Concussions, cuts and cracked bones : A systematic literature review on protective headgear and head injury prevention in Olympic boxing

publishedVersio

The effects of acute dopamine reuptake inhibition on performance

Introduction: Acute bupropion (BUP; dopamine/noradrenaline reuptake inhibitor) administration significantly improved time trial performance and increased core temperature in the heat (30°C). Purpose: The present study was performed to examine the effect of a dopaminergic reuptake inhibitor on exercise capacity and thermoregulation during prolonged exercise in temperate and warm conditons. Methods: Eight healthy well-trained male cyclists participated in this study. Subjects ingested either a placebo (PLAC; lactose; 20mg) or Ritalin (RIT; methylphenidate (MPH); 20mg) one hour before the start of exercise in temperate (18°C) or warm (30°C) conditions and cycled for 60 min at 55% Wmax, immediately followed by a time trial (TT; pla18 and rit18; pla30 and rit30) to measure exercise performance. Results: Ritalin did not influence TT performance at 18oC (P=0.397). TT was completed 16% faster in rit30 (38.1±6.4min) than in pla30 (45.4±7.3min; p=0.049). Power output was higher in rit30, compared to pla30 (p<0.05). In the heat Tcore was significantly higher at rest (p=0.009), at the start of exercise and throughout rit30 (p<0.05). Throughout rit30 heart rates were significantly higher (p<0.05). Prolactin concentrations decreased after one hour cycling in 18°C (p=0,036) and at rest in 30°C (p=0,007) after RIT administration. Conclusions: These results show that RIT has a clear ergogenic effect that was not apparent in 18°C. The combination of a dopamine reuptake inhibitor and exercise in the heat clearly improved performance and appeared to increase metabolic heat production, suggesting an important role for dopamine in the fatigue process

Effects of Mental Fatigue on Endurance Performance in the Heat

PURPOSE: Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity and has been observed to decrease time-trial (TT) endurance performance by ~3,5% in normal ambient temperatures. Recently it has been suggested that heat may augment the negative effect of mental fatigue on cognitive performance, raising the question whether it may also amplify the effect of mental fatigue on TT-performance. METHODS: In 30 °C and 30% relative humidity, ten endurance-trained male athletes (Age: 22 ± 3 y; Wmax: 332 ± 41 W) completed two experimental conditions: intervention (I; 45-min Stroop task) and control (C; 45-min documentary). Pre and post intervention/control, cognitive performance was followed up with a 5-min Flanker task. Thereafter subjects cycled for 45 min at a fixed pace equal to 60%-Wmax, immediately followed by a self-paced TT in which they had to produce a fixed amount of work (equal to cycling 15 min at 80%-Wmax) as fast as possible. RESULTS: Self-reported mental fatigue was significantly higher after I compared to C (P<0.05). Moreover electroencephalographic measures also indicated the occurrence of mental fatigue during the Stroop (P<0.05). TT-time did not differ between conditions (I: 906 ± 30 s, C: 916 ± 29 s). Throughout exercise, physiological (heart rate, blood lactate, core and skin temperature) and perceptual measures (perception of effort and thermal sensation) were not affected by mental fatigue. CONCLUSION: No negative effects of mild mental fatigue were observed on performance and the physiological and perceptual responses to endurance exercise in the heat. Most plausibly mild mental fatigue does not reduce endurance performance when the brain is already stressed by a hot environment

Urinary proteomics combined with home blood pressure telemonitoring for health care reform trial: rational and protocol

Background: Hypertension and diabetes cause chronic kidney disease (CKD) and diastolic left ventricular dysfunction (DVD) as forerunners of disability and death. Home blood pressure telemonitoring (HTM) and urinary peptidomic profiling (UPP) are technologies enabling prevention. Methods: UPRIGHT-HTM (Urinary Proteomics Combined with Home Blood Pressure Telemonitoring for Health Care Reform [NCT04299529]) is an investigator-initiated 5-year clinical trial with patient-centred design, which will randomise 1148 patients to be recruited in Europe, sub-Saharan Africa and South America. During the whole study, HTM data will be collected and freely accessible for patients and caregivers. The UPP, measured at enrolment only, will be communicated early during follow-up to 50% of patients and their caregivers (intervention), but only at trial closure in 50% (control). The hypothesis is that early knowledge of the UPP risk profile will lead to more rigorous risk factor management and result in benefit. Eligible patients, aged 55-75 years old, are asymptomatic, but have ≥5 CKD- or DVD-related risk factors, preferably including hypertension, type-2 diabetes, or both. The primary endpoint is a composite of new-onset intermediate and hard cardiovascular and renal outcomes. Demonstrating that combining UPP with HTM is feasible in a multicultural context and defining the molecular signatures of early CKD and DVD are secondary endpoints. Expected outcomes: The expected outcome is that application of UPP on top of HTM will be superior to HTM alone in the prevention of CKD and DVD and associated complications and that UPP allows shifting emphasis from treating to preventing disease, thereby empowering patients

Hoe Gezond en veilig is fietsen op een fiets met trapondersteuning?

We zien steeds meer fietsen met trapondersteuning (ETO-fietsen) in het straatbeeld en dat is een goede zaak. ETO-fietsen geeft namelijk de mogelijkheid om te bewegen aan mensen die niet fit genoeg zijn om met een conventionele fiets te fietsen, de mogelijkheid om langere afstanden te overbruggen, meer gewicht te vervoeren, heuvelachtig gebied te overwinnen en onbezweet op een bestemming aan te komen. Met een toename in het gebruik zien we ook een toename in het maatschappelijke debat. Zo horen we maar al te vaak dat ETO-fietsen te gemakkelijk is en daarom geen effect heeft op de gezondheid. Verder lezen we ook wel eens dat het risico op ongevallen hoger is bij ETO-fietsen in vergelijking met conventionele fietsen. In dit artikel trachten we een antwoord te geven op de volgende twee vragen: 1. Is fietsen op een ETO-fiets wel gezond? En 2. Is fietsen op een ETO-fiets wel veilig? Onder ETO-fietsen verstaan we fietsen die een trapondersteuning bieden tot een snelheid van 45km/u. Voor het schrijven van dit artikel hebben we ons gebaseerd op de meest recente wetenschappelijk literatuur in binnen- en buitenland en in het bijzonder op een recente studie uitgevoerd in België en Nederland waarin onderzoek gedaan werd naar ongevallen met conventionele fietsen en fietsen met trapondersteuning in een populatie van mannen en vrouwen van 40 jaar en ouder

Dans quelle mesure l’utilisation d’un vélo à assistance électrique est-elle bonne pour la santé et sans danger ?

Nous voyons de plus en plus de vélos à assistance électrique (VAE ou cycle à pédalage assisté) dans les rues, et c’est une bonne chose. En effet, ils permettent aux personnes qui ne sont pas suffisamment en forme pour rouler sur un vélo classique de faire de l’exercice, de parcourir de plus longues distances, de porter un poids plus important, de sillonner des régions vallonnées et d’arriver à destination sans (trop) transpirer. L’utilisation croissante du VAE s’accompagne également d’une intensification du débat social. Ainsi, on entend trop souvent dire que le VAE est trop facile et qu’il n’a donc aucun effet sur la santé. Par ailleurs, on lit parfois que le risque d’accident est plus élevé avec des VAE qu’avec des vélos classiques. Dans cet article, nous tentons de répondre aux deux questions suivantes: l’utilisation d’un VAE est-elle bénéfique? Et l’utilisation d’un VAE est-elle sans danger? Les VAE désignent des vélos qui fournissent une assistance au pédalage jusqu’à une vitesse de 45km/h. Pour rédiger cet article, nous nous sommes appuyés sur la littérature scientifique la plus récente en Belgique et à l’étranger, et en particulier sur une étude récente menée en Belgique et aux Pays-Bas, portant sur les accidents impliquant des vélos classiques et des VAE au sein d’une population d’hommes et de femmes âgés de 40 ans et plus

Concussions, cuts and cracked bones : A systematic literature review on protective headgear and head injury prevention in Olympic boxing

publishedVersio

No effect of caffeine on exercise performance in high ambient temperature

Caffeine, an adenosine receptor antagonist, has shown to improve performance in normal ambient temperature, presumably via an effect on dopaminergic neurotransmission through the antagonism of adenosine receptors. However, there is very limited evidence from studies that administered caffeine and examined its effects on exercise in the heat. Therefore, we wanted to study the effects of caffeine on performance and thermoregulation in high ambient temperature. Eight healthy trained male cyclists completed two experimental trials (in 30°C) in a double-blind-randomized crossover design. Subjects ingested either placebo (6 mg/kg) or caffeine (6 mg/kg) 1 h prior to exercise. Subjects cycled for 60 min at 55% W (max), immediately followed by a time trial to measure performance. The significance level was set at p < 0.05. Caffeine did not change performance (p = 0.462). Rectal temperature was significantly elevated after caffeine administration (p < 0.036). Caffeine significantly increased B-endorphin plasma concentrations at the end of the time trial (p = 0.032). The present study showed no ergogenic effect of caffeine when administered 1 h before exercise in 30°C. This confirms results from a previous study that examined the effects of caffeine administration on a short (15 min) time trial in 40°C. However, caffeine increased core temperature during exercise. Presumably, the rate of increase in core temperature may have counteracted the ergogenic effects of caffeine. However, other factors such as interindividual differences in response to caffeine and changes in neurotransmitter concentrations might also be responsible for the lack of performance improvement of caffeine in high ambient temperature