Is aerobic endurance a determinant of cardiac autonomic regulation?

Post-exercise heart rate recovery and its speed are associated with resting-reactivity cardiovagal modulation in healthy women

The present study sought to expand upon prior investigations of the relationship between post-exercise heart rate recovery (HRR) and cardiovagal resting-reactivity modulation. HRR from 1st to 5th min after maximal exercise test was correlated with a cardiovagal index of heart rate variability (SD1) at resting (supine and orthostatic positions) and its reactivity after the orthostatic stress test in 34 healthy women. Statistical analysis employed non-parametric tests with a p-value set at 5%. HRR, ∆%HRR, and coefficient of HRR (CHRR) at the 3rd and 5th min correlated with SD1 and SD1n (normalized units) in the supine position (rs = 0.36 to 0.47; p =  < 0.01). From the 1st to 5th min, HRR, ∆%HRR, and CHRR correlated with SD1 and SD1n in the orthostatic position (rs = 0.29 to 0.47; p =  ≤ 0.01 to 0.05), except for HRR at 5th min with SD1n (p = 0.06). Following the orthostatic stress test, HRR at 3rd and HRR, %∆HRR at 5th min correlated with ∆absSD1 (rs = 0.28 to 0.35; p = 0.02 to 0.05). All HRR measurements at 1st min correlated with ∆absSD1n (rs = 0.32 to 0.38; p = 0.01 to 0.03), and the CHRR at 1st min correlated with ∆%SD1(rs = 0.37; p = 0.01). After the sample was divided into high and low cardiovagal modulation subgroups, the subgroup with high modulation at rest (supine and orthostatic) and higher cardiovagal reactivity (reduction) showed faster HRR (p =  ≤ 0.01 to 0.05; ES:0.37 to 0.50). HRR throughout the 1st to 5th min positively correlates with cardiovagal modulation in the orthostatic position, and the 3rd and 5th min positively correlate with cardiovagal modulation in both postures at rest. Faster HRR following the maximal exercise test is associated with high resting-reactivity cardiovagal modulation in healthy women.

Influence of Sports Participation on the Behaviors of Customers of Sports Services: Linear and Qualitative Comparative Analysis Models

Sports services have become an important enclave for our society. Due to its complete sports offer, customers can perform physical activity that helps them to improve their health and well-being. In fitness centers, managers try to know what their customers are looking for in order to create more personalized experiences, as well as to improve their health. This study seeks to understand the influence that sports frequency has on the future behavior of users of a sports center, using two complementary methodologies. A sample of 383 users of a private sports center was used. The two complementary methodologies used were linear models and comparative qualitative analysis, based on the combination of sets. The results show how sports frequency influences the process of creating users' future behaviors. Considering that none of the variables are necessary, it is observed that perceived value has a significant influence on users' future behaviors. The use of two complementary methodologies provides a more complete understanding, which helps sports managers to plan and manage effectively to ensure user satisfaction and loyalty. In addition, facilities can incentivize customers through loyalty programs and promotions to maintain their engagement, as well as healthy styles to encourage service recommendations.

Correlation between physical efficiency index using Harvard step test and heart rate variation in college students

The purpose of this study is to investigate the relationship between physical efficiency index (PEI) calculated by the Harvard step test and heart rate variation (HRV), and to identify parameters of HRV that can predict PEI in college students. Sixteen college students were participated in this study and they were randomly divided into two groups; higher PEI group (HPEI, n=6) and lower PEI group (LPEI, n=10). To investigate the relationship between PEI and HRV, we were measured HRV and Harvard step test. HRV test was the resting, immediately, 15 min and 30 min after the Harvard step test using electrocardiography device polyG-I. Relationship between PEI and HRV were determined Pearson correlation coefficient, and multiple regression analysis was performed for examining HRV parameters to predict PEI. As shown in the result, not only PEI was negatively correlated with root mean squared differences between adjacent normal RR intervals (RMSSD), but had a positive correlation with low-frequency/high-frequency, but also normalized low frequency (normLF), the ratio of LF, and RMSSD, the change in RR interval showed a significant difference at each time point of measurement according to PEI levels. But, there were no significant differences among the HRV variables except normLF and RMS-SD. Our findings suggest a critical information that PEI calculated by the Harvard step test can be used as an index to predict the autonomic nerve function, and high PEI may have a positive effect on changes in autonomic nerve activity during recovery after exercise intervention.

Can resting heart rate explain the heart rate and parasympathetic responses during rest, exercise, and recovery?

The effect of resting heart rate (RHR) on the heart rate (HR) dynamics and parasympathetic modulation at rest, exercise, and recovery remain to be clarified. This study compares HR and parasympathetic responses at rest, during submaximal exercise testing and recovery in young, physically active men with different RHR average values. HR and parasympathetic responses were compared between two groups: bradycardia group-RHR < 60 bpm (BG, n = 20) and normocardia group-RHR ≥ 60 ≤ 100 bpm (NG, n = 20). A Polar RS800® was used to record the RR-interval series and HR at rest in the supine position, following the postural change (from supine to orthostatic position) and in the orthostatic position for 5 minutes, as well as during and after a submaximal exercise testing. Statistical analysis employed the MANOVA, Mann-Whitney, and Simple Linear regression test with a two-tailed p-value set at ≤ 0.05. BG at rest showed lower HR in the orthostatic position, higher parasympathetic activity in the supine and orthostatic positions, and higher parasympathetic reactivity than NG (p ≤ 0.01) after the postural change. BG before exercise showed lower HR and higher values of the chronotropic reserve and parasympathetic withdrawal than NG (p ≤ 0.01) throughout the exercise. Following the exercise, BG showed higher values of HR recovery (HRR) and parasympathetic reactivation in the 3rd and 5th minutes of recovery than NG (p ≤ 0.01). Lastly, the RHR can explain the variance of the HR at rest, during exercise testing, and recovery from 11 to 48%. We concluded that BG (RHR < 60 bpm) showed higher chronotropic and parasympathetic modulation at rest, higher chronotropic reserve, parasympathetic withdrawal during the submaximal exercise test, and faster HRR and parasympathetic reactivation after effort in young physically active men.

Heart Rate Variability and Cardiovascular Fitness: What We Know so Far

Fluctuation analysis in intervals between heartbeats provides important indices related to autonomic modulation of heart rate variability (HRV). These indices are considered predictors of morbidity and mortality as they are frequently altered in patients with chronic degenerative diseases, especially in those with cardiovascular and metabolic diseases. Similarly, a reduction in HRV is common with aging. In all cases, cardiovascular fitness is often reduced to below the predicted values. In turn, increases in cardiovascular fitness through regular physical exercise, especially aerobic exercise, represent an important therapeutic tool capable of promoting positive adjustments in cardiac autonomic modulation. These adjustments are characterized by reduced sympathetic modulatory influence and/or increased vagal modulatory influence on the heart, increasing the HRV. Therefore, several methodological tools have been used to assess the degree of impairment of autonomic modulation and the therapeutic effects of physical exercise. In contrast, establishment of strict protocols in experimental design is a main challenge in establishing HRV analysis as a robust parameter for evaluating cardiovascular homeostasis. Thus, this review aimed to contribute to the understanding of autonomic modulation of HRV and its relationship with cardiovascular fitness, highlighting the advances made thus far, the applicability of analysis tools, and the confounding factors observed frequently.

Brain-heart autonomic axis across different clinical status and severity of chronic obstructive pulmonary disease

PURPOSE

Impairment of cardiac autonomic integrity is common in chronic obstructive pulmonary disease (COPD) patients. The influence of the interaction between clinical and severity status on brain-heart autonomic axis (BHAA) is not well known. We aimed to investigate the BHAA function across different clinical status and severity of COPD.

METHODS

Cross-sectional study involving 77 COPD patients allocated into four groups according to clinical status [acute exacerbation (GAE) or stable (GST)] and severity [less (-) or more (+)]: 1) GAE-, n = 13; 2) GAE+, n = 20; 3) GST-, n = 23; and 4) GST+, n = 21. Heart rate variability (HRV) at rest and heart rate recovery (HRR) after 6-min walk test were markers of BHAA. Mean R-R, STDRR, RMSSD, RRtri, HF, LF, SD1, SD2, ApEn and SampEn were the HRV indexes and, HRR was obtained as: HR at 1st min of recovery minus peak HR.

RESULTS

A main effect of clinical status (p < 0.001) was found to vagal modulation in GAE-vs. GST- (RMSSD: 25.0 ± 14.8 vs. 12.6 ± 5.5 ms; SD1: 18.0 ± 10.6 vs. 8.9 ± 3.9 ms) and to GAE + vs. GST+ (RMSSD: 26.4 ± 15.2 vs. 15.4 ± 6.3 ms; SD1: 18.3 ± 11.2 vs. 10.9 ± 4.5 ms). An effect of clinical status (p = 0.032) and severity (p = 0.030) were found to HF (vagal) in GAE + compared to GAE- and GST+ (264.7 ± 239.0 vs. 134.7 ± 169.7 and 135.8 ± 139.7 ms²). Lower HRR was found in GAE-compared to GST- (8.0 ± 2.4 vs. 19.6 ± 2.4 bpm), p = 0.002.

CONCLUSION

In COPD patients, clinical status (AECOPD or stable) was more dominant than the severity on BHAA function. A more pronounced parasympathetic modulation was found in AECOPD patients with a lower HRR to exercise.

Influence of Physical Fitness on Special Judo Fitness Test Performance: A Multiple Linear Regression Analysis

ABSTRACT

Lopes-Silva, JP, Panissa, VLG, Julio, UF, and Franchini, E. Influence of physical fitness on Special Judo Fitness Test performance: a multiple linear regression analysis. J Strength Cond Res 35(6): 1732-1738, 2021-The purpose of this study was to identify the physical fitness variables that best predict Special Judo Fitness Test (SJFT) performance. Thirty-five male experienced judo athletes took part in this study. All athletes performed 5 tests: upper- and lower-body cycle ergometer graded exercise tests; upper- and lower-body Wingate tests; and SJFT. The peak oxygen consumption (V̇o2peak), maximum heart rate (HRmax), maximum aerobic power, and the variables corresponding to onset blood lactate accumulation (OBLA) were determined during the graded exercise tests. For the Wingate tests, peak power (PP) and mean power were used. Furthermore, the total number of throws, heart rate (HR) immediately and 1 minute after, and SJFT index were calculated. Four separated forward multiple linear regressions (forward model) were used to identify the physical fitness variables that best explained the SJFT variables. Upper-body V̇o2peak (ml·min-1·kg-1) explained 27% of variance in the total number of throws, whereas an additional 7% was explained by upper-body PP. Upper-body HRmax explained 46% of the variance in the HR immediately after the SJFT, whereas lower-body HR at OBLA accounted for an additional 8%. Lower-body HRmax explained 21% of the variance in the HR 1 minute after the SJFT, whereas peak lactate ([La-]peak) after the lower-body graded exercise test accounted for an additional 12%. Upper-body V̇o2peak (ml·min-1·kg-1) alone accounted for 15% of the variance in the SJFT index. Based on these results, the data suggest that physical fitness variables, derived from upper- and lower-body aerobic and anaerobic tests, have a small ability to predict the SJFT variables.

Post-exercise heart rate recovery and its speed are associated with cardiac autonomic responsiveness following orthostatic stress test in men

Objective: The present study sought to expand upon prior investigations of the relationship between the post-exercise heart rate recovery (HRR) and the cardiac autonomic responsiveness after orthostatic stress test.Method: HRR at the 1st, 3rd, and 5th min after maximal exercise test were correlated with relative change (Δ%) of time-domain (CV, pNN50, and rMSSD) and frequency-domain (TP, LF, HF, and LF/HF ratio) indices of heart rate variability (HRV) after active orthostatic test in 46 healthy men. Statistical analysis employed non-parametric tests with a p-value set at 5%.Results: HRR at 1st min correlated with Δ%pNN50 (r_s:0.36 - p = .02). In the 3rd and 5th min, these measures correlated with Δ%pNN50, Δ%rMSSD, Δ%CV, Δ%TP, and Δ%HF indices (r_s:0.33, 0.59 - p ≤ .05). Coefficient of HRR at the 1st min correlated with Δ%pNN50, Δ%rMSSD, and Δ%HF (r_s:0.28, 0.45 - p ≤ .05). The 3rd and 5th min showed correlation with Δ%pNN50, Δ%rMSSD, Δ%HF, Δ%CV, and Δ%TP (r_s:0.37, 0.64 - p ≤ .05). No correlation was found with indices combined sympathetic-parasympathetic modulation and HRR. After the sample was divided into high and low parasympathetic responsiveness subgroups after the orthostatic test, faster HRR was associated with the degree of parasympathetic responsiveness (reduction) following postural change (p ≤ .05).Conclusion: HRR throughout the 1st to 5th min is positively correlated with parasympathetic responsiveness and overall cardiac autonomic modulation of HRV after the orthostatic stress test, and faster HRR is positively correlated with the relative degree of parasympathetic responsiveness after the active postural change at rest in healthy men.

An examination of single day vs. multi-day heart rate variability and its relationship to heart rate recovery following maximal aerobic exercise in females

The purpose of this study was to examine the relationship of a single day measure of heart rate variability (HRV), and the averaged baseline measures of HRV to heart rate recovery (HRR) following maximal exercise. Thirty females (22.9 ± 3.2 years, 64.8 ± 8.4 kg) completed four visits (V1-V4), where a 10-min HRV was recorded. Upon completing the V4 recording, a treadmill graded exercise test (GXT) was performed, followed by a 5-min active cool down. HRV was assessed through time domain measures [natural log of root mean square of successive R-R differences (lnRMSSD) and standard deviation of normal to normal intervals (lnSDNN)] and natural log frequency domain measures [low frequency (lnLF) and high frequency (lnHF)]. Variables collected over V1-V4 were measured as; day of (DO) GXT, 3 day (AV3), and 4 day average (AV4). HRR was calculated as the maximal HR achieved minus the HR at: 30-s (HRR30), 1-min (HRR1), 2-min (HRR2), 3-min (HRR3), 4-min (HRR4) or 5-min (HRR5) of recovery. Pearson's Product correlations revealed significant correlations (P = < 0.05) between all HRV_DO measures to each HRR measure and are presented in ranges: lnSDNN (r = 0.442-0.522), lnRMSSD (r = 0.458-0.514), lnLF (r = 0.368-0.469), lnHF (r = 0.422-0.493). For HRV_AV3, lnRMSSD_AV3 and HRR1 were positively correlated (r = 0.390, P = 0.033). Last, HRV_AV4 showed positive relationships (P = < 0.05) between lnRMSSD_AV4 and HRR30 (r = 0.365, P = 0.048); and for HRR1 and lnSDNN_AV4 (r = 0.400, P = 0.029), lnRMSSD_AV4 (r = 0.442, P = 0.014), and lnHF_{AV4 (}r = 0.368, P = 0.045); and lnRMSSD_AV4 and HRR3 (r = 0.381, P = 0.038). Within the current study HRV_DO displayed the strongest correlations to HRR therefore, averaged resting HRV measures do not strengthen the prediction of cardiovascular recovery following a GXT in this population.

Presence of age- and sex-related differences in heart rate variability despite the maintenance of a suitable level of accelerometer-based physical activity

There is currently a lack of information adjacent on the influence of sex and age in heart rate variability (HRV), adjusted according to accelerometer-based physical activity (PADL). We hypothesized that the effect of sex and age on the HRV should be reduced or absent in individuals with a suitable PADL level. We aim to evaluate the influence of sex and age on HRV, adjusted for the confounding effects of the PADL level. A total of 485 age-stratified subjects (18–39, 40–59, and ≥60 years) underwent HRV analyses at rest and 7-day assessments of accelerometer-based PADL. Multivariate analyses of covariance were done using log-transformed HRV indices as outcomes, age and sex as fixed factors, and PADL, cardiovascular risk, fat body mass, and heart rate (HR) at rest as covariates. Despite the adjustment for directly measured PADL, women had better indices of vagal tone, whereas men had higher sympathetic influence. Also, compared to middle-aged and older adults, younger individuals (ages 18–39 years) presented better HRV. Multiple regression analyses confirmed that age and sex were the main predictors of HRV indices, even after adjusting for PADL directly assessed by triaxial accelerometer and HR. We also observed that the correlation between some HRV indexes and the different indexes of physical activity directly evaluated was significant, but not very consistent. Thus, HRV indices are influenced by age and sex, regardless of accelerometer-based physical activity. Interventions with physical activity and exercise aimed at improving the autonomic modulation of asymptomatic adults should take such differences into account.

Usefulness of heart rate recovery parameters to monitor cardiovascular adaptation in elite athletes: The impact of the type of sport

PURPOSE

The purpose of this study is to determine heart rate (HR) recovery after maximal test in elite athletes who compete in high dynamic, high static, and in mixed sport disciplines; to assess differences in HR recovery between these groups of athletes; and to measure the association of HR index (HRI) with heart adaptation variables to determine whether these values were correlated with the type of exercise.

METHODS

One hundred and ninety-four elite athletes were divided into three groups according to the predominant type of exercise performed: endurance (n = 40), strength-sprinter (n = 36), and ball-game players (n = 118). They performed maximal cardiopulmonary exercise testing on a treadmill and were subjected to echocardiography. The rate of decline (HR recovery) was calculated as the difference between maximum and recovery HRs (HRrec1 and HRrec3). The HRI was calculated as HR_max - 1-min post-exercise HR (HRrec1).

RESULTS

The most significant correlation of HRI was with posterior wall diameter and left ventricular (LV) mass index (r = 0.43 and r = 0.51; p = 0.012 and p = 0.003, respectively). LV mass index [Beta (B) = 0.354, p = 0.001] was an independent predictor of HRI and HRrec1. HRI may be an effective tool for discrimination of physiological and "gray zone" LV hypertrophy, with area under the curve of 0.545 (95% CI = 0.421-0.669, p = 0.0432). HRI displayed a sensitivity of 50% and specificity of 52.2% at the optimal cut-off value of 23.5.

CONCLUSION

HR recovery pattern, especially HRI, may offer a timely and efficient tool to identify athletes with autonomous nervous system adaptive changes.

Short-Term Heart Rate Recovery is Related to Aerobic Fitness in Elite Intermittent Sport Athletes

Watson, AM, Brickson, SL, Prawda, ER, and Sanfilippo, JL. Short-term heart rate recovery is related to aerobic fitness in elite intermittent sport athletes. J Strength Cond Res 31(4): 1055-1061, 2017-Although heart rate recovery (HRR) has been suggested as a measure of fitness, minimal data exist among athletes. The purpose of this study was to determine if HRR is related to aerobic fitness in elite athletes and whether this relationship is influenced by sex or body composition. Eighty-four collegiate athletes (45 male athletes) underwent body fat percentage (BF%) determination by dual-energy x-ray absorptiometry and maximal treadmill testing followed by 5 minutes of recovery. V[Combining Dot Above]O2max and heart rate (HRmax) were determined, and HRR was calculated as a percentage of HRmax at 10 seconds, 30 seconds, and 1, 2, 3, 4, and 5 minutes after test completion. After stratifying by sex, participants were grouped as high fit or low fit based on V[Combining Dot Above]O2max median split. Heart rate recovery was compared between sexes and fitness level at each time point. Multivariable regression analysis was used to identify independent predictors of HRR using V[Combining Dot Above]O2max, BF%, and sex as covariates. Heart rate recovery did not differ significantly between sexes and was faster among high-fit participants at 10 and 30 seconds, but at no other time. V[Combining Dot Above]O2max was significantly correlated with HRR at 10 and 30 seconds (r = -0.34, p < 0.001 and r = -0.28, p = 0.008) only. After controlling for BF% and sex, V[Combining Dot Above]O2max remained significantly associated with HRR at 10 seconds (p = 0.007) but not at 30 seconds (p = 0.067) or any time thereafter. Aerobic capacity is related to faster HRR during the first 30 seconds only, suggesting that only very short term HRR should be used as a measure of aerobic fitness in intermittent sport athletes.

Heritability of heart rate recovery and vagal rebound after exercise

Purpose

The prognostic power of heart rate recovery (HRR) after exercise has been well established but the exact origin of individual differences in HRR remains unclear. This study aims to estimate the heritability of HRR and vagal rebound after maximal exercise in adolescents. Furthermore, the role of voluntary regular exercise behavior (EB) in HRR and vagal rebound is tested.

Methods

491 healthy adolescent twins and their siblings were recruited for maximal exercise testing, followed by a standardized cooldown with measurement of the electrocardiogram and respiratory frequency. Immediate and long-term HRR (HRR60 and HRR180) and vagal rebound (heart rate variability in the respiratory frequency range) were assessed 1 and 3 min after exercise. Multivariate twin modeling was used to estimate heritability of all measured variables and to compute the genetic contribution to their covariance.

Results

Heritability of HRR60, HRR180 and immediate and long-term vagal rebound is 60 % (95 % CI: 48–67), 65 % (95 % CI: 54–73), 23 % (95 % CI: 11–35) and 3 % (95 % CI: 0–11), respectively. We find evidence for two separate genetic factors with one factor influencing overall cardiac vagal control, including resting heart rate and respiratory sinus arrhythmia, and a specific factor for cardiac vagal exercise recovery. EB was only modestly associated with resting heart rate (r = −0.27) and HRR (rHRR60 = 0.10; rHRR180 = 0.19) with very high genetic contribution to these associations (88–91 %).

Conclusions

Individual differences in HRR and immediate vagal rebound can to a large extent be explained by genetic factors. These innate cardiac vagal exercise recovery factors partly reflect the effects of heritable differences in EB.

Post-exercise heart-rate recovery correlates to resting heart-rate variability in healthy men

JUSTIFICATIVE

The relationship between post-exercise heart-rate recovery (HRR) and resting cardiac autonomic modulation is an incompletely explored issue.

OBJECTIVE

To correlate HRR with resting supine and orthostatic autonomic status.

METHOD

HRR at the 1st, 3th, and 5th min following maximal treadmill exercise were correlated with 5-min time-domain (CV, pNN50 and rMSSD) and frequency-domain (TP, LF, HF, LFn, HFn, and LF/HF ratio) indices of heart-rate variability (HRV) in both supine and standing positions in 31 healthy physically active non-athletes men. Statistical analysis employed non-parametric tests with two-tailed p value set at 5 %.

RESULTS

Absolute HRR and Δ %HRR at each post-exercise time did not correlated with HRV in supine position, as well as at 1st min in standing position. At the 3rd min and 5th min, these measures negatively correlated with pNN50, rMSSD, TP, and HF indices, and only in the 5th min, they showed negative correlation with HFn and positive correlation with LF, LFn, and LF/HF ratio in the standing position. Coefficient of HRR (CHRR) at the 1st min negatively correlated with pNN50 and rMSSD and at 3rd and 5th min showed positive correlation with LFn and LF/HF ratio in supine position. With HRV indices in standing position CHRR from the 1st to 5th min showed the same respective negative and positive correlations as the other measures.

CONCLUSION

HRR from the 1st to 5th min post-exercise negatively correlated with parasympathetic modulation in resting orthostatic, but showed no correlation in supine position. At the 3rd and 5th min, a positive correlation with combined sympathetic-parasympathetic modulation in both positions was observed.

Heart Rate Variability Is Associated with Exercise Capacity in Patients with Cardiac Syndrome X

Heart rate variability (HRV) reflects the healthiness of autonomic nervous system, which is associated with exercise capacity. We therefore investigated whether HRV could predict the exercise capacity in the adults with cardiac syndrome X (CSX). A total of 238 subjects (57±12 years, 67.8% men), who were diagnosed as CSX by the positive exercise stress test and nearly normal coronary angiogram were enrolled. Power spectrum from the 24-hour recording of heart rate was analyzed in frequency domain using total power (TP) and spectral components of the very low frequency (VLF), low frequency (LF) and high frequency (HF) ranges. Among the study population, 129 subjects with impaired exercise capacity during the treadmill test had significantly lower HRV indices than those with preserved exercise capacity (≥90% of the age predicted maximal heart rate). After accounting for age, sex, and baseline SBP and heart rate, VLF (odds ratio per 1SD and 95% CI: 2.02, 1.19–3.42), LF (1.67, 1.10–2.55), and TP (1.82, 1.17–2.83) remained significantly associated with preserved exercise capacity. In addition, increased HRV indices were also associated with increased exercise duration, rate-pressure product, and heart rate recovery, independent of age, body mass index, and baseline SBP and heart rate. In subgroup analysis, HRV indices demonstrated similar predictive values related to exercise capacity across various subpopulations, especially in the young. In patients with CSX, HRV was independently associated with exercise capacity, especially in young subjects. The healthiness of autonomic nervous system may have a role in modulating the exercise capacity in patients with CSX.

Motivational State and Personality in Relation to Emotion, Stress, and HRV Responses to Aerobic Exercise

Abstract. This study examined emotion, stress, and performance during aerobic exercise performed in the telic and paratelic states, in relation to telic and paratelic dominance. The study tested the misfit effect and is the first to examine heart rate variability (HRV) responses to exercise in relation to both personality and motivational state. Based on their Paratelic Dominance Scale scores, participants identified as telic dominant (TD) and paratelic dominant (PD) completed ramp tests following telic and paratelic state manipulations (repeated measures). In each condition, participants watched “serious” (telic) or “playful” (paratelic) videos for 10 min, then performed a ramp test on a cycle ergometer while continuing to watch the videos throughout the entire protocol. Motivational state (telic/paratelic), HRV, emotion, and stress levels were measured at baseline, pre, post, and 15 min post-ramp test. Time to exhaustion was measured as an index of performance. Limited support was obtained for the misfit effect as interactions between state and dominance were not revealed for any of the variables with the exception of low frequent (LF) and the low frequent/high frequent ratio (LF/HF % normalized), which can be interpreted as indicating that both groups were more relaxed in their preferred state condition. Regardless, findings offer useful insight into methodological considerations for similar studies, such as consideration of the moderating effects of exercise characteristics. Our findings also confirm a number of reversal theory ( Apter, 1982 ) proposals including the concept of dominance as an individual difference factor, with varying characteristics of different dominances, based on physiological response variables. We recommend continued research into the misfit effect with larger samples, and designs that accommodate the methodological considerations raised by the present results.

Heart rate recovery in elite athletes: the impact of age and exercise capacity

There is compelling evidence that postexercise heart rate recovery (HRR) is a valid indicator of sympaticovagal balance. It is also used in prescription and monitoring of athletic training. The purpose of our study was to determine HRR after maximal exercise among elite athletes with respect to age. A total of 274 elite male Caucasian athletes were randomly selected from the larger sample and divided into two groups: adolescent (group Y) and adult athletes (≥18 years; group A). They performed maximal cardiopulmonary exercise testing on a treadmill. Heart rate recovery was calculated as the rate of decline of HR from peak exercise to rates 1, 2 and 3 min after cessation of exercise (HRR1, HRR2 and HRR3). A significantly higher HRR1 was found in group A (29·5 ± 15·6 versus 22·4 ± 10·8, P<0·001), but HRR3 was higher in group Y (82·7 ± 10·2 versus 79·9 ± 12·25; P = 0·04). Stepwise multivariate linear regression analysis showed that, among all subjects, the HRR1 alone was independently associated with age (P<0·001). The maximal oxygen consumption (VO₂ max) was in a negative relationship with HRR1 and in a positive one with HRR3 (P<0·05) with respect to all athletes. The HRR during 3 min postexercise should be reported for the purpose of better assessing functional adaptation to exercise among elite athletes as well as the age-associated differences in recovery. Higher values of HRR1 should be expected in older athletes, and HRR3 could be used as an index of aerobic capacity, irrespective of age.

Parasympathetic reactivation after maximal CPET depends on exercise modality and resting vagal activity in healthy men

Purpose

The main purpose of this study was to investigate parasympathetic reactivation of the heart [evaluated through heart rate recovery (HRR) and HR variability (HRV)] after maximal cardiopulmonary exercise testing (CPET) using three different exercise modalities.

Methods

Twenty healthy men, aged 17 to 28 yr, performed three maximal CPETs (cycling, walking, and running) separated by 72 h and in a randomized, counter-balanced order. HRR was determined from the absolute differences between HR_peak and HR at 1–3 min after exercise. The root mean square of successive R-R differences calculated for consecutive 30-s windows (rMSSD_30s) was calculated to assess the parasympathetic reactivation after maximal CPET.

Results

Lower HR_peak, VO_2peak and energy expenditure were observed after the cycling CPET than the walking and running CPETs (P < 0.001). Both HRR and rMSSD_30s were significantly greater during recovery from the cycling CPET compared to the walking and running CPETs (P < 0.001). Furthermore, Δ rMSSD (i.e. resting minus postexercise rMSSD every 30 s into the recovery period) was positively related to the resting high-frequency component (HF), rMSSD, and standard deviation of all normal R-R intervals (SDNN) (r_s = 0.89 to 0.98; P < 0.001), and negatively related to the resting low-frequency component (LF) and sympathovagal balance (LF:HF ratio) after all exercise conditions (r_s = −0.73 to −0.79 and −0.86 to −0.90, respectively; P < 0.001).

Conclusions

These findings support that parasympathetic reactivation after maximal CPET (as assessed by HRR and rMSSD_30s) depends on exercise modality and cardiac autonomic control at rest.

The exercise heart rate profile in master athletes compared to healthy controls

Endurance exercise protects the heart via effects on autonomic control of heart rate (HR); however, its effects on HR indices in healthy middle-aged men are unclear. This study compared HR profiles, including resting HR, increase in HR during exercise and HR recovery after exercise, in middle-aged athletes and controls. Fifty endurance-trained athletes and 50 controls (all male; mean age, 48·7 ± 5·8 years) performed an incremental symptom-limited exercise treadmill test. The electrocardiographic findings and HR profiles were evaluated. Maximal O2 uptake (52·6 ± 7·0 versus 34·8 ± 4·5 ml kg(-1)  min(-1) ; P<0·001) and the metabolic equivalent of task (15·4 ± 1·6 versus 12·2 ± 1·5; P<0·001) were significantly higher in athletes than in controls. Resting HR was significantly lower in athletes than in controls (62·8 ± 6·7 versus 74·0 ± 10·4 beats per minute (bpm), respectively; P<0·001). Athletes showed a greater increase in HR during exercise than controls (110·1 ± 11·0 versus 88·1 ± 15·4 bpm; P<0·001); however, there was no significant between-group difference in HR recovery at 1 min after cessation of exercise (22·9 ± 5·6 versus 21·3 ± 6·7 bpm; P = 0·20). Additionally, athletes showed a lower incidence of premature ventricular contractions (PVCs) during exercise (0·0% versus 24·0%; P<0·001). Healthy middle-aged men participating in regular endurance exercise showed more favourable exercise HR profiles and a lower incidence of PVCs during exercise than sedentary men. These results reflect the beneficial effect of endurance training on autonomic control of the heart.

Cross-country skiing and postexercise heart-rate recovery

Postexercise heart-rate (HR) recovery (HRR) indices have been associated with running and cycling endurance-exercise performance. The current study was designed (1) to test whether such a relationship also exists in the case of cross-country skiing (XCS) and (2) to determine whether the magnitude of any such relationship is related to the intensity of exercise before obtaining HRR indices. Ten elite male cross-country skiers (mean ± SD; 28.2 ± 5.4 y, 181 ± 8 cm, 77.9 ± 9.4 kg, 69.5 ± 4.3 mL · min-1 · kg-1 maximal oxygen uptake [VO2max]) performed 2 sessions of roller-skiing on a treadmill: a 2 × 3-km time trial and the same 6-km at an imposed submaximal speed followed by a final 800-m time trial. VO2 and HR were monitored continuously, while HRR and blood lactate (BLa) were assessed during 2 min immediately after each 6-km and the 800-m time trial. The 6-km time-trial time was largely negatively correlated with VO2max and BLa. On the contrary, there was no clear correlation between the 800-m time-trial time and VO2, HR, or BLa. In addition, in no case was any clear correlation between any of the HRR indices and performance time or VO2max observed. These findings confirm that XCS performance is largely correlated with VO2max and the ability to tolerate high levels of BLa; however, postexercise HRR showed no clear association with performance. The homogeneity of the group of athletes involved and the contribution of the arms and upper body to the exercise preceding determination of HRR may explain this absence of a relationship.

Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring

The measurement of heart rate variability (HRV) is often considered a convenient non-invasive assessment tool for monitoring individual adaptation to training. Decreases and increases in vagal-derived indices of HRV have been suggested to indicate negative and positive adaptations, respectively, to endurance training regimens. However, much of the research in this area has involved recreational and well-trained athletes, with the small number of studies conducted in elite athletes revealing equivocal outcomes. For example, in elite athletes, studies have revealed both increases and decreases in HRV to be associated with negative adaptation. Additionally, signs of positive adaptation, such as increases in cardiorespiratory fitness, have been observed with atypical concomitant decreases in HRV. As such, practical ways by which HRV can be used to monitor training status in elites are yet to be established. This article addresses the current literature that has assessed changes in HRV in response to training loads and the likely positive and negative adaptations shown. We reveal limitations with respect to how the measurement of HRV has been interpreted to assess positive and negative adaptation to endurance training regimens and subsequent physical performance. We offer solutions to some of the methodological issues associated with using HRV as a day-to-day monitoring tool. These include the use of appropriate averaging techniques, and the use of specific HRV indices to overcome the issue of HRV saturation in elite athletes (i.e., reductions in HRV despite decreases in resting heart rate). Finally, we provide examples in Olympic and World Champion athletes showing how these indices can be practically applied to assess training status and readiness to perform in the period leading up to a pinnacle event. The paper reveals how longitudinal HRV monitoring in elites is required to understand their unique individual HRV fingerprint. For the first time, we demonstrate how increases and decreases in HRV relate to changes in fitness and freshness, respectively, in elite athletes.

Monitoring training status with HR measures: do all roads lead to Rome?

Measures of resting, exercise, and recovery heart rate are receiving increasing interest for monitoring fatigue, fitness and endurance performance responses, which has direct implications for adjusting training load (1) daily during specific training blocks and (2) throughout the competitive season. However, these measures are still not widely implemented to monitor athletes' responses to training load, probably because of apparent contradictory findings in the literature. In this review I contend that most of the contradictory findings are related to methodological inconsistencies and/or misinterpretation of the data rather than to limitations of heart rate measures to accurately inform on training status. I also provide evidence that measures derived from 5-min (almost daily) recordings of resting (indices capturing beat-to-beat changes in heart rate, reflecting cardiac parasympathetic activity) and submaximal exercise (30- to 60-s average) heart rate are likely the most useful monitoring tools. For appropriate interpretation at the individual level, changes in a given measure should be interpreted by taking into account the error of measurement and the smallest important change of the measure, as well as the training context (training phase, load, and intensity distribution). The decision to use a given measure should be based upon the level of information that is required by the athlete, the marker's sensitivity to changes in training status and the practical constrains required for the measurements. However, measures of heart rate cannot inform on all aspects of wellness, fatigue, and performance, so their use in combination with daily training logs, psychometric questionnaires and non-invasive, cost-effective performance tests such as a countermovement jump may offer a complete solution to monitor training status in athletes participating in aerobic-oriented sports.

Resting heart rate variability and heart rate recovery after submaximal exercise

PURPOSE

Aerobic training accelerates Heart Rate Recovery after exercise in healthy subjects and in patients with coronary disease. As shown by pharmacological autonomic blockade, HRR early after exercise is dependent primarily on parasympathetic reactivation. Thus, accelerated HRR early after exercise in endurance-trained athletes may be attributed to augmented parasympathetic reactivation. In the present study, we tested the hypothesis that the HRR early after submaximal exercise is related to the pre-exercise parasympathetic modulation.

METHODS

Thirty endurance-trained athletes (20 males, 50 ± 7 years) and thirty control subjects (20 males, 52 ± 6 years) performed a submaximal exercise on a cyclo-ergometer. Pre-exercise resting short-term heart rate variability (HRV) parameters in time and frequency-domains were correlated with HRR during the first 30 s, 1 and 2 min after cessation of exercise.

RESULTS

We found that HRR was statistically significantly faster in athletes than in controls at all examination time points (p < 0.05). HF, SDNN and RMSSD were statistically significantly higher in athletes than in controls (p < 0.05), but other resting HRV parameters were not statistically different between groups. After 30 s, 1 and 2 min of recovery, HRR correlation with total power, HF, HFnu and RMSSD was positive, while the correlation with LF/HF was negative for small and positive for larger values. The opposite was true for SDNN.

CONCLUSIONS

These findings support the hypothesis that HRR early after submaximal exercise is related to resting parasympathetic modulation in the middle-aged subjects. In addition, they suggested an optimal range of HRV for maximal HRR after exercise.

Is baseline cardiac autonomic modulation related to performance and physiological responses following a supramaximal Judo test?

Little research exists concerning Heart Rate (HR) Variability (HRV) following supramaximal efforts focused on upper-body explosive strength-endurance. Since they may be very demanding, it seems of interest to analyse the relationship among performance, lactate and HR dynamics (i.e. HR, HRV and complexity) following them; as well as to know how baseline cardiac autonomic modulation mediates these relationships. The present study aimed to analyse associations between baseline and post-exercise HR dynamics following a supramaximal Judo test, and their relationship with lactate, in a sample of 22 highly-trained male judoists (20.70±4.56 years). A large association between the increase in HR from resting to exercise condition and performance suggests that individuals exerted a greater sympathetic response to achieve a better performance (Rating of Perceived Exertion: 20; post-exercise peak lactate: 11.57±2.24 mmol/L; 95.76±4.13 % of age-predicted HR_max). Athletes with higher vagal modulation and lower sympathetic modulation at rest achieved both a significant larger ∆HR and a faster post-exercise lactate removal. A enhanced resting parasympathetic modulation might be therefore related to a further usage of autonomic resources and a better immediate metabolic recovery during supramaximal exertions. Furthermore, analyses of variance displayed a persistent increase in α₁ and a decrease in lnRMSSD along the 15 min of recovery, which are indicative of a diminished vagal modulation together with a sympathovagal balance leaning to sympathetic domination. Eventually, time-domain indices (lnRMSSD) showed no lactate correlations, while nonlinear indices (α₁ and lnSaEn) appeared to be moderate to strongly correlated with it, thus pointing to shared mechanisms between neuroautonomic and metabolic regulation.

Cardiac autonomic modulation is determined by gender and is independent of aerobic physical capacity in healthy subjects

BACKGROUND

Aerobic physical capacity plays an important role in reducing morbidity and mortality rates in subjects with cardiovascular diseases. This action is often related to an improvement in the autonomic modulation of heart rate variability (HRV). However, controversies remain regarding the effects of physical training on cardiac autonomic control in healthy subjects. Therefore, our objective was to investigate whether aerobic capacity interferes with the autonomic modulation of HRV and whether gender differences exist.

METHODS

Healthy men and women (N=96) were divided into groups according to aerobic capacity: low (VO2: 22-38 ml/kg(-1) min(-1)), moderate (VO2: 38-48 ml/kg(-1) min(-1)) and high (VO2 >48 ml/kg(-1) min(-1).) We evaluated the hemodynamic parameters and body composition. The autonomic modulation of HRV was investigated using spectral analysis. This procedure decomposes the heart rate oscillatory signal into frequency bands: low frequency (LF=0.04-0.15Hz) is mainly related to sympathetic modulation, and high frequency (HF=0.15-0.5Hz) corresponds to vagal modulation.

RESULTS

Aerobic capacity, regardless of gender, determined lower values of body fat percentage, blood pressure and heart rate. In turn, the spectral analysis of HRV showed that this parameter did not differ when aerobic capacity was considered. However, when the genders were compared, women had lower LF values and higher HF values than the respective groups of men.

CONCLUSION

The results suggest that aerobic physical capacity does not interfere with HRV modulation; however, the cardiac modulatory balance differs between genders and is characterized by a greater influence of the autonomic vagal component in women and by the sympathetic component in men.

Longitudinal changes in cardiac autonomic function and aerobic fitness indices in endurance runners: a case study with a high-level team

To determine the effects of preparatory phase training on aerobic parameters, resting heart rate variability (HRV) and 5-km performance of high-level endurance runners and the relationship between the percentage change (% change) of resting HRV with the % change of aerobic parameters and 5-km performance. Six runners were assessed before and after seven weeks of training. The aerobic parameters were determined in an incremental test. The HRV was assessed by a heart rate monitor. Athletes performed a 5-km running test in a track. The analysis revealed 'likely' and 'very likely' improvements for velocity associated with maximal oxygen uptake ([Formula: see text]O2max) (20.0±1.0 km·h(-1) to 21.2±0.6 km·h(-1)) and 5-km performance (18.0±0.4 km·h(-1) to 18.9±0.7 km·h(-1)), respectively, as well as 'likely' decrease in high frequency (41.4±18.5 nu to 30.4±14.3 nu), and increase in low frequency (58.5±18.5 nu to 69.6±14.3 nu) band densities. The variation in the velocity associated with [Formula: see text]O2max showed the highest correlation with 5-km performance (r=0.95). The % change in the square root of the mean sum of the squared differences between R-R intervals and standard deviation 1 were highly correlated with variation in 5-km performance (r=0.69 and 0.66). Changes in the velocity associated with [Formula: see text]O2max and vagally mediated HRV were highly associated with 5-km running performance within the investigated team. These results have important implications because these parameters can be assessed longitudinally to monitor adaptation to training.

A systematic review on heart-rate recovery to monitor changes in training status in athletes

Heart-rate recovery (HRR) has been proposed as a marker of autonomic function and training status in athletes. The authors performed a systematic review of studies that examined HRR after training. Five cross-sectional studies and 8 studies investigating changes over time (longitudinal) met our criteria. Three out of 5 cross-sectional studies observed a faster HRR in trained compared with untrained subjects, while 2 articles showed no change as a result of training. Most longitudinal studies observed a corresponding increase in HRR and power output (training status). Although confounding factors such as age, ambient temperature, and the intensity and duration of the exercise period preceding HRR make it difficult to compare these studies, the available studies indicated that HRR was related to training status. Therefore, the authors conclude that HRR has the potential to become a valuable tool to monitor changes in training status in athletes and less well-trained subjects, but more studies and better standardization are required to match this potential.

Effect of maturation on hemodynamic and autonomic control recovery following maximal running exercise in highly trained young soccer players

The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly trained young male soccer players (12-18 years) classified as pre-, circum-, or post-peak height velocity (PHV) performed a graded running test to exhaustion on a treadmill. Before (Pre) and after (5th-10th min, Post) exercise, heart rate (HR), stroke volume (SV), cardiac output (CO), arterial pressure (AP), and total peripheral resistance (TPR) were monitored. Parasympathetic (high frequency [HF(RR)] of HR variability (HRV) and baroreflex sensitivity [Ln BRS]) and sympathetic activity (low frequency [LF(SAP)] of systolic AP variability) were estimated. Post-exercise blood lactate [La](b), the HR recovery (HRR) time constant, and parasympathetic reactivation (time-varying HRV analysis) were assessed. In all three groups, exercise resulted in increased HR, CO, AP, and LF(SAP) (P < 0.001), decreased SV, HF(RR), and Ln BRS (all P < 0.001), and no change in TPR (P = 0.98). There was no "maturation × time" interaction for any of the hemodynamic or autonomic variables (all P > 0.22). After exercise, pre-PHV players displayed lower SV, CO, and [La](b), faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La](b), and Pre parasympathetic activity were the strongest predictors of HRR (r(2) = 0.62, P < 0.001). While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis, and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.

Relationship between exercise capacity and heart rate variability: supine and in response to an orthostatic stressor

The study investigated whether supine-measured HRV indicators, and/or HRV indicators measured during orthostatic stress are related to conventional measures of exercise and performance ability such as VO(2max). Only two significant correlations (p<0.05) out of 30 tests were found between supine-determined HRV indicators and conventional measures. In contrast, fifteen of the 30 relationships calculated during orthostatic stress were significant. Relationships were at best low to moderate (0.2<|corr|<0.4). As expected, the relationships obtained during orthostatic stress were reversed from that obtained in the supine position. In summary, although HRV indicators are related to cardiovascular fitness, correlations between VO(2max) and these parameters are found only under very specific conditions. HRV parameters explain very little of the variance in VO(2max). In addition, estimating the exercise capacity from HRV indicators requires experience and extreme caution.