Heart rate variability of elite female rowers in preparation for and during the national selection regattas: a pilot study on the relation to on water performance.

Elite athletes require a delicate balance of physiological and psychological stress and recovery-essential for achieving optimal performance. Monitoring heart rate variability (HRV) provides a non-invasive estimation of both physiological and psychological stress levels, offering potentially valuable insights into health, performance, and adaptability. Previous studies, primarily conducted on male participants, have shown an association between HRV and performance in the context of rowing training. However, given the rigorous nature of rowing training, it is crucial to investigate HRV in elite rowers, particularly during the U.S. national selection regattas (NSR). Purpose: To comprehensively analyze elite female rowers, evaluating acute changes in HRV and subjective psychometrics during the NSR. Methods: Five elite female rowers (26 ± 2 years, 180 ± 8 cm, 82 ± 8 kg, 19 ± 6%fat) were recruited and tracked prior to and during NSR I and II. Morning HRV measures were completed using photoplethysmography (HRV4training) along with self-reported levels of fatigue, soreness, rating of perceived exertion, mentally energy and physical condition. Results: Significant decreases were observed in log transformed root-mean square of successive differences (LnRMSSD; p = 0.0014) and fatigue (p = 0.01) from pre-to-during NSR, while mental energy (p = 0.01), physical condition (p = 0.01), and motivation (p = 0.006) significantly increased. These psychometric measures returned to pre-NSR levels, at post-NSR (all p < 0.05), though HRV remained slightly suppressed. NSR on-water performance was not correlated to LnRMSSD or the change in LnRMSSD (p > 0.05). Discussion: HRV and psychometric measures are sensitive to the stress of elite rowing competition in females. However, HRV was not associated with on-water rowing performance during an elite rowing competition.

Does Eligibility Classification Matter? Tracking Cardiac Autonomic Function during a Collegiate Soccer Season.

The current study examined differences in heart rate (HR) variability (HRV) across student-athlete eligibility classifications within a men's soccer team. The study also aimed to identify any differences in HRV while competing at home or away. Data collection covered an entire collegiate season, commencing in the preseason and concluding upon elimination from the NCAA Soccer tournament. Comparisons of HR and HRV, paired with self-reported subjective measures, were documented between student-athlete eligibility classifications, home versus away games, and based on soccer position (forward, midfielder, defender, goalkeeper). HR and HRV were similar based on student-athlete eligibility. Heart rate exhibited a small, but statistically significant decrease (ß = -1.7 bpm (95% CI: -2.9, 0.57), p = 0.003) for the away games relative to home. HRV showed a statistically significant increase in the away game setting (ß = 2.1 (95% CI: 0.78, 3.38), p = 0.002). No difference in HRV was observed across eligibility classification. This lack of difference may be attributed to a different perception of stress amongst male athletes. Athletes also exhibited a reduced HRV at home, likely as an indication of their readiness to compete paired with an increased self-confidence, given there was no difference in any subjective measures of mood or stress or between games played away or at home.

Eligibility Classification as a Factor in Understanding Student-Athlete Responses to Collegiate Volleyball Competition.

The current study examined differences in heart rate variability (HRV) across student-athletes of different eligibility classifications and analyzed differences in HRV when competing at home or away. Fourteen female collegiate volleyball players volunteered for the study. Data collection encompassed an entire collegiate season, with comparisons in HRV made between home and away games, as well as pre-gameday, gameday, and post-gameday recordings for the whole squad. Comparisons were also made between student-athlete eligibility classification, with self-reported measures of sleep quality, fatigue, muscle soreness, stress, and mood recorded at the time of HRV measurement. Freshman athletes reported a significantly (p < 0.05, η2 = 0.17) lower HRV (80.3 ± 9.7) compared to sophomore (85.7 ± 7.2), junior (91.2 ± 8.3), and senior (86.5 ± 7.2) athletes, while junior athletes had a significantly higher HRV when compared to sophomore and senior athletes. All athlete classifications reported similar HRV for home and away games, and there was no difference in HRV for any athlete classification group when comparing pre-gameday, gameday, and post-gameday measures. Freshman athletes reported significantly (p < 0.05, η2 = 0.23) worse mood states compared to the other eligibility classifications, while self-reported stress was significantly (p < 0.05) worse in junior and senior athletes. Results suggest that monitoring the workload of student-athletes based on their eligibility classification holds merit. Collegiate coaching and support staff should be aware of the academic and competitive demands placed on their student-athletes. In particular, freshman athletes adjusting to the increased demands placed on them as collegiate student-athlete may warrant additional support.

Heart Rate Variability Responses to a Training Cycle in Female Youth Rowers.

Heart rate variability (HRV) is a reputable estimate of cardiac autonomic function used across multiple athletic populations to document the cardiac autonomic responses to sport demands. However, there is a knowledge gap of HRV responses in female youth rowers. Thus, the purpose of this study was to measure HRV weekly, over a 15-week training period, covering pre-season and up to competition in youth female rowers, in order to understand the physiological response to long-term training and discern how fluctuations in HRV may relate to performance in this population. Measures of heart rate and heart rate variability were recorded before training each Friday over the monitoring period in seven athletes. Analysis of heart rate variability focused on time domain indices, the standard deviation of all normal to normal R-R wave intervals, and the root mean square of successive differences as markers of cardiac parasympathetic modulation. Training load was quantified by multiplying the rating of perceived exertion of the weeks training and training duration. A decrease was identified in cardiac parasympathetic modulation as the season progressed (Effect Size (Cohen's d) = -0.34 to -0.8, weeks 6 and 11-15), despite no significant relationship between training load and heart rate variability. Factors outside of training may further compound the reduction in heart rate variability, with further monitoring of external stressors (e.g., school) in adolescent athletes.

The Efficacy of Heart Rate Variability in Tracking Travel and Training Stress in Youth Female Rowers: A Preliminary Study.

Egan-Shuttler, JD, Edmonds, R, and Ives, SJ. The efficacy of heart rate variability in tracking travel and training stress in youth female rowers: A preliminary study. J Strength Cond Res 34(11): 3293-3300, 2020-Heart rate variability (HRV) is a reliable indicator of cardiac parasympathetic activity and has been used in athletic populations to measure training adaptations. To date, there is limited research showing whether HRV is practical in youth female athletes and rowers during short periods of overload training. The purpose of this study was to evaluate the practicality of HRV in documenting training responses during a period of overload training in youth female rowers. Time-domain (SD of N-N intervals, SDNN; root mean square of successive differences, RMSSD) and nonlinear (SD1) indices of HRV were recorded during baseline training, daily during the 6-day training camp, and 1 week after the camp in 5 athletes from an elite, high-school, rowing team. Training duration and rate of perceived exertion were recorded to document training load. Training load during the camp was 76% above the athlete's normal workload (2,258 ± 459 vs. 1,280 ± 356 arbitrary units (a.u.)). Using progressive statistics, cardiac vagal activity (RMSSD and SD1) was very likely reduced during each day of the camp when compared with baseline training, although returned to baseline within a week of the training camp. Interestingly, SDNN was reduced throughout the training camp and remained reduced up to a week after the training camp (78% likely; effect size = -0.32). These insights add value to HRV's use in youth sport and provides coaches with an easy, cost-effective means to monitor the physiological response to training, allowing fine-tuning of training, potentially enhancing performance.

Beyond Peak, a Simple Approach to Assess Rowing Power and the Impact of Training: A Technical Report.

Recently, rowing power has been shown to be a key determinant of rowing performance. However, rowing power testing can vary greatly, and is not standardized. Here we sought to evaluate rowing power over a 15 sec rowing test utilizing a stroke-by-stroke analysis before and after 4 weeks of training in youth rowers. METHODS: 18 adolescent male rowers were assigned to complete either 4 weeks of plyometric training (PLYO, n=9), or steady state cycling (Control, n=9), for 30 minutes before on water training three days/week. Each group was matched for training volume. Peak power (PP) was assessed via a 15 sec maximal rowing ergometer test. Using the Ergdata mobile app, PP, peak force (PF), average force (AF), drive speed (DS), and stroke at which PP was achieved (PPstroke) were measured and recorded for later offline analysis. RESULTS: Before training PP, PF, AF and DS did not differ between groups. After training, PP trended towards a significant difference between groups PLYO and CON (569±75 v. 629±51 Watts, control v. PLYO, p=0.08). Stroke-by-stroke analysis indicated more power was produced over the test following training (p<0.05), but no group differences existed. There was also a trend towards PLYO achieving PP earlier in the test (7.7±0.9 to 6.9±0.9 strokes, p=0.08). Finally, DS during the test was significantly increased for PLYO after training (p<0.05). CONCLUSION: This novel method of evaluating rowing power was able to detect changes in rowing power indices, providing coaches with a cost effective method of evaluating responses to rowing training.

The Impact of a Ballet and Modern Dance Performance on Heart Rate Variability in Collegiate Dancers.

Heart rate (HR) variability (HRV) is a useful tool for assessing cardiac autonomic function and identifying potential readiness to perform in athletic populations, but has yet to be investigated in dance populations. As such, HRV may be able to provide valuable insight into the preparedness of dancers and the demands of performance in a collegiate dance population. 29 female dancers were monitored leading up to and following a dance performance. Analysis of HRV focused on the square root of the mean squared differences of the successive RR intervals (RMSSD). A one-way ANOVA, with Bonferroni post-hoc, paired with magnitude-based-inferences (MBI) with effect sizes (ES) were used to analyze changes during the Winter Dance Concert, while the Recovery-Stress Questionnaire for Athletes (REST-Q Sport) measured the frequency of stress of dancers. When compared to baseline (69.8 ± 1.7 bpm), mean (HR) was increased at both pre-show recordings (76.5 ± 2.1 bpm and 75.6 ± 1.8 bpm). In contrast, RMSSD was significantly diminished (p < 0.05) at both pre-show recordings (40.6 ± 28.4 ms and 40.5 ± 21.8 ms) as compared to baseline (70.3 ± 38.4 ms). Dancers reported increased (p < 0.05) self-efficacy before the second show and at 36 h post-concert. As expected, Dance Exposure (DE) increased significantly (p < 0.05), while Academic Exposure (AE) was similar, during the week leading up to the dance concert. The results suggest dancers responded to concert dance performances similarly to other athletic populations approaching intense competition by exhibiting decreased parasympathetic activity prior to the dance performances, which returned to baseline values 36 h after their performances. Given the increase in self-efficacy, these fluctuations may indicate a readiness to a performance comparable to athletes.

The Effect of Concurrent Plyometric Training Versus Submaximal Aerobic Cycling on Rowing Economy, Peak Power, and Performance in Male High School Rowers.

BACKGROUND: Plyometric training has been shown to increase muscle power, running economy, and performance in athletes. Despite its use by rowing coaches, it is unknown whether plyometrics might improve rowing economy or performance. The purpose was to determine if plyometric training, in conjunction with training on the water, would lead to improved rowing economy and performance. METHODS: Eighteen male high school rowers were assigned to perform 4 weeks of either plyometric training (PLYO, n = 9) or steady-state cycling below ventilatory threshold (endurance, E, n = 9), for 30 min prior to practice on the water (matched for training volume) 3 days per week. Rowing performance was assessed through a 500-m rowing time trial (TT) and peak rowing power (RP), while rowing economy (RE) was assessed by measuring the oxygen cost over four work rates (90, 120, 150, and 180 W). RESULTS: Rowing economy was improved in both PLYO and E (p < 0.05). The 500-m TT performance improved significantly for PLYO (from 99.8 ± 9 s to 94.6 ± 2 s, p < 0.05) but not for E (from 98.8 ± 6 s to 98.7 ± 5 s, p > 0.05). Finally, RP was moderately higher in the PLYO group post-training (E 569 ± 75 W, PLYO 629 ± 51 W, ES = 0.66) CONCLUSIONS: In a season when the athletes performed no rowing sprint training, 4 weeks of plyometric training improved the 500-m rowing performance and moderately improved peak power. This increase in performance may have been mediated by moderate improvements in rowing power, but not economy, and warrants further investigation.

Protein-Pacing Caloric-Restriction Enhances Body Composition Similarly in Obese Men and Women during Weight Loss and Sustains Efficacy during Long-Term Weight Maintenance.

Short-Term protein-pacing (P; ~6 meals/day, >30% protein/day) and caloric restriction (CR, ~25% energy deficit) improves total (TBF), abdominal (ABF) and visceral (VAT) fat loss, energy expenditure, and biomarkers compared to heart healthy (HH) recommendations (3 meals/day, 15% protein/day) in obese adults. Less is known whether obese men and women respond similarly to P-CR during weight loss (WL) and whether a modified P-CR (mP-CR) is more efficacious than a HH diet during long-term (52 week) weight maintenance (WM). The purposes of this study were to evaluate the efficacy of: (1) P-CR on TBF, ABF, resting metabolic rate (RMR), and biomarkers between obese men and women during WL (weeks 0-12); and (2) mP-CR compared to a HH diet during WM (weeks 13-64). During WL, men (n = 21) and women (n = 19) were assessed for TBF, ABF, VAT, RMR, and biomarkers at weeks 0 (pre) and 12 (post). Men and women had similar reductions (p < 0.01) in weight (10%), TBF (19%), ABF (25%), VAT (33%), glucose (7%-12%), insulin (40%), leptin (>50%) and increase in % lean body mass (9%). RMR (kcals/kg bodyweight) was unchanged and respiratory quotient decreased 9%. Twenty-four subjects (mP-CR, n = 10; HH, n = 14) completed WM. mP-CR regained significantly less body weight (6%), TBF (12%), and ABF (17%) compared to HH (p < 0.05). Our results demonstrate P-CR enhances weight loss, body composition and biomarkers, and maintains these changes for 52-weeks compared to a traditional HH diet.

Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study.

We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW), three of which included whey protein (WP) supplementation) combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE) improves body composition in overweight individuals. The purpose of this study was to extend these findings and determine whether protein-pacing with only food protein (FP) is comparable to WP supplementation during RISE training on physical performance outcomes in overweight/obese individuals. Thirty weight-matched volunteers were prescribed RISE training and a P diet derived from either whey protein supplementation (WP, n = 15) or food protein sources (FP, n = 15) for 16 weeks. Twenty-one participants completed the intervention (WP, n = 9; FP, n = 12). Measures of body composition and physical performance were significantly improved in both groups (p < 0.05), with no effect of protein source. Likewise, markers of cardiometabolic disease risk (e.g., LDL (low-density lipoprotein) cholesterol, glucose, insulin, adiponectin, systolic blood pressure) were significantly improved (p < 0.05) to a similar extent in both groups. These results demonstrate that both whey protein and food protein sources combined with multimodal RISE training are equally effective at improving physical performance and cardiometabolic health in obese individuals.

Cardiac Autonomic and Salivary Responses to a Repeated Training Bout in Elite Swimmers.

This study examined the acute training responses of heart rate variability (HRV) and salivary biomarkers (immunoglobulin A and alpha-amylase) following a standardised training bout in Paralympic swimmers. Changes in HRV, sIgA and sAA were documented Monday morning, Monday afternoon and Tuesday morning over a 14-week monitoring period leading into international competition. Magnitude based inferences with effect sizes (ES) were used to assess the practical significance of changes each week. Normal training responses elicited increases in HR, α1, sAA and sIgA, accompanied by decreases in HF(nu), standard deviation of instantaneous RR variability (SD1) and the root mean square of successive differences (RMSSD) from Monday morning to Monday afternoon, and to Tuesday morning with similar week to week responses for most variables. Changes in RMSSD from Monday a.m. to p.m. were likely smaller (less negative) for Week 7 (78/18/3, ES = 0.40) following a competition weekend with similar changes observed from Monday a.m. to Tuesday a.m. (90/5/5, ES = 1.30). In contrast, the change in sAA from Monday a.m. to p.m. was very likely less (more negative) at Week 7 (0/0/99, ES = -2.46), with similar changes observed from Monday a.m. to Tuesday a.m. (0/0/99, ES = -4.69). During the taper period, there were also likely increases in parasympathetic modulations (RMSSD, Weeks 12⁻14) along with increased immune function (sIgA, Week 13) that demonstrated a favourable state of athlete preparedness. Used together, HRV and sAA provide coaches with valuable information regarding physiological changes in response to training and competition.

Effect of chronic training on heart rate variability, salivary IgA and salivary alpha-amylase in elite swimmers with a disability.

The purpose of this study was to a) determine the heart rate variability (HRV) and saliva markers of immunity (salivary immunoglobulin A; sIgA) and stress (salivary alpha-amylase; sAA) responses to chronic training in elite swimmers with a disability; and b) identify the relationships between HRV, sIgA, sAA and training volume. Eight members of a high performance Paralympic swimming program were monitored for their weekly resting HRV, sIgA and sAA levels in the 14 weeks leading up to a major international competition. The 14 week training program included aerobic, anaerobic, power and speed, and taper training phases, while also incorporating two swimming step tests and two swimming competitions. Specific time (root mean square of the successive differences; RMSSD) and frequency (high frequency normalized units [HFnu]) domain measures, along with non-linear indices (standard deviation of instantaneous RR variability; SD1 and short term fractal scaling exponent; α1) of HRV were used for all analyses with effects examined using magnitude-based inferences. Relationships between HRV and saliva markers were identified by Spearman rank rho (ρ) correlation coefficients. Compared with week 1, SD1 was very likely lower (96/4/0, ES = -2.21), while sAA was very likely elevated (100/0/0, ES = 2.32) at the beginning of week 7 for all athletes. The training program did not alter HRV or saliva whereas competition did. There were also no apparent differences observed for HRV, sIgA and sAA between each of the training phases during the 14 week swimming program. Correlations were observed between sAA and SD1 (ρ = -0.212, p<0.05), along with sAA and mean HR (ρ = 0.309, p<0.05). These results show that high level national competition influences depresses HRV (SD1) and increases saliva biomarkers of stress (sAA). It appears that a well-managed and periodised swimming program can maintain these indices within normal baseline levels. The study also highlighted the parasympathetic nervous system influence on sAA.