External training loads and smartphone-derived heart rate variability indicate readiness to train in elite soccer

Player readiness can affect the ability to perform and tolerate prescribed training load (TL); therefore, in a time-efficient and practice compatible manner, practitioners need objective evidence to inform readiness to train. Six male professional footballers (mean ± standard deviation [SD]; 26 ± 2 years, 79.0 ± 4.9 kg, 1.82 ± 0.05 m) participated. Heart rate variability (HRV) was recorded using a smartphone application prior to the daily training sessions (247 training sessions [41.17 ± 7.41 per player]). External TL was monitored during training using global positioning system devices. Linear mixed models were used to examine variations in HRV and TL across the study period and to determine relationships between HRV and TL. Differences in TL and HRV were expressed as standardised effect sizes (ES) ± 90% confidence limits. Changes in HRV (outcome) were expressed as the expected change for a 2-SD change in TL (predictor). Across the study period, all external TL measures varied substantially, demonstrating weekly fluctuations in load (ES range = 0.00–7.40). The relationship between morning HRV and external TL ranged from −0.10 for distance and 1.89 for equivalent distance index (EDI). Overall, EDI demonstrated the strongest relationship with morning HRV; therefore, EDI and smartphone-derived HRV may provide an indicator of readiness to train within elite soccer

Subjective and objective responses to two Rugby Sevens World Series competitions

The purpose was to examine the utility of subjective and objective measures of player preparedness, interpreted at both group level and individual level, during 2 consecutive competitions of the World Rugby Sevens Series (WRSS). Subjective (sleep, energy, and muscle soreness ratings) and objective (heart rate [HR] at rest [HRREST] and in response to submaximal exercise [HREX]) measures were obtained from 16 male rugby 7s players from 1 team for 3 consecutive days (D1-3) at home (HOME) and on arrival at 4 tournament (T1-4) locations (T1-New Zealand; T2-USA; T3-Hong Kong T4-Tokyo) across 2 WRSS competitions (2 tournaments per competition) separated by 1 month. At a group level, energy ratings were significantly lower in T2 and T4 compared with HOME, and on D1 T2 compared with D1 T1 (p ≤ 0.05). Greatest variability in subjective ratings was observed during T1 and T3 at an individual level, particularly for sleep quality. Although at a group level HRREST and HREX significantly decreased in T1-4 compared with HOME (p ≤ 0.05), there was only a ∼50% agreement between the direction of change in HR indices at an individual level. Results from this study suggest that relocation between tournaments within WRSS competitions disrupts player preparedness measures to the largest degree. Hence, this period could be targeted by practitioners with appropriate recovery and/or sleep-promoting interventions or modulation of match-/training-load. Moreover, subjective rather than objective measures seem to be of greater use to inform player preparedness decision making, particularly at an individual level compared with a group level

Trackman 4: Within and between-session reliability and inter-relationships of launch monitor metrics during indoor testing in high-level golfers

The aims of the present study were to: 1) investigate the within and between-session reliability of the Trackman 4 launch monitor system, and 2) determine the inter-relationships of some of these commonly used metrics. Golfers attended two test sessions at an indoor golf academy and performed 10 shots using their own driver. Results showed excellent within and between-session reliability for CHS (ICC = 0.99; SEM = 1.64–1.67 mph), ball speed (ICC = 0.97–0.99; SEM = 2.46–4.42 mph) and carry distance (ICC = 0.91–0.97; SEM = 7.80–14.21 mph). In contrast, spin rate showed the worst reliability (ICC = 0.02–0.60; SEM = 240.93–454.62 º/s) and also exhibited significant differences between test sessions (g = –0.41; p g = 0.47; p g = –0.21; p r = 0.98–0.99), CHS and carry distance (r = 0.94–0.95), ball speed and carry distance (r = 0.97–0.98), and launch angle and dynamic loft (r = 0.98–0.99). Collectively, CHS, ball speed and carry distance serve as the most consistently reliable metrics making them excellent choices for practitioners working with golfers. </p

Summary of passive membrane and action potential properties of spontaneous EVN, non-spontaneous EVN, and MVN neurons.

<p>All data are presented as means ± SD.</p><p>** <i>p</i><0.01 between spontaneous EVN neurons and MVN neurons</p><p>^†††<i>p</i><0.001 between non-spontaneous EVN neurons and MVN neurons</p><p>^‡‡‡<i>p</i><0.001 between spontaneous and non-spontaneous EVN neurons</p><p>Comparisons made using student’s unpaired <i>t</i>-test.</p><p>Summary of passive membrane and action potential properties of spontaneous EVN, non-spontaneous EVN, and MVN neurons.</p

Associations and within-group differences in physical characteristics and golf performance data in high-level amateur players

The aim of the present study was to assess the relationship between a comprehensive physical testing battery and golf performance, as quantified through a variety of previously determined usable metrics from launch monitor data. Twenty-six high-level, amateur golfers undertook a series of physical assessments, including anthropometry measurements, isometric mid-thigh pull (IMTP), isometric bench press, countermovement jump (CMJ), seated medicine ball throws for distance, and seated thoracic rotation tests. In addition, golf shot data were recorded in an indoor biomechanics laboratory, with a driver and 6-iron to quantify clubhead speed (CHS), ball speed, carry distance, and smash factor. Pearson’s r associative analyses showed that the strongest relationships with the golf shot data were with the isometric bench press for the upper body (r values up to 0.76) and countermovement jump for the lower body (r values up to 0.82). In addition, the median split analysis of the physical performance data revealed that players who were able to exhibit greater maximal and explosive strength capabilities in the IMTP, isometric bench press, and CMJ assessments had a significantly greater CHS (g range = 1.09–1.28; p < 0.05), ball speed (g range = 1.18–1.41; p < 0.05), carry distance (g range = 1.06–1.53; p < 0.05), and smash factor (g range = 0.81–1.17; p < 0.05). These data underscore the importance of superior physical capacity for golfers, especially for maximal force production in both the lower and upper body, as well as explosive force production for the lower body

Discharge profiles of spontaneous and non-spontaneous EVN neurons.

<p><b>(A)</b> Schematic view of transversely sectioned mouse brainstem. Inset shows map of recording sites from a subset of EVN neurons (37/54 recorded neurons). <i>VN</i>: vestibular nucleus; <i>G7n</i>: genu of seventh cranial nerve (facial nerve); <i>6n</i>: sixth cranial nerve nucleus (abducens nucleus); <i>4V</i>: fourth ventricle; <i>EVN</i>: efferent vestibular nucleus. <b>(B)</b> EVN neurons are either spontaneous firing (<i>n</i> = 16) (<i>top trace</i>) or non-spontaneously firing (<i>n</i> = 38) (<i>bottom</i> trace) at resting membrane potential and display homogenous discharge profiles in response to depolarizing <b>(C)</b> and hyperpolarizing <b>(E)</b> step currents. EVN neurons respond with a short burst (*) of high frequency action potentials (AP) at the onset of a depolarizing stimulus or the cessation of a hyperpolarizing stimulus. <b>(D)</b> Comparison of instantaneous frequencies as a function of injected depolarizing current from a subset of MVN and EVN neurons from which the slope of linear fit was used to calculate the gain of each neuron. *** <i>p</i><0.001. <b>(F)</b> EVN neurons displayed an afterdepolarization (ADP) following release from inhibition (arrow in <b>(E)</b>). The ADP was mediated by T-type calcium channels—TTX (1 μM) abolished all APs, and TTA-P2 (1 μM) abolished the remaining response.</p

Practices and perceptions of strength and conditioning training in female golf: A cross-sectional survey study of high-level amateur players

This study aims to ascertain an in-depth understanding of current  practices and perceptions of S&C training in high-level amateur  female golfers. A cross-sectional, explorative survey study was  constructed which asked questions relating to four key areas: i) general  participant information, ii) current strength and conditioning  (S&C) practices, iii) the perceived influence of S&C training on  golf performance, and iv) knowledge and awareness of S&C. Results  showed that the majority of female players had participated in some form  of S&C training in the past, with the majority believing that  clubhead speed and carry distance were the primary golfing metrics which  could be positively impacted. More specifically, 91–97% of the players  “Strongly agreed” or “Agreed” that the key physical characteristics for  golf were strength and power for the lower and upper body, and  flexibility. Interestingly, 58% of the players believed that S&C  training should mimic the movement of the golf swing, which based off  current evidence, is not how drive metrics and ultimately shots gained,  can be maximised. This survey study provides useful information relating  to the practices and perceptions of S&C training in high-level  female amateur players and areas where education may be able to further  advance player understanding of physical preparation. </p