Study of the energy supply of muscular activity in the Cooper test among sportsmen-gamers according to the individual heart rate response to the load

In this study, using the example of the Cooper test, pulse zones were identified in percentage ratio, which allow indirectly judging the contribution of a particular energy supply system for each athlete during cyclic work. Keywords: Cooper's test, energy supply, athletes-game players, pulse zones, heart rate monitoring, Polar.

A Neural Network Model for Estimating the Heart Rate Response to Constant Intensity Exercises

Estimating the heart rate (HR) response to exercises of a given intensity without the need of direct measurement is an open problem of great interest. We propose here a model that can estimate the heart rate response to exercise of constant intensity and its subsequent recovery, based on soft computing techniques. Multilayer perceptron artificial neural networks (NN) are implemented and trained using raw HR time series data. Our model’s input and output are the beat-to-beat time intervals and the HR values, respectively. The numerical results are very encouraging, as they indicate a mean relative square error of the estimated HR values of the order of 10−4 and an absolute error as low as 1.19 beats per minute, on average. Our model has also been proven to be superior when compared with existing mathematical models that predict HR values by numerical simulation. Our study concludes that our NN model can efficiently predict the HR response to any constant exercise intensity, a fact that can have many important applications, not only in the area of medicine and cardio-vascular health, but also in the areas of rehabilitation, general fitness, and competitive sport.

THE ROLE OF β, α1 AND α2-ADRENO RECEPTORS IN THE REGULATION OF THE HEART RATE OF LABORATORY ANIMALS EXPOSED TO VARIOUS MODES OF MOTOR ACTIVITY

For the first time, studies were conducted to study the features of the heart rate response of laboratory animals exposed to various modes of motor activity when administered with β, α1 and α2-blockers. It was found that in all the experimental groups of animals studied, a decrease in the heart rate response was observed in the first week after the introduction of β, α1 and α2-adreno blockers. It was revealed that the initial reaction of the heart rate on the introduction of β, α1 and α2-blockers depends on the level of motor activity of laboratory animals. It was found that the most pronounced decrease in the heart rate response to the introduction of different subtypes of adreno-blockers is observed in the group of animals with limited motor activity. At the same time, the smallest decrease in the heart rate response occurs in the group of animals subject to enhanced motor mode. It was revealed that in the group of experimental animals, during further muscle training, by the end of the fourth week, there was a less pronounced decrease in the heart rate response to the administration of β, α1 and α2-adreno blockers. It was found that in a group of animals subject to a regime of limited motor activity, by the end of the fourth week of hypokinesia, the most pronounced decrease in the heart rate response to the introduction of β, α1-targeted blockers occurs.

Effects of pre-exercise acupuncture stimulation on heart rate response during short-duration exercise

Background The purpose of the present study was to investigate the effects of bradycardia induced by pre-exercise acupuncture on heart rate responses during short-duration exercise. Methods A total of 29 healthy subjects underwent two protocols: protocol 1 assessed the effects of manual acupuncture on heart rate response during rest, and protocol 2 tested the hypothesis that the bradycardic effects induced by pre-exercise acupuncture continue during low- and high-intensity exercise. Their average age, height, weight, and body mass index were 21.2 ± 2.0 years, 167.2 ± 8.8 cm, 63.8 ± 12.8 kg, and 22.7 ± 3.5 kg/m2, respectively. In acupuncture stimulations for protocols 1 and 2, an acupuncture needle was inserted into the lower leg and manual acupuncture stimulation was performed at 1 Hz. Results In protocol 1 (resting condition), acupuncture stimulation induced a bradycardic response, which continued for 4 min after the cessation of acupuncture stimulation (p < 0.05). In protocol 2, the bradycardic response induced by pre-exercise acupuncture stimulation remained during low-intensity exercise and in the beginning of high-intensity exercise performed immediately after the cessation of acupuncture stimulation (p < 0.05). However, the effects disappeared when post-acupuncture exercise was performed when the heart rate was approximately 140 beats/min during high-intensity exercise. The rating of perceived exertion after exercise differed significantly between the acupuncture stimulation task (7.9 ± 1.6) and no-stimulation task (8.5 ± 2.0) (p = 0.03) only in the low intensity group. Conclusion This study may provide new insights into the effect of acupuncture stimulation on psycho-physiological conditions during exercise.

THE EFFECT OF A TRAUMATIC BRAIN INJURY ON CHANGES IN THE HEART RATE OF RATS SUBJECT TO VARIOUS MODES OF MOTOR ACTIVITY

For the first time, studies have been conducted to study the reaction of animal heart rate to various modes of motor activity after a traumatic brain injury. It was revealed that on the first day after modeling an open head injury in rats of all age groups, a pronounced increase in heart rate was observed. In this case, the smallest heart rate response to brain injury is observed in animals of immature age. It was found that the implementation of systematic dynamic exercises by animals of mature and preschool age after modeling a craniocerebral injury contributes to a significant decrease in heart rate. A more pronounced formation of training bradycardia is observed in immature animals. It was revealed that limiting motor activity and performing isometric exercises after a traumatic brain injury maintain heart rate at an increased level in all age groups of animals and significantly inhibits the natural, age-related decrease in heart rate in immature animals.

O014 Heart rate response to obstructive respiratory events in children born preterm with OSA

Background Preterm-born (PT) children have an increased risk for obstructive sleep apnoea (OSA) and adverse cardiovascular outcomes. Respiratory events elicit acute changes in heart rate (HR) in term-born (T) children. Whether this response is augmented in PT children with OSA remains unclear. We aimed to analyse the HR response during obstructive respiratory events in PT children with OSA. Methods Nine PT children (3–12 y), were matched for obstructive apnoea hypopnoea index (OAHI), age and gender with T children. Beat-to-beat HR was averaged 10s before, during and the peak after (post) each obstructive event, and peak HR was expressed as percentage change. Results 323 obstructive events in PT and 376 in T children were identified, consisting of 681 hypopnoeas (PT 320; T 361) and 18 apnoeas (PT 3; T 15). There were insufficient apnoeas in the PT group for analysis. For hypopnoeas during total sleep, the PT group had significantly lower HR compared to the T group before median 81bpm (IQR 74–87) vs 88 bpm (79–99); p&lt;0.001), during (76 bpm (69–83) vs 82 bpm (74–92; p&lt;0.001) and post (97 bpm (89–103) vs 105 bpm (95–115; p&lt;0.001) events. The post event increase in HR was significantly higher in the PT (26%, (16–39)) compared with the T (23%, (14–36)) group, p=0.008. Conclusion Although HR was lower during obstructive hypopnoeas in preterm compared with term-born children, the post event surge was significantly higher. This heightened HR response to respiratory events in children born preterm may underlie the worse cardiovascular outcomes in these children.

Mortality among patients undergoing dipyridamole 99mTc Sestamibi SPECT: impact of blunted heart rate response and abnormal scans

Background Blunted heart rate response (BHRR) caused by cardiac neuropathy associated with dipyridamole stress, has been linked to cardiovascular (CV) outcome events. Whether BHRR is necessarily associated with abnormal perfusion is unknown. The aim of the study was to assess the incremental prognostic value of BHRR in a single center population undergoing Dipyridamole 99mTc Sestamibi SPECT test (DSPECT) for predicting late CV events. Methods 388 patients (aged 73±10 years, 45% females, 51% with known coronary disease) that underwent DSPECT over 3 years period were included. Abnormal DSPECT and BHRR were evaluated in relation to late death. Results Mean follow up period was 1560±565 (15–2431) days. During follow up period, 90 patients died. Mode of death was CV in 20 and non-CV in 70. BHRR (&lt;20% heart rate increase), abnormal DSPECT, post-stress LVEF &lt;60% and reversible defects were observed in 63%, 41%, 23% and 20% of patients, respectively. BHRR (HR -2.41, p&lt;0.0006) and abnormal DSPECT (HR-1.62, p=0.02) were predictors of all-cause death. BHRR had incremental prognostic value over abnormal DSPECT (Figure, p&lt;0.0005). Multivariable analysis identified age, dyspnea, insulin treated diabetes mellitus and dialysis as independent predictors of death while DSPECT and BHRR did not. However, BHRR remained a significant predictor of CV death [HR 8.1 (1.06, 62.0), p&lt;0.05]. Conclusions In this contemporary DSPECT cohort, BHRR and DSPECT failed to predict all-cause mortality. However, BHRR was an independent predictor of CV death. FUNDunding Acknowledgement Type of funding sources: None. BHRR stratifies abnormal DSPECT