Cardiac muscle is unique because it has the capability of maintaining its own rhythm. If left to this inherent rhythmicity, the heart would beat steadily between 70 and 80 beats per minute. Extrinsic regulation provides for heart rates that may be as slow as 30 beats per minute at rest in highly trained endurance athletes and as fast as 220 beats per minute in maximum exercise. In our research we analyzed different strength training methodics, dynamic and isometric exercise’s influence to the heart rate in fast adaptation. Research showed, that while working at 80% of maximum, isometric physical activity provides higher heart rate than dynamic physical activity at the same intensity.

Darbo tikslas: nustatyti skirtingo pobūdžio sveikatą stiprinančių pratybų (jėgos lavinimo pratimų ir šiaurietiško ėjimo) poveikį širdies ir kraujagyslių sistemos greitosios ir lėtosios adaptacijos ypatybėms. Darbo metodika: Darbą sudaro šeši skyriai: literatūros apžvalga, tyrimo organizavimas ir metodika, rezultatai, rezultatų aptarimas, praktinės rekomendacijos bei išvados. Tyrimo metodai: elektrokardiografija (EKG), arterinio kraujo spaudimo (AKS) matavimas, Rufje fizinio krūvio mėginys. Buvo atlikti du tyrimai: I tyrimo metu tirta greitosios adaptacijos poveikis širdies ir kraujagyslių sistemai. II tyrimo metu tirta šešių mėnesių trukmės pratybų sporto salėje ir šiaurietiško ėjimo pratybų įtaka širdies ir kraujagyslių sistemai. Tyrimų metu buvo vertinama širdies ir kraujagyslių sistemos funkcija atliekant Rufje fizinio krūvio mėginį. I tyrimo metu dalyvavo 10 tiriamųjų, kuriems buvo taikytas ir šiaurietiškas ėjimas ir pratybos sporto salėje. II tyrime dalyvavo 28 savanoriai, kurie buvo atsitiktine tvarka suskirstyti į dvi grupes. I-jai grupei buvo taikomas šiaurietiškas ėjimas, II-jai grupei buvo taikomos pratybos prie treniruoklių. Tyrimo išvados: 1. Po pratybų, tiek sporto salėje, tiek po šiaurietiško ėjimo pratybų tiriamiesiems esant santykinės ramybės būsenoje registruojama reikšmingai padidėjęs širdies susitraukimų dažnis (ŠSD), padidėjusios elektrokardiogramos JT/RR santykio reikšmės, ir arterinio kraujo spaudimo rodikliai liudija apie pokrūvinę hipotenziją. Po... [toliau žr. visą tekstą] / The aims of the thesis: to identify the properties of different kinds of health enhancing exercises on the cardiovascular system in fast and slow adaptation. Two studies were performed: Study I investigated quick adaptation effects on the cardiovascular system. Study II investigated the effects of six-month exercise at the gym and Nordic walking exercise on cardiovascular system. The studies were evaluated using the Ruffier exercise test. 10 volunteers participated in Study I; they were subjected to Nordic walking and exercise at the gym. Study II involved 28 volunteers who were randomly divided into two groups. Nordic walking was applied to Group I, while fitness exercises were applied to Group II. The findings of the study: 1. After the exercise and the gym, as well as after Nordic Walking exercise in subjects at rest significantly increased heart rates were recorded, also JT / RR ratio values increased , and arterial blood pressure indicators showed post-load hypotension. After the exercise it was observed that the stress transient ischemic functional effects in the myocardium were less expressed. 2. Comparing Nordic walking exercise effects with the effects of exercise at the gym during the sample load, less increased heart rate and systolic blood pressure were observed; significantly higher decrease in diastolic blood pressure, and significantly lower degree of short-term effects of functional ischemic myocardium were recorded. 3. Six-month health-enhancing exercises... [to full text]

This dissertation seeks to merge the ideas from robust control theory such as H-Infinity control design and the Small Gain Theorem, L stability theory and Lyapunov stability from nonlinear control, and recent theoretical achievements in adaptive control. The fusion of frequency domain and linear time domain ideas allows the derivation of an H-Infinity Norm Minimization Approach (H-Infinity-NMA) for adaptive control architecture that permits a control designer to simplify the adaptive tuning process and tune the uncertainty compensation characteristics via linear control design techniques, band limit the adaptive control signal, efficiently handle redundant actuators, and handle unmatched uncertainty and matched uncertainty in a single design framework. The two stage design framework is similar to that used in robust control, but without sacrificing performance. The first stage of the design considers an ideal system with the system uncertainty completely known. For this system, a control law is designed using linear H-Infinity theory. Then in the second stage, an adaptive process is implemented that emulates the behavior of the ideal system. If the linear H-Infinity design is applied to control the emulated system, it then guarantees closed loop system stability of the actual system. All of this is accomplished while providing notions of transient performance bounds between the ideal system and the true system. Extensions to the theory include architectures for a class of output feedback systems, limiting the authority of an adaptive control system, and a method for improving the performance of an adaptive system with slow dynamics without any modification terms. Applications focus on using aerodynamic flow control for aircraft flight control and the Crew Launch Vehicle.