Biomedical subjects

C Tranquilli

Publications and source records attributed to C Tranquilli.

3 recordsLinked to original sources

PubMed1997

Effect of oral creatine supplementation on jumping and running performance.

The study was designed to investigate the effect of creatine monohydrate ingestion (20 g daily for 5 days) on performance in 45 s maximal continuous jumping and in all-out treadmill running at 20 km x h(-1), (inclination 5 degrees, duration approximately 60s). The participants were qualified sprinters and jumpers. The effect of creatine was compared with placebo in a double-blind design. Creatine (Cr) supplementation led to a significant enhancement of performance capacity in the jumping test by 7% during the first 15 s and by 12% during the second 15 s of the exercise. The positive effect of Cr supplementation was not observed in the last third of the continuous jumping exercise, when the contribution of anaerobic metabolism was decreasing. The time of intensive running up to exhaustion improved by 13%. The results show that Cr supplementation helps to prolong the time during which the maximal rate of power output could be maintained.

Adult↗

PubMed1996

Hormonal responses in strenuous jumping effort.

In order to test the possibility for rapid responses of blood hormone levels in short-term supramaximal exercises, serum concentrations of corticotropin (ACTH), cortisol (C), total testosterone (tT), free testosterone (fT), growth hormone (GH), thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), prolactin (PRL), insulin-like growth factor (IGF-I), and sex hormone-binding globulin (SHBG) were determined by RIA procedures in blood samples obtained before and immediately after a 60-s period of consecutive vertical jumps (Bosco test). The study subjects were 16 Italian professional soccer players. Immediately after exercise, significant increases (p < 0.05) were found in the concentrations of ACTH (by 39%), C (by 14%), TSH (by 20%), fT3 (by 28%), fT4 (by 30%), tT (by 12%), fT (by 13%), and SHBG (by 21%). Significant changes were not detected in the blood levels of GH, IGF-I and PRL. Most pronounced testosterone responses were typical for persons of high jumping performance (the increase of serum tT correlated with average power output, r = 0.61 and jumping height, r = 0.66). The larger the drop in power output during 60-s jumping, the higher was the thyroid response: the difference in jumping height between the first and last 15-s period correlated with increases in TSH (r = 0.52) and in fT4, (r = 0.55). In conclusion, the obtained results indicate that in intense exercise, causing the rapid development of fatigue, rapid increases in serum levels of hormones of the pituitary-adrenocortical, pituitary-gonadal and pituitary-thyroid systems occur.

Adrenocorticotropic Hormone↗

PubMed1995

A dynamometer for evaluation of dynamic muscle work.

The validation of a new dynamometer for evaluation of dynamic muscle work is presented. The device was based on a precise measurement of load displacements of any machine using gravitational loads as external resistance. It allowed, through a sensor consisting of an infrared photo interrupter, the calculation of velocity, force and power during concentric, eccentric and stretch-shortening cycle activity. To validate the dynamometer 33 male and female track and field athletes (12 throwers and 21 jumpers) participated in the study. The throwers (4 women and 8 men) were asked to perform half-squat exercises on a slide machine with a load of 100% of the subject's body mass. The day-to-day reproducibility of half-squat exercises gave a correlation coefficient of r = 0.88, 0.97 and 0.95 for average push-off force (AF), average push-off velocity (AV), and average push-off power (AP) respectively. Comparison of half-squat measurements was performed against jumping and running test evaluation by the jumpers (7 women and 14 men). The interrelationships among the different variables studied demonstrated a strong correlation between AF, AV and AP and sprinting and jumping parameters (r = 0.53-0.97; P < 0.05-0.001). Using values of AF, AV and AP developed in half-squat exercises executed with different loads, ranging from 35% to 210% of the subject's body mass, it was also possible to establish the force-velocity and power-velocity relationships for both male and female jumpers. In any individual case, the maximal error due to the measurement system was calculated to be less than 0.3%, 0.9% and 1.2% for AF, AV, and AP respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗