Ray Lloyd

Contemporary training practices in elite British powerlifters: survey results from an international competition.

Swinton, PA, Lloyd, R, Agouris, I, and Stewart, A. Contemporary training practices in elite British powerlifters: survey results from an international competition. J Strength Cond Res 23(2): 380-384, 2009-The primary objective of this study was to investigate current powerlifting training methods in light of anecdotal evidence purporting increased similarity with the explosive training practices of weightlifters. The study also assessed the prevalence of contemporary training practices frequently recommended for powerlifters in the popular literature. A 20-item survey was distributed to 32 elite British powerlifters at an International competition. The subject group included multiple national, international, and commonwealth champions and record holders. Based on 2007 competition results, the average Wilks score of the group was 450.26 ± 34.7. The response rate for the surveys was 88% (28 of 32). The survey was sectioned into 6 areas of inquiry: a) repetition speed, b) explosive training load, c) resistance materials used, d) adjunct power training methods, e) exercise selection, and f) training organization. The results demonstrate that the majority of powerlifters train with the intention to explosively lift maximal and submaximal loads (79 and 82%, respectively). Results revealed that 39% of the lifters regularly used elastic bands and that 57% incorporated chains in their training. Evidence for convergence of training practices between powerlifters and weightlifters was found when 69% of the subjects reported using the Olympic lifts or their derivatives as part of their powerlifting training. Collectively, the results demonstrate that previous notions of how powerlifters train are outdated. Contemporary powerlifters incorporate a variety of training practices that are focused on developing both explosive and maximal strength.

A biomechanical comparison of the traditional squat, powerlifting squat, and box squat

Abstract Swinton, PA, Lloyd, R, Keogh, JWL, Agouris, I, and Stewart, AD. A biomechanical comparison of the traditional squat, powerlifting squat, and box squat. J Strength Cond Res 26(7): 1805–1816, 2012. The purpose of this study was to compare the biomechanics of the traditional squat with 2 popular exercise variations commonly referred to as the powerlifting squat and box squat. Twelve male powerlifters performed the exercises with 30, 50, and 70% of their measured 1 repetition maximum (1RM), with instruction to lift the loads as fast as possible. Inverse dynamics and spatial tracking of the external resistance were used to quantify biomechanical variables. A range of significant kinematic and kinetic differences (p < 0.05) emerged between the exercises. The traditional squat was performed with a narrow stance, whereas the powerlifting squat and box squat were performed with similar wide stances (48.3 ± 3.8, 89.6 ± 4.9, 92.1 ± 5.1 cm, respectively). During the eccentric phase of the traditional squat, the knee traveled past the toes resulting in anterior displacement of the system center of mass (COM). In contrast, during the powerlifting squat and box squat, a more vertical shin position was maintained, resulting in posterior displacements of the system COM. These differences in linear displacements had a significant effect (p < 0.05) on a number of peak joint moments, with the greatest effects measured at the spine and ankle. For both joints, the largest peak moment was produced during the traditional squat, followed by the powerlifting squat, then box squat. Significant differences (p < 0.05) were also noted at the hip joint where the largest moment in all 3 planes were produced during the powerlifting squat. Coaches and athletes should be aware of the biomechanical differences between the squatting variations and select according to the kinematic and kinetic profile that best match the training goals.

A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads.

Swinton, PA, Stewart, A, Agouris, I, Keogh, JWL, and Lloyd, R. A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads. J Strength Cond Res 25(7): 2000-2009, 2011—The purpose of the investigation was to compare the kinematics and kinetics of the deadlift performed with 2 distinct barbells across a range of submaximal loads. Nineteen male powerlifters performed the deadlift with a conventional straight barbell and a hexagonal barbell that allowed the lifter to stand within its frame. Subjects performed trials at maximum speed with loads of 10, 20, 30, 40, 50, 60, 70, and 80% of their predetermined 1-repetition maximum (1RM). Inverse dynamics and spatial tracking of the external resistance were used to quantify kinematic and kinetic variables. Subjects were able to lift a heavier 1RM load in the hexagonal barbell deadlift (HBD) than the straight barbell deadlift (SBD) (265 ± 41 kg vs. 245 ± 39 kg, p < 0.05). The design of the hexagonal barbell significantly altered the resistance moment at the joints analyzed (p < 0.05), resulting in lower peak moments at the lumbar spine, hip, and ankle (p < 0.05) and an increased peak moment at the knee (p < 0.05). Maximum peak power values of 4,388 ± 713 and 4,872 ± 636 W were obtained for the SBD and HBD, respectively (p < 0.05). Across the submaximal loads, significantly greater peak force, peak velocity and peak power values were produced during the HBD compared to during the SBD (p < 0.05). The results demonstrate that the choice of barbell used to perform the deadlift has a significant effect on a range of kinematic and kinetic variables. The enhanced mechanical stimulus obtained with the hexagonal barbell suggests that in general the HBD is a more effective exercise than the SBD.

High Intensity Training Improves Health and Physical Function in Middle Aged Adults

High intensity training (HIT) is effective at improving health; however, it is unknown whether HIT also improves physical function. This study aimed to determine whether HIT improves metabolic health and physical function in untrained middle aged individuals. Fourteen (three male and eleven female) untrained individuals were recruited (control group n = 6: age 42 ± 8 y, weight 64 ± 10 kg, BMI 24 ± 2 kg·m−2 or HIT group n = 8: age 43 ± 8 y, weight 80 ± 8 kg, BMI 29 ± 5 kg·m−2). Training was performed twice weekly, consisting of 10 × 6-second sprints with a one minute recovery between each sprint. Metabolic health (oral glucose tolerance test), aerobic capacity (incremental time to exhaustion on a cycle ergometer) and physical function (get up and go test, sit to stand test and loaded 50 m walk) were determined before and after training. Following eight weeks of HIT there was a significant improvement in aerobic capacity (8% increase in VO2 peak; p < 0.001), physical function (11%–27% respectively; p < 0.05) and a reduction in blood glucose area under the curve (6% reduction; p < 0.05). This study demonstrates for the first time the potential of HIT as a training intervention to improve skeletal muscle function and glucose clearance as we age.

Relationships between ball release velocity and kinematic variables in fast bowling in cricket

Soccer instep kick kinematics has been examined in the literature through 2D analysis and more recently 3D analysis (Levanon and Dapena, 1998: Medicine and Science in Sports and Exercise, 30, 917–927). The importance of ball approach prior to kick execution has been recognised in other sports such as rugby (Jackson and Baker, 2001: The Sport Psychologist, 15, 48–65). However, there is limited research on the relationship between ball approach, shot accuracy and kick kinematics in soccer. The objective of this case study was to establish the effect of altering the ball approach, on kick kinematics and shot accuracy, when performing instep penalty kicks.Annual Conference of the British Association of Sport and Exercise Sciences Liverpool, 7th – 9th September 2004 PART I. BIOMECHANICS 20. Parameter determination for a torque-driven model of springboard diving takeoff P.W. Kong, M.R. Yeadon and M.A. King School of Sport and Exercise Sciences, Loughborough University, Ashby Road, Loughborough, LE11 3TU In order to develop a planar computer simulation model of a springboard and a 8-segment diver suitable for investigating diving takeoffs (Fig. 1), it is necessary to determine subject-specific model parameters. These include: 1) springboard, 2) segmental inertia, 3) strength, 4) wobbling mass, and 5) foot-springboard interface parameters. The aim of this study was to determine such parameters either directly from measurements or indirectly using an angle-driven model. Subject-specific parameters were determined from an elite female diver who provided informed consent. Testing procedures were approved by the University Ethical Advisory Committee. The vertical behaviour of the springboard was modelled as a linear mass-spring system with no damping and with stiffness as a linear function of foot placement. The stiffness and effective board mass were measured using a dynamic board loading method (Miller and Jones, 1999: Research Quarterly for Exercise and Sport, 70, 395–400). The horizontal deflection was a quadratic function of the vertical deflection and the board angle was a linear function of the vertical deflection. Body segmental inertias were calculated from 95 anthropometric measurements of the diver using a mathematical model of the human body (Yeadon, 1990: Journal of Biomechanics, 23, 67–74). To ensure that the torque generators produced realistic joint torques, maximum isometric and isovelocity torques of the diver were obtained using an isokinetic dynamometer. Movements measured included flexion and extension of shoulder, hip, knee and ankle. A 10parameter fit was used to express torque as a function of joint angle and angular velocity. Wobbling masses were included in the shank, thigh and trunk segments to model the movement of soft tissues during impact. The wobbling mass inertias were calculated from body composition and density reported in the literature and scaled to the diver. Each wobbling mass was attached to the body segment through two pairs of non-linear damped springs. Initial estimates of stiffness and damping were chosen so as to produce appropriate displacement and oscillation frequency. The elastic properties of the foot-springboard interface were represented by three pairs of spring-dampers acting on the heel, ball and toes. The stiffness and damping of these elastic elements, along with the refined estimation ofwobblingmass parameters and springboard stiffness, were determined using an angle-driven model. This was achieved by driving the model with joint angle time histories obtained from 200 Hz video recordings of diving performance from a one-metre springboard and minimising the difference in orientation and linear and angular momentum between simulation and performance using the Simulated Annealing optimisation algorithm (Corana et al., 1987: ACM Transactions on Mathematical Software, 13, 262–280). Four dives with minimum and maximum angular momentum in the Fig. 1. Simulation model of a springboard and a diver. Journal of Sports Sciences, 2005, 23, 93–223 Journal of Sports Sciences ISSN 0264-0414 print/ISSN 1466-447X online # 2005 Taylor & Francis Group Ltd DOI: 10.1080/02640410512331334413 forward and reverse groups were used to obtain a common set of parameters. The mean difference between simulation and performance was 8.3%. This paper described how subject-specific parameters could be measured experimentally or determined indirectly using an angle-driven model. These model parameters will then be used in a torque-driven model which, after satisfactory evaluation, will be used to investigate diving takeoff techniques and to optimise performance. Acknowledgment: This study was supported by the International Society of Biomechanics. 21. Strategies for maximum velocity movements in relation to reaction time and performance

The reliability of the Extra Load Index as a measure of relative load carriage economy

Abstract The aim of this study was to measure the reliability of the extra load index (ELI) as a method for assessing relative load carriage economy. Seventeen volunteers (12 males, 5 females) performed walking trials at 3 km·h−1, 6 km·h−1 and a self-selected speed. Trial conditions were repeated 7 days later to assess test–retest reliability. Trials involved four 4-minute periods of walking, each separated by 5 min of rest. The initial stage was performed unloaded followed in a randomised order by a second unloaded period and walking with backpacks of 7 and 20 kg. Results show ELI values did not differ significantly between trials for any of the speeds (p = 0.46) with either of the additional loads (p = 0.297). The systematic bias, limits of agreement and coefficients of variation were small in all trial conditions. We conclude the ELI appears to be a reliable measure of relative load carriage economy. Practitioner Summary: This paper demonstrates that the ELI is a reliable measure of load carriage economy at a range of walking speeds with both a light and heavy load. The ELI, therefore, represents a useful tool for comparing the relative economy associated with different load carriage systems.

A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading

Abstract It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3 km.h−1 with loads of 0, 3, 6, 9, 12, 15 and 20 kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p = .483), despite differences in the change in trunk forward lean (p = .001) and trunk angle excursion (p = .021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements. Practitioner summary: This article shows, based on mean data, that there is no difference in economy among back, back/front and head-loading, despite differences in trunk movement. It is possible a combination of factors align to influence individual economy, rather than a single set of factors, applicable to all individuals for each method.

Effects of increasing cold exposure on the oxygen uptake of walking unloaded and loaded

Introduction: Cold exposure and load carriage is an understudied area. Most research shows that VO2max is generally unaffected by cold exposure, however the majority of research suggests that sub-maximal O2 consumption increases for a given workload [1]. This pilot study assessed the effects of cold on load carriage. Methods: 4 male participants (age: 21.8 ± 3.4 years, height: 182.5 ±5.0 cm, weight: 77.8 ± 13.5 kg) completed a walking protocol of ~1 hour in a range of different ambient temperatures within an environmental chamber (20 °C, 10 °C, 5 °C, 0 °C, -5 °C and -10 °C). Humidity was controlled at ~50% while altitude was 0 m (20.95% FiO2). Participants wore shorts and t-shirt for all trials. The protocol included a 15 minute rest period, unloaded walking at 4 km.hr-1 for 4 minutes at 0% and 10% gradient. The same workloads were repeated loaded (18 kg) after a 5 minute rest. Heart rate returned to resting levels before each exercise section to ensure prior activity did not influence findings. Unloaded walking was then repeated. Expired air was collected and analysed using a Cortex 3B Metalyzer (Germany). Statistical analysis was performed using SPSS version 22, with significance denoted by p < 0.05. Results: Table ​Table1 shows a significant increase in VO2 with load (p = 0.019). At all workloads, significant increases in VO2 were associated with decreasing temperature (p = 0.048). ΔVO2 values suggest that the effect of loading was consistent, regardless of ambient temperature (p = 0.997). When comparing the first unloaded exercise bout with the second, VO2 for 20 °C, 10 °C and 5 °C was similar, whereas at 0 °C and below, VO2 was higher in the second unloaded bout, but this interaction was not significant (p = 0.158).

The effect of two different types of resistance load on strength gain in novices during early phase training

Soccer instep kick kinematics has been examined in the literature through 2D analysis and more recently 3D analysis (Levanon and Dapena, 1998: Medicine and Science in Sports and Exercise, 30, 917–927). The importance of ball approach prior to kick execution has been recognised in other sports such as rugby (Jackson and Baker, 2001: The Sport Psychologist, 15, 48–65). However, there is limited research on the relationship between ball approach, shot accuracy and kick kinematics in soccer. The objective of this case study was to establish the effect of altering the ball approach, on kick kinematics and shot accuracy, when performing instep penalty kicks.Annual Conference of the British Association of Sport and Exercise Sciences Liverpool, 7th – 9th September 2004 PART I. BIOMECHANICS 20. Parameter determination for a torque-driven model of springboard diving takeoff P.W. Kong, M.R. Yeadon and M.A. King School of Sport and Exercise Sciences, Loughborough University, Ashby Road, Loughborough, LE11 3TU In order to develop a planar computer simulation model of a springboard and a 8-segment diver suitable for investigating diving takeoffs (Fig. 1), it is necessary to determine subject-specific model parameters. These include: 1) springboard, 2) segmental inertia, 3) strength, 4) wobbling mass, and 5) foot-springboard interface parameters. The aim of this study was to determine such parameters either directly from measurements or indirectly using an angle-driven model. Subject-specific parameters were determined from an elite female diver who provided informed consent. Testing procedures were approved by the University Ethical Advisory Committee. The vertical behaviour of the springboard was modelled as a linear mass-spring system with no damping and with stiffness as a linear function of foot placement. The stiffness and effective board mass were measured using a dynamic board loading method (Miller and Jones, 1999: Research Quarterly for Exercise and Sport, 70, 395–400). The horizontal deflection was a quadratic function of the vertical deflection and the board angle was a linear function of the vertical deflection. Body segmental inertias were calculated from 95 anthropometric measurements of the diver using a mathematical model of the human body (Yeadon, 1990: Journal of Biomechanics, 23, 67–74). To ensure that the torque generators produced realistic joint torques, maximum isometric and isovelocity torques of the diver were obtained using an isokinetic dynamometer. Movements measured included flexion and extension of shoulder, hip, knee and ankle. A 10parameter fit was used to express torque as a function of joint angle and angular velocity. Wobbling masses were included in the shank, thigh and trunk segments to model the movement of soft tissues during impact. The wobbling mass inertias were calculated from body composition and density reported in the literature and scaled to the diver. Each wobbling mass was attached to the body segment through two pairs of non-linear damped springs. Initial estimates of stiffness and damping were chosen so as to produce appropriate displacement and oscillation frequency. The elastic properties of the foot-springboard interface were represented by three pairs of spring-dampers acting on the heel, ball and toes. The stiffness and damping of these elastic elements, along with the refined estimation ofwobblingmass parameters and springboard stiffness, were determined using an angle-driven model. This was achieved by driving the model with joint angle time histories obtained from 200 Hz video recordings of diving performance from a one-metre springboard and minimising the difference in orientation and linear and angular momentum between simulation and performance using the Simulated Annealing optimisation algorithm (Corana et al., 1987: ACM Transactions on Mathematical Software, 13, 262–280). Four dives with minimum and maximum angular momentum in the Fig. 1. Simulation model of a springboard and a diver. Journal of Sports Sciences, 2005, 23, 93–223 Journal of Sports Sciences ISSN 0264-0414 print/ISSN 1466-447X online # 2005 Taylor & Francis Group Ltd DOI: 10.1080/02640410512331334413 forward and reverse groups were used to obtain a common set of parameters. The mean difference between simulation and performance was 8.3%. This paper described how subject-specific parameters could be measured experimentally or determined indirectly using an angle-driven model. These model parameters will then be used in a torque-driven model which, after satisfactory evaluation, will be used to investigate diving takeoff techniques and to optimise performance. Acknowledgment: This study was supported by the International Society of Biomechanics. 21. Strategies for maximum velocity movements in relation to reaction time and performance

Relationships between physiological and postural adjustments to load carriage for two rucksack designs

Whole-body bone mineral density and bone mineral mass in young adult rugby union players.