Purpose: To examine potential differences in internal and external workload variables between playing positions and between training drills and games within an elite netball team during training and competition. Methods: Nine elite female netballers were monitored during 15 games and all training sessions over 28 weeks. Workload variables assessed were relative PlayerLoad (PL per minute), accelerations, decelerations, jumps, changes of direction, high-intensity events, medium-intensity events, low-intensity events, PL in a forward direction, PL in a sideways direction, PL in a vertical direction, and summated heart-rate zones using heart-rate monitors and inertial measurement units. Results: Conditioning and match play during training were the only drills that matched or exceeded game workloads. Workloads during small-sided games were lower than game workloads for all variables. In games, goalkeeper, goal attack, and goal shooter had a greater frequency of jumps compared with other positions. Midcourt positions had a greater frequency of low-intensity events in a game. Conclusions: Workloads during small-sided games were lower than game workloads across all external and internal variables; therefore, netball staff should modify these small-sided games if they wish them to develop game-based qualities. Specific game workload variables indicate that there are differences within some positional groups; coaches need to be aware that positional groupings may fail to account for differences in workload between individual playing positions.
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Marni J. Simpson, David G. Jenkins, and Vincent G. Kelly
Rich D. Johnston, Tim J. Gabbett, and David G. Jenkins
Purpose:
To determine the influence the number of contact efforts during a single bout has on running intensity during game-based activities and assess relationships between physical qualities and distances covered in each game.
Methods:
Eighteen semiprofessional rugby league players (age 23.6 ± 2.8 y) competed in 3 off-side small-sided games (2 × 10-min halves) with a contact bout performed every 2 min. The rules of each game were identical except for the number of contact efforts performed in each bout. Players performed 1, 2, or 3 × 5-s wrestles in the single-, double-, and triple-contact game, respectively. The movement demands (including distance covered and intensity of exercise) in each game were monitored using global positioning system units. Bench-press and back-squat 1-repetition maximum and the 30−15 Intermittent Fitness Test (30−15IFT) assessed muscle strength and high-intensity-running ability, respectively.
Results:
There was little change in distance covered during the single-contact game (ES = −0.16 to −0.61), whereas there were larger reductions in the double- (ES = −0.52 to −0.81) and triple-contact (ES = −0.50 to −1.15) games. Significant relationships (P < .05) were observed between 30–15IFT and high-speed running during the single- (r = .72) and double- (r = .75), but not triple-contact (r = .20) game.
Conclusions:
There is little change in running intensity when only single contacts are performed each bout; however, when multiple contacts are performed, greater reductions in running intensity result. In addition, high-intensity-running ability is only associated with running performance when contact demands are low.
Rich D. Johnston, Tim J. Gabbett, and David G. Jenkins
Purpose:
To assess the influence of playing standard and physical fitness on pacing strategies during a junior team-sport tournament.
Methods:
A between-groups, repeated-measures design was used. Twenty-eight junior team-sport players (age 16.6 ± 0.5 y, body mass 79.9 ± 12.0 kg) from a high-standard and low-standard team participated in a junior rugby league tournament, competing in 5 games over 4 d (4 × 40-min and 1 × 50-min game). Players wore global positioning system (GPS) microtechnology during each game to provide information on match activity profiles. The Yo-Yo Intermittent Recovery Test (level 1) was used to assess physical fitness before the competition.
Results:
High-standard players had an initially higher pacing strategy than the low-standard players, covering greater distances at high (ES = 1.32) and moderate speed (ES = 1.41) in game 1 and moderate speed (ES = 1.55) in game 2. However, low-standard players increased their playing intensity across the competition (ES = 0.57–2.04). High-standard/high-fitness players maintained a similar playing intensity, whereas high-standard/low-fitness players reduced their playing intensities across the competition.
Conclusions:
Well-developed physical fitness allows for a higher-intensity pacing strategy that can be maintained throughout a tournament. High-standard/low-fitness players reduce playing intensity, most likely due to increased levels of fatigue as the competition progresses. Low-standard players adopt a pacing strategy that allows them to conserve energy to produce an “end spurt” in the latter games. Maximizing endurance fitness across an entire playing group will maximize playing intensity and minimize performance reductions during the latter stages of a tournament.
Suzanna Russell, Angus G. Evans, David G. Jenkins, and Vincent G. Kelly
Purpose: To determine the efficacy of 20 minutes of external counterpulsation (ECP) on subsequent 1.2-km shuttle run test (1.2SRT) performance and perceived recovery following fatiguing high-intensity exercise. Methods: After familiarization, 13 recreationally active males (21.4 [1.9] y) participated in 2 experimental trials in a randomized crossover design. At 8:00 AM, participants completed a 1.2SRT, followed by an individualized high-intensity exercise bout and 20 minutes of ECP or supine passive rest (control). At 2:00 PM a second 1.2SRT was completed. Completion time for 1.2SRT (measured in seconds), heart rate, and Borg rating of perceived exertion were compared across conditions. Total quality of recovery and 100-mm visual analogue scale of perceived benefit of recovery were assessed at multiple time points. Results: A significantly smaller decline in PM 1.2SRT completion time compared with AM (baseline) was found for ECP compared with control (P = .008; moderate, very likely beneficial effect size of −0.77 [−1.53 to 0.05]). Total quality of recovery was significantly higher for ECP than control (P < .001), and perceived benefit of recovery was higher following ECP (P < .001, very large, most likely beneficial effect size of 2.08 [1.22 to 2.81]). Conclusions: Twenty minutes of ECP was found to be an effective recovery modality for within-day, between-bouts exercise, positively influencing subsequent 1.2SRT performance and enhancing perceptual recovery. ECP may be applied as a viable alternative to optimize and accelerate the recovery process, particularly in the event of congested training or competition demands.
Marni J. Simpson, David G. Jenkins, Aaron T. Scanlan, and Vincent G. Kelly
Purpose: To examine relationships between external- and internal-workload variables in an elite female netball team, with consideration of positional differences. Methods: Nine elite female netball athletes had their weekly workloads monitored across their preseason and competition phases of a season. Internal workload was determined using summated heart-rate (HR) zones and session ratings of perceived exertion (sRPE), whereas external workload was determined using inertial movement units and included absolute PlayerLoad (PL), relative PL (PL per minute), accelerations (ACCEL), decelerations (DECEL), jumps, changes of direction (COD), high-intensity events, medium-intensity events, low-intensity events, PL in the forward direction, PL in the sideways direction, and PL in the vertical direction. Relationships between external- and internal-workload variables in the team and relative to playing position were examined. Results: Across the team, the strongest external workloads that correlated with summated HR zones were PL (r = .65), COD (r = .64), ACCEL (r = .61), and DECEL (r = .61). The strongest external workloads that correlated with sRPE were COD (r = .79), followed by jumps (r = .76), ACCEL (r = .75), and DECEL (r = .75). For all positions, except-goal shooter, the strongest correlation was between PL and sRPE (r = .88–.94). In the goal-shooter position, the strongest correlation was between summated HR zones and DECEL (r = .89). Conclusions: The inertial movement unit-derived external-workload variables are strongly related to common internal-workload variables. In particular, COD and sRPE appear to provide a good monitoring combination of external and internal training loads for elite netball players.
Vincent G. Kelly, Liam S. Oliver, Joanna Bowtell, and David G. Jenkins
Professional rugby league (RL) football is a contact sport involving repeated collisions and high-intensity efforts; both training and competition involve high energy expenditure. The present review summarizes and critiques the available literature relating the physiological demands of RL to nutritional requirements and considers potential ergogenic supplements that could improve players’ physical capacity, health, and recovery during the preparatory and competition phases of a season. Although there may not be enough data to provide RL-specific recommendations, the available data suggest that players may require approximately 6–8 g·kg−1·day−1 carbohydrate, 1.6–2.6 g·kg−1·day−1 protein, and 0.7–2.2 g·kg−1·day−1 fat, provided that the latter also falls within 20–35% of total energy intake. Competition nutrition should maximize glycogen availability by consuming 1–4 g/kg carbohydrate (∼80–320 g) plus 0.25 g/kg (∼20–30 g) protein, 1–4 hr preexercise for 80–120 kg players. Carbohydrate intakes of approximately 80–180 g (1.0–1.5 g/kg) plus 20–67 g protein (0.25–0.55 g/kg) 0–2 hr postexercise will optimize glycogen resynthesis and muscle protein synthesis. Supplements that potentially improve performance, recovery, and adaptation include low to moderate dosages of caffeine (3–6 mg/kg) and ∼300 mg polyphenols consumed ∼1 hr preexercise, creatine monohydrate “loading” (0.3 g·kg−1·day−1) and/or maintenance (3–5 g/day), and beta-alanine (65–80 mg·kg−1·day−1). Future research should quantify energy expenditures in young, professional male RL players before constructing recommendations.
Marni J. Simpson, David G. Jenkins, Mark Connick, and Vincent G. Kelly
Purpose: This study examined the relationships between training workloads, game workloads, and match performance in an elite netball team. Methods: Ten elite female netball athletes were monitored over a complete season. Training and game external workloads were determined through inertial movement units and expressed as absolute PlayerLoad (PL) and change of direction (COD). Monthly workload and training efficiency index were also calculated, which used internal workloads (session rating of perceived exertion and summated heart-rate zones). Game performance was assessed through a performance analysis statistic algorithm called NetPoints. To account for the influence of team game workloads on each other, the average workload for midcourt positions (avgMC) was calculated for each game. Data for each athlete were transformed into z scores, and linear mixed modeling was used to build models to examine the relationships between workloads and game performance. Results: Monthly PL, training efficiency index PL, and avgMC PL were statistically significant (P < .05) and positively related to game PL (z = 0.20–0.35, P < .001–.02). For game COD, statistically significant positive relationships were found between monthly COD (z = 0.29 [0.11], P = .01) and avgMC COD (z = 0.21 [0.09], P = .03). The models for NetPoints found significant negative relationships with monthly PL (z = 0.46 [0.12], P < .001) and COD (z = −0.36 [0.11], P = .01). Conclusions: Higher monthly workloads are related to higher game workload; however, they are also related to decreases in match performance. Therefore, netball practitioners should consider that increases to training workload in a 4-week period prior to a game can influence game workloads and performance.
Eric C. Haakonssen, David T. Martin, David G. Jenkins, and Louise M. Burke
Purpose:
This study investigated the satisfaction of elite female cyclists with their body weight (BW) in the context of race performance, the magnitude of BW manipulation, and the association of these variables with menstrual function.
Methods:
Female competitors in the Australian National Road Cycling Championships (n = 32) and the Oceania Championships (n = 5) completed a questionnaire to identify current BW, BW fluctuations, perceived ideal BW for performance, frequency of weight consciousness, weight-loss techniques used, and menstrual regularity.
Results:
All but 1 cyclist reported that female cyclists are “a weight-conscious population,” and 54% reported having a desire to change BW at least once weekly; 62% reported that their current BW was not ideal for performance. Their perceived ideal BW was (mean ± SD) 1.6 ± 1.6 kg (2.5% ± 2.5%) less than their current weight (P < .01), and 73% reported that their career-lowest BW was either “beneficial” or “extremely beneficial” for performance. 65% reported successfully reducing BW in the previous 12 months with a mean loss of 2.4 ± 1.0 kg (4.1% ± 1.9%). The most common weight-loss technique was reduced energy intake (76%). Five cyclists (14%) had been previously diagnosed as having an eating disorder by a physician. Of the 18 athletes not using a hormonal contraceptive, 11 reported menstrual dysfunction (oligomenorrhea or amenorrhea).
Conclusion:
Elite Australian female cyclists are a weight-conscious population who may not be satisfied with their BW leading into a major competition and in some cases are frequently weight conscious.
Eric C. Haakonssen, David T. Martin, Louise M. Burke, and David G. Jenkins
Body composition in a female road cyclist was measured using dual-energy X-ray absorptiometry (5 occasions) and anthropometry (10 occasions) at the start of the season (Dec to Mar), during a period of chronic fatigue associated with poor weight management (Jun to Aug), and in the following months of recovery and retraining (Aug to Nov). Dietary manipulation involved a modest reduction in energy availability to 30–40 kcal · kg fat-free mass−1 · d−1 and an increased intake of high-quality protein, particularly after training (20 g). Through the retraining period, total body mass decreased (−2.82 kg), lean mass increased (+0.88 kg), and fat mass decreased (−3.47 kg). Hemoglobin mass increased by 58.7 g (8.4%). Maximal aerobic- and anaerobic-power outputs were returned to within 2% of preseason values. The presented case shows that through a subtle energy restriction associated with increased protein intake and sufficient energy intake during training, fat mass can be reduced with simultaneous increases in lean mass, performance gains, and improved health.
Gary J. Slater, Anthony J. Rice, David Jenkins, Jason Gulbin, and Allan G. Hahn
To strengthen the depth of lightweight rowing talent, we sought to identify experienced heavyweight rowers who possessed physique traits that predisposed them to excellence as a lightweight. Identified athletes (n = 3) were monitored over 16 wk. Variables measured included performance, anthropometric indices, and selected biochemical and metabolic parameters. All athletes decreased their body mass (range 2.0 to 8.0 kg), with muscle mass accounting for a large proportion of this (31.7 to 84.6%). Two athletes were able to maintain their performance despite reductions in body mass. However, performance was compromised for the athlete who experienced the greatest weight loss. In summary, smaller heavyweight rowers can successfully make the transition into the lightweight category, being nationally competitive in their first season as a lightweight.
