Inflammatory Cytokines Response to Isometric Handgrip Exercise and the Effects of Duration and Intensity of the Isometric Effort in Prehypertensive Subjects

BACKGROUND Chronic low grade systemic inflammation has been identified as a major risk factor for chronic diseases. The potential for physical exercise to induce anti-inflammatory effect is now increasingly being explored but there is paucity of data regarding the effects isometric exercise on inflammatory cytokines. The objective of this study was to investigate the responses of selected inflammatory cytokines to isometric handgrip exercise and identify possible effects of intensity and duration of the isometric effort on these variables. CASE PRESENTATION: A total of one hundred and ninety two (N=192) sedentary pre-hypertensive subjects, aged between 30-50years were recruited into the study and randomly distributed into three groups of 64 subjects each. The subjects performed a 24 consecutive day’s isometric hand grip exercise at 30% Maximum Voluntary Contraction. At the end of the 24 days, the group one (GP1) discontinued with the exercise protocol while the group two (GP2) continued the exercise protocol for another 24 consecutive days and the group three (GP3) continued with the exercise protocol for another 24 consecutive days but at 50%MVC. The parameters used to assess for the inflammatory cytokine variables included interleukin 10, interleukin 6 and tumor necrotic factor. At the end of the study, there was an increase in the resting values of interleukin 10 across the three groups while the resting values of interleukin 6 and tumor necrotic factor reduced significantly across groups. CONCLUSIONS: The reductions noted in the pro-inflammatory cytokines and increase in the anti-inflammatory cytokines could have a positive impact in the management of chronic diseases. It was also found that increase in intensity and/or duration produced more proportionate effect.

Izometric effort in the balance stance of handball throw

Postural balance plays an important role in high performance sports. The line between success and failure may be decided at such a small scale. In handball, postural balance may affect the accuracy of every technique that a played use, especially the throwing of the ball towards the goal. Our study aimed to identify the degree of influence that izometric effort has over the balance stance during a handball throw. Subjects: 210 1st year students from the Faculty of Physical Education and Sport, Babeș-Bolyai University from Cluj-Napoca, were involved in this study. The subjects were both male and female, with the ages between 18 and 21 years old, with and without former performance athlete background. Materials: We’ve conducted the balance test using the AMTI NETforce BP 400600 force platform and the actual isometric exercises were completed in the same laboratory. Two types of planks and a half-squat were used as the isometric exercises. Results: There was no significant statistical difference between the balance variables before and after isometric exercises while holding the ball in hand. There was a significant statistical difference between the displacement before and after for the position without the ball. Conclusion: There is no impact of the isometric effort over the balance stance while holding the handball ball in the throwing position. We’ve identified a strong relation between the isometric effort and the balance stance without the ball in hand.

An Investigation of the Relationship between Hip Extension Torque, Hip Extension Velocity, and Muscle Activation

The purpose of this study was to determine if the characteristic Hill model, used to describe me force–velocity relationship for isolated tetanically stimulated muscle, could be modified and used to describe me torque–velocity behavior of me hip for maximally and submaximally stimulated hip extensor muscles. Fourteen subjects performed hip extension movements at effort levels of 100%, 70%, and 40% of a maximum isometric effort. A solenoid provided isometric resistance to hip extension. Once the desired effort level was achieved, as indicated by me isometric force, the solenoid released and me hip moved against an opposing elastic resistance equal to 75%, 50%, 25%, and 0% of the specified effort level. An electrogoniometer quantified hip angle. Hip velocity was determined by numerically differentiating the angle data. Torque-velocity-activation (or effort level) data were determined for each trial. Model parameters were determined to give me best fit to the data for each subject. Average parameter values were determined for each gender and for the entire group. The modified Hill-type model, Tm = (Tmax · A − K1 · ω)/(K2 · ω + 1), accurately describes me relationship between joint torque (Tm), maximum isometric joint torque (Tmax), joint velocity (ω), and muscle activation level (A) for subject-specific parameters (K1 and K2), but not for parameters averaged across genders or the entire group. Values for Tmax, K1, and K2 ranged from 90 to 385 Nm, 6.1 to 47.9 Nms, and 0.030 to 0.716 s, respectively.