即刻,大鼠血清GH水平明显升高(P＜0.01);运动组与对照组相比,骨骼肌IGF-I水平有明显升高(P＜0.01),表明运动对骨骼肌组织内IGF的分泌有调节作用.     

运动后收缩压恢复与单纯性肥胖(超重)的关系

分析运动后收缩压恢复(PSBPR)与单纯性肥胖(超重)的关系,探索PSBPR延迟作为肥胖(超重)患者新的调控标志物的可行性。将169名志愿者按照身体质量指数(BMI)分为肥胖(超重)组(BMI≥24 kg/m2,n=91名)和正常体重组(18 kg/m2≤BMI<24 kg/m2,n=78名)。所有受试者均进行一次递增负荷功率车实验,分别测定运动前安静时、运动中以及运动后恢复期的收缩压,以运动后第3分钟的收缩压与运动后第1分钟收缩压的比值(第3分钟收缩压恢复比,rSBPR)超过1.0作为PSBPR延迟的指标。比较两组rSBPR和PSBPR延迟发生率的差别并分析肥胖指数(体脂百分比、身体质量指数(BMI)、腰围(WC)、腰臀比(WHR)、腰围身高比(WSR))与rSBPR的相关性。结果:肥胖(超重)组rSBPR(男:0.97±0.03;女:0.95±0.05)高于正常体重组(男:0.79±0.02;女:0.80±0.04)(均为P<0.01);肥胖(超重)组PSBPR延迟发生率(男:16.0%;女:23.4%)显著高于正常体重组(男:2.7%;女:4.3%)(均为P<0.01);肥胖(超重)的男性和女性发生PSBPR延迟的危险性分别是正常体重者的8.0倍和4.6倍。相关分析显示,肥胖(超重)组男性体脂百分数、BMI与rSBPR相关系数分别为0.381(P<0.01)和0.316(P<0.01),肥胖(超重)组女性WSR与rSBPR相关系数为0.402(P<0.01),正常体重组男性体脂百分数、BMI与rSBPR相关系数分别为0.436(P<0.01)和0.310(P<0.01)。结果表明:PSBPR延迟可能是肥胖(超重)患者可调控的心血管危险因素     

Individualized sleep education improves subjective and objective sleep indices in elite cricket athletes: A pilot study

ABSTRACT

The aim of the current study was to evaluate the effect of personalized sleep hygiene education on sleep indices in elite athletes. Nine elite male cricket players performed 3 weeks of baseline sleep monitoring (PRE), followed by group and individualized sleep hygiene education and a further 3 weeks of sleep monitoring (POST). Subjective sleep questionnaires included the Athlete Sleep Behaviour Questionnaire (ASBQ), the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). Objective sleep indices were monitored via wrist actigraphy. There were significant improvements (p < 0.05) in two of the sleep questionnaires (ESS and PSQI) and in sleep efficiency (+5%), sleep latency (?29 min) and sleep onset variance (?28 min) following the intervention, all associated with large or very large effect sizes (d= 1.38, ?0.85 and ?0.88, respectively). The current study reports that personalized sleep hygiene education using the ASBQ to target maladaptive sleep behaviours may be effective in acutely improving sleep indices in elite male athletes.     

递增负荷运动大鼠下丘脑-垂体超微结构变化及其恢复过程观察

对递增负荷运动及恢复不同阶段大鼠下丘脑及垂体组织细胞的超微结构进行了透射电镜观察，发现在长期递增负荷运动训练过程中，大鼠下丘脑弓状核神经元出现渐进性的细胞器变性、轴突髓鞘分离、突触小泡及微管微丝减少、树突棘减少等异常变化，垂体促性腺细胞及生长激素细胞出现渐进性的细胞器变性及核膜异常，溶酶体增多等，而ACTH细胞形态结构变化较小，与同期测定的较低FSH、IH水平和较高CRH及GC水平具有一致性。结果表明，长期训练可致大鼠脑组织神经元间的相互联系减弱，促性腺激素释放激素的合成及分泌均受到抑制。这种变化与训练周期的增长及运动负荷的增大具有显著递进关系。而经过4个动情周期的恢复，结构逐渐复原，为一可逆性变化过程。     

Young,talented and injured: Injury perceptions,experiences and consequences in adolescent elite athletes

Even though injury is common in elite sports, there is still a lack of knowledge of young athletes’ injury perception both during and after injury. The aim of this mixed-method study was, therefore, to explore, in-depth, data on injury consequences and adolescent elite athletes’ perceptions and experience of injury. Three hundred and forty adolescent elite athletes (age range 15–19), from 16 different sports, were bi-weekly monitored over 52 weeks using a valid questionnaire. Twenty athletes from the same cohort were interviewed in focus groups about injury experience and perceptions. The results show that the average bi-weekly prevalence of injury was 38.7% (95% CI 37.3–40.1), with 30.0% (n?=?102) of the athletes injured for more than half of all reporting times. An overarching theme from the focus groups highlighted the risk among young athletes of a loss of identity while injured. The findings support several suggestions that may improve the rehabilitation process and enhance rehabilitation outcomes: (a) provide clear pathways to the medical team, (b) recognize the identity loss, (c) involve the injured athletes with the rest of the teammates and (d) educate athletes about how to interpret pain signals. Future research should explore and evaluate the effectiveness and generalization of such interventions.     

Oxygen uptake during mini trampoline exercise in normal-weight,endurance-trained adults and in overweight-obese,inactive adults: A proof-of-concept study

Objectives: To examine cardiorespiratory exertion during mini trampoline exercises of different intensities in both endurance-trained athletes and overweight-obese adults. Methods: Physically healthy participants (Group A: normal-weight, endurance-trained athletes; Group B: inactive, overweight-obese adults) participated in two measurement appointments and three training sessions in between appointments, in which participants familiarized themselves with the use of the mini trampoline and the execution of the exercises. The primary outcome was the ?O_2peak for each of the six mini trampoline exercises relative to the ?O_2peak as established during an all-out exercise test on a bike ergometer during the first measurement appointment. Secondary outcomes were average ?O₂ as well as maximum and average heart rate. Results: The six mini trampoline exercises generated ?O_2peak values between 42% and 81% in the endurance-trained athletes and between 58% and 87% in the overweight-obese participants, both in relation to the bike ergometer ?O_2peak. Average ?O₂ values ranged from 35% to 69% (endurance-trained athletes) and from 48% to 71% (overweight-obese participants), depending on exercise. Average heart rate likewise lay in a range that can be categorized as moderate-to-vigorous aerobic exercise for both groups. A moderate-to-strong correlation (0.658 to 0.875, depending on exercise) between bike ergometer ?O_2peak and mini trampoline ?O_2peak was found for all six exercises. Conclusions: Mini trampoline exercise has the potential to produce training intensities that concur with established exercise guidelines. The exercise intensity is self-adjusting and allows for an effective and safe workout for different users with a wide range of fitness levels.     

Confounding compression: the effects of posture,sizing and garment type on measured interface pressure in sports compression clothing

The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.     

Image recovery from negative media coverage of a sport event: Destination,venue, and event considerations

The successful hosting of test events in the lead-up to a major event is not only a useful logistical tool and systems evaluation, but also signals to the world that the host city is ready and competent to host the main event. With the intense scrutiny of the media on all aspects of the venue, the city, and the competition, test events offer the potential for a city to establish (or enhance) its reputation as an event host, or to create doubt in its ability to host major events. The case follows the media coverage of the 2014 Pan Pacific Swimming Championships held on the Gold Coast Queensland, Australia, which served as a test event for the newly renovated Gold Coast Aquatics Centre in the lead-up to the 2018 Commonwealth Games. The case considers the implications and impacts of negative media coverage of an international event on the destination image of the host city. The case highlights the need for image recovery strategies for stakeholders within the destination who are concerned with the city's ability to host international sport events.     

Biological maturity status,body size,and exercise behaviour in British youth: A pilot study

In this study we examined the performance during, and the physiological and metabolic responses to, prolonged, intermittent, high-intensity shuttle running in hot (～30 C, dry bulb temperature) and moderate (～20 C) environmental conditions. Twelve male students, whose mean (s x ) age, body mass and maximal oxygen uptake (V O 2m ax ) were 22 ± 1 years, 69.8 ± 01.8 kg and 56.9 ± 1.1 ml . kg ?1 . min ?1 respectively, performed intermittent high- and low-speed running involving five sets of ～15 min of repeated cycles of walking and variable speed running followed by 60 s run/rest exercise until fatigue. The total distance completed in the hot and moderate trials was 8842 3790 m and 11,280 214 m respectively (P < 0.01). This decrement in performance occurred even though no differences existed in the level of dehydration, rating of perceived exertion, blood glucose and lactate, plasma free fatty acid and ammonia concentrations between the two trials. However, water consumption was almost twice as great in the hot trial (hot vs moderate: 1.18 ± 0.12 vs 0.63 ± 0.07 l . h ?1 , P < 0.01). Rectal temperature (hot vs moderate: 39.4 ± 0.1 vs 38.0 ± 0.1 C, P < 0.01) and heart rate (hot vs moderate: 186 ± 2 vs 179 ± 2 beats . min ?1 , P < 0.05) were higher at the end of the hot condition than at the same point in time in the moderate condition. The correlation between the rate of rise in rectal temperature and the distance completed during the hot condition was -0.94 (P < 0.01); for the moderate condition it was -0.65 (P <0.05). The reduced performance in the hot condition was associated with high body temperature; the precise mechanisms by which the performance decrement was brought about are, however, unclear.     

Energy,macronutrient and water intake during a mountain ultramarathon event: The influence of distance

Adequate dietary strategies are essential for the successful participation in ultra-endurance races. The aim of this study was to evaluate and compare the energy and water intakes of participants during three different mountain ultra-endurance runs. The study took place at the “Ultra Mallorca Serra de Tramuntana” (Mallorca, Spain), an ultra-endurance mountain event with runners participating either in a 44-km (Marathon, n = 51), a 67-km (Trail, n = 109) or a 112-km (Ultra, n = 53) run competition. Participants in the study answered a questionnaire focused on the nutritional intake within an hour after finishing the competition. Mean energy intake during the competitions was 183 kcal · h^¯1, with an average carbohydrate intake of 31 g · h^¯1 (52.1% of participants consumed less than 30 g · h^¯1). No significant differences between competitions were found in these parameters. However, a higher percentage of energy from lipids in participants in the Trail and the Ultra was found (P = 0.034). Furthermore, significant differences were observed in water intake per hour of competition (P = 0.039), with the lowest value for the intake during the Ultra competition. In conclusion, the majority of the participants in the study present low carbohydrate intakes. However, fluid intake seems to be adequate. Different distances did not significantly influence the participants’ nutritional strategies.     

Effect of novel recovery garments utilising nanodiamond- and nanoplatinum-coated materials (DPV576-C) on physical and psychological stress in baseball players: A randomised,placebo-controlled trial

Abstract

Based on research suggesting that nanomaterial containing nanodiamond- and nanoplatinum-coated fibres (DPV576-C) may reduce the stress response, garments to enhance athletes’ recovery from training-induced stress have been manufactured. This study examined the effects of wearing recovery garments on the physical and psychological stress of Japanese male baseball players. Thirty-eight players aged 18–21 (19.6?±?0.2 years) who participated in a two-week intensified training programme were randomly assigned to two groups: 19 wore recovery (DPV576-C) garments (RG group) and 19 wore non-recovery garments (placebo group). Both groups wore the garments overnight. Mood states, using the Profile of Mood States questionnaire, and salivary cortisol levels were measured before (day 0) and after (day 14) the training period. Saliva samples were collected from 07:00–07:30 am. Both groups’ fatigue scores significantly increased after the training period (RG: 8.4?±?0.8–10.1?±?0.8 score; placebo: 9.8?±?1.0–11.7?±?1.0 score). The total mood disturbance (TMD) score increased significantly in the placebo group (21.0?±?2.3–27.2?±?3.0 score) but not in the RG group (17.4?±?2.7–20.2?±?2.2 score). Salivary cortisol concentrations decreased significantly in the RG group (0.71?±?0.08–0.49?±?0.05?μg/dL) but not in the placebo group (0.61?±?0.06–0.58?±?0.10?μg/dL). Therefore, wearing the DPV576-C garments overnight attenuated increases in TMD levels and decreased salivary cortisol levels following intensified training. DPV576-C garments may have beneficial effects on training-induced physical and psychological stress among athletes.     

Consistency of kinematic and kinetic patterns during a prolonged spell of cricket fast bowling: an exploratory laboratory study

Due to the high incidence of lumbar spine injury in fast bowlers, international cricket organisations advocate limits on workload for bowlers under 19 years of age in training/matches. The purpose of this study was to determine whether significant changes in either fast bowling technique or movement variability could be detected throughout a 10-over bowling spell that exceeded the recommended limit. Twenty-five junior male fast bowlers bowled at competition pace while three-dimensional kinematic and kinetic data were collected for the leading leg, trunk and bowling arm. Separate analyses for the mean and within-participant standard deviation of each variable were performed using repeated measures factorial analyses of variance and computation of effect sizes. No substantial changes were observed in mean values or variability of any kinematic, kinetic or performance variables, which instead revealed a high degree of consistency in kinematic and kinetic patterns. Therefore, the suggestion that exceeding the workload limit per spell causes technique- and loading-related changes associated with lumbar injury risk is not valid and cannot be used to justify the restriction of bowling workload. For injury prevention, the focus instead should be on the long-term effect of repeated spells and on the fast bowling technique itself.     

Load,stress, and recovery in adolescent rugby union players during a competitive season

Abstract

Despite increased professionalization of adolescent sport and improved articulation to elite adult participation, the impact of sports such as rugby union among adolescents is under-explored. This study describes psychological stress–recovery responses relative to training loads in 106 male adolescent rugby union players. The results showed that players with the highest training and physical activity volumes during the season demonstrated more favourable recovery–stress states than moderate- and low-volume groups. Stress and under-recovery did not increase with increases in weekly volume when assessed across a season. When assessed more acutely during intensive competition phases, stress and under-recovery increased with increases in participation demands. Despite better psychological stress and recovery profiles of more elite, higher-load players, not all participants demonstrated favourable capacities to deal with stress and recovery processes. Seven participants were in at least two of three categories of highest volume, highest stress, and poorest recovery. Even in the absence of a full understanding of the impact of high-volume, high-stress, poor-recovery participation among adolescent athletes, these markers may be precursors for more deleterious outcomes such as injury, performance decrements, and overtraining. Findings support the efficacy of serially monitoring young athletes.     

Screen time and moderate-to-vigorous physical activity changes and displacement in adolescence: A prospective cohort study

Background: This paper determines longitudinal changes in the time Spanish adolescents devote to moderate-to-vigorous physical activity (MVPA) and screen media activity (SMA). Moreover, it examines the displacement hypothesis between time spent on SMA and MVPA.

Methods: A cohort of 755 adolescents participated in a prospective cohort study over a three-year period. Repeated measures ANOVA to highlight interaction effects among all variables and Structural Equation Modeling (SEM) techniques were employed.

Results: Age and gender-related variations in longitudinal changes in time spent on MVPA and SMA evolved in the inverse direction (decreased on MVPA/increased on SMA) according to the ANOVA. The potential displacement between time spent on SMA and MVPA from Wave I to Wave II was analysed via SEM. The first model, estimated in the overall sample, showed no evidence for the displacement hypothesis. Subsequently, a multigroup sequence of panel models was performed and a partial displacement was observed only in boys. Hence, boys who spent more time on SMA were more likely to devote less time to MVPA three years later.

Conclusion: This study confirms the opposite trend on the time spent on MVPA and SMA over a three-year period, being clearly higher in SMA. Further SEM analyses reveal a deferred displacement hypothesis between SMA and MVPA only in boys. This partial gendered displacement may be linked to the different uses adolescents make of screen media. The incursion of new technological devices (smartphones or tablets) and their wide range of possibilities for social networking or gaming could explain this displacement     

Correlates of health in adolescent elite athletes and adolescents: A cross-sectional study of 1016 adolescents

The primary aim of this cross-sectional study was to compare subjective correlates of health, such as nutrition, self-esteem, sleep and stress, between adolescent elite athletes (n?=?625) and a reference group of adolescents (n?=?391) not involved in elite sports. A secondary aim was to study predictors for self-perceived stress. A questionnaire was e-mailed to all participants containing valid questions about competence-based self-esteem, nutrition, self-perceived stress and sleep. Our results show that adolescent elite athletes reported significantly (p?p?相似文献