The relative contribution of training intensity and duration to daily measures of training load in professional rugby league and union.

This study examined the relative contribution of exercise duration and intensity to team-sport athlete's training load. Male, professional rugby league (n = 10) and union (n = 22) players were monitored over 6- and 52-week training periods, respectively. Whole-session (load) and per-minute (intensity) metrics were monitored (league: session rating of perceived exertion training load [sRPE-TL], individualised training impulse, total distance, BodyLoad™; union: sRPE-TL, total distance, high-speed running distance, PlayerLoad™). Separate principal component analyses were conducted on the load and intensity measures to consolidate raw data into principal components (PC, k = 4). The first load PC captured 70% and 74% of the total variance in the rugby league and rugby union datasets, respectively. Multiple linear regression subsequently revealed that session duration explained 73% and 57% of the variance in first load PC, respectively, while the four intensity PCs explained an additional 24% and 34%, respectively. Across two professional rugby training programmes, the majority of the variability in training load measures was explained by session duration (~60-70%), while a smaller proportion was explained by session intensity (~30%). When modelling the training load, training intensity and duration should be disaggregated to better account for their between-session variability.

Quantifying the External and Internal Loads of Professional Rugby League Training Modes: Consideration for Concurrent Field-Based Training Prescription.

Weaving, D, Jones, B, Till, K, Marshall, P, Earle, K, and Abt, G. Quantifying the external and internal loads of professional rugby league training modes: consideration for concurrent field-based training prescription. J Strength Cond Res 34(12): 3514-3522, 2020-Practitioners prescribe numerous training modes to develop the varied physical qualities that professional rugby league players must express during competition. The aim of this study was to determine how the magnitude of external and internal training load per minute of time differs between modes in professional rugby league players. These data were collected from 17 players across 716 individual sessions (mean [SD] sessions: 42 [13] per player) which were categorized by mode (conditioning [CON], small-sided games, skills, and sprint training). Derived from global positioning systems (5 Hz with 15 Hz interpolation), the distances covered within arbitrary speed and metabolic power thresholds were determined to represent the external load. Session rating of perceived exertion and individualized training impulse represented the internal load. All data were made relative to the session duration. The differences in time-relative load methods between each mode were assessed using magnitude-based inferences. Small-sided games and CON very likely to almost certainly produced the greatest relative internal and external loads. Sprint training provided players with the greatest sprinting and maximal-power distances without a concomitant increase in the internal load. The metabolic power method complements speed-based quantification of the external load, particularly during small-sided games and skills training. In practice, establishing normative loads per minute of time for each mode can be useful to plan future training by multiplying this value by the planned session duration.

Walking cadence required to elicit criterion moderate-intensity physical activity is moderated by fitness status.

The aims of this study were to estimate the walking cadence required to elicit a VO2reserve (VO2R) of 40% and determine if fitness status moderates the relationship between walking cadence and %VO2R. Twenty participants (10 male, mean(s) age 32(10) years; VO2max 45(10) mL·kg-1·min-1) completed resting and maximal oxygen consumption tests prior to 7 x 5-min bouts of treadmill walking at increasing speed while wearing an Apple Watch and measuring oxygen consumption continuously. The 7 x 5-min exercise bouts were performed at speeds between 3 and 6 km·h-1 with 5-min seated rest following each bout. Walking cadence measured at each treadmill speed was recorded using the Apple Watch "Activity" app. Using Bayesian regression, we predict that participants need a walking cadence of 138 to 140 steps·min-1 to achieve a VO2R of 40%. However, these values are moderated by fitness status such that those with lower fitness can achieve 40% VO2R at a slower walking cadence. The results suggest that those with moderate fitness need to walk at ~40% higher than the currently recommended walking cadence (100 steps·min-1) to elicit moderate-intensity physical activity. However, walking cadence required to achieve moderate-intensity physical activity is moderated by fitness status.

Pilot Study Assessing the Influence of Skin Type on the Heart Rate Measurements Obtained by Photoplethysmography with the Apple Watch.

Photoplethysmographic imaging (PPG) is currently used to measure heart rate (HR) and the accuracy of PPG can be influenced by pigmentation of the skin; however, the effects of skin color-related artifacts on PPG during exercise remain unclear. This study aimed to assess the agreement between the Apple Watch photoplethysmography sensor and a criterion, for measuring heart rate across a range of intensities during exercise and to determine the influence of skin type on the accuracy of the measure. Forty-five males (20-43 y) completed the Fitzpatrick Skin Scale and were classified into three different skin type groups: a) types II (n = 15), III (n = 15) and IV (n = 15). Participants performed a graded incremental cycle-ergometer test while simultaneously wearing the Apple Watch and a Polar monitor as a criterion measure. Data from both devices were collected in 5-s epochs. Correlations between devices were very good (0.96-0.99 [95%CI: 0.94 to 0.99]). Significant differences were observed between skin types II and III when the intensity of the exercise was increased, albeit with trivial to small effect sizes (ES: 0.05 to 0.28). All significant differences corresponded to <2% of relative difference between both devices. Bland-Altman analyses showed a trivial but systematic underestimation of HR in the Apple Watch compared to Polar for all skin types during exercise. In conclusion, the Apple Watch accurately measures HR when cycling at different intensities and certain types of skin seem not to influence these measures, which may have important implications for controlling the intensity of exercise.

The validity and inter-device variability of the Apple Watch™ for measuring maximal heart rate.

Maximal heart rate (HRmax) is a fundamental measure used in exercise prescription. The Apple Watch™ measures heart rate yet the validity and inter-device variability of the device for measuring HRmax are unknown. Fifteen participants completed a maximal oxygen uptake test while wearing an Apple Watch™ on each wrist. Criterion HRmax was measured using a Polar T31™ chest strap. There were good to very good correlations between the watches and criterion (left: r = 0.87 [90%CI: 0.67 to 0.95]; right: r = 0.98 [90%CI: 0.94 to 0.99]). Standardised mean bias for the left and right watches compared to the criterion were 0.14 (90%CI: -0.12 to 0.39; trivial) and 0.04 (90%CI: -0.07 to 0.15; trivial). Standardised typical error of the estimate for the left and right watches compared to the criterion were 0.51 (90%CI: 0.38 to 0.80; moderate) and 0.22 (90%CI: 0.16 to 0.34; small). Inter-device standardised typical error was 0.46 (90%CI: 0.36 to 0.68; moderate), ICC = 0.84 (90%CI: 0.65 to 0.93). The Apple Watch™ has good to very good criterion validity for measuring HRmax, with no substantial under- or over-estimation. There were moderate and small prediction errors for the left and right watches. Inter-device variability in HRmax is moderate.

Multiple Measures are Needed to Quantify Training Loads in Professional Rugby League.

This study aims to investigate the effect of training mode (conditioning and skills) on multivariate training load relationships in professional rugby league via principal component analysis. Four measures of training load (internal: heart rate exertion index, session rating of perceived exertion; external: PlayerLoad™, individualised high-speed distance) were collected from 23 professional male rugby league players over the course of one 12 wk preseason period. Training was categorised by mode (skills or conditioning) and then subjected to a principal component analysis. Extraction criteria were set at an eigenvalue of greater than 1. Modes that extracted more than 1 principal component were subject to a varimax rotation. Skills extracted 1 principal component, explaining 57% of the variance. Conditioning extracted 2 principal components (1st: internal; 2nd: external), explaining 85% of the variance. The presence of multiple training load dimensions (principal components) during conditioning training provides further evidence of the influence of training mode on the ability of individual measures of external or internal training load to capture training variance. Consequently, a combination of internal and external training-load measures is required during certain training modes.

Misuse of "Power" and Other Mechanical Terms in Sport and Exercise Science Research.

Despite the Système International d'Unitès (SI) that was published in 1960, there continues to be widespread misuse of the terms and nomenclature of mechanics in descriptions of exercise performance. Misuse applies principally to failure to distinguish between mass and weight, velocity and speed, and especially the terms "work" and "power." These terms are incorrectly applied across the spectrum from high-intensity short-duration to long-duration endurance exercise. This review identifies these misapplications and proposes solutions. Solutions include adoption of the term "intensity" in descriptions and categorizations of challenge imposed on an individual as they perform exercise, followed by correct use of SI terms and units appropriate to the specific kind of exercise performed. Such adoption must occur by authors and reviewers of sport and exercise research reports to satisfy the principles and practices of science and for the field to advance.

Effect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment.

PURPOSE: The aim of this study was to investigate the effect of tyrosine (TYR) ingestion on cognitive and physical performance during soccer-specific exercise in a warm environment. METHODS: Eight male soccer players completed an individualised 90 min soccer-simulation intermittent soccer performance test (iSPT), on a non-motorised treadmill, on two occasions, within an environmental chamber (25 °C, 40 % RH). Participants ingested tyrosine (TYR; 250 mL sugar free drink plus 150 mg kg body mass(-1) TYR) at both 5 h and 1 h pre-exercise or a placebo control (PLA; 250 mL sugar free drink only) in a double-blind, randomised, crossover design. Cognitive performance (vigilance and dual-task) and perceived readiness to invest physical effort (RTIPE) and mental effort (RTIME) were assessed: pre-exercise, half-time, end of half-time and immediately post-exercise. Physical performance was assessed using the total distance covered in both halves of iSPT. RESULTS: Positive vigilance responses (HIT) were significantly higher (12.6 ± 1.7 vs 11.5 ± 2.4, p = 0.015) with negative responses (MISS) significantly lower (2.4 ± 1.8 vs 3.5 ± 2.4, p = 0.013) in TYR compared to PLA. RTIME scores were significantly higher in the TYR trial when compared to PLA (6.7 ± 1.2 vs 5.9 ± 1.2, p = 0.039). TYR had no significant (p > 0.05) influence on any other cognitive or physical performance measure. CONCLUSION: The results show that TYR ingestion is associated with improved vigilance and RTIME when exposed to individualised soccer-specific exercise (iSPT) in a warm environment. This suggests that increasing the availability of TYR may improve cognitive function during exposure to exercise-heat stress.

The reliability and validity of a soccer-specific nonmotorised treadmill simulation (intermittent soccer performance test).

This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: <4.6%; intraclass correlation coefficient: >0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.

Health and lifestyle advisors in support of primary care: An evaluation of an innovative pilot service in a region of high health inequality.

INTRODUCTION: A health and lifestyle advisor service embedded within primary care was piloted in Kingston-upon-Hull from January 2021. We aimed to evaluate the first two years of service delivery by identifying patient demographics referred to the service, reason for referral, determine uptake and retention rates, and monitor individual lifestyle-related risk factor changes following discharge. METHODS: Anonymised data were extracted from the SystmOne database for all patients referred to the service between January 2021 and January 2023. RESULTS: In the initial two years of the service, 705 unique patients were referred at a mean rate of ∼29 per month. Each unique patient received a median (robust median absolute deviation; [MAD]) of 3 (Steel N, et al 2018) planned consultations prior to discharge over this period. The majority of referrals were for symptom management and health promotion purposes (95%). Of those referred, 69% attended their appointments, and 14% did not attend. The majority of referrals were white British (55%), however, the service did receive a substantial number of referrals from minority ethnic groups, with only 67% of referrals speaking English as their main language. Eighteen distinct languages were spoken. Most referrals were classified as class I obese (59.4%). Across initial and final appointments, median (robust MAD) systolic blood pressure was 130 (15) mmHg and 130 (15) mmHg, and median (robust MAD) waist circumference was 103.0 (13.3) cm and 101.0 (13.3) cm. CONCLUSION: The evaluation highlighted the demand for this service embedded within primary care settings in Kingston-upon-Hull. Service engagement was evident, and a large proportion of those who engaged were from minority ethnic groups. A high proportion of referrals presented with obesity and/or hypertension which requires further investigation.

Associations between physical activity, sedentary behaviour, and alcohol consumption among UK adults: Findings from the Health Behaviours during the COVID-19 pandemic (HEBECO) study.

INTRODUCTION: The COVID-19 pandemic and attendant lockdowns have had a substantial negative effect on alcohol consumption and physical activity globally. Pre-pandemic evidence in the adult population suggests that higher levels of physical activity were associated with higher levels of drinking, but it is unclear how the pandemic may have affected this. Therefore, this study aims to assess the association between alcohol consumption and physical activity in a UK cohort established during the COVID-19 pandemic. METHODS: Analyses utilized data from the Health Behaviours during the COVID-19 pandemic (HEBECO) study involving 2,057 UK adults (≥18 years). Participants completed self-report measures of alcohol consumption [frequency, quantity, frequency of heavy episodic drinking (HED) and AUDIT-C score] and physical activity [moderate-vigorous physical activity (MVPA), frequency of muscle strengthening activity (MSA) and sedentary behaviour] between November 2020 and January 2021. Ordinal logistic regression models were conducted, adjusting for sociodemographic factors. RESULTS: Fifteen percent of the sample reported abstinence from drinking. Overall, 23.4% of participants drank ≥4 times/week, 13.9% drank more than 6 units/single drinking occasion (HED), 7.5% reported HED daily/almost daily and 4.2% scored ≥11 on AUDIT-C. MSA 3 days/week compared with no MSA was significantly associated with higher odds of alcohol frequency [OR (95 CI%) = 1.41 (1.04-1.91)], quantity [OR (95 CI%) = 1.38 (1.02-1.87)], HED [OR (95 CI%) = 1.42 (1.05-1.94)] and possible dependence [OR (95 CI%) = 1.47 (1.05-2.06)]. The association of MVPA and sedentary behaviour with drinking measures was not significant (p>0.05). CONCLUSION: In contrast with previous research, MSA rather than aerobic physical activity was associated with increased alcohol consumption during the COVID-19 pandemic. It is conceivable that during lockdown while drinking was used as a coping strategy, limited opportunities for aerobic exercise made MSA a more convenient form of physical activity. To guide public health interventions, more research is required to examine the temporal relationship between different forms of physical activity and alcohol consumption.

Methods of monitoring the training and match load and their relationship to changes in fitness in professional youth soccer players.

Previous studies examining methods of monitoring the training and match load in soccer players have simply compared those methods to each other, not to changes in fitness. Training and match load measures from nine professional youth soccer players were collected for a period of six weeks. A lactate threshold test was conducted before and after this period. Mean weekly training and match load as determined by session-RPE, Banister's TRIMP, Team TRIMP and individualised TRIMP (iTRIMP) were correlated with each other, percentage changes in the velocity at 2 mmol · L(-1) (vLT) and 4 mmol · L(-1) (vOBLA) blood lactate concentration, and heart rate at 2 mmol · L(-1) (LT(HR)) and 4 mmol · L(-1) (OBLA(HR)). There were no significant changes in fitness across the six weeks: vLT (p = 0.54), vOBLA (p = 0.16), LT(HR) (p = 0.51) and OBLA(HR) (p = 0.63). Banister's TRIMP was significantly correlated with session-RPE (r = 0.75; p = 0.02) and Team TRIMP (r = 0.92; p < 0.001). The percentage change in vLT was significantly correlated to mean weekly iTRIMP (r = 0.67; p = 0.04). The results suggest that an individualised measure of internal load (iTRIMP) related better than other methods to changes in vLT in professional youth soccer players.

Quantifying technical actions in professional soccer using foot-mounted inertial measurement units.

OBJECTIVES: This study aimed to (i) establish the concurrent validity and intra-unit reliability of a foot-mounted inertial measurement unit for monitoring soccer technical actions, (ii) quantify the within-microcycle inter-positional differences in the technical actions of professional soccer training, and (iii) determine the influence of drill category on the technical actions of professional soccer training. METHODS: Twenty-one professional soccer players' technical performance data (ball touches, releases, ball touches per minute, releases per minute), collected during training sessions throughout twenty-four weekly microcycles, were analysed using general linear modelling. RESULTS: The inertial measurement unit exhibited good concurrent validity (PA = 95.1% - 100.0%) and intra-unit reliability (PA = 95.9% - 96.9%, CV = 1.4% - 2.9%) when compared with retrospective video analyses. The most ball touches (X‾ = 218.0) and releases (X‾ = 110.8) were observed on MD - 1, with MD - 5 eliciting the highest frequency of ball touches (X‾ = 3.8) and releases (X‾ = 1.7) per minute. Central midfielders performed the most ball touches (X‾ = 221.9), releases (X‾ = 108.3), ball touches per minute (X‾ = 3.4) and releases per minute (X‾ = 1.6). Small-sided games evoked more ball touches (X‾diff = 1.5) and releases per minute (X‾diff = 0.1) than previously reported in match-play. The fewest ball touches (X‾ = 1.2) and releases per minute (X‾ = 0.5) were observed during tactical drills. CONCLUSION: The results of this study provide a novel understanding of the within-microcycle, inter-positional and drill category differences in the technical actions performed by professional players during training.

Misuse of the term 'load' in sport and exercise science.

Despite the International System of Units (SI), as well as several publications guiding researchers on correct use of terminology, there continues to be widespread misuse of mechanical terms such as 'work' in sport and exercise science. A growing concern is the misuse of the term 'load'. Terms such as 'training load' and 'PlayerLoad' are popular in sport and exercise science vernacular. However, a 'load' is a mechanical variable which, when used appropriately, describes a force and therefore should be accompanied with the SI-derived unit of the newton (N). It is tempting to accept popular terms and nomenclature as scientific. However, scientists are obliged to abide by the SI and must pay close attention to scientific constructs. This communication presents a critical reflection on the use of the term 'load' in sport and exercise science. We present ways in which the use of this term breaches principles of science and provide practical solutions for ongoing use in research and practice.