scholarly journals Effects of a Short-Term Cycling Interval Session and Active Recovery on Non-Linear Dynamics of Cardiac Autonomic Activity in Endurance Trained Cyclists

2019 ◽  
Vol 8 (2) ◽  
pp. 194 ◽  
Author(s):  
Thomas Gronwald ◽  
Olaf Hoos ◽  
Kuno Hottenrott
Keyword(s):  
Heart Rate ◽  
Exercise Heart Rate ◽  
Scaling Exponent ◽  
Autonomic Activity ◽  
Active Recovery ◽  
Short Term ◽  
Linear Dynamics ◽  
Non Linear ◽  
Correlation Properties ◽  
Cardiac Autonomic Activity

Measurement of the non-linear dynamics of physiologic variability in a heart rate time series (HRV) provides new opportunities to monitor cardiac autonomic activity during exercise and recovery periods. Using the Detrended Fluctuation Analysis (DFA) technique to assess correlation properties, the present study examines the influence of exercise intensity and recovery on total variability and complexity in the non-linear dynamics of HRV. Sixteen well-trained cyclists performed interval sessions with active recovery periods. During exercise, heart rate (HR) and beat-to-beat (RR)-intervals were recorded continuously. HRV time domain measurements and fractal correlation properties were analyzed using the short-term scaling exponent alpha1 of DFA. Lactate (La) levels and the rate of perceived exertion (RPE) were also recorded at regular time intervals. HR, La, and RPE showed increased values during the interval blocks (p < 0.05). In contrast, meanRR and DFA-alpha1 showed decreased values during the interval blocks (p < 0.05). Also, DFA-alpha1 increased to the level in the warm-up periods during active recovery (p < 0.05) and remained unchanged until the end of active recovery (p = 1.000). The present data verify a decrease in the overall variability, as well as a reduction in the complexity of the RR-interval-fluctuations, owing to increased organismic demands. The acute increase in DFA-alpha1 following intensity-based training stimuli in active recovery may be interpreted as a systematic reorganization of the organism with increased correlation properties in cardiac autonomic activity in endurance trained cyclists.

scholarly journals Analysis of Fractal Correlation Properties of Heart Rate Variability during an Initial Session of Eccentric Cycling

2021 ◽  
Vol 18 (19) ◽  
pp. 10426
Author(s):  
Bruce Rogers ◽  
Thomas Gronwald ◽  
Laurent Mourot
Keyword(s):  
Heart Rate ◽  
Exercise Prescription ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Short Term ◽  
Initial Session ◽  
Correlation Properties ◽  
Detrended Fluctuation ◽  
Improve Muscle Strength ◽  
Current Report

Eccentric cycling (ECC) has attracted attention as a method to improve muscle strength and aerobic fitness in populations unable to tolerate conventional methods. However, agreement on exercise prescription targets have been problematic. The current report is an initial exploration of a potentially useful tool, a nonlinear heart rate (HR) variability (HRV) index based on the short-term scaling exponent alpha1 of detrended fluctuation analysis (DFA a1), which has been previously shown to correspond to exercise intensity. Eleven male volunteers performed 45 min of concentric (CON) cycling and ECC separated by 1 month. Work rates were matched for HR (~50% of the maximal HR) during the first 5 min and remained stable thereafter. HRV, HR, oxygen consumption (VO2), and cycling power were monitored and evaluated at elapsed times of 10 (T10) and 45 (T45) minutes duration. HR significantly increased between ECC T10 and ECC T45 (p = 0.003, d = 1.485), while DFA a1 significantly decreased (p = 0.004, d = 1.087). During CON, HR significantly increased (p < 0.001 d = 1.570) without significant DFA a1 change (p = 0.48, d = 0.22). Significantly higher HR was observed at T45 in ECC than in CON (p = 0.047, d = 1.059). A session of unaccustomed ECC lead to decreased values of DFA a1 at T45 in comparison to that seen with CON at similar VO2. ECC lead to altered autonomic nervous system balance as reflected by the loss of correlation properties compared to CON.

Non-linear dynamics of cardiac autonomic activity during cycling exercise with varied cadence

2018 ◽  
Vol 60 ◽  
pp. 225-233 ◽  
Author(s):  
Thomas Gronwald ◽  
Sebastian Ludyga ◽  
Olaf Hoos ◽  
Kuno Hottenrott
Keyword(s):  
Autonomic Activity ◽  
Cycling Exercise ◽  
Linear Dynamics ◽  
Non Linear ◽  
Cardiac Autonomic Activity

scholarly journals Sleep Indices and Cardiac Autonomic Activity Responses during an International Tournament in a Youth National Soccer Team

2021 ◽  
Vol 18 (4) ◽  
pp. 2076
Author(s):  
Pedro Figueiredo ◽  
Júlio Costa ◽  
Michele Lastella ◽  
João Morais ◽  
João Brito
Keyword(s):  
Heart Rate ◽  
Frequency Domain ◽  
Sleep Duration ◽  
Time Domain ◽  
Soccer Players ◽  
Autonomic Activity ◽  
Male Youth ◽  
Youth Soccer ◽  
Wrist Actigraphy ◽  
Cardiac Autonomic Activity

This study aimed to describe habitual sleep and nocturnal cardiac autonomic activity (CAA), and their relationship with training/match load in male youth soccer players during an international tournament. Eighteen elite male youth soccer players (aged 14.8 ± 0.3 years; mean ± SD) participated in the study. Sleep indices were measured using wrist actigraphy, and heart rate (HR) monitors were used to measure CAA during night-sleep throughout 5 consecutive days. Training and match loads were characterized using the session-rating of perceived exertion (s-RPE). During the five nights 8 to 17 players slept less than <8 h and only one to two players had a sleep efficiency <75%. Players’ sleep duration coefficient of variation (CV) ranged between 4 and 17%. Nocturnal heart rate variability (HRV) indices for the time-domain analyses ranged from 3.8 (95% confidence interval, 3.6; 4.0) to 4.1 ln[ms] (3.9; 4.3) and for the frequency-domain analyses ranged from 5.9 (5.6; 6.5) to 6.6 (6.3; 7.4). Time-domain HRV CV ranged from 3 to 10% and frequency-domain HRV ranged from 2 to 12%. A moderate within-subjects correlation was found between s-RPE and sleep duration [r = −0.41 (−0.62; −0.14); p = 0.003]. The present findings suggest that youth soccer players slept less than the recommended during the international tournament, and sleep duration was negatively associated with training/match load.

Diaphragm does not produce ammonia or lactate during high-intensity short-term exercise

1990 ◽  
Vol 259 (4) ◽  
pp. H1185-H1189 ◽  
Author(s):  
M. Manohar ◽  
A. S. Hassan
Keyword(s):  
Heart Rate ◽  
High Intensity ◽  
Work Of Breathing ◽  
Lactate Production ◽  
Exercise Heart Rate ◽  
Short Term ◽  
Energy Needs ◽  
Standard Procedures ◽  
O2 Extraction ◽  
Limb Muscles

To ascertain whether costal diaphragm engages in ammonia and lactate production (like limb muscles) during high-intensity short-term exercise, experiments were carried out on six healthy trained ponies in which phrenic venous catheters had been implanted 5-9 days earlier. Simultaneous anaerobically obtained blood samples from abdominal aorta and the phrenic vein at rest and during 4 min of exertion at 32 km/h and at a 7% grade were analyzed for blood-gas variables as well as lactate and ammonia concentrations using standard procedures. At rest, heart rate was 47 +/- 4 beats/min and the diaphragmatic O2 extraction was 26.5%. With exercise, heart rate rose to 218 +/- 6 beats/min, marked acidosis and hyperventilation occurred, and the diaphragmatic O2 extraction increased threefold (80.9%). Such exercise is known to dramatically increase the work of breathing as respiratory frequency and change in pleural pressure approach 138 +/- 4 breaths/min and 30 +/- 3 cmH2O, respectively. Despite the fact that phrenic-venous O2 tension of exercised ponies decreased to 15.5 +/- 0.6 Torr, the phrenic-venous lactate and ammonia concentrations did not exceed corresponding arterial values. These data thus revealed that the diaphragm is uniquely unlike limb muscles, which at high workloads readily engage in net ammonia and lactate production, and that the diaphragmatic energy needs during high-intensity short-term exercise are primarily met by aerobic metabolism.

Heart rate non linear dynamics in patients with persistent vegetative state: a preliminary report

Brain Injury ◽  
2008 ◽  
Vol 22 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Marco Sarà ◽  
Fabio Sebastiano ◽  
Simona Sacco ◽  
Francesca Pistoia ◽  
Paolo Onorati ◽  
...  
Keyword(s):  
Heart Rate ◽  
Preliminary Report ◽  
Vegetative State ◽  
Persistent Vegetative State ◽  
Linear Dynamics ◽  
Non Linear

Correlation Properties and Complexity of Perioperative RR-Interval Dynamics in Coronary Artery Bypass Surgery Patients

2000 ◽  
Vol 93 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Timo T. Laitio ◽  
Heikki V. Huikuri ◽  
Erkki S. H. Kentala ◽  
Timo H. Mäkikallio ◽  
Jouko R. Jalonen ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Heart Rate ◽  
Intensive Care ◽  
Artery Bypass ◽  
Scaling Exponent ◽  
Short Term ◽  
Cabg Surgery ◽  
Rr Interval ◽  
Heart Rate Dynamics ◽  
Dynamic Measures

Background Dynamic measures of heart rate variability (HRV) may uncover abnormalities that are not easily detectable with traditional time and frequency domain measures. The purpose of this study was to characterize changes in RR-interval dynamics in the immediate postoperative phase of coronary artery bypass graft (CABG) surgery using traditional and selected newer dynamic measures of HRV. Methods Continuous 24-h electrocardiograph recordings were performed in 40 elective CABG surgery patients up to 72 h postoperatively. In one half of the patients, Holter recordings were initiated 12-40 h before the surgery. Time and frequency domain measures of HRV were assessed. The dynamic measures included a quantitative and visual analysis of Poincaré plots, measurement of short- and intermediate-term fractal-like scaling exponents (alpha1 and alpha2), the slope (beta) of the power-law regression line of RR-interval dynamics, and approximate entropy. Results The SD of RR intervals (P &lt; 0.001) and the ultra-low-, very-low-, low-, and high-frequency power (P &lt; 0.01, P &lt; 0.001, P &lt; 0.001, P &lt; 0.01, respectively) measures in the first postoperative 24 h decreased from the preoperative values. Analysis of Poincaré plots revealed increased randomness in beat-to-beat heart rate behavior demonstrated by an increase in the ratio between short-term and long-term HRV (P &lt; 0.001) after CABG. Average scaling exponent alpha1 of the 3 postoperative days decreased significantly after CABG (from 1.22 +/- 0.15 to 0.85 +/- 0.20, P &lt; 0.001), indicating increased randomness of short-term heart rate dynamics (i.e., loss of fractal-like heart rate dynamics). Reduced scaling exponent alpha1 of the first postoperative 24 h was the best HRV measure in differentiating between the patients that had normal (&lt;/= 48 h, n = 33) or prolonged (&gt; 48 h, n = 7) intensive care unit stay (0.85 +/- 0.17 vs. 0.68 +/- 0.18; P &lt; 0.05). In stepwise multivariate logistic regression analysis including typical clinical predictors, alpha1 was the most significant independent predictor (P &lt; 0.05) of long intensive care unit stay. None of the preoperative HRV measures were able to predict prolonged intensive care unit stays. Conclusions In the selected group of patients studied, a decrease in overall HRV was associated with altered nonlinear heart rate dynamics after CABG surgery. Current results suggest that a more random short-term heart rate behavior may be associated with a complicated clinical course. Analysis of fractal-like dynamics of heart rate may provide new perspectives in detecting abnormal cardiovascular function after CABG.

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