Publications by authors named "Andrew Flatt"

Article Synopsis
  • Visceral adipose tissue (VAT) is linked to autonomic impairment, so this study aimed to compare heart rate variability (HRV) across different visceral fat levels in healthy men.
  • * In this cross-sectional study of 99 men, those with lower visceral fat ratings (VFR) showed significantly higher HRV measurements than those with higher VFR.
  • * The findings suggest that reducing VAT could be crucial for improving cardiac-autonomic function, as VFR was a stronger predictor of HRV than overall body fat percentage.
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Tendero-Ortiz, E, Johnson, MJ, Horsfall, CM, Vondrasek, JD, Grosicki, GJ, Riemann, BL, and Flatt, AA. Tournament recovery profiles and physical demands in a collegiate women's tennis team. J Strength Cond Res XX(X): 000-000, 2024-We aimed to characterize recovery profiles and tournament physical demands in women's collegiate tennis players.

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Balancing of strength programming intensity with sport demands is necessary to avoid excessive workloads that could inhibit performance. To expand previous jump height focused literature, this study evaluated whether countermovement jump (CMJ) movement strategies, including eccentric characteristics, might reveal CMJ execution strategy shifts to achieve similar afternoon CMJ height following a morning resistance training session (RTS). Fifteen collegiate women's soccer and volleyball athletes (18-24 years, 73.

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  • Slow-paced breathing can enhance heart rate variability (HRV) and is facilitated by free apps like Elite HRV.
  • Researchers studied 20 young adults to compare HRV measurements from Elite HRV with those from reference ECG during both spontaneous and paced breathing.
  • The findings showed that while Elite HRV typically underestimated HRV values from ECG, it effectively increased low-frequency power during paced breathing, though it was more accurate during spontaneous breathing.
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  • Black Americans experience higher blood pressure due to various social, lifestyle, and physiological factors, with reduced nitric oxide (NO) bioavailability as a possible contributor.
  • A study involving 18 Black and 20 White young adults tested the impact of beetroot juice (BRJ) on blood pressure, finding that it effectively lowered resting blood pressure in both groups, but more notably in males.
  • Although Black adults had higher resting blood pressure levels initially, BRJ supplementation reduced systolic blood pressure similarly in both Black and White participants, highlighting the importance of NO in cardiovascular health.
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Whether morning heart rate variability (HRV) predicts the magnitude of its circadian variation in the absence of disease or is influenced by chronotype is unclear. We aimed to quantify associations between (1) morning HRV and its diurnal change, and (2) morning HRV and a Morningness−Eveningness Questionnaire (MEQ)-derived chronotype. Resting electrocardiograms were obtained in the morning and evening on separate days in a counterbalanced order to determine the mean RR interval, root mean square of successive differences (RMSSD), and standard deviation of normal-to-normal RR intervals (SDNN) in 23 healthy men (24.

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Cardiovascular reactivity (CVR) during physical stress is prognostic for incident cardiovascular disease. CVR is influenced by perceived pain. However, there is limited data on the effect of sex differences and repeated exposures to painful stimuli on CVR.

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The aim of this study was to investigate the training-induced effect on cardiac parasympathetic nervous system (PNS) activity, assessed by resting heart rate variability (HRV) and post-exercise heart rate recovery (HRR), in sedentary healthy people. Electronic searches were carried out in PubMed, Embase, and Web of Science. Random-effects models of between-group standardised mean difference (SMD) were estimated.

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Flatt, AA, Hornikel, B, Nakamura, FY, and Esco, MR. Effect of competitive status and experience on heart rate variability profiles in collegiate sprint-swimmers. J Strength Cond Res 36(10): 2898-2904, 2022-Interindividual differences in training history may be a determinant of heart rate variability (HRV) profiles in collegiate sprint-swimmers and may account for differences observed between elite and subelite athletes.

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Purpose: To quantify associations between self-recorded heart rate variability (HRV) profiles and various health and lifestyle markers in young adults.

Methods: Otherwise healthy volunteers (n = 40, 50% male) recorded 60-s, post-waking HRV with a cost-free mobile application in supine and standing positions for 7 days. The 7-day average and coefficient of variation (CV, reflects daily fluctuation) for the mean RR interval and root mean square of successive differences (LnRMSSD) were assessed.

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Objectives: The aim of this study was to determine whether cardiorespiratory fitness (CRF), expressed as VO 2 max (mL/kg/min), is associated with resting AS (carotid-femoral pulse wave velocity [cf-PWV]) and the AS response to simulated fire suppression activities in firefighters.

Methods: In firefighters (n = 20, 34 ± 8 years), AS was determined using cf-PWV (m/s) before and after a fire simulation exercise. VO 2 max was determined using a standard treadmill protocol.

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Article Synopsis
  • Sleep irregularity, characterized by unpredictable sleep patterns, is linked to higher risks for cardiometabolic disease, particularly in young adults who often experience such patterns.
  • A study involving 44 young adults found that while average sleep duration did not correlate with cardiometabolic health measures, the variability in sleep duration (standard deviation) was associated with increased blood pressure levels.
  • Specifically, higher sleep duration variability correlated with elevated brachial and aortic systolic and diastolic blood pressure, highlighting the need for better sleep regularity in maintaining cardiometabolic health.
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Exercise-based cardiac rehabilitation may be an effective non-pharmacological intervention for improving endothelial function in coronary artery disease patients. Therefore, this systematic review with meta-analysis aimed to (a) estimate the training-induced effect on endothelial and vascular smooth muscle function, assessed by flow-mediated dilation and nitroglycerin-mediated dilation, respectively, in coronary artery disease patients; and to (b) study the influence of potential trial-level variables (i. e.

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Background And Purpose: Most studies on heart rate variability (HRV) in professional athletes concerned linear, time-, and frequency-domain indices, and there is lack of studies on non-linear parameters in this group. The study aimed to determine the inter-day reliability, and group-related and individual changes of short-term symbolic dynamics (SymDyn) measures during sympathetic nervous system activity (SNSa) stimulation among elite modern pentathletes.

Methods: Short-term electrocardiographic recordings were performed in stable measurement conditions with a 7-day interval between tests.

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Purpose: To report the impact of long-haul travel and the Olympic tournament on heart-rate variability and subjective well-being in a rugby sevens team.

Methods: Players (N = 12 men) recorded daily root mean square of successive differences (LnRMSSD) and brief subjective well-being assessments before and throughout the Olympic tournament. Following a 7-day baseline involving a tournament simulation, 2 flights were taken to Brazil (20-h travel and 4-h time gain) on day 1.

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We compared physiological and perceptual responses to submaximal, moderate-vigorous, heart rate-based cycle ergometry with and without a fan. Sixteen recreationally active adults (25 ± 3 years; 8 men and 8 women) participated in the study. After an initial visit to assess cardiorespiratory fitness, each participant performed two 40-min training sessions on a cycle ergometer, either with or without a fan (~4 m/s), while workload was continually adjusted to elicit and maintain 70% of heart rate reserve.

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Background: The prevalence of mental health disorders is rising globally. Despite the popularity of exercise as a strategy to improve mental health in individuals with anxiety or depression, there is a paucity of literature on this topic in apparently healthy young individuals who are free from mental illness.

Methods: We characterized relationships between actigraphy-derived physical activity levels and cardiorespiratory fitness (V̇O2max; via maximal graded exercise testing), with mental health assessed using psychometric questionnaires (POMS and PSS) in apparently healthy young adults (26±4.

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Purpose: This systematic review with meta-analysis was conducted to establish whether heart rate variability (HRV)-guided training enhances cardiac-vagal modulation, aerobic fitness, or endurance performance to a greater extent than predefined training while accounting for methodological factors.

Methods: We searched Web of Science Core Collection, Pubmed, and Embase databases up to October 2020. A random-effects model of standardized mean difference (SMD) was estimated for each outcome measure.

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We aimed to examine changes in resting heart rate variability, submaximal exercising heart rate (HRex), countermovement-jump height (CMJ), perceptual wellbeing, and internal load throughout preparatory training in elite women's volleyball players. We also aimed to determine which HRV measurement position (supine vs. seated) provided greater associations with the various markers of training adaptation.

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Background: Foam rolling (FR) is a self-myofascial release technique with unclear effects on autonomic functioning, indexed by heart rate variability (HRV). FR can be perceived as painful or relaxing, which may explain interindividual HRV responses.

Purpose: To determine if acute FR alters resting HRV.

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Purpose: To track cardiac-autonomic functioning, indexed by heart-rate variability, in American college football players throughout a competitive period.

Methods: Resting heart rate (RHR) and the natural logarithm root mean square of successive differences (LnRMSSD) were obtained throughout preseason and ∼3 times weekly leading up to the national championship among 8 linemen and 12 nonlinemen. Seated 1-minute recordings were performed via mobile device and standardized for time of day and proximity to training.

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Background: The association between heart rate variability (HRV), training load (TL), and performance is poorly understood.

Methods: A middle-aged recreational female runner was monitored during a competitive 20-wk macrocycle divided into first (M1) and second mesocycle (M2) in which best performances over 10 km and 21 km were recorded. Volume (km), session rating of perceived exertion (sRPE), TL, and monotony (mean TL/SD TL) were the workload parameters recorded.

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Hydration practices may confound heart rate variability (HRV) measurements when collected in the pre-training period. We aimed to determine the effects of ingesting a hypertonic, sugar-sweetened sports beverage on HRV and hemodynamic parameters in physically active young men. Fifteen subjects consumed 591 mL of Gatorade (6% carbohydrate, ∼330 mOsmol/kg), 591 mL water, or 10 mL water (control) in random order on separate days following overnight fasting.

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Purpose: To assess heart rate (HR) variability responses to various markers of training load, quantify associations between HR variability and fitness, and compare responses and associations between 1-minute ultrashort and 5-minute criterion measures among a girls' field hockey team.

Methods: A total of 11 players (16.8 [1.

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This study aimed to develop a predictive explanatory model for the 1,000-m time-trial (TT) performance in young national-level kayakers, from biomechanical and physiological parameters assessed in a maximal graded exercise test (GXT). Twelve young male flat-water kayakers (age 16.1 ± 1.

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