Long jump training emphasizing plyometric exercises is more effective than traditional long jump training: A randomized controlled trial

The aim of the study was to evaluate the impact of an 8-weeksplyometric training program on the sprint and jump performance. The intervention study employed a controlled experimental design with two parallel groups of male long jumpers. While the experimental group (n = 18) trained with plyometric exercises, the control group (n=10) performed classical long jump training. Both groups were examined for athletic performance (30m sprint, standing long jump, vertical jump) and biomechanical parameters of a long-jump movement (max vertical height, horizontal and vertical velocity at take-off, flight time, take-off duration) prior and following the intervention. The experimental group demonstrated significantly better developments than the control group in most of the physical and biomechanical parameters respectively and improved their long jump records. Combining an 8-weeksplyometricprogram with athletics training significantly develops long jump and general athletic performance as well as biomechanical parameters. Therefore, plyometric training can be recommended to athletics coaches as an additional training alternative to improve sprint and long jump abilities in athletes

Associations between Physical Activity and Health Parameters in Adolescent Pupils in Egypt

Physical activity (PA) could be protective against hypertension, atherosclerosis, coronary heart disease and cardiovascular disease. This quantitative study assessed the association between a PA intervention and three anthropometric parameters (weight, body mass index, body fat) and four physiological parameters (cholesterol level, systolic blood pressure, diastolic blood pressure, heart rate) among secondary school pupils (N = 160) in Egypt through the school term. The pupils were randomised to an intervention group (80 pupils) and controls (80 pupils). Measurements were obtained for all pupils twice: at baseline; and then again after three months. The PA intervention programme comprised an ‘afterschool’ one hour of moderate exercise three times a week for three months. Both the controls and the intervention pupils attended the ‘normal’ exercise schedule provided by the school; in addition, the intervention group attended afterschool PA programme from about 2–3 o’clock in the afternoon. At baseline, employing pupil’s BMI, 27.5% and 28.8% of the intervention and control pupils respectively were classified as overweight. After three months, the percentage of overweight decreased to 12.5% in the intervention pupils, while it increased to 37.3% in the controls. At the end of the three months period, there were significant improvements across most anthropometric and physiological parameters of the intervention pupils when compared with the control children. The correlation coefficient of the improvements for the boys and the girls was 0.97, indicating clearly that the intervention was having nearly the same beneficial effect for boys and girls. A moderate PA programme for a modest period of 3 months could be effective in maintaining or enhancing pupil’s anthropometric and physiological parameters in comparison to the controls where there was deterioration in both parameters. Policy makers and secondary schools in Egypt might need to pay more attention to PA programmes conducted on school days, in order to motivate pupils to attend such programmes. There is also an urgent need to look at current PA systems within schools in Egypt in order to assess PA outside school times

Cardio-Respiratory Endurance Responses Following a Simulated 3 × 3 Minutes Amateur Boxing Contest in Elite Level Boxers

This study aimed at examining physiological responses (i.e., oxygen uptake [VO2] and heart rate [HR]) to a semi-contact 3 × 3-min format, amateur boxing combat simulation in elite level male boxers. Eleven boxers aged 21.4 ± 2.1 years (body height 173.4 ± 3.7, body mass 74.9 ± 8.6 kg, body fat 12.1 ± 1.9, training experience 5.7 ± 1.3 years) volunteered to participate in this study. They performed a maximal graded aerobic test on a motor-driven treadmill to determine maximum oxygen uptake (VO2max), oxygen uptake (VO2AT) and heart rate (HRAT) at the anaerobic threshold, and maximal heart rate (HRmax). Additionally, VO2 and peak HR (HRpeak) were recorded following each boxing round. Results showed no significant differences between VO2max values derived from the treadmill running test and VO2 outcomes of the simulated boxing contest (p > 0.05, d = 0.02 to 0.39). However, HRmax and HRpeak recorded from the treadmill running test and the simulated amateur boxing contest, respectively, displayed significant differences regardless of the boxing round (p < 0.01, d = 1.60 to 3.00). In terms of VO2 outcomes during the simulated contest, no significant between-round differences were observed (p = 0.19, d = 0.17 to 0.73). Irrespective of the boxing round, the recorded VO2 was >90% of the VO2max. Likewise, HRpeak observed across the three boxing rounds were ≥90% of the HRmax. In summary, the simulated 3 × 3-min amateur boxing contest is highly demanding from a physiological standpoint. Thus, coaches are advised to systematically monitor internal training load for instance through rating of perceived exertion to optimize training-related adaptations and to prevent boxers from overreaching and/or overtraining

Sex-related differences in joint-angle-specific functional hamstring-to-quadriceps strength ratios

Purpose To examine and compare sex-related differences in the functioning of the hamstrings and quadriceps muscles and the isokinetic hamstrings eccentric-to-quadriceps concentric functional ratio (H/Q FUNC). Methods Fifty male and 46 female young adults completed this study. Each participant carried out an isokinetic assessment to determine isokinetic concentric and eccentric torques during knee extension and flexion actions at 3 different angular velocities (60, 180 and 300°/s) adopting a lying position. The H/Q FUNC was calculated using peak torque (PT) values and 3 different joint-angle-specific torque values (15°, 30° and 45° of knee extension). A repeated measures analysis of variance was used to compare the results, and post hoc analyses using Friedman correction were employed. Results There were statistically significant effects of angular velocity, joint angle and sex on the H/Q FUNC (p < 0.01). Thus, the H/Q FUNC ratio in both males and females decreases closer to full knee extension and with increasing movement velocity. The H/Q FUNC was also significantly lower in females compared to males, irrespective of moment velocity and joint angle. Conclusions The findings of the current study reinforce the need to examine the H/Q FUNC ratio closer to full knee extension (where knee injury is most likely to occur) rather than using PT values which may not be as informative, as well as to focus preventive and rehabilitation training programmes on reducing quadriceps dominance by enhancing eccentric hamstring strength (especially in females who are at higher risk of injury)

Optimization of a Fluorescence-Based Assay for Large-Scale Drug Screening against <i>Babesia</i> and <i>Theileria</i> Parasites

<div><p>A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against <i>Babesia</i> parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in <i>in vitro</i> cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine <i>Babesia</i> parasites and 5% for equine <i>Babesia</i> and <i>Theileria</i> parasites. The IC₅₀ values of diminazene aceturate obtained by fluorescence and microscopy did not differ significantly. Likewise, the IC₅₀ values of luteolin, pyronaridine tetraphosphate, nimbolide, gedunin, and enoxacin did not differ between the two methods. In conclusion, our fluorescence-based assay uses low HCT and does not require daily replacement of culture medium, making it highly suitable for <i>in vitro</i> large-scale drug screening against <i>Babesia</i> and <i>Theileria</i> parasites that infect cattle and horses.</p></div

Growth inhibition of <i>B</i>. <i>bovis</i>, <i>B</i>. <i>bigemina</i>, <i>T</i>. <i>equi</i>, and <i>B</i>. <i>caballi</i> by diminazene aceturate on the fourth day estimated by the fluorescence-based method (black) and microscopy (gray).

<p>(A) Growth inhibition of <i>B</i>. <i>bovis</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). (B) Growth inhibition of <i>B</i>. <i>bigemina</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). (C) Growth inhibition of <i>T</i>. <i>equi</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). (D) Growth inhibition of <i>B</i>. <i>caballi</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). Each value is presented as the mean of three triplicate wells ± SD.</p

IC₅₀ values of the diminazene aceturate drug evaluated for <i>B</i>. <i>bovis</i> and <i>T</i>. <i>equi</i> with and without daily replacement of the medium using the fluorescence-based method.

<p>^a IC₅₀ values for diminazene aceturate were determined on the fourth day of <i>in vitro</i> culture using the fluorescence-based method with 2.5% and 5% HCTs for <i>B</i>. <i>bovis</i> and <i>T</i>. <i>equi</i>, respectively, in three separate experiments. Each drug concentration was made in triplicate in each experiment, and the final obtained IC₅₀s were the mean of three obtained values from separate experiments.</p><p>^b The differences between IC₅₀ values determined using the fluorescence-based method with and without daily replacement of the medium were not statistically significant.</p><p>IC₅₀ values of the diminazene aceturate drug evaluated for <i>B</i>. <i>bovis</i> and <i>T</i>. <i>equi</i> with and without daily replacement of the medium using the fluorescence-based method.</p

Growth inhibition of <i>B</i>. <i>bovis</i> and <i>T</i>. <i>equi</i> by diminazene aceturate estimated by the fluorescence-based method without daily replacement of the medium (black) and with daily replacement of the medium (gray).

<p>(A) Growth inhibition of <i>B</i>. <i>bovis</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). (B) Growth inhibition of <i>T</i>. <i>equi</i> (y-axis) and log concentration of diminazene aceturate (nM) (x-axis). Each value is presented as the mean of three triplicate wells ± SD after subtraction of the background fluorescence for non-parasitized RBCs.</p