Behind enemy lines: Expressing locomotor movements of athletes in the National Rugby League Women's (NRLW) competition relative to opposition data.

We provide a novel analysis of the locomotor movements of athletes in the National Rugby League Women's (NRLW) competition by presenting the data of opposing teams expressed as a relative (%) difference and explore the association with match outcome. 117 rugby league athletes from the four NRLW clubs participated in this study. Mean speed (m·min-1), mean high-speed running (>12 km·h-1; m·min-1), and mean acceleration (m·s-2) were measured in 12 matches (370 individual match files) using the Global Navigation Satellite System (GNSS). Individual GNSS-derived data from each match-half were summed across each team and the association with total points and the points differential in each match-half was determined using linear mixed models. Greater high-speed running and lower mean acceleration were associated with more points being scored. A greater relative difference in mean high-speed running between competing teams was associated with a higher points differential. That is, if a team completed 10% more high-speed running than their opposition, they were likely to score an average of 3.2 points more during a given match-half. This unique analysis of GNSS-derived data may assist coaches and performance support staff to interpret the locomotor movements of female rugby league players with the appropriate considerations for the opposition team.

Performance analysis of professional, semiprofessional, and junior elite rugby league match-play using global positioning systems.

The aim of the present study was to examine the positional differences in physical performance measures of professional, semiprofessional, and junior elite rugby league match-play using portable Global Positioning Systems (GPSs). Twelve professional, 12 semiprofessional, and 18 junior elite male rugby league players were monitored during 5 regular-season competition matches using portable GPS software. The mean total distance traveled during professional (8,371 ± 897 m) and semiprofessional (7,277 ± 734 m) match-play was significantly (p < 0.05) greater than that traveled during elite junior (4,646 ± 978 m) match-play. Position-specific total distance traveled and distance traveled per minute of playing time were significantly (p < 0.05) less for junior elite backs (5,768 ± 765 m; 74 ± 11 m·min) and forwards (4,774 ± 564 m; 82 ± 5 m·min) in comparison to those in professional (backs: 8,158 ± 673 m; 101 ± 8 m·min and forwards: 8,442 ± 812 m; 98 ± 12 m·min) and semiprofessional (backs: 7,505 ± 765 m; 94 ± 8 m·min and forwards: 6,701 ± 678 m; 89 ± 8 m·min) match-play. Maximum running speed, maximum sprints, and total sprint distance traveled by professional players were all significantly (p < 0.05) greater than those traveled by junior elite players but not semiprofessional players during match-play. Professional backs and forwards performed significantly (p < 0.05) more maximum sprints and traveled greater total distance during match-play in comparison to semiprofessional and junior elite players. The present findings demonstrate minimal differences in the physical performance measures of professional and semiprofessional rugby league match-play. The position-specific performance characteristics of junior elite match-play indicate that current junior elite player-development pathways may not provide adequate preparation for players transitioning into professional competition.

The aerobic performance of trained and untrained handcyclists with spinal cord injury.

The purpose of this study was to compare the cardiorespiratory response and mechanical efficiency (ME) of highly trained spinal cord injured (SCI) handcyclists with untrained SCI men. Ten trained handcyclists (≥ 2 years training) and ten untrained but physically active SCI men completed an incremental exercise test to exhaustion and a sub-maximal test (50 and 80 W) on an electromagnetically braked arm ergometer. The trained participants completed a questionnaire on their training and race performance over the past year, including average training volume (in kilometers), number of training sessions per week and best 20-km time trial. The trained SCI men had higher VO2 peak, peak power (p ≤ 0.001) and peak heart rate (p = 0.021) compared to the untrained SCI men. The trained men had higher (p ≤ 0.001) ME at 50 W (14.1 ± 2.0%) and 80 W (17.2 ± 2.6) compared to the untrained men (50 W; 12.5 ± 1.8 and 80 W; 15.7 ± 2.1). Peak power (r = -0.87, p = 0.001), VO2 peak (r = -0.67, p = 0.033) and ME (r = -0.58, p = 0.041) were negatively correlated with the participants best 20-km time trial. Multiple linear regression indicated peak power (p < 0.001) and VO2 peak (p = 0.021) were the best predictors (87%) of 20-km time trial performance. Highly trained SCI handcyclists have a greater aerobic capacity and ME compared to untrained SCI, and are able to reach their maximum age-predicted heart rate during an incremental exercise test. The best predictor of 20 km race performance in highly trained SCI handcyclists is peak power attained during an incremental exercise test.

Neuromuscular responses to impact and collision during elite rugby league match play.

The purpose of this study was to investigate the relationship between the prematch and short-term postmatch neuromuscular responses to the intensity, number, and distribution of impacts associated with collisions during elite Rugby League match play. Twenty-two elite male Rugby League players were monitored during 8 regular season competition matches using portable global positioning system (GPS) technology. The intensity, number, and distribution of impact forces experienced by players during match play were recorded using integrated accelerometry. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump on a force plate 24 hours prematch, 30 minutes prematch, 30 minutes postmatch and then at 24-hour intervals for a period of 5 days postmatch. The change in the dependent variables at each sample collection time was compared with that at 24 hours prematch and 30-minute prematch measures. There were significant (p < 0.05) decreases in PRFD and PP up to 24 hours postmatch with PF significantly (p < 0.05) being decreased 30 minutes postmatch. Significant (p < 0.05) correlations were found between the total number of impacts and PRFD and PP 30 minutes postmatch. Impact zones 4 (7.1-8.0 G), 5 (>8.1-10.0 G), and 6 (>10.1 G) were significantly (p < 0.05) correlated to PRFD and PP 30 minutes postmatch with the number of zone 5 and 6 impacts significantly (p < 0.05) correlated to PRFD and PP 24 hours postmatch. Elite Rugby League match play resulted in significant neuromuscular fatigue and was highly dependent on the number of heavy collisions >7.1G. Results demonstrate that neuromuscular function is compromised for up to 48 hours postmatch indicating that at least 2 days of modified activity is required to achieve full neuromuscular recovery after elite Rugby League match play. Position-specific demands on energy systems and the influence of repeated blunt force trauma during collisions during elite Rugby League match play should be considered when planning postmatch recovery protocols and training activities to optimize subsequent performance.

Long-term Return to Sports After Anterior Cruciate Ligament Injury: Reconstruction vs No Reconstruction-A Comparison of 2 Case Series.

BACKGROUND: Reconstruction is considered to provide the best opportunity for return to sports (RTS) after anterior cruciate ligament (ACL) rupture. However, recent studies report that <50% of athletes return to preinjury sporting levels and that RTS rates at 1 year after injury are the same for athletes undergoing reconstruction and nonoperative management. Long-term studies are essential to confirm these findings and guide decisions regarding surgery. PURPOSE: First, to compare long-term sports participation after ACL reconstruction and nonreconstruction and, second, to relate RTS level to strength and stability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHOD: Patients with ACL deficiency (n = 101) who were referred for physical therapy at the time of diagnosis were followed long term: 56 were treated surgically 2.5 years (interquartile range [IQR], 1-4) after injury and 45 were treated nonoperatively. At long-term follow-up, the reconstructed group was at 9 years (IQR, 7-11) after injury and aged 33.3 ± 6.2 years (mean ± SD, 70% male; 61% meniscal injury), and the nonreconstructed group was at 11 years (IQR, 7-14) after injury and aged 38.7 ± 8.3 years (67% male; 58% meniscal injury). Measures of objective stability, subjective stability, and quadriceps/hamstring strength were compared between groups using independent-samples t tests. Current RTS level, scored on a 6-point scale, was compared between groups using chi-square tests. Spearman rho correlated RTS with outcome measures. RESULTS: Of the total group of patients, 96% with reconstruction and 93% without continued to play sports. In the reconstructed and nonreconstructed groups, 4% and 7% did not RTS, and 8% and 17% returned to safe sports, respectively: 13% and 12% to running, 20% and 26% to sports involving limited twisting, 12% and 24% to recreational pivoting sports, and 43% and 14% to competitive pivoting sports. The only significant difference was in return to competitive pivoting sports (P = .003). Five patients with reconstruction ruptured the contralateral ACL, and 1 ruptured his graft. Most patients treated nonoperatively modified their sports participation. Their RTS levels correlated significantly with quadriceps strength (r = 0.65; P < .001), hamstring strength (r = 0.721; P < .001), and subjective stability (r = 0.405; P = .01). CONCLUSION: Surgically treated patients returned to competitive pivoting sports at 3 times the rate of those managed nonoperatively, confirming that reconstruction provides the best opportunity for continued participation in competitive pivoting sports. Regardless of grouping, RTS correlated with modifiable factors, including strength and stability. Higher rates of subsequent injuries observed after reconstruction may result from increased participation in competitive pivoting sports.

The role of rate of force development on vertical jump performance.

The purpose of this study was to examine a) the relationship between rate of force development (RFD) and vertical jump (VJ) performance during a counter movement jump (CMJ), and b) the reliability of RFD recorded during the CMJ and squat jump (SJ) forms of the VJ. Twenty-three physically active men aged 23 ± 3.9 years participated in the study. Subjects completed 3 unloaded CMJ and 3 unloaded SJ in random order on a force plate. The RFD was measured during CMJ and SJ movements with vertical jump displacement (VJD) measured simultaneously during the CMJ only. Subjects incorporated arm swing to their CMJ technique to reach up as high as possible, and VJD was measured. All SJ were executed with both hands on the hips throughout the full range of movement. Peak rate of force development (PRFD), peak force (PF), and time to peak force (TPF) were significantly correlated to VJD during the CMJ (r = 0.68, r = 0.51, and r = -0.48, respectively). The RFD and TPF during the CMJ and SJ were associated with low test-retest reliability (coefficient of variation [CV]: 11.8-7.9%). Peak and average power, PF, and VJD produced high test-retest reliability (CV: 2.8-5.1%) during both the CMJ and SJ movements. Our results indicate that PRFD, a measure of explosive strength, and PF, a measure of maximal strength, are the primary contributors to VJD during the CMJ in physically active men. However, caution must be used when interpreting data using PRFD because of its low retest reliability.

Markers of postmatch fatigue in professional Rugby League players.

The aim of the present study was to identify neuromuscular, biochemical, and endocrine markers of fatigue after Rugby League match play. Seventeen elite Rugby League players were monitored for a single match. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump (CMJ) on a force plate pre and postmatch play. Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 120 hours to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). There were significant (p < 0.05) decreases in PRFD and PP up to 24 hours postmatch with PF significantly (p < 0.05) decreased immediately postmatch. The [sCort] significantly (p < 0.05) increased from 24 hours prematch to 30 minutes prematch and up to 24 hours postmatch compared with 24 hours prematch. Plasma [CK] significantly (p < 0.05) increased 30 minutes postmatch with a peak occurring 24 hours postmatch and remained elevated above 24 hours prematch for at least 120 hours postmatch. There were significant (p < 0.05) correlations between the increase in [CK] and reduction in PRFD 30 minutes postmatch and 24 hours postmatch. The [sCort] was significantly (p < 0.05) correlated with the reduction in PF 30 minutes postmatch. Results demonstrate that neuromuscular function is compromised for up to 48 hours after match play. Elevated [CK] despite 120-hour recovery indicate that damage to muscle tissue after Rugby League match play may persist for at least 5 days postmatch. Despite the prolonged presence of elevated [CK] postmatch, strength training 48 hours postmatch may have resulted in a compensatory increase in PRFD supporting the inclusion of strength training during the short-term postmatch recovery period.

Biochemical and endocrine responses to impact and collision during elite Rugby League match play.

The purpose of this study was to investigate the relationship between the prematch and short-term postmatch biochemical and endocrine responses to the intensity, number, and distribution of impacts associated with collisions during elite Rugby League match play. Seventeen elite male Rugby League players each provided blood and saliva samples 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 5 days postmatch to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). The intensity, number, and distribution of impact forces experienced by players during match play were recorded using portable global positioning systems (GPSs). The change in the dependent variables at each sample collection time was compared to 24 hours prematch and 30-minute prematch measures. The [CK] and [sCort] increased significantly (p < 0.05) during match play. Significant correlations (p < 0.05) were observed between the number of hit-ups and peak [CK] 24 hours postmatch, 48 hours postmatch, and 72 hours postmatch (p < 0.05). The number of impacts recorded in zone 5 (8.1-10.0G) and zone 6 (>10.1G) during match play was significantly correlated (p < 0.05) to [CK] 30 minutes postmatch, 24 hours post, 48 hours post, and 72 hours postmatch. The GPS was able to provide data on the intensity, number, and distribution of impacts resulting from collisions during match play. Elite Rugby League match play resulted in significant skeletal muscle damage and was highly dependent on the number of heavy collisions >8.1G. [CK] remained elevated 120 hours postmatch identifying that at least 5 days modified activity is required to achieve full recovery after elite Rugby League match play.

Performance analysis of elite Rugby League match play using global positioning systems.

The aim of this study was (a) to examine the physiological demands of competitive Rugby League match play using portable Global Positioning Systems (GPSs) to monitor players' movement patterns and heart rate (HR) and (b) examine positional comparisons to determine if players' physiological requirements are influenced by their playing position during Rugby League match play. Twenty-two elite male Rugby League players were monitored during 5 regular season competition matches using portable GPS software. There was no difference in the total distance traveled between backs (5,573 ± 1,128 m) and forwards (4,982 ± 1,185 m) during match play. Backs and forwards had an average HR of approximately 80% of their maximum (162 ± 11 and 165 ± 12 b · min(-1), respectively) throughout each match. Backs achieved greater maximum running speed (8.6 ± 0.7 m · s(-1)), completed a greater number of sprints (18 ± 6), had less time between sprints (3.2 ± 1.1 minutes), achieved a greater total duration of sprinting (44.7 ± 9.1 seconds), and covered more distance sprinting (321 ± 74 m) than forwards did (6.8 ± 0.7 m · s(-1), 11 ± 5, 5.2 ± 2.2 minutes, 25.8 ± 9.2 seconds, and 153 ± 38 m, respectively). The GPS successfully provided real-time feedback to identify significant positional differences in distances covered, running speed characteristics, and the physiological demands of competitive Rugby League match play.

Do compression garments enhance the active recovery process after high-intensity running?

Lovell, DI, Mason, DG, Delphinus, EM, and McLellan, CP. Do compression garments enhance the active recovery process after high-intensity running? J Strength Cond Res 25(12): 3264-3268, 2011-This study examined the effect of wearing waist-to-ankle compression garments (CGs) on active recovery after moderate- and high-intensity submaximal treadmill running. Twenty-five male semiprofessional rugby league players performed two 30-minute treadmill runs comprising of six 5-minute stages at 6 km·h, 10 km·h, approximately 85% VO(2)max, 6 km·h as a recovery stage followed by approximately 85% VO(2)max and 6 km·h wearing either CGs or regular running shorts in a randomized counterbalanced order with each person acting as his own control. All stages were followed by 30 seconds of rest during which a blood sample was collected to determine blood pH and blood lactate concentration [La]. Expired gases and heart rate (HR) were measured during the submaximal treadmill tests to determine metabolic variables with the average of the last 2 minutes used for data analysis. The HR and [La] were lower (p ≤ 0.05) after the first and second 6 km·h recovery bouts when wearing CGs compared with when wearing running shorts. The respiratory exchange ratio (RER) was higher and [La] lower (p ≤ 0.05) after the 10 km·h stage, and only RER was higher after both 85% VO(2)max stages when wearing CGs compared with when wearing running shorts. There was no difference in blood pH at any exercise stage when wearing the CGs and running shorts. The results of this study indicate that the wearing of CGs may augment the active recovery process in reducing [La] and HR after high-intensity exercise but not effect blood pH. The ability to reduce [La] and HR has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery.

The effect of strength training and short-term detraining on maximum force and the rate of force development of older men.

This study examined the effect of strength training (ST) and short-term detraining on maximum force and rate of force development (RFD) in previously sedentary, healthy older men. Twenty-four older men (70-80 years) were randomly assigned to a ST group (n = 12) and C group (control, n = 12). Training consisted of three sets of six to ten repetitions on an incline squat at 70-90% of one repetition maximum three times per week for 16 weeks followed by 4 weeks of detraining. Regional muscle mass was assessed before and after training by dual-energy X-ray absorptiometry. Training increased RFD, maximum bilateral isometric force, and force in 500 ms, upper leg muscle mass and strength above pre-training values (14, 25, 22, 7, 90%, respectively; P < 0.05). After 4 weeks detraining all neuromuscular variables were significantly (P < 0.05) lower than after 16 weeks training but remained significantly (P < 0.05) higher than pre-training levels except for RFD which had returned to pre-training levels. These findings demonstrate that high-intensity ST can improve maximum force and RFD of older men. However, older individuals may lose some neuromuscular performance after a period of short-term detraining and that resistance exercise should be performed on a regular basis to maintain training adaptations.

Creatine kinase and endocrine responses of elite players pre, during, and post rugby league match play.

The purpose of the present study was to (a) examine player-movement patterns to determine total distance covered during competitive Rugby League match play using global positioning systems (GPSs) and (b) examine pre, during, and postmatch creatine kinase (CK) and endocrine responses to competitive Rugby League match play. Seventeen elite rugby league players were monitored for a single game. Player movement patterns were recorded using portable GPS units (SPI-Pro, GPSports, Canberra, Australia). Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 5 days postmatch to determine plasma CK and salivary testosterone, cortisol, and testosterone:cortisol ratio (T:C). The change in the dependent variables at each sample collection time was compared to 24-hour prematch measures. Backs and forwards traveled distances 5,747 ± 1,095 and 4,774 ± 1,186 m, respectively, throughout the match. Cortisol and CK increased significantly (p < 0.05) from 30 minutes prematch to 30 minutes postmatch. Creatine kinase increased significantly (p < 0.05) postmatch, with peak CK concentration measured 24 hours postmatch (889.25 ± 238.27 U·L). Cortisol displayed a clear pattern of response with significant (p < 0.05) elevations up to 24 hours postmatch, compared with 24 hours prematch. The GPS was able to successfully provide data on player-movement patterns during competitive rugby league match play. The CK and endocrine profile identified acute muscle damage and a catabolic state associated with Rugby League match play. A return to normal T:C within 48 hours postmatch indicates that a minimum period of 48 hours is required for endocrine homeostasis postcompetition. Creatine kinase remained elevated despite 120 hours of recovery postmatch identifying that a prolonged period of at least 5 days modified activity is required to achieve full recovery after muscle damage during competitive Rugby League match play.

Fatigue Indices and Perceived Exertion Highlight Ergometer Specificity for Repeated Sprint Ability Testing.

This study aimed to compare the time course of measures of performance, fatigue, and perceived exertion during repeated-sprint ability (RSA) testing performed on a non-motorized treadmill (NMT) and cycling ergometer (CE). Fourteen physically active participants performed two 10 ×6 s-1 RSA tests with a 1:4 work-to-rest ratio (24 s recovery) on NMT and CE. Measures of performance [peak and mean power output (PPO and MPO), cadence, and the time to reach PPO (TTP)] and of fatigue (fatigue index and decrement score) and ratings of perceived exertion (RPE) were collected during each session. The level of significance was set at p < 0.05. Participants completed the RSA test at a MPO of 1,041 ± 141 W on CE and 431 ± 48 W on NMT, achieving PPO of 2,310 ± 339 W on CE and 1,763 ± 289 W on NMT. Participants' weight was significantly correlated with PPO and MPO on CE (p < 0.001) and with MPO on NMT (p < 0.001). PPO on CE and NMT was significantly correlated only for absolute measures of power (p < 0.01). Cadence was higher and decreased throughout the RSA on NMT compared to CE, where it decreased only at the seventh bout. TTP was significantly shorter and more affected by fatigue on NMT than on CE. Fatigue indices were significantly greater on NMT compared to CE, with significant correlations between the decrement score and absolute and relative PPO on CE and NMT, between the fatigue index and absolute and relative PPO only on NMT, and no significant correlations with MPO. During RSA, RPE increased more on NMT compared to CE from bouts 3 to 7. During recovery, RPE was consistently higher on NMT at 1, 3, and 5 min post exercise compared to CE. These findings indicate that RSA performed on NMT induces greater fatigue and physiological load than CE, which originated in the lower resistive torque typically used on NMT compared to CE, resulting in a front loaded power output profile from the greater acceleration and cadence. From these results, we discuss that despite providing highly correlated measures of power output, NMT and CE should not be used interchangeably to assess RSA as they elicit markedly different responses. We also discuss these results from the fundamental differences in active muscle mass and power application patterns between running and cycling, which could form the basis of future studies.

Similar rates of fat oxidation during graded submaximal exercise in women of different body composition.

BACKGROUND: Moderate intensity exercise ranging 40-60% of maximum oxygen uptake is advised to promote energy expenditure and fat oxidation in overweight and obese people. Although fat oxidation has been shown to be highly variable among individual, there is still a relative uncertainty regarding exercise prescription for women specifically. This article aimed to determine whether indicators of body composition can be used to narrow the exercise intensity range for exercise prescription in women. METHODS: A total of 35 healthy women (age 30.8±9.5 yr) classified according to their BMI in normal weight (NOR; ≤24.9 kg·m2), overweight (OVW; 25-29.9 kg·m2) and obese groups (OBE; ≥30 kg·m2) completed a submaximal graded test (intensities eliciting ~30%, 40%, 50% and 60% of maximum oxygen uptake). Blood lactate, perceived exertion and absolute and relative substrate oxidation for fat (OXFAT) and carbohydrates (OXCHO) were measured at each stage. RESULTS: Perceived exertion and blood lactate increased as a function of exercise but did not differ across groups. There were no significant changes in absolute and relative OXFAT across groups, or as a function of exercise intensity. Peak OXFAT occurred at the 40%, 50% and 40% stages for NOR, OVW and OBE groups, respectively, with no significant differences across groups. CONCLUSION: We measured no differences, but considerable inter-individual variation, in fat oxidation in women of different body composition. This result is in agreement with previous research based on exercise performed at constant rate and in independent participant groups. Our findings do not support the fat oxidation hypothesis, and further emphasise the perspective that exercise prescription should be individualised and likely be based on considerations other than substrate oxidation.

Body composition influences blood pressure during submaximal graded test in women.

This study aimed to determine whether body composition affected cardiovascular responses of normal, overweight and obese women by comparing heart rate (HR) and blood pressure (BP) during a graded submaximal treadmill exercise. Thirty five healthy non-smoking, premenopausal women (age 30.8 ±â€¯9.5 yr; height 1.66 ±â€¯0.05 m; weight 73.8 ±â€¯18.9 kg; body fat 36.2 ±â€¯9.5%; maximum oxygen uptake 33.5 ±â€¯8.1 mL·min·kg-1) volunteered for this study, and were classified into three groups based on BMI: normal weight (NOR; ≤24.9 kg·m2), overweight (OVW; 25-29.9 kg·m2) and obese (OBE; ≥30 kg·m2). Participants performed a submaximal graded test at 30%, 40%, 50% and 60% of maximal oxygen uptake, during which HR, systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were measured. At rest, participants of OBE group had higher BP than NOR and OVW. During the submaximal graded test, HR, SBP and MAP increased as a function of intensity. There were no group differences in HR, but greater SBP, DBP and MAP in OBE compared to NOR and OBW at all intensities except 60%. Overall, our study further contributes to underscore the importance of stress testing specifically to evaluate the increased risks apparently healthy obese women are placed at to developing diseases from the chronic exposure to raised BP, despite normal resting BP and HR responses during exercise.

Strength training improves submaximum cardiovascular performance in older men.

PURPOSE: To determine if 16 weeks of strength training can improve the cardiovascular function of older men during submaximum aerobic exercise. METHODS: Twenty four men aged 70-80 yr were randomly assigned to a strength training (ST; n = 12) and control group (C; n = 12). Training consisted of 3 sets of 6 - 10 repetitions at 70% to 90% of 1RM, 3 times per week, on an incline squat machine for 16 weeks, followed by 4 weeks detraining. Leg strength and maximum oxygen consumption (VO2 max) were assessed every 4 weeks of the 20-week study. Cardiovascular function was assessed during submaximum cycle exercise at 40 Watts, 50% and 70% of VO2 max before training, after 16 weeks training, and after 4 weeks detraining. RESULTS: At 40 Watts, heart rate (HR), systolic blood pressure, and rate pressure product (RPP) were lower and stroke volume (SV) significantly higher after 16 weeks training and 4 weeks detraining: at 50% VO2 max, HR and RPP were lower after 16 weeks training and 4 weeks detraining: at 70% VO2 max, cycle ergometry power, VO2 and arterio-venous oxygen difference (a - vO2 ) were higher after 16 weeks training. Leg strength and VO2 max increased after 16 weeks training, with leg strength remaining above pre-training levels after 4-weeks detraining. CONCLUSIONS: Sixteen weeks of strength training significantly improves the cardiovascular function of older men. Therefore strength training not only increases muscular strength and hypertrophy but also provides significant cardiovascular benefits for older individuals.

Correction to: Current Methodologies and Implications of Phase Identification of the Vertical Jump: A Systematic Review and Meta-analysis.

Pages 1313-5, table 1, column 1: The cell entries in the 'Reference' column, which previously read.

Factors that influence ground reaction force profiles during counter movement jumping.

BAKGROUND: The purpose of this study was to examine how hip, knee and ankle kinetics and kinematics influence effective impulse production during countermovement jumps. METHODS: Eighteen semi-professional soccer players (22.8±2.2 years) volunteered to participate in the study. Participants completed three maximal countermovement jumps on two force platforms (1000 Hz) that were linked to a nine camera infrared motion capture system (500 Hz). RESULTS: Kinetic and kinematic data revealed jumpers who fail to achieve uniform ground reaction force curves that result in optimal impulse production during their jump always display hip adduction and or hip internal rotation during the concentric phase of the countermovement jump. The variation of hip adduction and or internal rotation likely represents failed joint transition during the concentric phase of the countermovement jump and appears to account for a non-uniform force trace seen in these jumpers. CONCLUSIONS: The findings suggest rehabilitation and conditioning exercises for injury prevention and performance may benefit from targeting frontal and transverse plane movement.

The Effect of Previous Wingate Performance Using one Body Region on Subsequent Wingate Performance Using a Different Body Region.

The 30 second Wingate Anaerobic Test (WAnT) is the gold standard measure of anaerobic performance. The present investigation aimed to determine if a previous WAnT using one body region significantly affected a subsequent WAnT using a different body region. Twelve male university students (n = 12, 23 ± 2 years, 84 ± 16.1 kg, 178.5 ± 7.4 cm) volunteered to complete two repeated WAnT protocols (either lower body WAnT followed by an upper body WAnT or vice versa) on two separate testing occasions. The upper body WAnT was conducted on a modified electromagnetically braked cycle ergometer using a flywheel braking force corresponding to 5% bodyweight. The lower body WAnT was conducted on an electronically braked cycle ergometer using a flywheel braking force corresponding to 7.5% bodyweight. Participants had a 1 minute rest period for transition between WAnTs. Data are reported as mean ± standard deviation. No significant differences were identified in power indices for the lower body between 30 s WAnTs. When the upper body WAnT was performed 2nd, absolute peak power (p < 0.01), mean power (p < 0.001) and relative mean power (p < 0.001) were significantly lower compared to when the upper body WAnT was performed 1st. The value of maximum revolutions per minute was significantly lower (p < 0.001) when the upper body WAnT was performed after the lower body WAnT, compared to when it was performed 1st (193.3 ± 11.4 1st vs 179.8 ± 14.4 2nd). Previous upper body sprint exercise does not significantly affect lower body sprint exercise; however, previous lower body sprint exercise severely compromises subsequent upper body sprint performance.

Changes in sleep quantity and efficiency in professional rugby union players during home-based training and match play.

BACKGROUND: Adequate sleep is paramount to athlete recovery and performance, however little is known about the typical sleep patterns of professional rugby union players during home based training and match play in the competitive season. The aim of the present study was to monitor changes in sleep quantity and efficiency of elite male rugby union players over a twelve-night period, which included training and two competitive matches. METHODS: A total of ten elite male rugby union players from a selected team, participated in the study. Athletes' sleep quantity and efficiency was monitored over a twelve-night period using the BodyMedia SenseWear units (BSU). RESULTS: There was a significant difference in sleep quantity (P<0.05) on game nights compared to non-game night, with players sleeping less on game nights. Time to sleep on game nights was also significantly (P<0.05) later than non-game nights. There was no significant difference in sleep efficiency or time at wake over the twelve-night period. Sleep efficiency is defined as a percentage score calculated by incorporating movement and physiological measures over the sleep duration as determined by the BSU. Also there was no significant difference between sleep parameters on the game nights. The findings show players have significantly (P<0.05) reduced sleep following a home game, which is of concern considering the established negative influence of sleep deprivation on cognitive and physical performance. CONCLUSIONS: This data may assist coaching, medical and performance staff to develop and implement team and individualised sleep monitoring regimes to optimise training and on-field performance.