Unexpected perturbations (UP) of the support base challenge balance control and require effective reactive postural mechanisms. Continuous perturbations (CPs) of the base of support also affect postural stability but their influence on reactive postural mechanisms is unclear. This study investigated the acute effects of sine-wave (SIN) and random-wave (RND) CPs on reactive postural control, and the impact of prior perturbation exposure on the subsequent static standing (ST). Twenty-seven participants (21.56 ± 0.25 years) performed a perturbation-based protocol on an electrically driven platform. A force plate was positioned on the movable platform to calculate the center of pressure (CoP) trajectory. Five 30-s SIN and RND CPs, as well as a control condition (CTRL) without CP, were administered in a randomized order, each followed by either an UP or no perturbation (NUP) in randomized and counterbalanced sub-trials. Balance performance during CPs, UP, and ST was assessed via CoP velocity and displacement, while Sample Entropy (SampEn) and Power Spectral Density (PSD) analyzed postural control mechanisms during ST. Both SIN and RND CPs enhanced (p < .01) reactive balance performance during UP compared to CTRL. Static balance performance deteriorated (p < .01) following perturbation exposure versus CTRL. SampEn decreased (p < .05) across all post-perturbation conditions, indicating a shift from automatic to voluntary control, with more pronounced reductions following the RND condition. PSD analysis revealed general post-perturbation reweighting toward proprioceptive myotatic and plantar cutaneous contributions (p < .05) which was accentuated after RND compared to SIN and CTRL. Results suggest that both predictable (SIN) and unpredictable (RND) CPs enhance reactive balance in the subsequent UP, likely by potentiating sensory feedback and adaptive motor responses. Conversely, the worsening of static balance performance appears related to the temporal proximity to the preceding perturbation, regardless of perturbation type.

Abstract Background Time-restricted eating (TRE) is a dietary regimen that limits food intake for at least 12 h daily. Unlike other fasting protocols, TRE does not dictate what or how much to eat but rather focuses on the timing of meals. This approach has been previously demonstrated to improve body composition in individuals with obesity or metabolic impairments. However, its impact on body composition and cardiometabolic factors in healthy individuals remains unclear. Furthermore, the optimal fasting duration is still debated. Thus, we aimed to compare the effects of 8 weeks of different fasting durations on body composition and biochemical parameters in metabolically healthy, non-trained individuals using a parallel randomized controlled trial. Methods Forty-one volunteers were randomly assigned to one of the four experimental groups: TRE 16:8 (16 h of fasting,8 h of eating), TRE 14:10 (14 h of fasting,10 h of eating), TRE 12:12 (12 h of fasting,12 h of eating) or a normal diet group (ND; no dietary restriction). Participants underwent body composition measurements and blood tests for lipid profiles (i.e., total cholesterol, LDL, HDL, and triglycerides), fasting glucose, leptin, and anabolic hormones (i.e., insulin and testosterone) levels. Data were analyzed using both intention-to-treat (ITT) and per-protocol (PP) analysis to account for compliance. A two-way ANOVA for repeated measures was employed to assess interactions between time and group. Results In the ITT analysis, TRE 16:8 reduced body mass (-2.46%, p = 0.003) and absolute fat mass (-8.65%, p = 0.001) with no changes in lean soft tissue and in calorie intake. These results were consistent with the PP analysis which included 8 participants in TRE 16:8, 5 in TRE 14:10, 9 in TRE 12:12, and the entire ND group. Participants in the TRE 16:8 group spontaneously reduced their total caloric intake, although this reduction was not statistically significant. None of the other measurements significantly changed after 8 weeks. Conclusions Our results suggest that a 16-hour fasting window, even without caloric restriction, may be a viable strategy for improving body composition in healthy and non-trained individuals, whereas a shorter fasting period may be insufficient to produce significant changes in a healthy population. Trial registration NCT, NCT04503005. Registered 4 August 2020, https://clinicaltrials.gov/study/NCT04503005.

Objectives. - Critical velocity and its related total distance covered above critical velocity can be used to evaluate and monitor the training and competition performance in athletes. While it is well researched in sports such as cycling and running, the literature on critical velocity in swimming is less available. Therefore, the objectives of this review are: (i) to methodologically evaluate the protocols used to obtain critical velocity; and (ii) eventually, to provide a standard operating procedure to evaluate critical velocity in front crawl swimming. Methods. - The review followed "Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews'' guidelines. PubMed, Web of Science and Scopus were used to find original studies written in English. No exclusion criteria were adopted for the country of origin. The results were analysed through a narrative synthesis. News. - A total of 41 studies were included. Sixteen different protocols were adopted withdifferent physiological thresholds as comparators with critical velocity. Conclusion. - Critical velocity evaluation presents different testing protocols, making this performance marker potentially inaccurate. As a consequence, we propose a standard operatingprocedure. (c) 2021 Elsevier Masson SAS. All rights reserved.

Strength, power and muscular endurance tests have been developed as means of assessing people's physical abilities. However, testing may be expensive or time consuming. A method to reduce the time of physical assessment could be to use predictive algorithms for indirect assessment. The aim of this study will be to determine a relationship between strength, power and muscular endurance in order to identify predictors for an easier and faster assessment. 33 male strength-trained participants (22.8 +/- 4.6 years, 172.5 +/- 6.7 cm, 68.0 +/- 10.6 kg) performed a single pull-up (SPU) and a single push-up (SPH) and a set of pull-ups (EPU) and push-ups (EPH) to exhaustion. The participants were divided into three sub-groups according to their training experience. Force(F), Power(P), Velocity(V) and relative power(R-P), extracted from an accelerometer (500 Hz), were compared between groups (ANOVA) and a subsequent linear regression analysis was performed to identify predictors of the performance measures. The regression models were able to explain 61% of the variance with the EPU as dependent variable and the V of the SPU as independent variable and 68% of the variance with the EPH as dependent variable and EPU as independent variable. In addition, increased performance measures were found according to training experience, in particular regarding muscular endurance of both the EPU and EPH (p < 0.001 and p < 0.01, respectively). A significant effect of training experience was also present for the V of the SPU (p < 0.001). The results indicate that a relation between muscular endurance and velocity is present. The generated equations allow to estimate both the number of EPH and EPU from a SPU. The equations may be helpful to reduce the time of assessment for upper body physical evaluation.

BACKGROUND: Calisthenics was a term used to define a generic set of body weight exercises. Such term is now used to define a world wide spread discipline based on body weight and gymnastics exercises.OBJECTIVE: The aim of this study was to administer a calisthenics training protocol and evaluate its effects on posture, strength and body composition in untrained individuals.METHODS: Twenty-eight male participants (24.2 +/- 4.2 years; 67.0 +/- 8.3 Kg; 173.3 +/- 5.2 cm) were divided into two groups, a Calisthenics based intervention group (SG) and a control group (CG). The SG exercised for 8 weeks. Each participant underwent a body composition analysis, a postural assessment, a handgrip test, a push-up and a pull-up test. Each participant was tested at baseline and post intervention.RESULTS: The SG improved their posture (with open eyes p < 0.001 and with closed eyes p < 0.05), their strength (push-up test p < 0.01 with a 16.4% increase and pull up test p < 0.0001 with a 39.2% increase) and their body composition (Fat mass 14.8 +/- 5.1 vs. 11.4 +/- 5.9, p < 0.01). No difference was shown for the handgrip test. No significant differences were displayed in any variable of the CG between pre and post measures.CONCLUSIONS: Calisthenics training is a feasible and effective training solution to improve posture, strength and body composition without the use any major training equipment.

AIM:There are limited studies that indicate the effects of trampoline exercise on strength and other physiological parameters. This study aims to determine whether twelve weeks of trampoline exercise would have any effects on the physical and physiological parameters of male gymnasts.METHODS:A number of 20 intercollegiate competitive male gymnasts (as experimental group) and 20 non-athlete male (as control group) participated voluntarily. Their anthropometric characteristics and the anaerobic power were measured and their back strength, vertical jump, standing long jump and 20 meter sprint performances were measured.RESULTS:As a result; whereas 12 weeks of trampoline exercise improved standing long jump (before 242.35±3.40 cm; after 251.70±2.95 cm) and also vertical jump, 20 meter sprint speed and anaerobic power of subjects. We did not observe significant changes on back strength performances (before 148.32±5.73 kg; after 148.10±5.71).CONCLUSION:The trampoline exercise protocol improved significantly speed, jump and anaerobic performances of the experimental group, while did not induced any changes on back strength performances. More studies are necessary to confirm the interesting results coming from this pilot intervention.

The impact of a sedentary lifestyle during childhood and adolescence on pathological processes has become a major public health threat. Regular participation in a variety of physical activities during the pediatric years could reduce chronic disease and improve the quality of life of active participants. Although resistance training (RT). was once considered inappropriate for youth, there is a compelling body of evidence which demonstrate the safety and efficacy of RT for children and adolescents. In addition to increasing muscular strength, RT can result in favorable changes in body composition, bone mineral density and motor skill performance provided that the training program is well-designed and supervised by qualified professionals. Preseason conditioning programs which include RT have also been found to reduce sports-related injuries in young athletes. The purpose of this review is to evaluate the risks and benefits associated with youth RT and discuss program design considerations for promoting RT in school- and community-based programs as an on-going lifestyle choice.

AIM The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. METHODS Thirty-one healthy adolescent girls, of which 11 age-matched control subjects [C], 10 basketballers (BP) and 10 volleyballers (VP) participated to the study. The throwing performance was assessed by seated backward overhead ball throw (SBOMBT) and seated chest pass throw (SCPT) using a 3-kg rubber medicine ball. Instead, the vertical jumping performance was evaluated by squat jump (SJ) and countermovement jump with (CMJ-AS) and without arm swing (CMJ) using Optojump system (Microgate srl, Italy). RESULTS During SJ and CMJ with and without arm swing VP group showed a higher vertical jump performance than BP and C ones. In particular we showed that VP exhibited a higher flight time and jump height than C (P<0.05) in SJ, CMJ and CMJ-AS tests. Players showed higher performances than C in SCPT and SBOMBT. However, we found only a significant difference (P<0.05) in the comparison between BP and C during SCPT. Moreover, we found significant correlations between SBOBMT performances and CMJ-AS jump heights in C (r= 0.60; p= 0.02) and VP (r= 0.81; p<0.01) groups compared to BP one (r= -0.47; p= 0.08). CONCLUSION These data suggest that 3 years of SSTB might be able to promote significant neuromuscular adaptations in volleyball and basketball athletes' maximal power compared to age-matched control subjects.

We measured respiratory ratio (RR), pulmonary ventilation (VE) and end-tidal carbon dioxide partial pressure (ETPCO2) at rest and during cycling aerobic workloads (20%, 40%, 60% of estimated maximal oxygen uptake). Measurements were taken after overnight fasting and after an oral glucose load. RR, VE and ETPCO2 increased with workload. Glucose load caused RR and VE increments at rest (0.75 ± 0.01 vs. 0.86 ± 0.02, p < 0.01, and 10.8 ± 0.43 vs. 12.1 ± 0.49 l/min, p < 0.01, respectively) and for each workload (20% estimated maximal oxygen uptake: 0.77 ± 0.01 vs. 0.855 ± 0.02, p < 0.01, and 16.2 ± 0.73 vs. 17.7 ± 0.8 l/min, p < 0.01; 40% estimated maximal oxygen uptake: 0.76 ± 0.02 vs. 0.82 ± 0.01, p < 0.01, and 25.9 ± 1.1 vs. 28.3 ± 1.3 l/min, p < 0.05; 60% estimated maximal oxygen uptake: 0.85 ± 0.02 vs. 0.91 ± 0.02, p < 0.01, and 37.4 ± 1.7 vs. 40.9 ± 1.9 l/min, p < 0.05) but ETPCO2 did not change. The differences in RR before and after glucose load became smaller as the workload increased. Linear regression analysis of VE and carbon dioxide output yielded virtually identical results for both fasting and glucose load conditions. We have concluded that: a) for the metabolic carbon dioxide load increment due to glucose-induced RR increment, the physiological response is an increase of VE at all workloads. This response modulates constant ETPCO2 values; b) on workload increment, skeletal muscle increasingly utilises more and more glycogen stores, regardless of the blood glucose availability. This reduces the usefulness of dietary manipulations decreasing carbon dioxide metabolic load during muscular work in respiratory failure; c) the absolute value of metabolic carbon dioxide load exerts a role in ventilation regulation at rest and during aerobic exercise.

Sepsis is often associated with upregulation of nitric oxide production and fever, and it is common to control an excessive febrile response with antipyretic therapy and external cooling. Our aim was to evaluate the effect of hypothermia on NO production in a model of septic shock. Rats were anesthetized, ventilated, and instrumented for hemodynamic monitoring and divided into four groups. Normothermic controls (NC) received saline intravenously and were maintained at 37 °C. Hypothermic controls (HC) received saline but were allowed to become hypothermic. Normothermic endotoxic (NE) received Escherichia Coli lipopolysaccharides (LPS) intravenously to induce endotoxic shock and was maintained at 37 °C. Hypothermic endotoxic (HE) received LPS intravenously and was allowed to become hypothermic. Exhaled NO (NOe) was measured from mixed expired gas at time zero and every 30 min, for 5 h. After injection of LPS, NOe increased substantially in the NE group (700 ± 24 ppb), but increased only to 25 ± 2 ppb in the HE group. NOe increased to 90 ± 3 ppb in the NC group, and to 17.6 ± 3.1 ppb in the HC group after 5 h ( P < 0.05), whilst blood pressure remained stable. In the HE group, blood pressure fell immediately after injection of the LPS, but thereafter remained stable despite the rise in NOe. In the NE group, the blood pressure fell gradually, and the animals became hypotensive. During the natural course of endotoxemia in anesthetized rats, allowing severe hypothermia to ensue by not actively managing temperature and hemodynamics resulted in significantly reduced expired NO concentrations, lung injury, and prolonged survival. The clinical benefits of such a finding currently remain unclear and merit further investigation.

During ageing skeletal muscles undergo a process of structural and functional remodelling that leads to sarcopenia, a syndrome characterized by loss of muscle mass and force and a major cause of physical frailty. To determine the causes of sarcopenia and identify potential targets for interventions aimed at mitigating ageing-dependent muscle wasting, we focussed on the main signalling pathway known to control protein turnover in skeletal muscle, consisting of the insulin-like growth factor 1 (IGF1), the kinase Akt and its downstream effectors, the mammalian target of rapamycin (mTOR) and the transcription factor FoxO. Expression analyses at the transcript and protein level, carried out on well-characterized cohorts of young, old sedentary and old active individuals and on mice aged 200, 500 and 800 days, revealed only modest age-related differences in this pathway. Our findings suggest that during ageing there is no downregulation of IGF1/Akt pathway and that sarcopenia is not due to FoxO activation and upregulation of the proteolytic systems. A potentially interesting result was the increased phosphorylation of the ribosomal protein S6, indicative of increased activation of mTOR complex1 (mTORC1), in aged mice. This result may provide the rationale why rapamycin treatment and caloric restriction promote longevity, since both interventions blunt activation of mTORC1; however, this change was not statistically significant in humans. Finally, genetic perturbation of these pathways in old mice aimed at promoting muscle hypertrophy via Akt overexpression or preventing muscle loss through inactivation of the ubiquitin ligase atrogin1 were found to paradoxically cause muscle pathology and reduce lifespan, suggesting that drastic activation of the IGF1-Akt pathway may be counterproductive, and that sarcopenia is accelerated, not delayed, when protein degradation pathways are impaired.

Introduction Les analogues du GLP-1, via leurs actions sur la satiete et la secretion de glucagon, pourraient etre interessants chez les patients diabetiques de type 2 evolues au stade de l'insulinotherapie surtout quand ils presentent une obesite difficile a maitriser. Objectif Evaluer, chez ces patients, l'impact ponderal et glycemique de l'introduction d'un analogue du GLP-1 en comparant deux modalites therapeutiques: association a l'insuline ou switch (en accord avec l'AMM). Patients et methodes Etude retrospective, realisee sur 148 patients au CHU de Reims, entre 2008 et 2010. Resultats 101 patients ont beneficie de l'association (gpe 1); 47 patients du switch (gpe 2). Les 2 groupes sont comparables: âge moyen: 59,3 vs 57,8 ans; IMC: 38,9 vs 39,3kg/m 2 ; anciennete diabete: 19,2 vs 16,3 ans; insuline apres 10 ans d'evolution; HBA1c: 8,6 %. Seules les doses d'insuline sont significativement inferieures dans le groupe 2 (0,97 vs 0,66U/j). L'association de l'analogue du GLP-1 a l'insuline fait baisser l'HbA1c de − 0,84 % a 6 mois et de − 0,34 % apres un an, en permettant une perte de 5Kg, une baisse de 9 % de la dose d'insuline lente et un arret de l'insuline rapide dans 30 % des cas. Le switch apporte un benefice ponderal plus important (p=0,007) mais aucun benefice sur l'equilibre glycemique avec un echappement glycemique chez 45 % (21/47) des patients. L'absence de resultat apres 6 mois de traitement est correlee avec une absence de resultat a long terme et doit conduire a l'arret du traitement. Conclusion Le maintien de l'insuline lors de l'introduction d'un analogue du GLP-1 chez ces patients, semble etre la strategie la plus sure. Cette association permet une perte de poids non negligeable, une amelioration modeste de l'HbA1C et une reduction des doses globales d'insuline.

The influence of nutrition on skin health is a growing research area but the findings of various studies on the effect of diet on the development of acne have often been contradictory. The general opinion among researchers has oscillated between two different, opposing positions: that diet either is or is not a key factor for acne development. This review examines the evidence supporting an influence of various dietary components on the development of acne particularly focusing on the role played by carbohydrates. The physiological and biochemical effects of the ketogenic diet are examined from this perspective and mechanisms will be proposed via which this type of diet could have a role in the treatment of acne.

The study investigated the effect of prolonged hypoxia on central [i.e., cardiovascular oxygen delivery (Q(a)O(2))] and peripheral (i.e., O(2) utilization) determinants of oxidative metabolism response during exercise in humans. To this aim, seven male mountaineers were examined before and immediately after the Himalayan Expedition Interamnia 8000-Manaslu 2008, lasting 43 days, among which, 23 days were above 5,000 m. The subjects showed a decrease in body weight (P < 0.05) and of power output during a Wingate Anaerobic test (P < 0.05) and an increase of thigh cross-sectional area (P < 0.05). Absolute maximal O(2) uptake (VO(2max)) did not change. The mean response time of VO(2) kinetics at the onset of step submaximal cycling exercise was reduced significantly from 53.8 s ± 10.9 to 39.8 s ± 10.9 (P < 0.05), whereas that of Q(a)O(2) was not. Analysis of single fibers dissected from vastus lateralis biopsies revealed that the expression of slow isoforms of both heavy and light myosin subunits increased, whereas that of fast isoforms decreased. Unloaded shortening velocity of fibers was decreased significantly. In summary, independent findings converge in indicating that adaptation to chronic hypoxia brings about a fast-to-slow transition of muscle fibers, resulting in a faster activation of the mitochondrial oxidative metabolism. These results indicate that a prolonged and active sojourn in hypoxia may induce muscular ultrastructural and functional changes similar to those observed after aerobic training.

Aim and methods. The influence of family history of non-insulin-dependent diabetes (NIDDM) on basal metabolic rate (BMR) has been investigated in 116 voluntarily women: 25 sedentary and 34 athletes without a family predisposition to type 2 diabetes (FH-); 21 sedentary and 15 athletes with a second degree predisposition to NIDDM (FM); 10 sedentary and 11 athletes with a first degree predisposition to NIDDM (FH++).Results. The results showed that family history on type 2 diabetes is strongly related to sedentary in women with significant high body weight values and an increased fat mass There was no significant difference in the body parameters among the athletes groups, confirming the protective role of regular physical activity on these parameters. Analysing basal energy expenditure showed that sedentary FH++ women had a significant increase in BMR in absolute values; however there were no differences in BMR when reported to body weight and body fat-free mass. In contrast, the FH++ athletes group had lower BMR (absolute values) than the sedentary group. No differences were found in the relative BMR either. By comparing the recorded BMR of the groups with the theoretical values, it has been shown that the FH++ athletes had a reduced increase in BMR with respect to the other groups. The FH- athletes showed a higher energy turnover compared to the other women and relative to predicted values.Conclusion. This study confirms that family history of type 2 diabetes has an important influence on the phenotype of women and it can be associated with significant metabolic and anthropometric modifications in young healthy subjects. It may also account for changes in the body composition and basal metabolic rate alterations in subjects with a predisposition to type 2 diabetes, by reducing the metabolic basal output expected in active subjects.