Bone Turnover Responses to Changed Physical Activity

The aim of the study was to compare bone turnover in male soccer players with controls and to follow bone turnover with changes in activity level. Serum-osteocalcin (OC), carboxy-terminal propeptide of type I collagen (PICP) and total alkaline phosphatases (tALP) were measured to assess bone formation. Bone resorption was detected by carboxyterminal cross-linked telopeptide of type I collagen (ICTP). Bone turnover of 12 male premier league soccer players (mean age 23 years, range, 17–34) exercising 12 hours/week (range, 8–15) were at the last day of the soccer season compared with 27 age- and gender-matched controls. Bone turnover was followed weekly during a 4-week resting period between two seasons, and a further 10 days following resumption of full training. Data are presented as mean ± SEM. Both OC (22 ± 12%) and ICTP (34 ± 17%) were higher in the players compared with the controls at the end of the season (both P < 0.05, respectively). After 2 weeks of reduced physical activity among the athletes, the PICP levels were 21 ± 4% (P < 0.05) lower and the ICTP levels 8 ± 12% higher (P = 0.07) compared with baseline. OC, PICP, and tALP was then no different compared with controls and ICTP was higher than controls (P < 0.001). Ten days within the new season, there was a 23 ± 5% increase in PICP (P < 0.001) and a 4 ± 4% decrease in ICTP (P < 0.05) compared with the end of the resting period. In summary, male soccer players have higher bone turnover compared with age- and gender-matched controls. Changes in physical activity level were associated with changes in bone formation and resorption as evaluated by bone markers within weeks, and after 2 weeks rest, ICTP was higher in the athletes than the controls. We conclude that the higher age-related diminution in BMD, previously reported in former soccer players compared with age- and gender-matched controls, may be the result of increased bone resorption, evaluated by ICTP, compared with the controls.     

Development of supine and standing knee joint position sense tests

ObjectivesWe aimed to assess the test-retest reliability of a supine and standing knee joint position sense (JPS) test, respectively, and whether they discriminate knees with anterior cruciate ligament (ACL) injury from asymptomatic knees.DesignRepeated measures and cross-sectional.SettingResearch laboratory.ParticipantsFor test-retest reliability, 24 persons with asymptomatic knees. For discriminative analysis: 1) ACLR - 18 persons on average 23 months after unilateral ACL reconstruction, 2) CTRL - 23 less-active persons, and 3) ATHL - 21 activity level-matched athletes.Main outcome measuresAbsolute error (AE) and variable error (VE).ResultsTest-retest reliability was generally highest for AE of the standing test (ICC 0.64–0.91). Errors were less for the standing compared to the supine test across groups. CTRL had greater knee JPS AE (P = 0.005) and VE (P = 0.040) than ACLR. ACLR knees showed greater VE compared to the contralateral non-injured knees for both tests (P = 0.032), albeit with a small effect size (η_p² = 0.244). Conclusions: Our standing test was more reliable and elicited lesser errors than our supine test. Less-active controls, rather than ACLR, produced significantly greater errors. Activity level may be a more predominant factor than ACLR for knee JPS ∼2 years post-reconstruction.     

The effects of repetitive head impacts on postural control: A systematic review

ObjectivesThe purpose of our study was to investigate the association between repetitive head impact (RHI) exposure and postural control.DesignSystematic review.MethodsPubMed, Embase and PsycInfo were searched using a self-developed search term including the keywords balance OR postural control AND repetitive OR sub-concussive head impacts. Twenty-one studies excluding non-peer reviewed studies, secondary studies, cross-sectional studies, animal studies, and studies investigating concussion were included for further analyses. We rated Level of Evidence and quality using the Centre for Evidence-Based Medicine tool, the Quality Assessment for the Systematic Review of Effectiveness, and the Sub-concussion Specific Tool.ResultsAll included studies were grouped into Category I and II studies. Category I included trials investigating the effects of controlled soccer heading on postural control (n = 8) and Category II studies were cohort studies investigating on-the-field changes between preseason and postseason assessments on postural control measures (n = 13). Findings were heterogeneous, with a tendency towards no effects of RHI on clinical postural control measures. Most laboratory studies in Category I used instrumented assessments whereas on-the-field studies in Category II used both instrumented and non-instrumented assessments.ConclusionsDue to heterogeneous findings, future studies aiming to investigate the effects of RHI on different athlete populations are needed on other participant cohorts. Furthermore, the combination of objective clinical balance measures may be a promising approach to accurately measure how, and to what degree, postural control may be affected by RHI.     

Is the consumption of beverages and food associated to dental erosion? A cross-sectional study in Portuguese athletes

ObjectivesThis cross-sectional study aimed to investigate if the consumption of acidic food and beverages, including energy drinks is associated with dental erosion in athletes.MethodsA questionnaire was applied in 110 athletes (swimmers, bodybuilders, football players, boxers, volleyball players and runners) to collect training and sport practice data, medical history and oral hygiene habits. A semi-quantitative food frequency questionnaire was used for acidic beverages and food consumption. The Basic erosive wear examination index was used to evaluate the presence of dental erosion lesions. Participants were organized into 4 groups: swimmers who consumed or did not consume energy drinks, and athletes (except swimmers) who consumed or did not consume energy drinks.ResultsThe prevalence of dental erosion was 83.6%. Of the 110 participants, 49.1% had low risk of erosion, 6.4% had an average risk of erosion, and 0.9% presented high risk of erosion. According to the multivariate logistic analysis, red wine (OR = 1.6; P = 0.038), citrus fruit (OR = 1.3; P = 0.037), frequency of tooth brushing (OR = 2.3; P = 0.018), energy drinks consumption in swimmers (OR = 15.2; P < 0.001), and energy drinks consumption in athletes (OR = 6.3; P = 0.003) were significant risk factors of dental erosion, whereas spicy food was a protective factor (OR = 0.64; P = 0.024).ConclusionsThe consumption of energy drinks by swimmers more than doubles the chance of dental erosion (BEWE score of “at least low risk”) when compared with non-swimmer athletes consuming the same energy drinks. Athletes consuming energy drinks should be clinical and regularly supervised, especially for dental erosion.     

Sports career-related concussion and mental health symptoms in former elite athletes

BackgroundIn elite sports, concussion is common and recurrent, especially in high-speed contact or collision sports such as american and australian football, ice hockey and rugby. Mental health symptoms (e.g., anxiety, depression, sleep disturbance) are often reported by former elite athletes, with prevalence ranging from 16% for distress to 26% for anxiety/depression. This article focuses on the potential relationship between sports career-related concussion and mental health symptoms in former elite athletes.MethodA narrative mini-review was based on the scientific literature.ResultsSome literature based on cross-sectional data suggests that sports career-related concussion might lead in the long term to mental health symptoms in former elite athletes. Retired professional American football players reporting three or more previous concussions were found to be three times more likely to be diagnosed with depression than those with no history of concussion. Former professional athletes from football, ice hockey and rugby who reported a history of six or more concussions were approximately up to five times more likely to report mental health symptoms.ConclusionsWhile longitudinal evidence about any causal relationship is lacking, the suggested relationship between sports career-related concussion and mental health symptoms in former elite athletes warrants the development of support measures for elite athletes transitioning out of sport, especially for those with a history of concussion.     

Incidence of Achilles tendinopathy and associated risk factors in recreational runners: A large prospective cohort study

ObjectivesTo determine the incidence of Achilles tendinopathy in a large group of recreational runners and to determine risk factors for developing AT.DesignObservational cohort study.MethodsRunners registering for running events (5–42 km) in the Netherlands were eligible for inclusion. Main inclusion criteria were: age ≥18 years, and registration ≥2 months before the running event. The digital baseline questionnaire obtained at registration consisted of demographics, training characteristics, previous participation in events, lifestyle and previous running-related injuries. All participants received 3 follow-up questionnaires up to 1 month after the running event with self-reported AT as primary outcome measure. To study the relationship between baseline variables and AT onset, multivariable logistic regression analyses were performed.ResultsIn total, 2378 runners were included, of which 1929 completed ≥1 follow-up questionnaire, and 100 (5.2%, 95%CI [4.2;6.2]) developed AT. Runners registered for a marathon (7.4%) had the highest incidence of AT. Risk factors for developing AT were use of a training schedule (odds ratio (OR) = 1.8 (95%Confidence Interval(CI)[1.1;3.0])), use of sport compression socks ((OR = 1.7, 95%CI[1.0;2.8]) and AT in the previous 12 months (OR = 6.3, 95%CI[3.9;10.0]). None of the demographic, lifestyle or training-related factors were associated with the onset of AT.ConclusionOne in twenty recreational runners develop AT. AT in the preceding 12 months is the strongest risk factor for having AT symptoms. Using a training schedule or sport compression socks increases the risk of developing AT and this should be discouraged in a comparable running population.Trial registration numberThe Netherlands Trial Register (ID number: NL5843).     

The impact of physiological fatigue and gaze behavior on shooting performance in expert biathletes

ObjectivesBiathlon is a discipline that combines cross country skiing with rifle shooting. It demands high shooting accuracy and fast shooting times under increasing levels of physiological fatigue. Building on Vickers and Williams (2007), the current study aimed at scrutinizing the impact of physiological fatigue and gaze behavior on shooting performance in elite and sub-elite biathletes.DesignTen members of the German national senior team (elite) and 13 members of the German national junior team (sub-elite) participated in a performance test. They conducted a roller skiing test on a treadmill including four increasing intensity levels followed by shooting blocks of five shots in both prone and standing position.MethodsPhysiological measurements consisted of heart rate and blood lactate, shooting performance data included shooting accuracy and time. Eye movements were assessed, i.e. the duration of the final fixation, using a gun-mounted eye tracking system.ResultsPhysiological fatigue systematically increased across intensity levels. There were no differences between elite and sub-elite biathletes in percentage shooting accuracy. However, elites needed shorter shooting times than sub-elites. Both groups showed increased range times with increased workload levels in prone and standing positions. Yet, there was no effect on shooting accuracy. Finally, analyses of a subset of data did not show any effect of final fixation duration on shooting accuracy.ConclusionsPhysiological fatigue seems to have no impact on shooting accuracy, but rather affects shooting times in expert biathletes. Furthermore, the duration of the final fixation does not seem to moderate shooting accuracy in elite biathletes.     

Le questionnaire de surentraînement de la Société française de médecine du sport : reproductibilité à court termeOvertraining questionnaire of the Société française de médecine du sport (French Society of Sport Medicine): short term reproducibility

Purpose. – To assess the short-term stability, over time, of a slightly modified version of the overtraining questionnaire proposed by the SFMS.Methods. – Three or 7-day test–retest of the questionnaire was completed in 30 high level athletes. In a first stage analysis, the score obtained during the first test was compared to and correlated with that obtained during the second one. Then, in a second stage analysis, the individual reproducibility of each item was assessed using a similitude index: a value of 100% meant that all the athletes gave an identical response for the two trials.Results. – Scores were not different between the two tests and intra-class correlation coefficients were r = 0.82. Overall reproducibility of the similitude index was quite good even if six items of 52 displayed a lower similitude index (around 80%).Conclusion. – The short-term reproducibility of the overtraining questionnaire is quite good. This result reinforces its reliability and warrants its use in a longitudinal follow-up framework aimed to detect precociously an overtraining syndrome.