From “sliding” to “winding” filaments theory: A narrative review of mechanisms behind skeletal muscle contraction

The physiological mechanisms behind muscle contraction are a main concept in sport medicine and rehabilitation. The sarcomere is the functional unit of skeletal muscle and several proteins definite its complex structure. The most common theory to explain muscle contraction was proposed in the last 50’s and has become widely popular and accepted: the “sliding filaments” theory. Even if this hypothesis was able to justify some form of muscle contraction, other processes are not fully described by it. Eccentric contraction and some phenomena, like the “force enhancement during stretch” concept described in the 2002, are not explicable according to the sliding filament theory. Therefore, several hypotheses have been suggested over the years, such as the “popping sarcomeres” theory and the “winding filament” theory. Some other proteins, like titin, have gained a main role in the physiology of the sarcomere and should be relevant to explain mechanisms of eccentric contraction, where the sarcomere generates highest level of tension while it is lengthening. The aim of this review is to summarize the physiological theories of muscle contraction and to define concepts applicable in sport medicine and in rehabilitation areas

Pilates Improvement the Individual Basics of Service and Smash in Volleyball

A sample of 20 players 12-to 14-year old young male volleyball athletes participated in this study to test the improvement of agonistic performance, especially for the individual basics of the service and smash, using Pilates method in additional training sessions. The research was conducted with observation and manual and computerized detection for six months with tests for explosive strength detection and smash precision. The measuring the length of the lower limbs with the ASIS method showed a diff erence of a few millimetres between the two lower limbs and hypertrophy of the longest limb and hypotrophy of the shortest one. The athletes were divided into group A control (10 athletes) and group B (10 athletes). Only Group B participated in 20 additional training sessions with the Pilates method. The study showed improvement in performances with particular reference to the average percentage of crushing between 4 and 7%. Group B athletes, they found a uniform muscle toning and improved breathing control. The A group, motivated to perform the workouts with greater concentration, showed a performance improvement of a few percentage points. These athletes can improve the eff ectiveness of using unconventional methods to improve sports performance in a Team Sport

Physical-technical conditions, coaching and nutrition: An integrated approach to promote cohesion in sports team

The aim was verified that the level of cohesion of a sports group is conditioned by numerous variables, which affect the athletes performance and lead to difficulties in adults relationships. The sample physical-technical and nutritional conditions and the help for the cohesion of a technique such as coaching were evaluated. Coaching can understand as the process in which individuals, mostly athletes, supported for their improvement and development in order to achieve performance high levels. 40 adults, aged between 35 and 45 years old, practicing football at amateur level for eight months, belonging to two different sports groups (blue and red group), have been observed. The results showed about 2.5% increase for blue group in Cooper test and about 1% in Sargent test, while for red group the improvement was approximately 1.5% in Cooper test and about 0.5% in Sargent test. 37 athletes correctly followed the nutrition specialists indications while 3 athletes showed negative responses. The personalized diets success confirmed by the decrease, in terms of kg, of the average percentage of athletes' body weight. All sample highlighted, with the answers to the 14 items of the questionnaire, significant percentage variations in lifestyles and relationships between group members

Use and attitudes toward dietary supplements and drugs amongst Italian elite athletes and its correlation with banned doping substances

Athletes frequently use dietary supplements (DS) to find better results as soon as possible. Moreover, they also will be occurring in “polypharmacy” or in substances prohibited for doping. The aim of this retrospective sectional study was to explore use and attitudes toward drugs and dietary supplements (DS) in Italian Sports Federations and its correlation with banned doping substances token amongst elite athletes. The data shows the results from 2012 to 2017, among Italian Sports Federations elite athletes and the analysis of the anti-doping controls from the Ministry of Health annual reports. The results show that the largest number of supplements consumption declarations was recorded in 2014 in sport as cycling and athletics. Moreover, in the same year and in 2012 there were 48 and 42 declarations on 58 and 52 doped athletes. Among the Italian federations, three are particularly controlled: FCI - cycling, FIDAL - athletics and FIGC – football. Most of the consumers subjects are male athletes. So maybe there is a link between NS and positive results in anti-doping test. The consumption of health products is constantly expanding and educational interventions will be needed to improve drugs and DS use about elite athletes as well in amateur athletes

Overtraining syndrome, stress and nutrition in football amateur athletes

In competitive sports is important optimizing and improving the recovery-stress state. We aimed to investigate the overtraining syndrome in the football, modulating the agonistic training and evaluating the nutritional status of the young amateur soccer players, thought monitoring of the capacity of endurance and strength in a sample of twenty athletes between the ages of 18 and 33 (mean 22 +/- 4.43 SD). Overtraining syndrome is a condition of physical, behavioural and emotional stress in sports and occurs when the physical activity is so intense as to prevent the athlete from performing a correct recovery totally eliminating the sense of fatigue. The athletes, from September 2016 to April 2017 were monitored with anthropometric tests (BMI calculation), nutritional tests (Recall test) and sportive (Cooper and Sargent test) to prevention of the overtraining syndrome with initial, intermediate and final measurements. Each player, during the observational period, performed normal athletic training sessions and participating two additional monthly sessions, for a total of sixteen sessions, with free overloads and, after intermediate verification, the exercises has been modified to reduce overtraining phenomenon. Tests initial results have been positive for defenders and midfielders while at the end of the search goalkeepers and forwards have significantly improved the performances. The total percentage increase of sample is around +/- 4% and the study confirmed that by modulating the intensity of training and controlling the athletes' diet, it is possible to reduce or eliminate overtraining effects

Chemometric-assisted cocrystallization: Supervised pattern recognition for predicting the formation of new functional cocrystals

Owing to the antimicrobial and insecticide properties, the use of natural compounds like essential oils and their active components has proven to be an effective alternative to synthetic chemicals in different fields ranging from drug delivery to agriculture and from nutrition to food preservation. Their limited application due to the high volatility and scarce water solubility can be expanded by using crystal engineering approaches to tune some properties of the active molecule by combining it with a suitable partner molecule (coformer). However, the selection of coformers and the experimental effort required for discovering cocrystals are the bottleneck of cocrystal engineering. This study explores the use of chemometrics to aid the discovery of cocrystals of active ingredients suitable for various applications. Partial Least Squares–Discriminant Analysis is used to discern cocrystals from binary mixtures based on the molecular features of the coformers. For the first time, by including failed cocrystallization data and considering a variety of chemically diverse compounds, the proposed method resulted in a successful prediction rate of 85% for the test set in the model validation phase and of 74% for the external test set

Jump and balance test in judo athletes with or without visual impairments

The study was conducted for four months with 8 judo athletes: 4 sighted people (4 M) and 4 visual impairment people (3 M and 1 F), aged between 18 and 52 (30.75 ± 12.74). According to the IBSA Visual Classification, all visual impairment subjects participating in our study were covered in the B1 category of visual deficit. This is a group represented by patients with no light perception in either eye up to light perception, and with an inability to recognize the shape of a hand at any distance or in any direction. From our cohort it was excluded subjects who have had low extremities musculoskeletal, neurological, or orthopaedic disorders in the previous six months. The aim of the study was to evaluate their balance with both closed and opened eyes and to set their lower limbs’ strength: these are indispensable characteristics to carry out technical actions of judo. Anthropometric measures were compared between groups and data about jump protocol and balance protocol were analysed. Results of current research showed that postural stability is different in function of assessment with closed and open eyes. The result of the jump tests differs because the data do not show significant differences between long jump and high jump. The comparison between blinded and sighted judo athletes highlighted greater difficulties with eyes closed for sighted athletes than blinded ones

Predictors of sacubitril/valsartan high dose tolerability in a real world population with HFrEF

Abstract Aims The angiotensin receptor‐neprilysin inhibitor (ARNI) sacubitril/valsartan (Sac/Val) demonstrated to be superior to enalapril in reducing hospitalizations, cardiovascular and all‐cause mortality in patients with ambulatory heart failure and reduced ejection fraction (HFrEF), in particular when it is maximally up‐titrated. Unfortunately, the target dose is achieved in less than 50% of HFrEF patients, thus undermining the beneficial effects on the outcomes. In this study, we aimed to evaluate the role of Sac/Val and its titration dose on reverse cardiac remodelling and determine which echocardiographic index best predicts the up‐titration success. Methods and results From January 2020 to June 2021, we retrospectively identified 95 patients (65.6 [59.1–72.8] years; 15.8% females) with chronic HFrEF who were prescribed Sac/Val from the HF Clinics of 5 Italian University Hospitals and evaluated the tolerability of Sac/Val high dose (the ability of the patient to achieve and stably tolerate the maximum dose) as the primary endpoint in the cohort. We used a multivariable logistic regression analysis, with a stepwise backward selection method, to determine the independent predictors of Sac/Val maximum dose tolerability, using, as candidate predictors, only variables with a P‐value < 0.1 in the univariate analyses. Candidate predictors identified for the multivariable backward logistic regression analysis were age, sex, body mass index (BMI), chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), dyslipidaemia, atrial fibrillation, systolic blood pressure (SBP), baseline tolerability of ACEi/ARBs maximum dose, left ventricle global longitudinal strain (LVgLS), LV ejection fraction (EF), tricuspid annulus plane systolic excursion (TAPSE), right ventricle (RV) fractional area change (FAC), RV global and free wall longitudinal strain (RVgLS and RV‐FW‐LS). After the multivariable analysis, only one categorical (ACEi/ARBs maximum dose at baseline) and three continuous (younger age, higher SBP, and higher TAPSE), resulted significantly associated with the study outcome variable with a strong discriminatory capacity (area under the curve 0.874, 95% confidence interval (CI) (0.794–0.954) to predict maximum Sac/Val dose tolerability. Conclusions Our study is the first to analyse the potential role of echocardiography and, in particular, of RV dysfunction, measured by TAPSE, in predicting Sac/Val maximum dose tolerability. Therefore, patients with RV dysfunction (baseline TAPSE <16 mm, in our cohort) might benefit from a different strategy to titrate Sac/Val, such as starting from the lowest dose and/or waiting for a more extended period of observation before attempting with the higher doses

24 Gliflozins and ventricular function in patients affected by chronic heart failure with diabetes mellitus

Abstract Aims Diabetes is the most common comorbidity of HF patients. SGLT2 inhibitors has been shown to reduce hospitalization in patients with HF. The cardioprotective mechanisms of gliflozines have not been elucidated. The aim of our study was to evaluate the effect of SGLT2 inhibitors on right and left ventricular function in T2DM patients with HF. Methods and results One hundred and fifteen consecutive outpatients with CHF and T2DM were screened in the Daunia Heart Failure Registry. Seventy-eight of them were enrolled and followed up between May 2019 and September 2020. All patients underwent conventional, TDI and strain echocardiography in an ambulatory setting, at the beginning and after 3 months of therapy with SGLT2 inhibitors. Seventy-eight consecutive outpatients with CHF and T2DM (mean age 67.4 ± 8.4 years, male: 83%) were enrolled in the study. Thirty-eight of them started the treatment with SGLT2 inhibitors, while the remaining forty continued their original therapy. After 3 months of therapy, LVEF, LVEDD, and LVESD statistically improved (respectively, from 39.68 ± 7.78% to 45.08 ± 9.04%, P: 0.001 and 57.32 ± 9.76 mm to 54.16 ± 6.54 mm, P: 0.01 and from 47.51 ± 1.58 mm to 43.24 ± 8.12, P: 0.0008). Changes in left ventricular function and dimensions were not significant in patients who did not started a therapy with SGLT2 inhibitors. There was a statistically significant reduction of E/E′ (from 16.51 ± 22.55 to 9.73 ± 3.35, P: 0.0007) in patients with treatment with SGLT2i. Moreover, there was an improvement of right ventricular function, due to a statistically significant reduction of PAPs and increase of TAPSE (respectively, from 30.63 ± 8.80 to 24.00 ± 8.35, P: 0.008; from 19.16 ± 2.54 to 21.18 ± 2.84, P: 0.0003) and S′ (10.42 ± 2.09 to 12.91 ± 2.50, P: 0.000) 3 months after the administration of SGLT2 inhibitors therapy vs. the control group. Conclusions In a real-world scenario, our results showed that the treatment with SGLT-2 inhibitors in patients with CHF and diabetes is associated with an echocardiographic biventricular function improvement