The effects of varying inertial loadings on power variables in the flywheel romanian deadlift exercise.

The aim of this study was to investigate the effect of four different inertial loads (0.025, 0.050, 0.075, and 0.100 kg· m²) on concentric (CON) power, eccentric (ECC) power, and ECC overload in the flywheel Romanian deadlift (RDL). Fourteen recreationally trained males (27.9 ± 6.4 years, 90 ± 10.7 kg, 180.7 ± 5.5 cm) volunteered for the study. They had a minimum of two years of resistance training experience, although none had experience in flywheel inertia training (FIT). All participants performed the flywheel RDL on a flywheel device (kBox 3, Exxentric, AB TM, Bromma, Sweden). Each set was performed using different inertial loads, those being 0.025, 0.050, 0.075, and 0.100 kg·m². For CON, ECC power, and ECC overload, there was a significant difference (p < 0.001) between inertial loadings. In conclusion, results highlight that lower inertial load leads to higher peak CON and ECC power values, precisely 0.025 kg· m². Regarding ECC overload, medium to higher loads (0.050, 0.075, and 0.100 kg·m²) will lead to higher values.

Interday Reliability of the Reactive Strength Index and Optimal Drop Height.

Byrne, DJ, Browne, DT, Byrne, PJ, and Richardson, N. Interday reliability of the reactive strength index and optimal drop height. J Strength Cond Res 31(3): 721-726, 2017-The purpose of this study was to investigate the interday reliability of the reactive strength index (RSI) and optimal drop height (ODH) identification from multiple drop heights. Nineteen male trained hurling players (23.1 ± 2.9 years, 83.1 ± 15.5 kg, and 182.5 ± 4.89 cm) completed 2 maximal depth jumps from 4 incremental drop heights (30, 40, 50, and 60 cm), over 2 separate testing sessions 48 hours apart. The RSI and ODH were analyzed for reliability using intraclass correlation coefficient (ICC) and coefficient of variation (CV). The RSI and ODH both demonstrated good reliability with ICC ≥0.80 (0.87 and 0.81) and CV ≤10% (4.2 and 2.98), respectively. The results of this study support the use of an incremental depth jump protocol to find the RSI and ODH in trained hurlers. It is recommended that the incremental depth jump protocol be used when assessing an athlete's reactive strength, as it allows a reactive strength profile, maximum RSI, and an ODH to be determined, all of which can provide vital information when determining an athletes training intensity and load.

Flywheel Romanian Deadlift: Intra- and Inter-Day Kinetic and Kinematic Reliability of Four Inertial Loads Using Cluster Sets.

The primary aim of this study was to investigate the intra- and inter-day reliability of flywheel cluster set training in concentric power (CON), eccentric power (ECC), and ECC overload during the Romanian deadlift exercise (RDL). A secondary aim was to assess the acute effect of internal and external attentional focus instructions on mean power when performing the flywheel RDL. Fourteen collegiate male field sport athletes (age, 23.3 ± 3.7 years; mass, 80.8 ± 9.9 kg; height, 1.79 ± 0.06 m) were randomized into internal (n = 7) or external (n = 7) attentional focus groups and attended four testing sessions, with a between-session separation of 7 days. Sessions consisted of four cluster sets of fifteen repetitions "excluding momentum repetitions" (4 × (5 + 5 + 5)) using a specific inertial load (0.025, 0.050, 0.075, and 0.100 kg·m-2) for a given set in a randomized ascending or descending order. Cluster sets were separated by a 45 s intra-set rest period. Both instructional focus groups attained familiarization, although the time taken to achieve familiarization (outcome stability) differed between groups. The external instructional group attained familiarization post-session 2 (Cohen's d (ES), ES = 0.11-0.65) with little volatility between performance measures (CV% = 4.61-9.59). Additionally, the internal group reported inconsistencies among all inertial loads, reporting large differences in MP in the 0.100 kg·m-2 inertial load from day 2 to day 3 (ES = 1.22) and both 0.050 kg·m2 (p = 0.010) and 0.075 kg·m-2 (p = 0.016) between day 3 and day 4. The flywheel RDL cluster set approach is a reliable training modality for maintaining mean power output during cluster set repetitions.

Intra- and Inter-Day Reliability of Inertial Loads with Cluster Sets When Performed during a Quarter Squat on a Flywheel Device.

The aims of this study were to (i) estimate the intra- and inter-day reliability of mean concentric (CON) and eccentric (ECC) power at different inertial loads during a flywheel quarter-squat using a cluster set approach and (ii) to determine the acute effect of internal and external attentional focus on mean power when performing the flywheel quarter squat. Twelve collegiate field sport male athletes (age 22.4 ± 3.2 years, weight 81.4 ± 10.3 kg, height 1.81 ± 0.06 m) attended four cluster set testing sessions separated by 7 days. Sessions consisted of 4 sets of 15 repetitions using 4 inertial loads (0.025, 0.050, 0.075, and 0.100 kg·m2). A cluster block consisted of 5 repetitions, including "momentum repetitions" (4 × 5 + 5 + 5). Mean power (MP), CON power, ECC power, and ECC overload were recorded for both internal and external attentional focus groups. The external instructional group attained familiarization after two flywheel sessions (ES = 0.03-0.15) with little volatility between performance measures (CV% = 3.39-9.22). The internal instructional group showed large differences in MP output from session 2 to session 3 for all loads (ES = 0.59-1.25). In conclusion, the flywheel cluster set approach is a reliable training modality for maintaining MP output during all repetitions.

The Efficacy of Flywheel Inertia Training to Enhance Hamstring Strength.

The purpose of this narrative review is to examine the efficacy of flywheel inertia training to increase hamstring strength. Hamstring strain injury is common in many sports, and baseline strength deficits have been associated with a higher risk of hamstring strain injury. As a result, strength and conditioning professionals actively seek additional techniques to improve hamstring strength with the aim of minimising the incidence of hamstring strain injury. One method of strength training gaining popularity in hamstring strength development is flywheel inertia training. In this review, we provide a brief overview of flywheel inertia training and its supposed adaptions. Next, we discuss important determinants of flywheel inertia training such as familiarisation, volume prescription, inertia load, technique and specific exercise used. Thereafter, we investigate its effects on hamstring strength, fascicle length and hamstring strain injury reduction. This article proposes that hamstring specific flywheel inertia training can be utilised for strength development, but due to the low number of studies and contrary evidence, more research is needed before a definite conclusion can be made. In addition, as with any training modality, careful consideration should be given to flywheel inertia training determinants. This review provides general recommendations of flywheel inertia training determinants that have value when integrating flywheel inertia training into a hamstring strengthening program.

Quantification of internal and external training load during a training camp in senior international female footballers.

OBJECTIVE: This study aimed to quantify the internal and external training load profile of an international training camp and identify any differences between positional groups or starting status. METHODS: 18 players were sampled using a global positioning system (GPS) and internal training load (TL) via session rate of perceived exertion (RPE). RESULTS: Internal and external training load variation was present across all six individual training sessions. Results indicated match day -7 (MD-7), had significantly (P= 0.001) less training volume (3339.5 m) than all other training sessions. MD-5 and MD-2 were the most intense (387.5 and 201 m very high speed running (VHSR) and 187.5 and 49 m sprint distance (SPD) respectively in combination with large volume (5933.5 and 5151.5 m). Differences in playing position and starting status were observed in MD-2. Forwards (FW) covered significantly greater distances of VHSR (P= 0.008) and SPD (P= 0.008) in comparison to midfielders (MF) whilst starters reported significantly (P = 0.013) higher internal training loads (TL). CONCLUSION: This study provides the first report on training load in elite female footballers during an international training camp including a competitive fixture highlighting the undulation of training loads across the individual training sessions, playing positions and starting status.

Comparing the Current Training Running Demands of Elite Camogie Players to Competitive Match-Play.

Training to meet match-play demands is a primary objective in an athlete's preparation for their games. Despite camogie match-play running demands being available, how current training practices compare, specifically individual training components, remains unknown. This study aimed to investigate and compare current elite camogie training to match-play demands. Thirty-three (n = 33) elite camogie players wore 10 Hz Playertek GPS units during twenty-five training sessions and ten competitive matches. Training sessions were analysed using ball-in-play time and split into warm-ups, drills, small-sided games, running, and training matches. Metrics were converted into relative terms (per minute), to allow comparisons. Players cover significantly greater (p < 0.05) total distance (non-parametric standardised effect sizes (r = 0.45)), peak speed (r = 0.45), high-speed running (r = 0.13), sprint distance (r = 0.20), and total decelerations (r = 0.12−0.22) during match-play than training. Relatively, players cover significantly greater distance during running, small-sided games, and training matches compared to match-play (r = 0.21−0.29). Compared with match-play, running results in significantly greater high-speed running and sprint distance (r = 0.18−0.41), with greater accelerations (3−4 m∙s−2) during warm-ups, running, and small-sided games (r = 0.14−0.28). Current total training demands seem to fall behind match-play. However, relatively, training matches and small-sided games match or surpass competitive match-play demands. These findings may be utilised in preparing camogie teams for competition.

The positional and temporal running demands of elite inter-county camogie match play across 5-min intervals.

Purpose: Camogie is a native Irish female field sport game. This investigation aimed to establish elite camogie players' positional and temporal running demands across 5-min intervals during competitive match play. Methods: Thirty-one (n = 31) inter-county camogie players (age: 24 ± 4 years; height: 167.2 ± 6.3 cm; body mass: 67.0 ± 7.5 kg) from two squads wore commercially available 10-Hz Playertek GPS units (Playertek by Catapult, Australia) during Senior All-Ireland Championship games (n = 8). Players were categorised according to match positions (defenders, mid-fielders, forwards). Games were split into quarters, and subsequently into 5-min intervals for analysis (5-min intervals are more closely associated with small-sided games and training than half-by-half comparisons). Results: Analysis revealed significant positional and temporal differences to exist (p < 0.05). Mid-fielders covered greater total (r = 0.16-0.19) and relative distance (r = 0.15-0.17), with forwards covering greater high-speed distances (r = 0.09-0.19). Mid-fielders had greater temporal performance decrements for sprint distance between all first quarter intervals and 55-60 interval (Kendall's W (W = 0.86-1.00), as well as the 0-5 and all final quarter intervals for total distance (W = 0.86-1.00). Defenders had significant performance decreases during the 25-30 (W = 0.29-0.60) and 40-45 interval (W = 0.14-0.57) for both total and relative distance. Forwards exhibited the lowest performance decrement, with no significant differences for peak speed, high-speed running, or sprint distance (W = 0.00-0.53). Conclusion: Positional and temporal differences are evident in elite camogie match play. Mid-fielders have the greatest total and sprint distance decrements, with defenders also exhibiting total and relative distance decreases. Coaches should focus on temporal differences with respect to position, to minimise performance decrements.

The physical characteristics of elite camogie players.

BACKGROUND: The aim of the current investigation was to establish the positional physical characteristics of elite intercounty camogie players and compare them to current female field sport athlete norms. METHODS: Forty-five elite intercounty camogie players (age: 23.31±3.47 years; height: 168.97±5.60 cm; body mass: 68.37±7.44 kg) completed preseason physical performance testing. Physical characteristics including isometric mid-thigh pull (IMTP) peak force, IMTP relative peak force, countermovement jump (CMJ) height, 10 to 5 repeated jump test Reactive Strength Index (RSI), 5-, 10- and 20-m sprint times and yo-yo intermittent recovery test level 1 (Yo-Yo IR1) accumulated distance were assessed. All players were subdivided into their playing positions (defenders, mid-fielders, forwards) by self-reported means, to investigate if any positional differences existed. RESULTS: A multivariate analysis of variance (MANOVA) and Kruskal-Wallis H tests revealed no significant positional difference for any physical tests (P>0.05). Moderate main effects for RSI between mid-fielders and forwards (ES=0.64) and for 20-m sprint time between defenders and midfielders (ES=0.63) were noted. Trivial to small main positional effects were evident for all other tests (ES=0.03-0.60). CONCLUSIONS: The relative homogeneity of results across performance measures indicates no obvious position specific characteristics within this cohort. This data will provide normative values for coaches to better inform training and return to play practices in camogie.

The Effects of Different Types of Eccentric Overload Training on Strength, Speed, Power and Change of Direction in Female Basketball Players.

The aim of this study was to investigate the effect of two types of eccentric (ECC) overload training on strength, speed, power and change of direction in female basketball players. Twenty amateur basketball players (mean ± SD: age: 23.67 ± 6.05 years; height: 1.73 ± 0.05 m; body mass: 80.28 ± 17.67 kg) participated in a randomized trial. The players performed either flywheel inertial training (FIT) (n = 11) or tempo ECC training (TET) (n = 9) for 4 weeks, performing two sessions weekly. Performance characteristics, one repetition back squat (1RM), counter-movement jump (CMJ), squat jump (SJ), 10-metre sprint (10 m), change of direction (COD) and sit and reach flexibility (S&R) were tested pre and post intervention. Post-hoc testing revealed significant improvements in the FIT group for 1RM (p ≤ 0.001; ES = 0.59), 10 m (p = 0.003; ES = -0.54) and CMJ (p ≤ 0.001; ES = 1.04), while significant improvements were revealed in the TET group for 1RM (p = 0.007; ES = 0.71) and S&R (p ≤ 0.001; ES = 0.58). In conclusion, both FIT and TET groups demonstrated a positive training stimulus for increasing muscular strength. FIT may produce superior adaptions in CMJ and 10-m sprint, while TET may produce superior adaptions in S&R. Neither group achieved increases in either SJ or COD.

Vitamin E and Alzheimer's disease: what do we know so far?

Vitamin E has been proposed as a potential clinical intervention for Alzheimer's disease (AD) given the plausibility of its various biological functions in influencing the neurodegenerative processes associated with the condition. The tocopherol and tocotrienol isoforms of vitamin E have multiple properties including potent antioxidant and anti-inflammatory characteristics, in addition to influences on immune function, cellular signalling and lowering cholesterol. Several of these roles offer a theoretical rationale for providing benefit for the treatment of AD-associated pathology. Diminished circulating concentrations of vitamin E have been demonstrated in individuals with AD. Reduced plasma levels have furthermore been associated with an increased risk of AD development while intake, particularly from dietary sources, may limit or reduce the rate of disease progression. This benefit may be linked to synergistic actions between vitamin E isoforms and other micronutrients. Nevertheless, randomised trials have found limited and inconsistent evidence of vitamin E supplementation as an effective clinical intervention. Thus, despite a strong rationale in support of a beneficial role for vitamin E for the treatment of AD, the evidence remains inconclusive. Several factors may partly explain this discrepancy and represent the difficulties of translating complex laboratory evidence and dietary interactions into clinical interventions. Methodological design limitations of existing randomised trials and restrictions to supplementation with a single vitamin E isoform may also limit the influence of effect. Moreover, several factors influence individual responsiveness to vitamin E intake and recent findings suggest variation in the underlying genetic architecture attenuates vitamin E biological availability and activity which likely contributes to the variation in clinical responsiveness and the failure of randomised trials to date. Importantly, the clinical safety of vitamin E remains controversial and warrants further investigation.

Serum xanthophyll carotenoids are associated with estimated glomerular filtration rate in an aged cohort.

Progressive renal decline is associated with increasing oxidative stress. However, the majority of studies have investigated endogenous antioxidants in predominantly advanced stages of kidney disease. Many traditional risk factors associated with renal dysfunction have been linked with cognitive decline as the kidneys and brain share comparable anatomic and haemodynamic characteristics that leave them susceptible to common pathogenic mechanisms. The objective of this study was to examine serum dietary antioxidants and their association with renal function characterised by estimated glomerular filtration rate (eGFR) in a cross-sectional analysis of 570 participants. High performance liquid chromatography quantified serum levels of retinol, α-tocopherol, γ-tocopherol and six carotenoids (α-carotene, ß-carotene, ß-cryptoxanthin, lutein, lycopene and zeaxanthin) in participants. Multiple regression analyses were used to evaluate associations while adjusting for potential confounders. A sensitivity analysis was performed in cognitively-intact participants only. Serum levels of the xanthophyll carotenoid lutein were positively associated with eGFR in analyses adjusted for age (years), gender, smoking, APOE4 status and Alzheimer's disease. Retinol was inversely associated with eGFR, although was no longer significant in the smaller sensitivity analysis. Our findings identify significant associations between the xanthophyll carotenoids and eGFR. Further investigations are required to confirm these findings.