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We believe one thing that sets Informed Performance is the scientific and academic background that runs alongside our real-world experience in high performance sport. Below is a list of our peer-reviewed publications, which we will continue to add to as additional articles are published.

 

THE MUSCLE MORPHOLOGY OF ELITE SPRINT RUNNING

Miller, R., Balshaw, T. G., Massey, G. J., Maeo, S., Lanza, M. B., Johnston, M., Allen, S. J., Folland, J. P.

Med Sci Sports Exerc. 2021

Purpose: This study aimed to investigate the differences in muscle volumes and strength between male elite sprinters, sub-elite sprinters, and untrained controls and to assess the relationships of muscle volumes and strength with sprint performance.

 

Methods: Five elite sprinters (100-m season's best equivalent [SBE100], 10.10 ± 0.07 s), 26 sub-elite sprinters (SBE100, 10.80 ± 0.30 s), and 11 untrained control participants underwent 1) 3-T magnetic resonance imaging scans to determine the volume of 23 individual lower limb muscles/compartments and 5 functional muscle groups and 2) isometric strength assessment of lower body muscle groups.

 

Results: Total lower body muscularity was distinct between the groups (controls < sub-elite +20% < elite +48%). The hip extensors exhibited the largest muscle group differences/relationships (elite, +32% absolute and +15% relative [per kg] volume, vs sub-elite explaining 31%-48% of the variability in SBE100), whereas the plantarflexors showed no differences between sprint groups. Individual muscle differences showed pronounced anatomical specificity (elite vs sub-elite absolute volume range, +57% to -9%). Three hip muscles were consistently larger in elite vs sub-elite (tensor fasciae latae, sartorius, and gluteus maximus; absolute, +45%-57%; relative volume, +25%-37%), and gluteus maximus volume alone explained 34%-44% of the variance in SBE100. The isometric strength of several muscle groups was greater in both sprint groups than controls but similar for the sprint groups and not related to SBE100.

 

Conclusions: These findings demonstrate the pronounced inhomogeneity and anatomically specific muscularity required for fast sprinting and provides novel, robust evidence that greater hip extensor and gluteus maximus volumes discriminate between elite and sub-elite sprinters and are strongly associated with sprinting performance.

ACUTE EFFECTS OF WEARABLE THIGH AND SHANK LOADING ON SPATIOTEMPORAL AND KINEMATIC VARIABLES DURING MAXIMUM VELOCITY SPRINTING.

Hurst O, Kilduff LP, Johnston M, Cronin J, Bezodis NE.

Sports Biomechanics. 2020

Light wearable resistance is used in sprint training but the scientific evidence to guide its implementation is limited. This study investigated thigh and shank loading protocols which were matched based on the average increase in moment of inertia about the hip over a stride cycle. Seven university-level sprinters completed three counterbalanced conditions (unloaded, shank-loaded, thigh-loaded), and kinematic variables were measured between 30 and 40 m. Both thigh and shank loading led to small reductions in step velocity (mean change = −1.4% and −1.2%, respectively). This was due to small reductions in step frequency (−1.8%; −1.7%) because of small increases in contact time (+2.7%; +1.5%) in both conditions and a small increase in flight time (+2.0%) in the shank-loaded condition. Both conditions led to moderate increases in hip extension at toe-off (+2.7°; +1.4°), whilst thigh loading led to a small reduction in peak hip flexion angle during swing (−2.5°) and shank loading led to a small increase in peak biceps femoris muscle-tendon unit length (+0.4%). Thigh and shank loading can both be used to provide small reductions in sprint velocity, and each has specific overload effects which must be considered in the rationale for their implementation.

THE EFFECT OF TRAINING ORDER ON NEUROMUSCULAR, ENDOCRINE AND MOOD RESPONSE TO SMALL SIDED GAMES AND RESISTANCE TRAINING SESSIONS OVER A 24-HOUR PERIOD

Sparkes W, Turner AN, Cook CJ, Weston M, Russell M, Johnston M, Kilduff LP.

Journal of Science and Medicine in Sport. 2020

OBJECTIVES: This study examined the acute effect of small-sided-game (SSG) and resistance training sequence on neuromuscular, endocrine and mood response over a 24-h (h) period.
DESIGN: Repeated measures.
METHODS: Fourteen semi-professional soccer players performed SSG-training (4vs4 + goalkeepers; 6 × 7-min, 2-min inter-set recovery) followed by resistance training 2 h later (back-squat, Romanian deadlift, barbell-hip-thrust; 4 × 4 repetitions, 4-min inter-set recovery; 85% 1 rep-max) (SSG + RES), and on a separate week reversed the session order (RES + SSG). Physical demands of SSG’s were monitored using global positioning systems (GPS) and ratings of perceived exertion (RPE). Countermovement-jump (CMJ; peak power output; jump height) and brief assessment of mood were collected before (pre), during (0 h) and after (+24 h) both protocols. Salivary testosterone and cortisol concentrations were obtained at the same time-points but with the inclusion of a measure immediately prior to the second training session (+2 h).
RESULTS: GPS outputs and RPE were similar between SSG-training during both protocols. Between-protocol comparisons revealed no significant differences at +24 h in CMJ performance, mood, and endocrine markers. Testosterone was higher at 0 h during RES + SSG in comparison to SSG + RES (moderate-effect; +21.4 ± 26.7 pg ml−1; p = 0.010), yet was similar between protocols by +2 h.
CONCLUSIONS: The order of SSG and resistance training does not appear to influence the physical demands of SSG’s with sufficient recovery between two sessions performed on the same day. Session order did not influence neuromuscular, endocrine or mood responses at +24 h, however a favourable testosterone response from the resistance first session may enhance neuromuscular performance in the second session of the day.

THE NEUROMUSCULAR, ENDOCRINE AND MOOD RESPONSES TO A SINGLE VERSUS DOUBLE TRAINING SESSION DAY IN SOCCER PLAYERS

Sparkes W, Turner AN, Cook CJ, Weston M, Russell M, Johnston M, Kilduff LP.

Journal of Science and Medicine in Sport. 2019

OBJECTIVES: This study profiled the 24 h neuromuscular, endocrine and mood responses to a single versus a double training day in soccer players.
DESIGN: Repeated measures.
METHODS: Twelve semi-professional soccer players performed small-sided-games (SSG’s; 4 vs 4 + goalkeepers; 6 × 7-min, 2-min inter-set recovery) with neuromuscular (peak-power output, PPO; jump height, JH), endocrine (salivary testosterone, cortisol), and mood measures collected before (pre) and after (0 h, +24 h). The following week, the same SSG protocol was performed with an additional lower body strength training session (back-squat, Romanian deadlift, barbell hip thrust; 4 × 4 repetitions, 4-min inter-set recovery; 85% 1 rep-max) added at 2 h after the SSG’s.
RESULTS: Between-trial comparisons revealed possible to likely small impairments in PPO (2.5 ± 2.2 W kg−1; 90% Confidence Limits: ±2.2 W kg−1), JH (−1.3; ±2.0 cm) and mood (4.6; ±6.1 AU) in response to the double versus single sessions at +24 h. Likely to very likely small favourable responses occurred following the single session for testosterone (−15.2; ±6.1 pg ml−1), cortisol (0.072; ±0.034 ug dl−1) and testosterone/cortisol ratio (−96.6; ±36.7 AU) at +24 h compared to the double session trial.
CONCLUSIONS: These data highlight that performance of two training sessions within a day resulted in possible to very likely small impairments of neuromuscular performance, mood score and endocrine markers at +24 h relative to a single training session day. A strategy of alternating high intensity explosive training days containing multiple sessions with days emphasising submaximal technical/tactical activities may be beneficial for those responsible for the design and delivery of soccer training programs.

TRAINING REGIMES AND RECOVERY MONITORING PRACTICES OF ELITE BRITISH SWIMMERS

Pollock S, Gaoua N, Johnston M, Cooke K, Girard, Mileva K.

Journal of Sports Science and Medicine. 2019

Consistent prescriptions for event-specific training of swimmers are lacking, which points to likely differences in training practices and a potential gap between practice and scientific knowledge. This study aimed to analyze the distance-specific training load of elite swimmers, derive a consistent training sessions' description and reflect on the current recommendations for training and recovery. The individual training regimes of 18 elite British swimmers were documented by surveying four swim and two strength and conditioning (S&C) coaches. The annual and weekly training load and content were compared between swimmers competing in sprint, middle and long-distance events. Thematic analysis of the surveys was conducted to identify key codes and general dimensions and to define a unified classification of the swimming and S&C training sessions. Weekly training loads and content of the swim (ƞ2 - effect size; p = 0.016, ƞ2 = 0.423) and S&C (p = 0.028, ƞ2 = 0.38) sessions significantly differed between the groups. Long-distance swimmers swam significantly longer distances (mean ± SD; 58.1 ± 10.2 km vs. 43.2 ± 5.3 km; p = 0.018) weekly but completed similar number of S&C sessions compared to sprinters. The annual swimming load distribution of middle-distance specialists did not differ from that of long-distance swimmers but consisted of more S&C sessions per week (4.7 ± 0.5 vs. 2.3 ± 2.3; p = 0.04). Sprinters and middle-distance swimmers swam similar distances per week and completed similar number of S&C sessions but with different proportional content. Whereas all coaches reported monitoring fatigue, only 51% indicated implementing individualized recovery protocols. We propose a consistent terminology for the description of training sessions in elite swimming to facilitate good practice exchanges. While the training prescription of elite British swimmers conforms to the scientific training principles, recommendations for recovery protocols to reduce the risk of injury and overtraining are warranted.

HAMSTRING REHABILITATION IN ELITE TRACK AND FIELD ATHLETES: APPLYING THE BRITISH ATHLETICS MUSCLE INJURY CLASSIFICATION IN CLINICAL PRACTICE

Macdonald B, Mcleer S, Chakraverty R, Johnston M, Pollock N.

British Journal of Sports Medicine. 2019

RATIONALE: Hamstring injuries are common in elite sports. Muscle injury classification systems aim to provide a framework for diagnosis. The British Athletics Muscle Injury Classification (BAMIC) describes an MRI classification system with clearly defined, anatomically focused classes based on the site of injury: (a) myofascial, (b) muscle–tendon junction or (c) intratendinous; and the extent of the injury, graded from 0 to 4. However, there are no clinical guidelines that link the specific diagnosis (as above) with a focused rehabilitation plan.
OBJECTIVE: We present an overview of the general principles of, and rationale for, exercise-based hamstring injury rehabilitation in British Athletics. We describe how British Athletics clinicians use the BAMIC to help manage elite track and field athletes with hamstring injury. Within each class of injury, we discuss four topics: clinical presentation, healing physiology, how we prescribe and progress rehabilitation and how we make the shared decision to return to full training. We recommend a structured and targeted diagnostic and rehabilitation approach to improve outcomes after hamstring injury.

NEUROMUSCULAR, PHYSIOLOGICAL AND PERCEPTUAL RESPONSES TO AN ELITE NETBALL TOURNAMENT.

Birdsey L, Weston W, Russell M, Johnston M, Cook CJ, Kilduff LP.

Journal of Sport Sciences. 2019

To examine responses to an International netball tournament, female athletes (n= 11) played three matches over consecutive days. External (accelerometry) and internal (heart rate; HR, session; sRPE, and differential; dRPE, rating of perceived exertion) load measures quantified match intensity. On match-day mornings, and three days after match 3, well-being (brief assessment of mood; BAM+), biochemical (creatine kinase concentration; CK), neuromuscular (jump height; JH, peak power output; PPO) and endocrine function (salivary cortisol; C, testosterone; T, concentrations) were assessed. External load was similar between matches whereas dRPE and sRPE were greatest for match 3. Following match 1, CK increased, whereas BAM+, JH, C and T decreased. Following two matches, BAM+, PPO, and T decreased with CK increasing versus baseline. Following consecutive matches, CK (likely moderate; 27.9% ± 19.5%) and C (possibly moderate; 43.3% ± 46.8%) increased, whilst BAM+ (possibly moderate; −20.6% ± 24.4%) decreased. Three days post-tournament BAM+, T, PPO, and JH decreased. Mid-court elicited higher mean HR (possibly moderate; 3.7% ± 3.8%), internal and external intensities (possibly very large; 85.7% ± 49.6%) compared with goal-based positions. Consecutive matches revealed a dose–response relationship for well-being and physiological function; a response evident three days post-tournament.

THE ROLE OF ARM MECHANICS DURING SPRINT RUNNING: A REVIEW OF THE LITERATURE AND PRACTICAL APPLICATIONS.

Macadam P, Cronin J, Uthoff A, Johnston M, Knicker AJ.

Strength and Conditioning Journal. 2018

THE IMPORTANCE OF ARM ACTION DURING SPRINT RUNNING HAS BEEN AN ONGOING DISCUSSION AMONG PRACTITIONERS. ALTHOUGH SOME COACHES BELIEVE THAT THE ARMS SERVE TO MERELY PROVIDE BALANCE TO THE ROTARY MOMENTUM OF THE LEGS, OTHERS BELIEVE THAT THE ARMS ARE VITAL TO SPRINT RUNNING PERFORMANCE AND CONTRIBUTE TO PROPULSIVE FORCES. ALTHOUGH A LARGE BODY OF RESEARCH HAS BEEN UNDERTAKEN INTO THE EFFECTS OF LEG KINEMATICS AND KINETICS ON SPRINT RUNNING PERFORMANCE, THE ROLE OF ARM ACTION REMAINS AMBIGUOUS AND UNDERINVESTIGATED. THEREFORE, THE PURPOSE OF THIS REVIEW IS TO IMPROVE UNDERSTANDING RELATED TO ARM MECHANICS DURING SPRINT RUNNING AND PROVIDE PRACTICAL CONTEXT GUIDELINES.

THE NEUROMUSCULAR, BIOCHEMICAL, ENDOCRINE AND MOOD RESPONSES TO SMALL SIDED GAMES TRAINING IN PROFESSIONAL SOCCER

Sparkes W, Turner A, Weston M, Russell M, Johnston M.

Journal of Strength and Conditioning Research. 2018

The 24-hour responses to small-sided games' (SSGs) soccer training were characterized. Professional soccer players (n = 16) performed SSG's (4vs4 + goalkeepers; 6 × 7-minutes, 2-minute interset recovery) with performance (peak power output [PPO] and jump height [JH]), physiological (blood creatine kinase [CK], lactate, salivary testosterone, and cortisol), and mood measures collected before (baseline), and after (immediately; 0, +2, and +24 hours). For PPO and JH, possibly small-moderate reductions occurred at 0 hour (−1.1 W·kg−1; ±0.9 W·kg−1, −3.2 cm; ±1.9 cm, respectively), before returning to baseline at +2 hours (trivial), and declining thereafter (small-moderate effect) at +24 hours (−0.9 W·kg−1; ±0.8 W·kg−1, −2.5 cm; ±1.2 cm, respectively). Lactate increased at 0 hours (likely large; +1.3 mmol·L−1; ±0.5 mmol·L−1), reduced at +2 hours (likely-small; −0.5 mmol·L−1; ±0.2 mmol·L−1), and returned to baseline at 24 hours (trivial). A very likely small increase in CK occurred at 0 hour (+97 μ·L−1; ±28 μ·L−1), persisting for +24 hours (very likely small; +94 μ·L−1; ±49 μ·L−1). Possibly small increases in testosterone (+20 pg·ml−1; ±29 pg·ml−1) occurred at 0 hour, before likely moderate declines at +2 hours (−61 pg·ml−1; ±21 pg·ml−1) returning to baseline at +24 hours (trivial). For cortisol, possibly small decreases occurred at 0 hour (−0.09 μg·dl−1; ±0.16 μg·dl−1), before likely large decreases at +2 hours (−0.39 μg·dl−1; ±0.12 μg·dl−1), which persisted for 24 hours (likely small; −0.12 μg·dl−1; ±0.11 μg·dl−1). Mood was disturbed by SSG's at 0 hour (likely moderate; +13.6 AU, ±5.6 AU) and +2 hours (likely small; +7.9 AU; ±5.0 AU), before returning to baseline at +24 hours (trivial). The movement demands of SSG's result in a bimodal recovery pattern of neuromuscular function and perturbations in physiological responses and mood for up to 24 hours. Accordingly, when programming soccer training, SSG's should be periodized throughout the competitive week with submaximal technical/tactical activities.

CLUSTERING AND CORRELATES OF SCREEN-TIME AND EATING BEHAVIOURS AMONG YOUNG CHILDREN

Pearson, N., Biddle, S. J., Griffiths, P., Johnston, J. P., & Haycraft, E.

BMC Public Health. 2018

BACKGROUND: Screen-time and unhealthy dietary behaviours are highly pervasive in young children and evidence suggests that these behaviours often co-occur and are associated. Identifying clusters of unhealthy behaviours, and their influences early in childhood, can assist in the development of targeted preventive interventions. The purpose of this study was to examine the sociodemographic, behavioural, and home physical environmental correlates of co-occurring screen-time and unhealthy eating behaviours and to assess the clustering of screen-time and unhealthy dietary behaviours in young children.
METHODS: Parents of 126 children, from the UK, aged 5–6 years (49% boys) completed a questionnaire which assessed their child’s screen-time (ST), fruit and vegetable (FV), and energy-dense (ED) snack consumption. Categories of health behaviours were created based on frequencies of children meeting recommendations for FV and ST and median splits of frequencies for ED snacks. Parents reported on their own behaviours (ST, FV, and ED snack consumption), how often they ate meals and watched TV with their child, and on the availability and accessibility of foods within the home. An observed over expected ratio (O/E) was used to assess behavioural clustering. Multivariable multinomial logistic regression was used to examine correlates of behaviour patterns.
RESULTS: Approximately 25% of children had two or three health risk behaviours. Correlates consistently associated with clusters included parental income, eating meals at the TV, parental ST and ED snack food consumption, and home availability of ED snack foods. Observed over expected ratios were close to 1 and ranged from 0.78 to 1.43. The three-risk behaviour combination of insufficient FV consumption, high ED snack consumption, and excessive ST occurred more frequently than expected (1.23 (95% CI 0.89, 1.58)).
CONCLUSIONS: ST and unhealthy dietary behaviours cluster in children as young as 5 years of age and parents’ own behaviours appear to be important influencing factors. Further research into the development of behavioural clustering in young children to identify and further understand the mechanisms underlying the synergy among health behaviours is needed. Feasibility interventions promoting reductions in both screen-time and unhealthy dietary behaviours reciprocally, while simultaneously focusing on changing parental behaviours, are warranted.

TEACHER PERCEPTIONS ON THE DELIVERY AND IMPLEMENTATION OF MOVEMENT INTEGRATION STRATEGIES: THE CLASS PAL (PHYSICALLY ACTIVE LEARNING) PROGRAMME.

Routen, A. C., Johnston, J. P., Glazebrook, C., & Sherar, L. B.

International Journal of Educational Research. 2018

Children sit for extended periods in the school classroom. Movement integration (MI) methods (e.g. active breaks, physically active lessons) could be used to break/reduce sitting time and improve classroom behaviour and engagement. Limited evidence is available on teacher perceptions of what influences the implementation of MI. Interviewed primary school teachers reported factors perceived to influence implementation at a variety of levels including individual (e.g. teacher and pupil characteristics, time, behavioural management) and school (e.g. whole school approach; and external to school expectations). In addition suggestions for increasing adoption and implementation of MI (e.g. communicating MI initiatives to schools) were identified.

RELIABILITY OF BOUNCE DROP JUMP PARAMETERS WITHIN ELITE MALE RUGBY PLAYERS

Costley L, Wallace E, Johnston M, Kennedy R.

Journal of Sports Medicine and Physical Fitness. 2017

BACKGROUND: The aims of the study were to investigate the number of familiarization sessions required to establish reliability of the bounce drop jump (BDJ) and subsequent reliability once familiarization is achieved.
METHODS: Seventeen trained male athletes completed 4 BDJs in 4 separate testing sessions. Force-time data from a 20 cm BDJ was obtained using two force plates (ensuring ground contact <250 ms). Subjects were instructed to “jump for maximal height and minimal contact time” while the best and average of four jumps were compared. A series of performance variables were assessed in both eccentric and concentric phases including jump height, contact time, flight time, Reactive Strength Index (RSI), peak power, rate of force development (RFD) and actual dropping height (ADH). Reliability was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV) while familiarization was assessed using a repeated-measures analysis of variance (ANOVA).
RESULTS: The majority of DJ parameters exhibited excellent reliability with no systematic bias evident, while the average of 4 trials provided greater reliability. With the exception of vertical stiffness (CV: 12.0%) and RFD (CV: 16.2%), all variables demonstrated low within subject variation (CV range: 3.1-8.9%). Relative reliability was very poor for ADH, with heights ranging from 14.87-29.85 cm.
CONCLUSIONS: High levels of reliability can be obtained from the BDJ with the exception of vertical stiffness and RFD, however, extreme caution must be taken when comparing DJ results between individuals and squads due to large discrepancies between actual drop height and platform height.

INDIVIDUAL, BEHAVIOURAL, AND HOME ENVIRONMENTAL FACTORS ASSOCIATED WITH EATING BEHAVIOURS IN YOUNG ADOLESCENTS.

Pearson, N., Griffiths, P., Biddle, S.J.H., Johnston, J.P., & Haycraft, E.

Apetitie. 2017

This study aimed to examine individual, behavioural and home environmental factors associated with frequency of consumption of fruit, vegetables and energy-dense snacks among adolescents. Adolescents aged 11-12 years (n = 521, 48% boys) completed a paper-based questionnaire during class-time which included a Food Frequency Questionnaire assessing their consumption of fruit, vegetables, and energy-dense (ED) snacks, and items assessing habits, self-efficacy, eating at the television (TV), eating with parents, parenting practices, and home availability and accessibility of foods. Multiple linear regression analyses showed that eating fruit and vegetables while watching TV and home availability and accessibility of fruit and vegetables were positively associated with frequency of fruit consumption and vegetable consumption, while home accessibility of ED snack foods was negatively associated with frequency of fruit consumption. Habit for eating ED snack foods in front the TV, eating ED snack foods while watching TV, and home availability of ED snacks were positively associated with frequency of ED snack consumption. This study has highlighted the importance of a healthy home environment for promoting fruit and vegetable intake in early adolescents and also suggests that, if snacking while TV viewing occurs, this could be a good opportunity for promoting fruit and vegetable intake. These findings are likely to be useful for supporting the development of multi-faceted interventions and aid us in knowing what advice to give to parents to help them to help their young adolescents to develop and maintain healthy eating habits.

CLUSTERING AND CORRELATES OF SCREEN-TIME AND EATING BEHAVIOURS AMONG YOUNG ADOLESCENTS.

Pearson, N., Griffiths, P., Biddle, S.J.H., Johnston, J.P., McGeorge, S., & Haycraft, E.
BMC Public Health. 2017

BACKGROUND: Screen-time and unhealthy dietary behaviours are highly pervasive in young children and evidence suggests that these behaviours often co-occur and are associated. Identifying clusters of unhealthy behaviours, and their influences early in childhood, can assist in the development of targeted preventive interventions. The purpose of this study was to examine the sociodemographic, behavioural, and home physical environmental correlates of co-occurring screen-time and unhealthy eating behaviours and to assess the clustering of screen-time and unhealthy dietary behaviours in young children.
METHODS: Parents of 126 children, from the UK, aged 5–6 years (49% boys) completed a questionnaire which assessed their child’s screen-time (ST), fruit and vegetable (FV), and energy-dense (ED) snack consumption. Categories of health behaviours were created based on frequencies of children meeting recommendations for FV and ST and median splits of frequencies for ED snacks. Parents reported on their own behaviours (ST, FV, and ED snack consumption), how often they ate meals and watched TV with their child, and on the availability and accessibility of foods within the home. An observed over expected ratio (O/E) was used to assess behavioural clustering. Multivariable multinomial logistic regression was used to examine correlates of behaviour patterns.
RESULTS: Approximately 25% of children had two or three health risk behaviours. Correlates consistently associated with clusters included parental income, eating meals at the TV, parental ST and ED snack food consumption, and home availability of ED snack foods. Observed over expected ratios were close to 1 and ranged from 0.78 to 1.43. The three-risk behaviour combination of insufficient FV consumption, high ED snack consumption, and excessive ST occurred more frequently than expected (1.23 (95% CI 0.89, 1.58)).
CONCLUSIONS: ST and unhealthy dietary behaviours cluster in children as young as 5 years of age and parents’ own behaviours appear to be important influencing factors. Further research into the development of behavioural clustering in young children to identify and further understand the mechanisms underlying the synergy among health behaviours is needed. Feasibility interventions promoting reductions in both screen-time and unhealthy dietary behaviours reciprocally, while simultaneously focusing on changing parental behaviours, are warranted.

SEDENTARY BEHAVIOUR ACROSS THE PRIMARY-SECONDARY SCHOOL TRANSITION: A SYSTEMATIC REVIEW.

Pearson, N., Haycraft, E., Johnston, J.P., & Atkins, A.J.

Preventative Medicine. 2017

The transition from primary/middle school to secondary/high school is likely to be a key period in children's development, characterised by significant changes in their social and physical environment. However, little is known about the changes in sedentary behaviour that accompany this transition. This review aimed to identify, critically appraise and summarise the evidence on changes in sedentary behaviour across the primary – secondary school transition. Published English language studies were located from computerised and manual searches in 2015. Inclusion criteria specified a longitudinal design, baseline assessment when children were in primary/middle school with at least one follow-up during secondary/high school and a measure of sedentary behaviour at both (or all) points of assessment. Based on data from 11 articles (19 independent samples), tracking coefficients were typically in the range of 0.3 to 0.5 and relatively consistent across the different sedentary behaviours examined and durations of follow-up. Both screen-based sedentary behaviour and overall sedentary time increased during the school transition. Overall there was an increase of approximately 10–20 min per day per year in accelerometer-assessed sedentary time. Consistent with the broader age-related changes in behaviour observed during this period, sedentary behaviour increases during the transition from primary/middle to secondary/high school. Investigating features of the social and physical environment that might exacerbate or attenuate this trend would be a valuable next step.

THE EFFECT OF SESSION ORDER ON THE PHYSIOLOGICAL, NEUROMUSCULAR, AND ENDOCRINE RESPONSES TO MAXIMAL SPEED AND WEIGHT TRAINING SESSIONS OVER A 24-HOUR PERIOD

Johnston M, Johnston J, Cook CJ, Costley L, Kilgallon M, Kilduff LP.

Journal of Science and Medicine in Sport. 2016

OBJECTIVES: Athletes are often required to undertake multiple training sessions on the same day with these sessions needing to be sequenced correctly to allow the athlete to maximize the responses of each session. We examined the acute effect of strength and speed training sequence on neuromuscular, endocrine, and physiological responses over 24h.
DESIGN: 15 academy rugby union players completed this randomized crossover study.
METHODS: Players performed a weight training session followed 2h later by a speed training session (weights speed) and on a separate day reversed the order (speed weights). Countermovement jumps, perceived muscle soreness, and blood samples were collected immediately prior, immediately post, and 24h post-sessions one and two respectively. Jumps were analyzed for power, jump height, rate of force development, and velocity. Blood was analyzed for testosterone, cortisol, lactate and creatine kinase.
RESULTS: There were no differences between countermovement jump variables at any of the post-training time points (p>0.05). Likewise, creatine kinase, testosterone, cortisol, and muscle soreness were unaffected by session order (p>0.05). However, 10m sprint time was significantly faster (mean±standard deviation; speed weights 1.80±0.11s versus weights speed 1.76±0.08s; p>0.05) when speed was sequenced second. Lactate levels were significantly higher immediately post-speed sessions versus weight training sessions at both time points (p<0.05).
CONCLUSIONS: The sequencing of strength and speed training does not affect the neuromuscular, endocrine, and physiological recovery over 24h. However, speed may be enhanced when performed as the second session.

THE NEUROMUSCULAR, BIOCHEMICAL AND ENDOCRINE RESPONSES TO A SINGLE SESSION VERSES DOUBLE SESSION TRAINING DAY IN ELITE ATHLETES

Johnston M, Cook CJ, Drake D, Costley L, Johnston, J, Kilduff LP.

Journal of Strength and Conditioning Research. 2016

The aim of this study was to compare the acute neuromuscular, biochemical, and endocrine responses of a training day consisting of a speed session only with performing a speed-and-weights training session on the same day. Fifteen men who were academy-level rugby players completed 2 protocols in a randomized order. The speed-only protocol involved performing 6 maximal effort repetitions of 50-m running sprints with 5 minutes of recovery between each sprint, whereas the speed-and-weights protocol involved the same sprinting session but was followed 2 hours later by a lower-body weights session consisting of 4 sets of 5 backsquats and Romanian deadlift at 85% one repetition maximum. Testosterone, cortisol, creatine kinase, lactate, and perceived muscle soreness were determined immediately before, immediately after, 2 hours after, and 24 hours after both the protocols. Peak power, relative peak power, jump height, and average rate of force development were determined from a countermovement jump (CMJ) at the same time points. After 24-hours, muscle soreness was significantly higher after the speed-and-weights protocol compared with the speed-only protocol (effect size η2 = 0.253, F = 4.750, p ≤ 0.05). There was no significant difference between any of the CMJ variables at any of the posttraining time points. Likewise, creatine kinase, testosterone, and cortisol were unaffected by the addition of a weight-training session. These data indicate that the addition of a weight-training session 2 hours after a speed session, whereas increasing the perception of fatigue the next day does not result in a difference in endocrine response or in neuromuscular capability.

POSITIVE YOUTH DEVELOPMENT AND TALENT DEVELOPMENT: IS THERE A BEST OF BOTH WORLDS?

Harwood, C.G., & Johnston, J.P.

In N.L. Holt (Ed.) Positive youth development through sport (2nd Ed.). New York: Routledge. 2016

Cutting through the political rhetoric about the power of sport as a tool for social change and personal improvement, this book offers insight into how and why participating in sport can be good for children and young people. As the first text to focus on the role of sport in positive youth development (PYD), it brings together high-profile contributors from diverse disciplines to examine critically the ways in which sport can be used to promote youth development.


Now in a fully updated, revised and expanded new edition, Positive Youth Development through Sport covers a wider range of disciplines including sport psychology, development psychology, physical education, sport development and sport sociology.

NEUROMUSCULAR, PHYSIOLOGICAL AND ENDOCRINE RESPONSES TO A MAXIMAL SPEED TRAINING SESSION IN ELITE GAMES PLAYERS

Johnston M, Cook CJ, Crewther BT, Drake D, Kilduff LP.

Eur J Sport Sci. 2015

The aim of this study was to determine the acute neuromuscular, biochemical and endocrine responses to a maximal speed training (MST) session. Eighteen male rugby players completed the protocol, which involved performing six maximal effort repetitions of 50 m running sprints with 5 minutes recovery between each sprint. Testosterone (T), cortisol (C), creatine kinase (CK), lactate (La), perceived muscle soreness (MS) and counter movement jump were collected immediately pre (PRE), immediately post (IP), 2 hours post (2P) and 24 hours post (24P) the sprint session. A bimodal recovery pattern was observed from the jump parameters with several declining significantly (p ≤ 0.05) IP, recovering 2P and suffering a secondary decline 24P. CK and perceived MS were elevated IP and continued to rise throughout the protocol, while La was only elevated IP. T and C were unaffected IP but showed significant declines 2P. These data indicate that MST results in a bimodal recovery pattern of neuromuscular function with changes most likely being related to metabolic and biochemical responses.

POSITIVE YOUTH DEVELOPMENT IN SPORT: ENACTING THE ROLES OF COACHES AND PARENTS.

Johnston, J.P., & Harwood, C.G.

In P. Davis (Ed.) The psychology of effective coaching and management. Hauppauge, NY: Nova Science Publishers Inc. 2015

This is a valuable resource for students, researchers, practitioners, educators, and administrators that want to increase their knowledge of psychological aspects associated with the development and practice of coaching and management. The reader is guided through models of the coaching process, approaches to coach learning, context specific education, and tools for observing coaching behaviors. Additionally, considerations for enhancing positive youth development, motivational climate, group dynamics, self-regulation, emotions, and mental toughness are outlined. The application of mental skills such as self-talk, the consideration of an athlete's personality in coaching practice, and leadership theories in management are also reviewed. Examples of highly effective sport organizations and approaches to optimizing relationships with support staff are presented, as well as research and implications of coach burnout. The book is written by world leading scholars, sport psychologists, coaches, and managers from the USA, Canada, Australia, New Zealand, Sweden, Spain, Greece, Croatia and the UK. Each chapter presents current research and offers suggestions for optimizing effective coaching and management. The chapters are written to be accessible to a wide range of readers, and each chapter offers a set of key considerations for enhancing practice. The aim of the book is to present up-to-date knowledge of the theories and research undertaken in sport coaching and management, with a particular focus upon applying understanding to maximize effective practice. This book will serve as essential reading for scholars and students; it can be used as a key text in sports coaching or coach education programs. Furthermore, coaches as well as their athletes will benefit from the recommendations for practice presented in the book.

POSITIVE YOUTH DEVELOPMENT IN SWIMMING: CLARIFICATION AND CONSENSUS OF KEY PSYCHOSOCIAL ASSETS.

Johnston, J.P., Harwood, C.G., & Minniti, A.M. 

Journal of Applied Sport Psychology. 2013

The purpose of this study was to gain a more cohesive understanding of the assets considered necessary to develop in young swimmers to ensure both individual and sport-specific development. This two-stage study involved (a) a content analysis of key papers to develop a list of both psychosocial skills for performance enhancement and assets associated with positive youth development, and (b) in-depth interviews involving 10 expert swim coaches, practitioners, and youth sport scholars. Five higher-order categories containing 17 individual assets emerged. These results are discussed in relation to both existing models of positive youth development and implications for coaches, practitioners and parents when considering the psychosocial development of young British swimmers.

THE ROLE OF THE FAMILY IN TALENT DEVELOPMENT.

Harwood, C.G., Douglas, J.P., & Minniti, A.M.

In S. Murphy (Ed.), Handbook on sport and performance psychology. New York, NY: Oxford University Press. 2012

The Oxford Handbook of Sport and Performance Psychology includes the latest research and applied perspectives from leaders in the field of performance psychology, presenting sport and performance psychology from myriad perspectives. It looks at individual psychological processes in performance such as attention, imagery, superior performance intelligence, motivation, anxiety, confidence, cognition, and emotion. Articles also consider the social psychological processes in performance including leadership, teamwork, coaching, relationships, moral behavior, and gender and cultural issues. The book further examines human development issues in performance, such as the development of talent and expertise, positive youth development, the role of the family, the end of involvement transitions, and both youth and masters-level sport and physical activity programs. Finally, the text looks at interventions in sport and performance psychology and counseling of performers in distress including such important issues for all performers as: appearance- and performance-enhancing drug use, injuries, managing pain, eating and weight issues, burnout, and the role of physical activity in maintaining health. The articles collected here also cover the history of sport and performance psychology; the scope and nature of the field; ethical issues in sport and performance psychology; performance psychology in the performing arts and other non-sporting fields; perfectionism and performance; the role of the performance coach and of the sport psychologist with a coach and team; supervision; and a look ahead to the future of the field.