Effects of Long-Haul Travel and the Olympic Games on Heart-Rate Variability in Rugby Sevens Medalists

Tournament Recovery Profiles and Physical Demands in a Collegiate Women's Tennis Team

ABSTRACT

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. A Division 1 team (n = 9) participated in the study. Markers of cardiac autonomic (resting heart rate [HR], HR variability), neuromuscular (isometric handgrip strength, seated single-arm shot-put test [SSAPT], hexagon agility, countermovement jump characteristics), and perceptual recovery were obtained before the tournament (baseline) and again 1 and 2 days posttournament. Cardiorespiratory (HR) and movement characteristics from matches were quantified with wearable devices. p values < 0.05 were statistically significant. No recovery markers differed from baseline (ps > 0.05), although small effect size reductions 1 day posttournament were noted for SSAPT, hexagon agility, and select countermovement jump characteristics. In addition, hexagon agility times and SSAPT were slower (p < 0.01) and shorter (p < 0.05), respectively, at 1 versus 2 days posttournament. Similarly, relative to 1 day posttournament, perceptual makers were improved 2 days posttournament (ps < 0.05). Mean and peak HR were higher for singles versus doubles matches  (ps < 0.05). Except for average speed, movement parameters were greater during singles versus doubles matches (ps < 0.05). Markers of recovery were minimally affected 1 day posttournament relative to baseline, but perceptual and select neuromuscular markers were most improved 2 days posttournament. Thus, passive rest or limited intensity training 1 day posttournament seems advisable. Competition HR and movement profiles inform practitioners of the cardiorespiratory and locomotor demands of women's collegiate tennis, which may be useful in designing preparatory conditioning programs to ensure that players attain match-specific physical capacities in training before competition.

Heart Rate Variability Applications in Strength and Conditioning: A Narrative Review

Heart rate variability (HRV) is defined as the fluctuation of time intervals between adjacent heartbeats and is commonly used as a surrogate measure of autonomic function. HRV has become an increasingly measured variable by wearable technology for use in fitness and sport applications. However, with its increased use, a gap has arisen between the research and the application of this technology in strength and conditioning. The goal of this narrative literature review is to discuss current evidence and propose preliminary guidelines regarding the application of HRV in strength and conditioning. A literature review was conducted searching for HRV and strength and conditioning, aiming to focus on studies with time-domain measurements. Studies suggest that HRV is a helpful metric to assess training status, adaptability, and recovery after a training program. Although reduced HRV may be a sign of overreaching and/or overtraining syndrome, it may not be a sensitive marker in aerobic-trained athletes and therefore has different utilities for different athletic populations. There is likely utility to HRV-guided programming compared to predefined programming in several types of training. Evidence-based preliminary guidelines for the application of HRV in strength and conditioning are discussed. This is an evolving area of research, and more data are needed to evaluate the best practices for applying HRV in strength and conditioning.

Validity and Efficacy of the Elite HRV Smartphone Application during Slow-Paced Breathing

Slow-paced breathing is a clinical intervention used to increase heart rate variability (HRV). The practice is made more accessible via cost-free smartphone applications like Elite HRV. We investigated whether Elite HRV can accurately measure and augment HRV via its slow-paced breathing feature. Twenty young adults completed one counterbalanced cross-over protocol involving 10 min each of supine spontaneous (SPONT) and paced (PACED; 6 breaths·min-1) breathing while RR intervals were simultaneously recorded via a Polar H10 paired with Elite HRV and reference electrocardiography (ECG). Individual differences in HRV between devices were predominately skewed, reflecting a tendency for Elite HRV to underestimate ECG-derived values. Skewness was typically driven by a limited number of outliers as median bias values were ≤1.3 ms and relative agreement was ≥very large for time-domain parameters. Despite no significant bias and ≥large relative agreement for frequency-domain parameters, limits of agreement (LOAs) were excessively wide and tended to be wider during PACED for all HRV parameters. PACED significantly increased low-frequency power (LF) for Elite HRV and ECG, and between-condition differences showed very large relative agreement. Elite HRV-guided slow-paced breathing effectively increased LF values, but it demonstrated greater precision during SPONT and in computing time-domain HRV.

Training and Competition Loads in Women's Rugby Sevens Athletes: Are There Implications for Cardiovascular Health?

National- and international-level rugby sevens athletes are exposed to high training and competition loads over the course of a competitive season. Research on load monitoring and body-system responses is widespread; however, the primary focus has been on optimizing performance rather than investigating or improving cardiovascular health. There is a degree of cardiovascular remodeling, as well as local and systemic inflammation, in response to excessive exercise. These responses are moderated by many factors including previous exercise exposure, current exercise intensity and duration, age, race, and gender, as well as sport-specific physiology. For these reasons, high-performing female rugby sevens athletes may have a unique cardiovascular risk profile different from males and other rugby codes. This review aimed to characterize the training and competition loads, as well as the anthropometric and physiological profiles, of female rugby sevens athletes; discuss the potential impacts these may have on the cardiovascular system; and provide recommendations on future research regarding the relationship between rugby sevens training and competition loads and cardiovascular health. Movement demands, competition formatting, and training routines could all contribute to adverse cardiovascular adaptations. Anthropometric data and physiological characteristics may also increase the risk of cardiovascular disease. Future research needs to adopt measures of cardiovascular health to obtain a greater understanding of cardiovascular profiles and risk factors in female rugby sevens athletes.