Although soccer is one of the most widely played sports around the world, studies about young players and the success factors in soccer are still scarce. Therefore, the purpose of this study was to offer some insight into the factors contributing to success in this sport and to describe how physiological and technical performance evolves in young soccer players. Soccer technical skills during match play, maximum voluntary isometric contraction and power of lower limbs, jumping ability and endurance parameters were assessed in 30 prepubescent male soccer players with the same experience in soccer training. Subjects were divided into 2 groups of 15 children, a younger group (YG), aged 9.4 +/- 0.3 years, and an older group (OG), aged 11.8 +/- 0.2 years. Correlations between technical and physiological parameters were also described. Significant difference was set at p < 0.05. Differences between YG and OG appeared in physiological performance, mainly in VO(2)peak expressed in absolute values, VO(2) at different speeds, perceived exertion in treadmill test, jump performance, strength, and peak power of lower limbs. Among the technical skills measured, significant differences were found only in heading. The differences found between groups showed that most physical capacities that were measured here have an important increase during the first stages of puberty, pointing out that a specific training at these ages is necessary to get an appropriate basis for future performance. Besides, over 30% of the technical performance measured in this study can be explained with the physiological parameters. The data shown in this paper help to determine the most important capacities in youth soccer, which can facilitate the development of more appropriate selection models and trainings.

Material and Method This is a prospective, cross-sectional, and correlational study with a probabilistic sampling in which 150 teenagers from three different high schools from the city of Toluca, Mexico, aged 15–17, were assessed. Objective To determine if weight, age, and gender have an influence on physical fitness evaluated with the EUROFIT and ALPHA-FITNESS batteries. Results Women have a higher overweight and obesity rate than men (3 : 1). Adolescents who have normal weight have regular physical fitness (74.9%). When comparing genders we found that men have a higher mean than women in the tests, except for skinfold thickness and waist circumference. Age was only correlated with the plate tapping test (p = 0.001). There are significant differences in the standing broad jump test and the Course-Navette of the EUROFIT and ALPHA-FITNESS batteries (p = 0.000). Conclusions It is likely that regular physical activity, and not normal weight, helps generate healthy physical fitness. Male subjects had a higher mean than women, reporting a better physical fitness and more frequent physical activity.

Having recognized the value of resistance training in patients with multiple sclerosis (PwMS), there are a lack of lower limb normative reference values for one repetition maximum (1RM) and maximal voluntary isometric contraction (MVIC) in this population. Hence, the purposes of this study were to provide reference values for 1RM and MVIC of knee extensors in PwMS across the disability spectrum and to examine knee extension strength asymmetry. Three hundred and ninety PwMS participated in the study, performing MVIC and 1RM tests of bilateral (both legs together at once) and unilateral (each leg singly) knee extensors. There was no difference in 1RM according to the disease course of MS, but there was according to the degree of neurological disability, being more preserved in those with a lower degree of disability. MVIC tends to be higher in patients with relapsing–remitting MS respect those with progressive MS, and in patients with lower levels of neurological disability. Asymmetry above the values considered normal in 1RM was present in 20–60% of patients and 56–79% in the MVIC test, depending on the type of MS and tended to be lower in those with less disability. Reference values are given by quartiles for 1RM, MVIC, and asymmetry.

This study examined the effects of six weeks strength training with elastic bands on different measures of strength manifestations, fatigue and functionality of multiple sclerosis (MS) patients. [Subjects] Sixteen MS patients (average age 44 years; range 33-56) with a diagnosis confirmed by a neurologist volunteered as subjects. They had mild to moderate disability and participated three times a week in a six-week elastic band strength training program. [Methods] Elastic band training progression was based on training volume using elastic bands of resistance of approximately 40% of a patient's previously measured maximal voluntary contraction. Outcome assessments included: maximal voluntary contraction with surface electromyography of the right and left legs, average and peak power with different submaximal loads of each leg, fatigue perception and functionality by the Timed Up-and-Go test. [Results] After the six-week strength training with elastic bands, average power with low load (98 N), peak power with very low load (49 N) and functionality had improved significantly. [Conclusion] A short and light training program using elastic bands can improve muscle function without injury and can be a good therapy for improving functionality of multiple sclerosis patients.

Background and objectives: Both antihypertensive peptide intake and physical activity help to control blood pressure. Our aim was to evaluate the impact of consuming amaranth antihypertensive peptides on systolic blood pressure (SBP) in normotensive rats and the magnitude and relevance of the peptide-induced antihypertensive effect in spontaneously hypertensive rats (SHR). Materials and Methods: Treatments (alcalase-generated amaranth protein hydrolysate, captopril, or water) were given by gavage and the SBP measured by the tail-cuff method. Physical activity was performed five days/week (for twenty weeks). Results: The normotensive rats’ SBP (mmHg, average/group) remained unaffected after amaranth antihypertensive peptide supplementation (121.8) (p > 0.05 vs controls). In SHR, the SBP was lowered by 24.6 (sedentary/supplemented at two weeks), 42.0 (sedentary/supplemented at eight weeks), and 31.5 (exercised/non-supplemented at eight weeks) (p < 0.05 vs sedentary/non-supplemented). The combination of supplementation and physical activity lowered the SBP by 36.2 and 42.7 (supplemented/exercised at two weeks and eight weeks, respectively) (p < 0.05 vs sedentary/non-supplemented), but it did not have additional antihypertensive benefits (p > 0.05 vs sedentary/supplemented at eight weeks or exercised/non-supplemented at eight weeks). Conclusions: Amaranth antihypertensive peptide supplementation has no impact on SBP in normotensive rats. This supplementation develops sustained antihypertensive benefits in SHR, which are similar to the antihypertensive effect developed after eight- or twenty-week low-intensity physical activity. These findings have implications for developing safe and effective peptide-based functional foods.