Damir Lukac

Cardiac power output and its response to exercise in athletes and non-athletes

Cardiac power output (CPO) is an integrative measure of overall cardiac function as it accounts for both, flow‐ and pressure‐generating capacities of the heart. The purpose of the present study was twofold: (i) to assess cardiac power output and its response to exercise in athletes and non‐athletes and (ii) to determine the relationship between cardiac power output and reserve and selected measures of cardiac function and structure. Twenty male athletes and 32 age‐ and gender‐matched healthy sedentary controls participated in this study. CPO was calculated as the product of cardiac output and mean arterial pressure, expressed in watts. Measures of hemodynamic status, cardiac structure and pumping capability were assessed by echocardiography. CPO was assessed at rest and after peak bicycle exercise. At rest, the two groups had similar values of cardiac power output (1·08 ± 0·2 W versus 1·1 ± 0·24 W, P>0·05), but the athletes demonstrated lower systolic blood pressure (109·5 ± 6·2 mmHg versus 117·2 ± 8·2 mmHg, P<0·05) and thicker posterior wall of the left ventricle (9·8 ± 1 mm versus 9 ± 1·1 mm, P<0·05). Peak CPO was higher in athletes (5·87 ± 0·75 W versus 5·4 ± 0·69 W, P<0·05) as was cardiac reserve (4·92 ± 0·66 W versus 4·26 ± 0·61 W, P<0·05), respectively. Peak exercise CPO and reserve were only moderately correlated with end‐diastolic volume (r = 0·54; r = 0·46, P<0·05) and end‐diastolic left ventricular internal diameter (r = 0·48; r = 0·42, P<0·05), respectively. Athletes demonstrated greater maximal cardiac pumping capability and reserve than non‐athletes. The study provides new evidence that resting measures of cardiac structure and function need to be considered with caution in interpretation of maximal cardiac performance.

Ultrasonographic observations of the maturation of basic movements in guinea pig fetuses

Ultrasonography has not previously been used for studying fetal movements in precocial rodents. The objective of this study was to ultrasonographically determine the sequence of the appearance of basic movements in a guinea pig fetus. The research included eight guinea pig females carrying one fetus each. Fetal movements were observed for 10 minutes each day, from the 25th to 38th day of gestation. The time and sequence of the appearance of movements was observed as follows: whole body flexion (mean 27.6 SD ± 1.68), whole body extension (mean 28.1 SD ± 1.12), head flexion (mean 28.1 SD ± 1.80), head extension (mean 30.5 SD ± 2.67) forelimbs flexion (mean 30.5 SD ± 2.32), forelimbs extension (mean 30.7 SD ± 1.84), trunk rotation (mean 31.9 SD ± 2.23), forelimbs alternating flexion and extension (mean 32.1 SD ± 2.1), hind limbs extension (mean 32.2 SD ± 3.2), hind limbs flexion (mean 32.4 SD ± 3.16), and hind limbs alternating flexion and extension (mean 33.5 SD ± 2.39). The identical sequences of basic movement appearances in guinea pigs, sheep, and rats suggest that the rostrocaudal gradient of basic movement appearance could be a general developmental pattern in mammalian species.

Anthropometric characteristics and functional capacity of elite rowers and handball players

INTRODUCTION Anthropometric and anaerobic profile of elite athletes are fundamental for the assessment of their respective performance. The present study was designed to evaluate the anthro- pornetric parameters, body composition and anaerobic characteristics of elite male handball players and rowers, and to compare them in relation to specific sport demands. MATERIAL AND METHODS The study group consisted of 41 elite national level athletes: 20 handball players (aged 23.7±3.72) and 21 rowers (aged 19.7±2.84). Anthropometric characteristics (body mass, body height, skinfold thickness, body circumferences), and body fat mass were evaluated, and Wingate anaerobic test for anaerobic power assessment Iwas applied. RESULTS The significant differences were noted in chest-upper arm, waist and hip circumferences, and supraspinal and calf skinfolds between the two investigated groups. Rowers showed higher values of fat body mass (13.2±3.76 vs. 10.7±3.76%), but lower body mass index (22.0±1,92 vs. 25.7?2.31 kg/in12) compared to handball players. When analyzing the Wingate test parameters, significantly higher values of absolute anaerobic power (786±127 vs. 691±140 W), absolute explosive power in the handball players compared to the rowers were recorded ( 18±26.3 vs. 105±27.8 W/s), whi le rowers achieved higher relative anaerobic capacity (192±3 1.2 vs. 177±E20.8 J/ kg). CONCLUSION Specific body composition and anthropometri- cal assessment as a part of morphological analysis should complement physiological profile of elite athletes. The analysis of the anaerobic performance shows that the handball players have greater alactic anaerobic and explosive power component, compared to the rowers in whom the anaerobic endurance and specific training have the greatest effect on the consumption of dominant metabolic substrate during the race.

Parameters of Anaerobic Physiological Profile of Elite Athletes

INTRODUCTION Anaerobic capacity is much less evaluated in literature compared to aerobic component. Anaerobic performance of athletes can be measured using different motoric tests, lasting 20 to 30 seconds, one of them being the Wingate anaerobic test (WAnT). OBJECTIVE The aim of this study was to determine the work performed and power generated by athletes and non-athletes during a 30-second high intensity exercise, as well as to compare explosive characteristics of subjects using a new parameter of WAnT, named explosive power, or slope of power. METHODS All parameters of anaerobic power were investigated in 152 subjects classed into different groups depending on their physical fitness and sport specialties as follows: non-athletes (n=31), rowers (n=26), volleyball players (n=37), handball players (n=34) and judo players (n=24). The WAnT, as well as basic anthropometric measurements, was administrated to all participants. RESULTS Values of anaerobic parameters were higher in the group of athletes compared to physically inactive subjects.The highest values of the WAnT parameters were registered in the group of volleyball players (AP=1 006 W; relative AP=11.4 W/ kg, AC=19.8 kJ), compared to athletes of other sport disciplines (volleyball, rowing and judo). The new parameter of the WAnT, explosive power, also showed highest values in volleyball players (EP=1 54 W/s; relative EP=1.74 W/s/kg). These differences were statistically significant (p<0.05). CONCLUSION The results of laboratory tests can provide useful information on improvements in training processes. The new parameter of the WAnT could be implemented in further analyses of explosive characteristics of muscle contraction.