Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 1)

The present study aimed to compare the changes of direction on repeated sprint ability (RSA) vs. intensive repeated sprint ability (IRSA) protocols in basketball. Eighteen young male basketball players performed on RSA [10 × 30-m (15 + 15-m, one change of direction)] and IRSA [10 × 30-m (10 + 10 + 10-m, two changes of direction)]. A correlation matrix between RSA, IRSA, “squat jump (SJ)–countermovement jump (CMJ)”, footstep analysis and total distance in Yo-Yo intermittent recovery level 1 was performed. The best time, worst time, total time and the number of footsteps were significantly smaller in the RSA test compared to IRSA test (P < 0.001), even though they were significantly correlated with each other (r > 0.80, P < 0.05). Blood lactate level and fatigue index did not show any difference between tests. The sensibility of the two tests assessed by the Bland–Altman analysis revealed a small bias (<1.5%) for almost all variables. Moreover, almost all time variables of the two tests were significantly correlated with the SJ (r > 0.478, P < 0.05), CMJ (r > 0.515, P < 0.05) and Yo-Yo (r > 0.489, P < 0.05) performances. The IRSA provided a reliable method for assessing specific sprint ability (with 10-m legs for IRSA ~2.3 s vs. 15 m for RSA ~3 s) with a closer link to basketball game’s actions (~2 s). Besides, IRSA could be an appropriate choice for assessing both RSA and changes of direction capacities in basketball players.     

“Real life use” of troponin in the emergency department: a survey of over 3000 cases

Introduction

The aim of this study was to identify clinical variables which may be independently associated with positivity of a cardiac troponin I (cTnI) assay in a large population of patients admitted to the emergency department (ED).

Materials and methods

3166 subjects, with at least two troponin I tests ordered within 6 hours in the ED, were studied. Patient data were statistically analyzed to identify clinical associations with increased values of Troponin I.

Results

Although patients with diagnosis of acute coronary syndrome displayed troponin I values significantly higher than those of other groups, positivity to troponin I (> 40 ng/L) was also observed in patients with other clinical conditions. In multivariate analysis, age, elevated heart rate and electrocardiographyc changes were independently associated with troponin I positivity at admission. In the whole study population troponin I positivity exhibited high sensitivity and negative predictive value, counterbalanced by low specificity and limited positive predictive value.

Conclusions

Troponin I positivity should be combined with history and clinical evaluation and cautiously interpreted in the ED, especially in patients exhibiting factors associated with higher troponin I levels such as older age, elevated heart rate or ECG changes.Key words: troponin I, acute coronary syndrome, emergency service, hospital, chest pain     

Can we estimate a monetary value of scientific publications?

In this paper, we analyze the compelling issue of monetary valuation of a scientific publication. While many academic scholars tend to overlook the topic, as being either too difficult or even meaningless, policymakers begin to use very rough tools for evaluating publications, which have many limitations, as we will discuss in this work. The main objective of this work is to address this open problem by stimulating further discussion on the topic and future research developments. We provide an overview of different methods to value scientific publications. We discuss their main hypotheses, pros and cons by means of an illustration based on Sapienza University of Rome. Although we begin to address the issue of monetary valuation of scientific publications, presenting a range of available methods and listing the limits and benefits of each, further methodological and empirical research is still needed to comply with policy and stakeholders' needs which we expect will increase in the near future.     

Defining laboratory medicine: a circle cannot be squared

At the down of the third millennium, it is rather misleading to consider the “whole population” as a conceptual entity, whereby the population is actually composed by single individuals, who differ broadly in terms of age, sex, ethnic origin, occupation, health, wellbeing, lifestyle and risk factors. While reaffirming strongly that laboratory medicine shall aim to provide data that could be translated into actionable information on “BOTH” an individual and universal level, we confute and refuse the naive and too simplistic approach that the common beneficence shall always be prioritized over the individual good, since the common good is just the sum of many individual beneficences.     

The effect of induced alkalosis and submaximal cycling on neuromuscular response during sustained isometric contraction

Abstract

The aim of this study was to determine if inducing metabolic alkalosis would alter neuromuscular control after 50 min of standardized submaximal cycling. Eight trained male cyclists (mean age 32 years, s = 7; [Vdot]O_2max 62 ml · kg^?1 · min^?1, s = 8) ingested capsules containing either CaCO₃ (placebo) or NaHCO₃ (0.3 g · kg^?1 body mass) in eight doses over 2 h on two separate occasions, commencing 3 h before exercise. Participants performed three maximal isometric voluntary contractions (MVC) of the knee extensors while determining the central activation ratio by superimposing electrical stimulation both pre-ingestion and post-exercise, followed by a 50-s sustained maximal contraction in which force, EMG amplitude, and muscle fibre conduction velocity were assessed. Plasma pH, blood base excess, and plasma HCO₃ were higher (P < 0.01) during the NaHCO₃ trial. After cycling, muscle fibre conduction velocity was higher (P < 0.05) during the 50-s sustained maximal contraction with NaHCO₃ than with placebo (5.1 m · s^?1, s = 0.4 vs. 4.2 m · s^?1, s = 0.4) while the EMG amplitude remained the same. Force decline rate was less (P < 0.05) during alkalosis-sustained maximal contraction and no differences were shown in central activation ratio. These data indicate that induced metabolic alkalosis can increase muscle fibre conduction velocity following prolonged submaximal cycling.     

Quantification of energy expenditure of recreational football

ABSTRACT

There is a strong relationship between low physical activity level and cardiovascular diseases (CVD). The popularity of football may be used to promote physical activity and previous evidence has shown it is effective to decrease the risk of CVD. However, the energy expenditure (EE) of recreational football is not well known but it is crucial to develop preventive health programmes.

Fifteen sedentary middle-aged male participants were involved (mean ± SDs; age 43.9 ± 3.1 years, weight 83.0 ± 13.6 kg, height 174.9 ± 6.8 cm). EE was estimated from the heart rate (HR)-VO₂ relation during 1-h 5-a-side matches (futsal). Participants covered 3412 ± 381 m in 52 ± 2 min, at an average HR of 85 ± 2% of maximum HR. Estimated EE during a recreational futsal match was 634 ± 92 kcal. One futsal recreational match corresponds to about 50% of American College of Sport Medicine recommended physical activity quantity per week. Based on this estimation: once, twice and 3 sessions per week are equivalent to 50% (634 kcal), 100% (1268 kcal) and 150% (1902 kcal), respectively, of EE suggested in international guidelines. This EE estimation may have important implications for designing recreational football training protocols in health programmes and dose response studies.