The Training-Performance Puzzle: How Can the Past Inform Future Training Directions?

Over the past 20 years, research on the training-load-injury relationship has grown exponentially. With the benefit of more data, our understanding of the training-performance puzzle has improved. What were we thinking 20 years ago, and how has our thinking changed over time? Although early investigators attributed overuse injuries to excessive training loads, it has become clear that rapid spikes in training load, above what an athlete is accustomed, explain (at least in part) a large proportion of injuries. In this respect, it appears that overuse injuries may arise from athletes being underprepared for the load they are about to perform. However, a question of interest to both athletic trainers (ATs) and researchers is why some athletes sustain injury at low training loads, while others can tolerate much greater training loads? A higher chronic training load and well-developed aerobic fitness and lower body strength appear to moderate the training-injury relationship and provide a protective effect against spikes in load. The training-performance puzzle is complex and dynamic-at any given time, multiple inputs to injury and performance exist. The challenge facing researchers is obtaining large enough longitudinal data sets to capture the time-varying nature of physiological and musculoskeletal capacities and training-load data to adequately inform injury-prevention efforts. The training-performance puzzle can be solved, but it will take collaboration between researchers and clinicians as well as an understanding that efficacy (ie, how training load affects performance and injury in an idealized or controlled setting) does not equate to effectiveness (ie, how training load affects performance and injury in the real-world setting, where many variables cannot be controlled).

Training Load and Its Role in Injury Prevention, Part I: Back to the Future.

The purpose of this 2-part commentary series is† to explain why we believe our ability to control injury risk by manipulating training load (TL) in its current state is an illusion and why the foundations of this illusion are weak and unreliable. In part 1, we introduce the training process framework and contextualize the role of TL monitoring in the injury-prevention paradigm. In part 2, we describe the conceptual and methodologic pitfalls of previous authors who associated TL and injury in ways that limited their suitability for the derivation of practical recommendations. The first important step in the training process is developing the training program: the practitioner develops a strategy based on available evidence, professional knowledge, and experience. For decades, exercise strategies have been based on the fundamental training principles of overload and progression. Training-load monitoring allows the practitioner to determine whether athletes have completed training as planned and how they have coped with the physical stress. Training load and its associated metrics cannot provide a quantitative indication of whether particular load progressions will increase or decrease the injury risk, given the nature of previous studies (descriptive and at best predictive) and their methodologic weaknesses. The overreliance on TL has moved the attention away from the multifactorial nature of injury and the roles of other important contextual factors. We argue that no evidence supports the quantitative use of TL data to manipulate future training with the purpose of preventing injury. Therefore, determining "how much is too much" and how to properly manipulate and progress TL are currently subjective decisions based on generic training principles and our experience of adjusting training according to an individual athlete's response. Our message to practitioners is to stop seeking overly simplistic solutions to complex problems and instead embrace the risks and uncertainty inherent in the training process and injury prevention.

Training Load and Its Role in Injury Prevention, Part 2: Conceptual and Methodologic Pitfalls.

In part 2 of this clinical commentary, we highlight the conceptual and methodologic pitfalls evident in current training-load-injury research. These limitations make these studies unsuitable for determining how to use new metrics such as acute workload, chronic workload, and their ratio for reducing injury risk. The main overarching concerns are the lack of a conceptual framework and reference models that do not allow for appropriate interpretation of the results to define a causal structure. The lack of any conceptual framework also gives investigators too many degrees of freedom, which can dramatically increase the risk of false discoveries and confirmation bias by forcing the interpretation of results toward common beliefs and accepted training principles. Specifically, we underline methodologic concerns relating to (1) measure of exposures, (2) pitfalls of using ratios, (3) training-load measures, (4) time windows, (5) discretization and reference category, (6) injury definitions, (7) unclear analyses, (8) sample size and generalizability, (9) missing data, and (10) standards and quality of reporting. Given the pitfalls of previous studies, we need to return to our practices before this research influx began, when practitioners relied on traditional training principles (eg, overload progression) and adjusted training loads based on athletes' responses. Training-load measures cannot tell us whether the variations are increasing or decreasing the injury risk; we recommend that practitioners still rely on their expert knowledge and experience.

Patterns of training volume and injury risk in elite rugby union: An analysis of 1.5 million hours of training exposure over eleven seasons.

Rugby union is a popular team sport that demands high levels of physical fitness and skill. The study aim was to examine trends in training volume and its impact on injury incidence, severity and burden over an 11-season period in English professional rugby. Data were recorded from 2007/08 through 2017/18, capturing 1,501,606 h of training exposure and 3,782 training injuries. Players completed, on average, 6 h 48 minutes of weekly training (95% CI: 6 h 30 mins to 7 h 6 mins): this value remained stable over the 11 seasons. The mean incidence of training-related injuries was 2.6/1000 player-hours (95% CI: 2.4 to 2.8) with a mean severity rising from 17 days in 2007/08 to 37 days in 2017/18 (Change/season = 1.773, P <0.01). Rate of change in severity was dependent on training type, with conditioning (non-gym-based) responsible for the greatest increase (2.4 days/injury/season). As a result of increasing severity, injury burden rose from 51 days absence/1000 player-hours in 2007/08 to 106 days' absence/1000 player-hours in 2017/18. Despite the low incidence of injury in training compared to match-play, training accounted for 34% of all injuries. Future assessments of training intensity may lead to a greater understanding of the rise in injury severity.

Scheduling of training and recovery during the in-season weekly micro-cycle: Insights from team sport practitioners.

The aim of this study was to determine the in-season micro-cycle scheduling strategies used in professional team sport with particular reference to the reasoning and perceptions that underpin current practice. An online survey was completed by 35 practitioners from professional collision (C; Australian rules football: n = 9; rugby league: n = 6; rugby union: n = 2) and non-collision (NC; soccer; n = 18) sports. Respondents identified a common 48 h post-match recovery period, with few scheduling training stimuli during this period (NC: range: 0-17%; C: range: 0-47%). The majority (C: 78%; NC: 89%) of resistance training sessions were concurrent in nature, often delivering resistance training in the afternoon following field-based training (C: 72%; NC: 92%). NC practitioners were less satisfied with the maintenance of strength, power and hypertrophy (33-44%) versus C sports (59-76%), reflected by the lower frequency of prescription reported (C: 2.4 ± 0.6; NC: 1.5 ± 0.9; p = .003). Cold water immersion following both matches and daily training was highly prevalent, as was the adoption of self-report tools to monitor recovery. The congested and concurrent nature of training prescription during the micro-cycle, together with the universal adoption of routine cold water immersion warrants further investigation to inform evidence-based prescription and scheduling of training and recovery modalities in professional team sports.

Efectos de un programa de intervención sobre el estilo interpersonal de entrenadores de fútbol base / Effects of an intervention program on the interpersonal style of football coaches / Efeitos de um programa de intervenção sobre o estilo interpessoal dos treinadores de futebol

El objetivo de este estudio era analizar los efectos de un programa de formación sobre la conducta verbal de entrenadores de fútbol base no cualificados. El programa estaba basado en el fomento de estrategias motivacionales y metodológicas para optimizar las necesidades psicológicas básicas de los deportistas, aumentando las conductas relacionadas a un estilo interpersonal de apoyo y, reduciendo las conductas asociadas a un estilo interpersonal controlador. Participaron ocho entrenadores distribuidos intencionadamente en dos grupos: grupo experimental (n = 4) y grupo control (n = 4). Tras la observación del estilo interpersonal de los entrenadores (pre y post) mediante un instrumento creado a propósito para el estudio, no se obtuvieron diferencias significativas entre los dos grupos, aunque los resultados del grupo experimental demostraron una tendencia positiva entre la medida pre-intervención y la post-intervención. Por tanto, el programa resulta eficaz pero no en la medida que se esperaba, por lo que es preciso seguir investigando en esta línea de trabajo

The main objective of this study was to analyze the effects of a training program on the verbal behavior of unskilled youth football coaches without training and academic qualification (related with physical and sport training). The program was based on the promotion of motivational and methodological strategies with the purpose of optimizing the athletes' basic psychological needs of autonomy, competence and relatedness, through an interpersonal style of support and, in turn, reducing the controlling behaviors. Participated eight coaches intentionally distributed in two groups: experimental group (n = 4) and control group (n = 4). After observing of the interpersonal style of the coaches (pre and post) by an instrument created on purpose for the study, there was not significant differences in the extent post-intervention between groups, regarding the repeated measures analysis of the experimental group there are improvements between pre-intervention and post-intervention measure. Therefore, the program is effective but not to the extent expected, so it is necessary to continue research in this line of work

O objetivo deste estudo foi analisar os efeitos de uma intervenção no comportamento verbal de treinadores sem formação federativa e acadêmica relacionada à atividade física e desporto. O programa foi baseado na promoção de estratégias motivacionais e metodológicas para otimizar as necessidades psicológicas básicas dos atletas de autonomia, competência e relações sociais, através de um estilo de apoio interpessoal e reduzindo os comportamentos controladores. Oito treinadores participaram intencionalmente e foram distribuídos em dois grupos: grupo experimental (n = 4) e grupo de controlo (n = 4). Depois de observar o estilo interpessoal dos treinadores (pré e pós) através de um instrumento criado para o propósito do estudo, não foram encontradas diferenças significativas entre os dois grupos, embora os resultados do grupo experimental tenham mostrado uma tendência positiva entre a medida pré-intervenção e a pós-intervenção. Portanto, o programa é eficaz, mas não na medida esperada, sendo por isso necessária mais investigação neste âmbito

Pulmonary hypertension and exercise training: a synopsis on the more recent evidences.

The benefits of exercise training in virtually all humans, including those with a clinically stable chronic disease are numerous. The potential value lies in the fact that functional capacity is oftentimes significantly compromised. Exercise training not only play a role in reversing some of the pathophysiologic processes associated with chronic diseases but also improves clinical trajectory. Given the significant pathologic consequences associated with pulmonary hypertension and its implications for deteriorating right ventricular function as well as the perceived potential for a precipitous and possibly critical drop in cardiac output during periods of physical exertion, exercise training was historically not recommended for these patients. More recently, a promising body of literature demonstrating the safety and efficacy of exercise training (with benefit on exercise capacity, peak oxygen consumption and quality of life) in pulmonary hypertension patients has emerged, but the conclusion about the effects of exercise training were non-exhaustive and therefore there is still a lack of knowledge regarding exercise training for these patients. Thus, we aim to ascertain the current effectiveness of exercise rehabilitation for pulmonary hypertension by performing a brief overview on the latest currently available evidences in such an "at a glance" synopsis addressed to summarize/quantify the more recent existing body of literature. KEY MESSAGES Exercise training was historically not recommended in pulmonary hypertension. Recently, exercise training safety-efficacy in pulmonary hypertension has emerged. Exercise training should be recommended in addition to optimal medical therapy.

Propuesta para la mejora de la condición física en militares veteranos / Proposal to improve the physical condition of the veteran military

Existen evidencias científicas fundadas de que el entrenamiento Interválico concurrente de alta intensidad mejora en gran medida la condición física de deportistas de todas las edades; además, bien dirigido permite reducir el riesgo de lesiones asociadas a la vejez. Material y método: Se realizó un estudio preexperimental con tratamiento de un grupo, formado por 7 Oficiales en la reserva del Ejército de Tierra (59,57 ± 2,07 años de edad, índice de masa corporal de 26,76 ± 2,84 kg/cm2) y deportistas habituales (4,14 ± 1,35 sesiones de entrenamiento a la semana). Durante 8 semanas, sustituyeron dos de sus días de entrenamiento habitual por dos días en los que se realizaban tareas de entrenamiento concurrente de alta intensidad, con una intensidad media (medida según la escala del esfuerzo percibido de 10 puntos de Borg) de 8,29 ± 0,74 puntos y una duración media de ejecución de 20,80 ± 5,77 minutos. Resultados: Se observaron mejoras estadísticamente significativas (p < 0,05) en las siguientes cualidades evaluadas mediante test validados de la condición física: agilidad en dos sentidos de giro distintos (derecho 3,81 ± 0,19 a 3,61 ± 0,21 segundos e izquierdo 3,90 ± 0,17 a 3,68 ± 0,18 segundos), potencia de tren inferior (salto horizontal, de 1,61 ± 0,09 a 1,72 ± 0,09 cm), resistencia muscular de tronco (flexo rotación en 90», de 39,14 ± 6,74 a 55,43 ± 10,94 repeticiones) y de tren superior (tracción, de 18,71 ± 7,52 a 26,29 ± 9,91 repeticiones y empuje, de 21,29 ± 4,82 a 29,71 ± 6,85 repeticiones) y resistencia cardiovascular (frecuencia de recuperación, de 96,57 ± 9,81 a 90,86 ± 8,69 pulsaciones min-1). Respecto a la cualidad flexibilidad, pese a que hubo variaciones positivas en los resultados, no fueron estadísticamente significativas. Conclusiones: La introducción de al menos dos rutinas semanales basadas en el entrenamiento concurrente de alta intensidad es positiva para militares veteranos, mejorando la mayoría de las cualidades físicas, especialmente, las manifestaciones de la fuerza (AU)

There is strong scientific evidence that concurrent high-intensity interval training improves the physical condition of athletes of all ages; in addition, if well-managed, it reduces the risk of injuries associated with old age. Material and method: A pre-experimental study was carried out with a treatment of a group consisting of 7 Officers in the reserve of the Army (59,57 ± 2,07 years old, body mass index of 26,76 ± 2,84 kg / cm2) and usual athletes (4,14 ± 1,35 training sessions per week). For 8 weeks, they replaced two of their usual training days for two days in which high-intensity concurrent training tasks were performed, with an average intensity (measured by Borg’s 10-point perceived effort scale) of 8,29 ± 0,74 points and an average execution time of 20,80 ± 5,77 minutes. Results: Statistically significant improvements (p < 0,05) were observed in the following qualities assessed by validated physical fitness tests: agility in two different directions of rotation (right, 3,81 ± 0,19 to 3,61 ± 0,21 seconds and left, 3,90 ± 0,17 to 3,68 ± 0,18 seconds); lower limb power (standing long jump, 1,61 ± 0,09 to 1,72 ± 0,09 cm); muscular strength of trunk (flexo rotation in 90”, 39,14 ± 6,74 to 55,43 ± 10,94 reps) and upper limb (pull 18,71 ± 7,52 to 26,29 ± 9,91 reps and push, 21,29 ± 4,82 to 29,71 ± 6,85 reps) and cardiovascular resistance (recovery frequency, 96,57 ± 9,81 to 90,86 ± 8,69 pulsations min-1). Regarding the flexibility quality, although there were positive variations in the results, they were not statistically significant. Conclusions: The introduction of at least two weekly routines based on concurrent high intensity training is positive for senior military personnel, improving most of the physical qualities, especially strength manifestations (AU)

[A time of change for men's health: a process of increasing medicalisation?]. / Männergesundheit im Wandel: Ein Prozess nachholender Medikalisierung?

These days, men suffer from a bad reputation when the media talk about health matters. Nonetheless, talking about men's health is problematic, as it considers the health behaviour of the male gender in an essentialistic manner. Such discourse is socially under-differentiated, frequently dramatises the gender difference rather than explaining it, makes inappropriate individualisations, draws on questionable benchmarks, makes women the positive model without first reflecting, and is ahistorical. Gender patterns have a major significance for health behaviour and have indeed considerably changed the health behaviour of men and women over the last 250 years. Women have been more seriously medicalised and have, on account of their life expectancy, profited more from modernisation, developments in hygiene, the expansion of medical services and state healthcare policies. However, over the last 30 years, besides a continuing parallel medicalisation of men, signs of it increasing can also be seen. Their behaviour has become more compatible with health. A more adequate description of the situation could be achieved through a more concentrated observation of health lifestyles.

Benefits and Limitations of Block Periodized Training Approaches to Athletes' Preparation: A Review.

The present review introduces innovative concepts of training periodization and summarizes a large body of findings characterizing their potential benefits and possible limitations. Evidence-based analysis of the traditional periodization model led to elaboration of alternative versions of athletic preparation. These alternative versions postulated the superiority of training programs with a high concentration of selected workloads compared with traditionally designed plans directed at the concurrent development of many athletic abilities at low/medium workload concentration. The training cycles of highly concentrated specialized workloads were coined "training blocks" by experts and practitioners; correspondingly, the alternative versions were termed "block periodized (BP) preparation systems" by their presenters. Ultimately, two BP training models were proposed: a concentrated unidirectional training model (CU) and a multi-targeted BP approach to athletes' preparation. The first innovative version postulated administration of highly concentrated training means for enhancement of one leading fitness component, whereas the second version proposed the development of many targeted abilities within sequenced block mesocycles containing a minimal number of compatible training modalities. Both versions differ in their methodological background, duration and content of training blocks, possibilities of providing multi-peak performances, and applicability to various sports. In recent decades, many studies have evaluated the effects of both BP training versions in different sports. Examination of the training effects producing by the CU model in combat and team sports has found significant gains in various fitness estimates but not in sport-specific performances. Similarly, utilization of a CU program by elite swimmers did not lead to substantial enhancement of their peak performances. In contrast, studies of multi-targeted BP training programs have revealed their distinct superiority compared with traditional preparation in endurance, team, and dual sports, and strength/power training and recreational athletes (28 studies). It is suggested that the CU training strategy suits athletic disciplines demanding one fitness component like explosive strength in jumping performances. Unlike this limitation, the multi-targeted BP system prompted a beneficial increase of specific preparedness in sports and disciplines in which peak performances require the application of many targeted athletic abilities.

NCAA strength and conditioning coach demographics, current practice trends and common injuries of athletes during strength and conditioning sessions.

BACKGROUND: NCAA strength and conditioning coaches are responsible for the day-to-day conditioning and strength training of collegiate athletes. NCAA regulations will likely require all strength and conditioning coaches to have a strength and conditioning certification. NCAA strength and conditioning coaches have varied philosophies on exercise programming based on educational background. The study aims to further evaluate the backgrounds and exercise philosophies of NCAA strength and conditioning coaches. METHODS: A survey (Survey Monkey®, Palo Alto, CA, USA) was distributed to NCAA strength and conditioning professionals to evaluate their education background, current practice trends, use of specific equipment and footwear, and what injuries occurred during sessions. RESULTS: Of the 208 survey participants, 77.9% were male with an average age of 34.5±9.1 years old. An exercise-related bachelor's degree was held by 80.4% and an exercise-related master's degree by 72.4%. Over 89% had a strength and conditioning certification. Having a master's, bachelor's, or type strength and conditioning certification had no difference in 1-repetition maximal practice with athletes. Lower extremity injuries made up the highest percentage (58.9%) of injuries seen by NCAA Strength and Conditioning Coaches than lumbar spine injuries (16.7%). The five most common injuries reported during workouts were lumbar strain (N.=431, 14.7%), hamstring strain (N.=332, 11.3%), ankle sprain (N.=299, 10.2%), patellar tendonitis (N.=232, 7.9%), and shin splints (N.=226, 7.7%). CONCLUSIONS: Collegiate education and certifications have impact on practice patterns of strength and conditioning coaches in the NCAA.

Prevalence trends in lifestyle-related risk factors.

BACKGROUND: The regional prevalence of risk factors can vary over time. The Study of Health in Pomerania (SHIP) addresses prevalence trends for common risk factors in a region in northeast Germany. METHODS: A longitudinal study was carried out from 1997 to 2001 (SHIP-0, with 4308 subjects), and a second, independent random sample of the population in the same region was studied from 2008 to 2012 (SHIP-Trend, with 4420 subjects). All data were standardized with post-stratification weighting derived from the adult population of the state of Mecklenburg-West Pomerania. RESULTS: SHIP reveals a marked decline of mean alcohol consumption in the adult population, from 5.57 g/day (95% confidence interval, 5.51-5.63) to 3.12 g/day (95% CI 3.09-3.15). The percentage of active smokers among men declined from 38.6% (95% CI 36.0-41.2) to 34.3% (95% CI 32.1-36.6). Simultaneously, however, there was a rightward shift of the BMI distribution, with a marked increase in the prevalence of obesity, from 24.7% to 32.0%. There was a corresponding increase in the prevalence of diabetes, from 9.1% to 13.8%. Compared to eleven years ago, the amount of exercise taken during free time has risen among the elderly, but fallen among young women. CONCLUSION: Tobacco and alcohol consumption have declined over the past decade, although this study may have overestimated these trends through a combination of selection bias and reporting bias. Meanwhile, the northeast German population now has a worse metabolic risk profile, as indicated by the increased prevalence of obesity and diabetes. Society as a whole must take measures to combat this trend.

Influencia del entorno donde se habita (rural vs urbano) sobre la condición física de estudiantes de educación primaria / Influence of environment (rural vs urban) on the physical condition of primary school students

Introducción: El objetivo de este estudio fue valorar la influencia del entorno donde se habita (rural vs urbano) sobre la condición física y parámetros antropométricos en estudiantes de educación primaria. Material y método: Se seleccionaron 509 sujetos (290 urbanos y 219 rurales) de entre 8 y 11 años, a los que se les realizó una valoración antropométrica (masa, talla, IMC, ratio cintura/cadera) y de la condición física (fuerza de prensión manual, salto vertical, flexibilidad y fitness cardiorrespiratorio).Resultados: Los resultados muestran que la población urbana obtiene valores más bajos en parámetros antropométricos, y la población rural mejores resultados en condición física: fuerza de prensión manual (15,72 ± 4,10 vs 19,78 ± 5,20 kg), flexibilidad (8,38 ± 4,59 vs 17,08 ± 6,24 cm) y fitness cardiorrespiratorio (46,00 ± 4,19 vs 46,79 ± 4,49 ml/kg/min), no existiendo diferencias para el salto vertical. Conclusiones: Se pone de manifiesto que el lugar de residencia (rural vs urbano) se debe tener en cuenta a la hora de aplicar programas de intervención para la promoción de la actividad física

Introduction: The aim of this study was to evaluate the influence of the environment (rural vs.urban) on fitness and anthropometric parameters in elementary education pupils. Material and method: A total of 509 subjects (290 urban and 219 rural) between 8 and 11 years were selected. Anthropometric variables (weight, height, BMI, weight/height ratio) and physical fitness (handgrip strength, vertical jump, flexibility and maximal oxygen consumption) were evaluated. Results: The results show lower values in anthropometric variables in the urban population and the best rural results in physical fitness: handgrip strength (15.72 ± 4.10 kg vs19.78 ± 5.20 kg), flexibility (8.38 ± 4.59 cm vs 17.08 ± 6.24 cm), and maximum oxygen consumption(46.00 ± 4.19 ml/Kg/min vs 46.79 ± 4.49 ml/Kg/min), with no differences for the verticaljump. Conclusions: The results show that the place of residence (rural vs urban) should be taken intoaccount when implementing effective intervention programs to promote physical activity

Postacute care: reasons for its growth and a proposal for its control through the early detection, treatment, and prevention of hospital-acquired disability.

Postacute care costs have doubled over the past decade and now account for 17% of Medicare fee-for-service spending. Costs are forecast to continue to rise, paradoxically in large part in response to federal policies and efforts to control health care costs. This commentary introduces a potential solution to this situation and is divided into 4 parts. The first provides a brief review of the policies fostering this growth. The second assesses how the responses of health care providers, while inherently rational, are destructive to the system. The third identifies hospital-acquired disability as a modifiable driver in this scenario, and the fourth discusses how an improvement in detection and a redistribution of hospital-based rehabilitation services may be able to reverse this unsustainable growth.

Thirty-eight years of training distribution in Olympic speed skaters.

UNLABELLED: During the last decade discussion about training-intensity distribution has been an important issue in sports science. Training-intensity distribution has not been adequately investigated in speed skating, a unique activity requiring both high power and high endurance. PURPOSE: To quantify the training-intensity distribution and training hours of successful Olympic speed skaters over 10 Olympiads. METHODS: Olympic-medal-winning trainers/coaches and speed skaters were interviewed and their training programs were analyzed. Each program was qualified and quantified: workout type (specific and nonspecific) and training zones (zone 1 2 mMol/L lactate, zone 2 2-4 mMol/L lactate, zone 3 lactate >4 mMol/L). Net training times were calculated. RESULTS: The relation between total training hours and time (successive Olympiads) was not progressive (r = .51, P > .5). A strong positive linear relation (r = .96, P < .01) was found between training distribution in zone 1 and time. Zones 2 and 3 both showed a strong negative linear relation to time (r = -.94, P < .01; r = -.97, P < .01). No significant relation was found between speed skating hours and time (r = -.11, P > .05). This was also the case for inline skating and time (r = -.86, P > .05). CONCLUSIONS: These data indicate that in speed skating there was a shift toward polarized training over the last 38 y. This shift seems to be the most important factor in the development of Olympic speed skaters. Surprisingly there was no relation found between training hours, skating hours, and time.