ABSTRACTQuinzi, F, Rosellini G, and Sbriccoli, P. Lower limb maximal power predicts punching speed in different static and dynamic attacking techniques in karate. J Strength Cond Res XX(X)000–000, ...2020—Punching performance of karate can be predicted from lower limb maximal power. However, this relationship was observed only in single actions starting from a static position, thus calling for an investigation on the applicability of this relationship to other conditions. This study aims at investigating whether the relationship between lower limb maximal power and punch speed holds true, not only for single actions, but also for a combination of upper limb techniques in static and dynamic conditions. Ten national-level karate athletes aged 22.3 ± 1.8 years were assessed for maximal power of upper and lower limbs during a bench press and a back squat, and for punching speed during 2 punching techniques (gyaku tsuki GT; kizami tsuki and gyaku tsuki KG) starting from a static (GTS; KGS) or a dynamic (GTD; KGD) condition. Pearsonʼs correlations were obtained between upper and lower limb maximal relative power and punch speed across tasks and conditions. Significance level was set at p < 0.05. Significant correlations were observed between lower limb maximal relative power and punch speed for all tasks and conditions (r = 0.66–0.80; p = 0.005–0.037). The present results further our knowledge on the relationship between lower limb maximal power and punch speed showing that this relationship holds true also for combinations of punching techniques performed also in dynamic conditions. This information can be useful for karate trainers to predict the punching performance of their athletes using a simple test to assess maximal lower limb power.
Exercise may differently affect the expression of key molecular markers, including skeletal muscle and circulating miRNAs, involved in cellular and metabolic pathways’ regulation in healthy ...individuals and in patients suffering from non-communicable diseases (NCDs). Epigenetic factors are emerging as potential therapeutic biomarkers in the prognosis and treatment of NCDs and important epigenetic factors, miRNAs, play a crucial role in cellular pathways. This systematic review aims to underline the potential link between changes in miRNA expression after different types of physical activity/exercise in some populations affected by NCDs. In June 2023, we systematically investigated the following databases: PubMed, MEDLINE, Scopus, and Web of Science, on the basis of our previously established research questions and following the PRISMA guidelines. The risk of bias and quality assessment were, respectively, covered by ROB2 and the Newcastle Ottawa scale. Of the 1047 records extracted from the initial search, only 29 studies were found to be eligible. In these studies, the authors discuss the association between exercise-modulated miRNAs and NCDs. The NCDs included in the review are cancer, cardiovascular diseases (CVDs), chronic obstructive pulmonary disease (COPD), and type 2 diabetes mellitus (T2DM). We evidenced that miR-146, miR-181, miR-133, miR-21, and miRNA-1 are the most reported miRNAs that are modulated by exercise. Their expression is associated with an improvement in health markers and they may be a potential target in terms of the development of future therapeutic tools.
This study explored the influence of living settings on physical activity (PA) levels and volition in exercise and their correlation, considering sex differences. Five hundred and sixty-six ...university students (261 rural and 305 urban) from Calabria region (Italy) attending universities courses filled an online survey where Global Physical Activity Questionnaire and Volition in Exercise Questionnaire were administered. Rural females (RF) showed lower PA levels and self-confidence than rural males (RM) (p<0.01). Postponing training and unrelated thoughts were higher in RF than RM (p<0.01 and p<0.05 respectively). PA levels, self-confidence and coping with failure were lower in urban females (UF) than urban males (UM) (p<0.01), Postponing training and unrelated thoughts were higher in UF than UM (p<0.01 and p<0.05). In RF and UF, PA levels positively correlated with self-confidence (Rho = 0.397) and coping with failure (Rho = 0.330), whereas negatively correlated with postponing training (Rho = -0.487) and unrelated thoughts (Rho = -0.283). In RM and UM, PA levels positively correlated with self-confidence (Rho = 0.270) and coping with failure (Rho = 0.258), whereas it negatively correlated with postponing training (Rho = -0.285). PA levels positively correlated with reasons (Rho = 0.260) only in UM. We showed for the first time the relationship between PA and volition factors considering the living setting in university students. Sex differences were observed in some volition facilitators and PA levels independently by the living context.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background Magnesium is a micronutrient and an intracellular cation responsible for different biochemical reactions involved in energy production and storage, control of neuronal and ...vasomotor activity, cardiac excitability, and muscle contraction. Magnesium deficiency may result in impaired physical performance. Moreover, magnesium plays an important role on delayed onset muscle soreness after training. Thus, physically active individuals and sport specialists have to pay attention to magnesium supplementation (MgS). However, the type, timing and dosage of magnesium intake are not well elucidated yet. Hence, we aimed to systematically review the literature regarding the effects of MgS on muscle soreness in physically active individuals. We focused exclusively on MgS, excluding those studies in which magnesium was administered together with other substances. Methods Three electronic databases and literature sources (PUBMED, SCOPUS and Web of Sciences-Core Collection) were searched, in accordance with PRISMA guidelines. After the database search, 1254 articles were identified, and after excluding duplicates, 960 articles remained. Among these, 955 were excluded following the title and abstract screening. The remaining 5 articles were screened in full text and 4 study met the eligibility criteria. Results These studies showed that MgS reduced muscle soreness, improved performance, recovery and induced a protective effect on muscle damage. Conclusion To reach these positive effects, individuals engaged in intense exercise should have a Mg requirement 10–20% higher than sedentary people, to be taken in capsules and 2 h before training. Moreover, it is suggested to maintain magnesium levels in the recommended range during the off-season. Systematic review registration PROSPERO registration number : CRD42024501822.
The existence of neural correlates of spatial attention is not limited to the reactive stage of stimulus processing: neural activities subtending spatial attention are deployed well ahead of stimulus ...onset. ERP evidence supporting this proactive (top-down) attentional control is based on trial-by-trial S1–S2 paradigms, where the onset of a directional cue (S1) indicates on which side attention must be directed to respond to an upcoming target stimulus (S2). Crucially, S1 onset trigger both attention and motor preparation, therefore, these paradigms are not ideal to demonstrate the effect of attention at preparatory stage of processing. To isolate top-down anticipatory attention, the present study used a sustained attention paradigm based on a steady cue that indicates the attended side constantly throughout an entire block of trials, without any onset of an attentional cue. The main result consists in the description of the attention effect on the visual negativity (vN) component, a growing neural activity starting before stimulus presentation in extrastriate visual areas. The vN was consistently lateralized in the hemisphere contralateral to the attended side, regardless of the hand to be used. At the opposite, the lateralized motor activity emerged long after, confirming that the hand-selection process followed the spatial attention orientation process. The present study confirms the anticipatory nature of the vN component and corroborate its role in terms of preparatory visuospatial attention.
•The prefrontal cortex is active prior to a perturbation of the lower limb.•Premotor and motor cortices are active before and after the perturbation.•A preparatory activity can be observed in the ...bilateral occipito-temporal cortex.
The contribution of higher-order cognitive functions to postural control is poorly understood. It is recognized that the prefrontal cortex (PFC) is active after postural perturbations, however little is known about anticipatory PFC activity occurring before an upcoming perturbation. Here we aim at advancing our understanding on the contribution of higher-order cognitive functions in the fore period before postural perturbations.
Thirteen healthy men underwent both self-paced and externally-triggered lower limb perturbations during high-resolution electroencephalography and surface electromyography (sEMG) recordings. Event-related potentials (ERP) and sEMG associated with perturbations were compared between conditions.
Both self-paced and externally-triggered perturbations elicited a large prefrontal negativity before the perturbation onset, but the externally-triggered condition evoked larger activity over the left hemisphere; source analysis localized this activity in the PFC. The motor readiness potential occurred earlier and was larger for self-paced perturbations and its origin in premotor areas was confirmed. A larger bilateral activity over lateral occipital derivations was observed for externally-triggered perturbations and was localized in the occipital-temporal cortex, likely within the extrastriate body area (EBA).
We confirm that the preparatory activity of premotor areas is associated with the intentional engagement of upcoming actions since it occurs only before self-paced perturbations. The PFC anticipating both perturbations can be interpreted as an unintentional top-down cognitive control required by the tasks, especially involving attention and inhibition. However, before externally-triggered perturbations also other cognitive resources are required. The EBA activity anticipating externally-triggered perturbation may represent a visual prediction of the desired posture.
Diet and exercise intervention are the first strategies to counteract obesity. An online home-based exercise program may be a feasible approach in an obese population. Therefore, this study aimed to ...investigate the effects of twelve weeks of online Pilates plus diet on body composition in individuals affected by obesity. Thirty-five females were randomly assigned to a home-based Pilates group (PG,
= 18) or a group without intervention (control group, CG,
= 17). All participants followed a Mediterranean diet. The PG followed a twelve-week online Pilates Matwork program (three times/week; 180 min/week), while the CG was not involved in any structured physical exercise program. Body composition and handgrip strength were evaluated at baseline (T
) and after the intervention (T
). A significant group × time interaction (
< 0.05) was found for the fat mass percentage (pFM). Specifically, the pFM was significantly lower at T
than at T
in the PG. Significant group × time interactions for fat-free mass (
< 0.05), appendicular skeletal muscle mass (
< 0.05), and skeletal muscle mass (
< 0.01) were found. All these variables were significantly higher at T
than at T
in the PG (
< 0.05). Home-based Pilates combined with diet intervention may represent an effective strategy to improve body composition in terms of fat mass reduction and muscle mass gain in adults affected by obesity.
Objective:
This study aimed at evaluating the acute effect of the combined and single use of two orthotic devices (neck balance system NBS and lumbar support LS) on muscle activity of neck and back ...muscles during typical computer working tasks.
Background:
An excessive activation of neck muscles could threaten the balance between agonist and antagonist muscles, resulting in a lower stability of the head and possibly leading to neck pain. At present, no study evaluated the effect of a specific orthotic device in reducing neck muscles activation.
Methods:
Surface electromyography (sEMG) from neck flexor (sternocleidomastoid SCMD) and extensor muscles (semispinalis capitis SPC) and back extensor muscles (erector spinae ERS) of 20 healthy individuals was recorded during three computer working tasks performed with the NBS, with NBS and LS, with the LS, and without devices (ND).
Results:
In the NBS condition, the SPC showed a reduced activation (NBS = 3.97%; NBS + LS = 4.49%; LS = 4.48%; ND = 4.61% of the maximal voluntary contraction) compared to the other conditions.
Conclusions:
The use of the NBS promotes a reduction of neck extensor muscles, possibly due to the inertial mass added in the occipital part of the head, producing an external neck extensor moment that cooperates with that produced by neck extensor muscles.
Application:
Orthotic devices such as the NBS may be used by computer workers to reduce the activation of their neck extensor muscles and possible risks of developing neck pain.
Whole-body vibration (WBV) has been employed for performance-enhancing purposes. WBV may positively affect muscular endurance and its underlying neural mechanisms due to an enhanced muscular blood ...circulation and oxygen uptake. However, the effects of WBV on endurance-related torque signal complexity have been understudied. This study aims to investigate the acute effects of WBV on i) maximal isometric torque production; ii) isometric knee extensors fatigability and iii) torque signal complexity during an isometric endurance task.
Thirty adult males performed an isometric intermittent endurance protocol on their dominant lower limb after performing: static half squat with WBV (WBV), static half squat without WBV (HS), and no exercise protocol (CC). For each repetition the maximal torque was identified. The maximal torque of the first repetition was identified as the PeakT. The Mean torque (MTorque) and fatigue index (pFatigue) were calculated as the mean and the percentage decay in torque across the entire set of eighteen repetitions (MTorque0–100 %, pFatigue0–100 %), and across shorter blocks of six repetitions (MTorque0–33 %, pFatigue0–33 %; MTorque34–66 %, pFatigue34–66 %, and MTorque67–100 %, pFatigue67–100 %). Torque fluctuations were analysed computing Sample Entropy (SampEn) and the coefficient of variation (CV).
PeakT was significantly higher in CC than in WBV (p < 0.01) and in HS (p < 0.01). PeakT was significantly higher in HS than in WB (p < 0.05). MTorque0–100 %, MTorque0–33 %, MTorque34–66 %, and MTorque67–100 % were significantly higher in CC than in WBV (all p-values <0.01) and in HS (p < 0.01). MTorque67–100 % was significantly higher in HS than in WB (p = 0.049). pFatigue34–66 % was significantly higher in WBV than in CC (p < 0.05) whereas pFatigue67–100 % was significantly higher in CC than in WB (p < 0.01) and in HS (p < 0.01). No effect of condition was observed for SampEn and CV.
Acute WBV does not lead to beneficial effects on maximal torque production and isometric knee extensors fatigability. These acute detrimental effects may be related to long-term WBV-related adaptations.
School-settings represent ideal context to promote healthy habits as in adolescence most risk factors may occur or intensify leading to the adoption of unhealthy lifestyles. Thus, a deeper ...understanding of the factors promoting healthy lifestyles in adolescents is of utmost importance.
This observational study aims to investigate: 1) gender-related differences in physical activity (Physical Activity Questionnaire for Adolescets – PAQ-A), sleep quality (Pittsburgh Sleep Quality Index - PSQI) and internet addiction (Internet Addiction Test – IAT) levels and Volition in Exercise (VE); 2) the relationship between PAQ-A and VE, PSQI and IAT; 3) the effects of a five-month (T0; T5) school-based physical activity (PA) intervention on the above-mentioned factors. PAQ-A,VE, PSQI and IAT were assessed before (T0) and after (T5) a school-based PA intervention. The PA intervention consisted of coordinative exercises and team sports performed for 1 h twice a week. At T0, girls showed lower PAQ-A, PSQI scores, lower volition facilitators (“self-confidence” and “coping with failure”) and higher volition inhibitor (“postponing training”) than boys. Significant correlations were observed for volition factors an IAT in males and volition and PSQI and IAT in females. After the PA intervention (T5), “postponing training” and “self-confidence” factors were reduced compared to T0.
Exercise specialists should consider gender differences in volition in exercise factors during a school-based PA to plan and realize PA protocols aiming at maximizing exercise adherence to tackle sedentary behaviors in adolescents.
