Robert W. Meyers

The Long-Term Athlete Development model: Physiological evidence and application

Abstract Within the UK, the “Long Term Athlete Development” (LTAD) model has been proposed by a variety of national governing bodies to offer a first step to considering the approach to talent development. The model, which is primarily a physiological perspective, presents an advancement of understanding of developing athletic potential alongside biological growth. It focuses on training to optimize performance longitudinally, and considers sensitive developmental periods known as “windows of opportunity”. However, it appears that there are a number of problems with this theoretical model that are not necessarily transparent to coaches. Principally, the model is only one-dimensional, there is a lack of empirical evidence upon which the model is based, and interpretations of the model are restricted because the data on which it is based rely on questionable assumptions and erroneous methodologies. Fundamentally, this is a generic model rather than an individualized plan for athletes. It is crucial that the LTAD model is seen as a “work in progress” and the challenge, particularly for paediatric exercise scientists, is to question, test, and revise the model. It is unlikely that this can be accomplished using classical experimental research methodology but this should not deter practitioners from acquiring valid and reliable evidence.

The Natural Development and Trainability of Plyometric Ability During Childhood

THE INCLUSION OF PLYOMETRICS WITHIN YOUTH-BASED STRENGTH AND CONDITIONING PROGRAMS IS BECOMING MORE POPULAR AS A MEANS TO DEVELOP STRETCH-SHORTENING CYCLE ABILITY. PLYOMETRIC TRAINING ADAPTATIONS HAVE PREVIOUSLY BEEN REPORTED FOR RUNNING VELOCITY, POWER, AGILITY, AND RUNNING ECONOMY, AND THEREFORE, ATHLETES SHOULD BE EXPOSED TO THIS TRAINING MODALITY AT SOME POINT DURING THEIR TRAINING PROGRAM. HOWEVER, SOME UNCERTAINTY STILL EXISTS WITH REGARD TO PROGRAM DESIGN, ESPECIALLY WHEN TAKING GROWTH AND MATURATIONAL FACTORS INTO ACCOUNT. THIS ARTICLE REVIEWS THE CURRENT YOUTH-BASED PLYOMETRIC LITERATURE AND PROVIDES A TRAINING PROGRESSION MODEL BASED AROUND THE LONG-TERM DEVELOPMENT OF YOUNG ATHLETES.

Effects of playing surface on physiological responses and performance variables in a controlled football simulation

Abstract In spite of the increased acceptance of artificial turf in football, few studies have investigated if matches are altered by the type of surface used and no research has compared physiological responses to football activity on artificial and natural surfaces. In the present study, participants performed a football match simulation on high-quality artificial and natural surfaces. Neither mean heart rate (171 ± 9 beats · min−1 vs. 171 ± 9 beats · min−1; P > 0.05) nor blood lactate (4.8 ± 1.6 mM vs. 5.3 ± 1.8 mM; P > 0.05) differed between the artificial and natural surface, respectively. Measures of sprint, jumping and agility performance declined through the match simulation but surface type did not affect the decrease in performance. For example, the fatigue index of repeated sprints did not differ (P > 0.05) between the artificial, (6.9 ± 2.1%) and natural surface (7.4 ± 2.4%). The ability to turn after sprinting was affected by surface type but this difference was dependent on the type of turn. Although there were small differences in the ability to perform certain movements between artificial and natural surfaces, the results suggest that fatigue and physiological responses to football activity do not differ markedly between surface-type using the high-quality pitches of the present study.

Training Elite Child Athletes: Promoting Welfare and Well-Being

CHILDREN CAN BENEFIT FROM, AND SAFELY ENGAGE IN, PHYSICAL CONDITIONING WHERE APPROPRIATE SUPERVISION IS PROVIDED. HOWEVER, ELITE CHILD ATHLETES REPRESENT A UNIQUE POPULATION WHO ARE EXPOSED TO POTENTIALLY LARGE VOLUMES OF SPECIALIZED TRAINING AND EARLY COMPETITION AT A TIME WHEN THEY ARE STILL MATURING. THIS SITUATION CAN EXPOSE THE ELITE CHILD ATHLETE TO A VARIETY OF RISKS THAT COULD AFFECT THEIR WELFARE AND WELL-BEING AND HAVE NEGATIVE CONSEQUENCES IN TERMS OF BOTH PERFORMANCE AND PERSONAL DEVELOPMENT. THIS ARTICLE IDENTIFIES RISKS AND PROVIDES RECOMMENDATIONS TO HELP COACHES PROMOTE THE WELFARE AND WELL-BEING OF ELITE CHILD ATHLETES DURING TRAINING.

Maximal Sprint Speed in Boys of Increasing Maturity

The purpose of this study was to examine the natural development of the mechanical features of sprint performance in relation to maturation within a large cohort of boys. Three hundred and thirty-six boys (11-15 years) were analyzed for sprint performance and maturation. Maximal speed, stride length (SL), stride frequency (SF), flight time (FT) and contact time (CT) were assessed during a 30m sprint. Five maturation groups (G1-5) were established based on age from peak height velocity (PHV) where G1=>2.5years pre-PHV, G2 = 2.49-1.5years pre-PHV, G3 = 1.49-0.5years pre-PHV, G4 = 0.49years pre- to 0.5years post-PHV and G5 = 0.51-1.5years post-PHV. There was no difference in maximal speed between G1, G2 and G3 but those in G4 and G5 were significantly faster (p < .05) than G1-3. Significant increases (p < .05) in SL were observed between groups with advancing maturation, except G4 and G5 (p > .05). SF decreased while CT increased (both p < .05) between G1, G2 and G3, but no further significant changes (p > .05) were observed for either variable between G3, G4 and G5. While G1-3 increased their SL, concomitant decreases in SF and increases in CT prevented them from improving maximal speed. Maximal sprint speed appears to develop around and post-PHV as SF and CT begin to stabilize, with increases in maximal sprint speed in maturing boys being underpinned by increasing SL.

Considerations for the Development of Agility During Childhood and Adolescence

ABSTRACT DESPITE BEING RECOGNIZED AS AN ESSENTIAL COMPONENT OF SPORTS PERFORMANCE, AGILITY DEVELOPMENT IN YOUTHS IS LARGELY UNDER-RESEARCHED. THIS ARTICLE REVIEWS THE EVIDENCE EXAMINING THE EFFECTS OF GROWTH, MATURATION AND TRAINING ON BOTH CHANGE OF DIRECTION SPEED AND COGNITIVE PROCESSING IN CHILDREN AND ADOLESCENTS, AND HOW COMBINED, THESE FACTORS MAY INFLUENCE AGILITY. TRAINING GUIDELINES ARE PROVIDED TO HELP STRENGTH AND CONDITIONING COACHES PRESCRIBE AGILITY TRAINING FOR YOUTHS AT DIFFERENT STAGES OF MATURATION, IN A SAFE AND EFFECTIVE MANNER.

Long-Term Athletic Development and Its Application to Youth Weightlifting

SUMMARY CONSIDERABLE CONTROVERSY AND MISGUIDED INFORMATION HAS SURROUNDED THE INCLUSION OF WEIGHTLIFTING WITHIN YOUTH-BASED STRENGTH AND CONDITIONING PROGRAMS TO DEVELOP STRENGTH, POWER, AND SPEED. THIS ARTICLE REVIEWS THE EVIDENCE TO SUPPORT ITS INCLUSION AS A SAFE AND EFFECTIVE MEANS TO ENHANCE ATHLETIC POTENTIAL. GUIDELINES ARE PRESENTED TO PROVIDE COACHES WITH A STRUCTURED AND LOGICAL PROGRESSION MODEL, WHICH IS ASSOCIATED WITH THE THEORETICAL CONCEPTS UNDERPINNING LONG-TERM ATHLETIC DEVELOPMENT. IT IS HOPED THAT THIS REVIEW WILL SERVE AS A USEFUL TOOL TO HELP STRENGTH AND CONDITIONING COACHES INTEGRATE WEIGHTLIFTING EXERCISES WITHIN TRAINING PROGRAMS OF YOUNG ATHLETES IN A SAFE AND EFFECTIVE MANNER.

The influence of playing surface on physiological and performance responses during and after soccer simulation

Abstract The aim of this study was to investigate the effect of playing surface on physiological and performance responses during and in the 48 h after simulated soccer match play. Blood lactate, single-sprint, repeated-sprint and agility of eight amateur soccer players were assessed throughout a 90-min soccer-simulation protocol (SSP) completed on natural turf (NT) and artificial turf. Counter-movement jump, multiple-rebound jump, sprint (10 m, 60 m), L-agility run (L-AR), creatine kinase (CK) and perception of muscle soreness (PMS) were measured before, immediately after, 24 h and 48 h after exercise. Analyses revealed significant changes in blood lactate and single-sprint performance (both P < 0.05) during the SSP but with no significant differences between surfaces. Conversely, repeated-sprint performance demonstrated an interaction effect, with reductions in performance evident on NT only (P < 0.05). Whilst L-AR and 10-m sprint performance remained unchanged, 60-m sprint and multiple-rebound jump performance were impaired, and PMS and CK were elevated immediately following the SSP (all P < 0.05) but with no surface effects. Although performance, CK and PMS were negatively affected to some degree in the 48 h after the SSP, there was no surface effect. For the artificial and natural surfaces used in the present study, physiological and performance responses to simulated soccer match play appear to be similar. Whilst a potential for small differences in performance response exists during activity, surface type does not affect the pattern of recovery following simulated match play.

Reliability of the Spatiotemporal Determinants of Maximal Sprint Speed in Adolescent Boys Over Single and Multiple Steps.

The purpose of this study was to examine the reliability of the spatiotemporal determinants of maximal sprinting speed in boys over single and multiple steps. Fifty-four adolescent boys (age = 14.1 ± 0.7 years [range = 12.9-15.7 years]; height = 1.63 ± 0.09 m; body mass = 55.3 ± 13.3 kg; -0.31 ± 0.90 age from Peak Height Velocity (PHV) in years; mean ± s) volunteered to complete a 30 m sprint test on 3 occasions over a 2-week period. Speed, step length, step frequency, contact time, and flight time were assessed via an optical measurement system. Speed and step characteristics were obtained from the single-fastest step and average of the 2 and 4 fastest consecutive steps. Pairwise comparison of consecutive trials revealed the coefficient of variation (CV) for speed was greater in 4-step (CV = 7.3 & 7.5%) compared with 2-step (CV = 4.2 & 4.1%) and 1-step (CV = 4.8 & 4.6%) analysis. The CV of step length, step frequency and contact time ranged from 4.8 to 7.5% for 1-step, 3.8-5.0% for 2-step and 4.2-7.5% for 4-step analyses across all trials. An acceptable degree of reliability was achieved for the spatiotemporal and performance variables assessed in this study. Two-step analysis demonstrated the highest degree of reliability for the key spatiotemporal variables, and therefore may be the most suitable approach to monitor the spatiotemporal characteristics of maximal sprint speed in boys.

The influence of age, maturity and body size on the spatiotemporal determinants of maximal sprint speed in boys

Abstract Meyers, RW, Oliver, JL, Hughes, MG, Lloyd, RS, and Cronin, JB. Influence of age, maturity, and body size on the spatiotemporal determinants of maximal sprint speed in boys. J Strength Cond Res 31(4): 1009–1016, 2017—The aim of this study was to investigate the influence of age, maturity, and body size on the spatiotemporal determinants of maximal sprint speed in boys. Three-hundred and seventy-five boys (age: 13.0 ± 1.3 years) completed a 30-m sprint test, during which maximal speed, step length, step frequency, contact time, and flight time were recorded using an optical measurement system. Body mass, height, leg length, and a maturity offset represented somatic variables. Step frequency accounted for the highest proportion of variance in speed (∼58%) in the pre–peak height velocity (pre-PHV) group, whereas step length explained the majority of the variance in speed (∼54%) in the post-PHV group. In the pre-PHV group, mass was negatively related to speed, step length, step frequency, and contact time; however, measures of stature had a positive influence on speed and step length yet a negative influence on step frequency. Speed and step length were also negatively influence by mass in the post-PHV group, whereas leg length continued to positively influence step length. The results highlighted that pre-PHV boys may be deemed step frequency reliant, whereas those post-PHV boys may be marginally step length reliant. Furthermore, the negative influence of body mass, both pre-PHV and post-PHV, suggests that training to optimize sprint performance in youth should include methods such as plyometric and strength training, where a high neuromuscular focus and the development force production relative to body weight are key foci.