PubMed Health⌕ Search

Biomedical subjects

G Cometti

Publications and source records attributed to G Cometti.

7 recordsLinked to original sources
PubMed1995

Effects of electromyostimulation and strength training on muscle soreness, muscle damage and sympathetic activation.

Electromyostimulation (EMS) is known to develop muscular strength and hypertrophy. The aim of this study was to compare EMS exercise-induced damage with concentric (CONC) exercise-induced damage. Twelve male athletes were randomly assigned to concentric exercise (five sets of 6 voluntary contractions) or to EMS (30 contractions of 6 s duration, 20 s rest between contractions) on day 0 (D0). The load was 80% of the maximal isometric force. Criterion measures of plasma creatine kinase (CK) activity and lactate dehydrogenase (LDH) activity, and subjective ratings of muscle soreness and urinary catecholamines, were assessed 1 day before and for 3 days after exercise. Among the members of the EMS group, there were significant increases in catecholamine urinary excretion, especially adrenaline (on days D+2 and D+3), plasma CK activity (on day D+2) and plasma LDH activity (on days D+1 and D+2). The changes among the members of the CONC group were smaller and no significant difference was noted. Muscular soreness was greatest in the EMS group, with the peak occurring on day D+2. Comparisons of enzyme release, muscular soreness and urinary catecholamines suggest that EMS induces myofibre membrane damage and a significant increase in sympathetic nervous activity.

Adult↗
PubMed1994

The influence of electrostimulation on mechanical and morphological characteristics of the triceps surae.

The present study assessed the effects of training using electrostimulation of muscle (EMS) on the torque-angular velocity and torque-angle relationships, and the cross-sectional area (CSA) of the triceps surae. Twelve physical education students, divided into two groups (6 controls, 6 experimental), participated in the experiment. The EMS sessions were undertaken using a 'Complex-type' stimulator. Flexible elastomer electrodes were used. The current used discharged pulses lasting for 200 microseconds at a frequency of 70 Hz. The durations of contraction and rest were 5 and 15 s, respectively. The session lasted for 10 min for each muscle. The training regimen was three sessions per week for 4 weeks. Biomechanical tests were performed with the Biodex (Biodex Corporation, Shirley, NY, USA) isokinetic ergometer. Plantar flexions of the ankle over a concentric range of voluntary contractions were performed at different angular velocities (1.05, 2.10, 3.14, 4.20, 5.23 and 6.28 rad s-1) and maximum voluntary isometric contractions were held for 5 s at several ankle flexion angles (-30 degrees, -15 degrees, 0 degree and 15 degrees; 0 degree corresponds to foot flexion of 90 degrees relative to the leg axis). The peak value of the torque was recorded. Morphological tests consisted of measuring the CSA of the triceps surae on the right leg, 15 cm below the tibial protuberance, by a computerized tomography technique. The torque-velocity relationship was seen to shift significantly upwards after EMS training. The increase in the isometric torque observed after EMS training was greater in dorsiflexion than in plantarflexion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Effects of different types of training on torque/angular velocity relationship. Experimental study by isokinetic ergometry in high-level basketball players].

The purpose of this study was to examine the alterations of the Torque/Angular Velocity relationship in knee extensor and flexor muscles due to a long-term training programme. Thirty five young elite basketball players were tested before, after 12 weeks of a common weight-lifting programme (including concentric and eccentric actions) and after 24 weeks including only concentric (C-E/C group) or concentric and eccentric actions (C-E/C-E group). After 12 weeks, significant decrease in torque of knee extensor muscles was observed. In contrast, significant increases in torque of knee flexor and shoulder flexor and extensor muscles were noted. After 24 weeks, significant increases were noted in torque of all muscular groups, for the C-E/C group but not for the C-E/C-E group. It is concluded that training including concentric and eccentric actions have not the same effect on agonist and antagonist muscular groups. The alternation of the contraction mode influences straingthly the strength restoration.

Adolescent↗
PubMed1988

Impairment of cytomegalovirus and host balance in elderly subjects.

The titres of IgG antibody against "late antigens", "immediate early antigens", and "early antigens" induced by cytomegalovirus (CMV) and IgM antibody against "late antigens" induced by CMV were analysed in 67 geriatric subjects by immunocytochemical techniques. The titres obtained were compared with those of an adult control population. Significantly increased titres of IgG antibody against induced antigens and a significant increase in CMV reactivated infections occurred in the elderly compared with control subjects. These findings indicate that the CMV and host balance in the elderly is disturbed, leading to activation of the CMV latent carrier state that follows primary CMV infection.

Aged↗