Effects of basic training in the British Army on regular and reserve army personnel

The aim of this study was to compare changes in aerobic fitness and body composition in response to British Army (regular) and Territorial Army (reserve) basic training. Eleven regular recruits, 14 reserve recruits, and 20 controls completed the study (all males). Initially, reserve recruits were significantly older and heavier and had greater fat-free mass (FFM; 64.6 vs. 59.3 kg) and lower maximal oxygen uptake (VO2max; 39.1 vs. 43.9 ml·kg21·min21) than regular recruits. Both regular and reserve training significantly increased FFM and VO2max and decreased percentage body fat. Regular training produced a greater increase in VO2max than reserve training (13.1 vs. 7.6%, p , 0.0005). Reserve training produced a greater increase in body mass (2.2 vs. 0.9 kg, p 5 0.019) and tended to produce a greater increase in FFM (2.6 vs. 1.6 kg, p 5 0.062). Although both training programs improve aerobic fitness and body composition, increasing the volume of physical training in the reserve training program would probably enhance the training adaptations achieved

An investigation into the validity of percentage body fat estimations by a commercially available bioelectrical impedance analyser

The present investigation examined the validity of bioelectrical impedance analysis (BIA) and selected skinfolds (Sum 4) when estimating percent body fat (% fat) in young, physically active adults (MEAN ± SEM = 18.3 ± 1.2 % fat) by comparing the estimates with values obtained from densitometry (D). Thirty-five Caucasian volunteers (21 males, 14 females; MEAN ± SEM = 22.9 ± 0.4 yr) served as subjects. The statistical analysis involved calculation of the bias and 95% limits of agreement. The results indicated that the Bodystat 1500 BIA system agreed better with D (bias and 95% limits = 0.7 ± 7.4 % fat) than Sum 4 (bias and 95% limits = 2.2 ± 8.5 % fat). However, the error observed for both predictive methods was too large to recommend use in assessing % fat in a young, physically active population, unless only a general estimation of % fat is required for work such as epidemiological studies.Chester College of Higher Education & CEWTEC

Specificity of acceleration, maximum speed and agility in professional soccer players

High-speed actions are known to impact soccer performance and can be categorized into actions requiring maximal speed, acceleration, or agility. Contradictory findings have been reported as to the extent of the relationship between the different speed components. This study comprised 106 professional soccer players who were assessed for 10-m sprint (acceleration), flying 20-m sprint (maximum speed), and zigzag agility performance. Although performances in the three tests were all significantly correlated (p , 0.0005), coefficients of determination (r2) between the tests were just 39, 12, and 21% for acceleration and maximum speed, acceleration and agility, and maximum speed and agility, respectively. Based on the low coefficients of determination, it was concluded that acceleration, maximum speed, and agility are specific qualities and relatively unrelated to one another. The findings suggest that specific testing and training procedures for each speed component should be utilized when working with elite players

Suitability of soccer training drills for endurance training

Recent evidence suggests that certain soccer drills produce exercise intensities suitable for physical conditioning. However, it remains debatable whether soccer drills can provide a sufficiently unified exercise intensity among different players and on repetition of a drill, because movement patterns cannot be externally controlled during soccer drills. Good reliability and low variability of exercise intensity would enable all players to receive an appropriate training stimulus. The purpose of this study was to investigate intersubject variability and intrasubject reliability in exercise intensity during soccer drills. It was hypothesized that soccer drills that involve the highest exercise intensities would demonstrate the lowest intersubject variability and the highest intrasubject reliability. Heart rates of 23 professional soccer players were recorded during a range of soccer training drills. The drills consisted of 2 vs. 2 to 8 vs. 8 normal scoring games and 2 further possession games. Heart rate responses were examined for variability, reliability, and suitability for soccer endurance training. Coeffi- cients of variation across players were less than 3% for all drills. Paired t-tests showed no significant differences in heart rate on repetition of the drills and 95% ratio limits of agreement were 1.8-3.8%. There were no significant correlations between exercise intensity and the statistical measures of variability and reliability. Several drills produced exercise intensities suitable for soccer endurance training with mean heart rate responses ranging from 87-91% HRmax. Soccer drills such as those used in the present study appear to be an adequate substitute for physical training without the ball and thus provide simultaneous skill and fitness training. The increase in training time spent developing technical ability and/or a reduction in total training time required may be useful for soccer teams

Effects of differential stretching protocols during warm-ups on high speed motor capacities in professional soccer players

The purpose of this study was to examine the effects of different modes of stretching within a pre-exercise warm-up on high-speed motor capacities important to soccer performance. Eighteen professional soccer players were tested for countermovement vertical jump, stationary 10-m sprint, flying 20-m sprint, and agility performance after different warm-ups consisting of static stretching, dynamic stretching, or no stretching. There was no significant difference among warm-ups for the vertical jump: mean 6 SD data were 40.4 6 4.9 cm (no stretch), 39.4 6 4.5 cm (static), and 40.2 6 4.5 cm (dynamic). The dynamic- stretch protocol produced significantly faster 10-m sprint times than did the no-stretch protocol: 1.83 6 0.08 seconds (no stretch), 1.85 6 0.08 seconds (static), and 1.87 6 0.09 seconds (dynamic). The dynamic- and static-stretch protocols produced significantly faster flying 20-m sprint times than did the nostretch protocol: 2.41 6 0.13 seconds (no stretch), 2.37 6 0.12 seconds (static), and 2.37 6 0.13 seconds (dynamic). The dynamic- stretch protocol produced significantly faster agility performance than did both the no-stretch protocol and the staticstretch protocol: 5.20 6 0.16 seconds (no stretch), 5.22 6 0.18 seconds (static), and 5.14 6 0.17 seconds (dynamic). Static stretching does not appear to be detrimental to high-speed performance when included in a warm-up for professional soccer players. However, dynamic stretching during the warm-up was most effective as preparation for subsequent high-speed performance

Genetic testing in exercise and sport - have direct-to-consumer genetic tests come of age?

The general consensus amongst sport and exercise genetics researchers is that genetic tests based on current knowledge have little or no role to play in talent identifi cation or the individualised prescription of training to maximise performance or minimise injury risk. Despite this, genetic tests related to sport and exercise are widely available on a commercial basis. This study assessed commercially-available genetic tests related to sport and exercise currently marketed via the internet. Twenty-two companies were identified as providing direct-to-consumer (DTC) genetic tests marketed in relation to human sport or exercise performance or injury. The most commonly-tested variant was the R577X SNP in the ACTN3 gene, tested by 85% of the 13 companies that appear to present information about their genetic tests on websites - which corresponds with our assessment that ACTN3 R577X is currently the polymorphism with the strongest scientific evidence in support of an association with sport and exercise phenotypes. 54% of companies that present information about their genetic tests used panels of 2-21 variants, including several with very limited supporting scientific evidence. 46% of companies tested just a single variant, with very low ability to explain complex sport and exercise phenotypes. It is particularly disappointing that 41% of companies off ering DTC genetic tests related to exercise and sport did not appear to state publicly the genetic variants they assess, making scrutiny by academic scholars and consumers impossible. Companies off ering DTC genetic tests related to sport and exercise should ensure that they are responsible in their activities

Comparative quasi-static mechanical characterization of fresh and stored porcine trachea specimens

Abstract: Tissues of the upper airways of critically ill patients are particularly vulnerable to mechanical damage associated with the use of ventilators. Ventilation is known to disrupt the structural integrity of respiratory tissues and their function. This damage contributes to the vulnerability of these tissues to infection. We are currently developing tissue models of damage and infection to the upper airways. As part of our studies, we have compared how tissue storage conditions affect mechanical properties of excised respiratory tissues using a quasi-static platform. Data presented here show considerable differences in mechanical responses of stored specimens compared to freshly excised specimens. These data indicate that implementation of storage and maintenance procedures that minimize rapid degradation of tissue structure are essential for retaining the material properties in our tissue trauma models

Training diagnosis for a load carriage test

To explore the possibility of training diagnosis for a 3.2-km loaded march with a 25 kg load, 50 men trained for 10 weeks using either running, marching, and endurance- based circuit training (Circuits), or running, marching, and resistance training (Resistance). The march was performed before and after training, and other measurements related to loaded marching were conducted before training only. Each group was ranked by improvement in the loaded march, and divided into significantly different subgroups of 'good' and 'poor' responders (improvements of approximately 20% vs. 10%). For Circuits, there were significant differences between good and poor responders to training in the pretraining ratios of shuttle run: isometric lift strength (p 5 0.031) and shuttle run: isometric back extension strength (p 5 0.033). Stronger subjects with lower endurance responded better to Circuits. Resistance tended to show the opposite effect (p , 0.2). These are the first objective data on which to prescribe training for load carriage on an individual basis

Erratum to: Variants within the MMP3 gene and patellar tendon properties in vivo in an asymptomatic population (vol 114, pg 2625, 2014)

Erratum to: Eur J Appl Physiol (2014) 114:2625–2634 DOI 10.1007/s00421-014-2986-7 Unfortunately, one of the affiliations of the co-author, Alun G. Williams, has been missed in the original publication of the article. The correct information is as follows: Alun G. Williams Institute for Performance Research, Manchester Metropolitan University, Crewe CW1 5DU, U

Human COL5A1 rs12722 gene polymorphism and tendon properties in vivo in an asymptomatic population

Purpose Gene variants encoding for proteins involved in homeostatic processes within tendons may influence its material and mechanical properties in humans. The purpose of this study was to examine the association between one such gene variant, gene encoding collagen type V alpha 1 chain (COL5A1) rs12722, and patellar tendon dimensions and mechanical properties in vivo. Methods Eighty-four recreationally active, Caucasian, men and women, aged 18–39, with no history of injuries to the knee and a body mass index between 18.5 and 30 were recruited. Women were not recruited if they were pregnant or using any form of hormone-based contraception. The COL5A1 rs12722 genotype was determined using real-time polymerase chain reaction. Patellar tendon dimensions (volume) and functional (elastic modulus) properties were assessed in vivo using geometric modelling, isokinetic dynamometry, electromyography and ultrasonography. Results After adjustments for non-genetic factors, no significant associations were evident between the COL5A1 rs12722 gene variant and either patellar tendon volume (P = 0.933) or elastic modulus (P = 0.206), nor with a calculated Z score that combined these dimensional and functional properties into a composite value (P = 0.647). Similarly, no association was evident when comparing individuals with/without the rare C allele (volume, P = 0.883; elastic modulus, P = 0.129; Z score, P = 0.631). Conclusions Tendon properties do not seem to be influenced by the COL5A1 rs12722 gene variant. Although the COL5A1 rs12722 polymorphism has previously been associated with the risk of tendon pathology, that association is unlikely to be mediated via underlying tendon dimensional and functional properties