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Laboratoire Interuniversitaire de Biologie de la Motricité

facilityVilleurbanne, Auvergne-Rhône-Alpes, France

Research output, citation impact, and the most-cited recent papers from Laboratoire Interuniversitaire de Biologie de la Motricité (France). Aggregated across the NobleBlocks index of 300M+ scholarly works.

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1.8K
Citations
54.9K
h-index
95
i10-index
1.3K
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Laboratoire Interuniversitaire de Biologie de la Motricité

Top-cited papers from Laboratoire Interuniversitaire de Biologie de la Motricité

Interpreting Power-Force-Velocity Profiles for Individualized and Specific Training
Jean-Benoı̂t Morin, Pierre Samozino
2015· International Journal of Sports Physiology and Performance466doi:10.1123/ijspp.2015-0638

Recent studies have brought new insights into the evaluation of power-force-velocity profiles in both ballistic push-offs (eg, jumps) and sprint movements. These are major physical components of performance in many sports, and the methods the authors developed and validated are based on data that are now rather simple to obtain in field conditions (eg, body mass, jump height, sprint times, or velocity). The promising aspect of these approaches is that they allow for more individualized and accurate evaluation, monitoring, and training practices, the success of which is highly dependent on the correct collection, generation, and interpretation of athletes' mechanical outputs. The authors therefore wanted to provide a practical vade mecum to sports practitioners interested in implementing these power-force-velocity-profiling approaches. After providing a summary of theoretical and practical definitions for the main variables, the authors first detail how vertical profiling can be used to manage ballistic push-off performance, with emphasis on the concept of optimal force-velocity profile and the associated force-velocity imbalance. Furthermore, they discuss these same concepts with regard to horizontal profiling in the management of sprinting performance. These sections are illustrated by typical examples from the authors' practice. Finally, they provide a practical and operational synthesis and outline future challenges that will help further develop these approaches.

A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity
Vincent Legros, Solène Denolly, Manon Vogrig, Bertrand Boson +4 more
2021· Cellular and Molecular Immunology338doi:10.1038/s41423-020-00588-2

Understanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and, thus, for public health policy and vaccine development for COVID-19. In this study, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections, including patients with mild symptoms and also more severe forms, including those that required intensive care. We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers; conversely, patients with milder disease symptoms had heterogeneous nAb titers, and asymptomatic or exclusive outpatient-care patients had no or low nAbs. We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses. Moreover, we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2. Finally, we found that the D614G mutation in the spike protein, which has recently been identified as the current major variant in Europe, does not allow neutralization escape. Altogether, our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease, and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted.

Effectiveness of an Individualized Training Based on Force-Velocity Profiling during Jumping
Pedro Jiménez‐Reyes, Pierre Samozino, Matt Brughelli, Jean‐Benoît Morin
2017· Frontiers in Physiology305doi:10.3389/fphys.2016.00677

Ballistic performances are determined by both the maximal lower limb power output (Pmax) and their individual force-velocity (F-v) mechanical profile, especially the F-v imbalance (FVimb): difference between the athlete’s actual and optimal profile. An optimized training should aim to increase Pmax and/or reduce FVimb. The aim of this study was to test whether an individualized training program based on the individual F-v profile would decrease subjects’ individual FVimb and in turn improve vertical jump performance. FVimb was used as the reference to assign participants to different training intervention groups. 84 subjects were assigned to three groups: an “optimized” group divided into velocity-deficit, force-deficit and well-balanced sub-groups based on subjects’ FVimb, a “non-optimized” group for which the training program was not specifically based on FVimb and a control group. All subjects underwent a 9-week specific resistance training program. The programs were designed to reduce FVimb for the optimized groups (with specific programs for sub-groups based on individual FVimb values), while the non-optimized group followed a classical program exactly similar for all subjects. All subjects in the three optimized training sub-groups (velocity-deficit, force-deficit and well-balanced) increased their jumping performance (12.7±5.7% ES= 0.93±0.09, 14.2±7.3% ES= 1.00±0.17, and 7.2±4.5% ES= 0.70±0.36 respectively) with jump height improvement for all subjects, whereas the results were much more variable and unclear in the non-optimized group. This greater change in jump height was associated with a markedly reduced FVimb for both force-deficit (57.9±34.7% decrease in FVimb) and velocity-deficit (20.1±4.3%) subjects, and unclear or small changes in Pmax (-0.40±8.4% and +10.5±5.2%, respectively). An individualized training program specifically based on FVimb (gap between the actual and optimal F-v profiles of each individual) was more efficient at improving jumping performance (i.e. unloaded squat jump height) than a traditional resistance training common to all subjects regardless of their FVimb. Although improving both FVimb and Pmax has to be considered to improve ballistic performance, the present results showed that reducing FVimb without even increasing Pmax lead to clearly beneficial jump performance changes. Thus, FVimb could be considered as a potentially useful variable for prescribing optimal resistance training to improve ballistic performance.

Neuromuscular Consequences of an Extreme Mountain Ultra-Marathon
Guillaume Y. Millet, Katja Tomažin, Samuel Vergès, Christopher K. Vincent +4 more
2011· PLoS ONE247doi:10.1371/journal.pone.0017059

We investigated the physiological consequences of one of the most extreme exercises realized by humans in race conditions: a 166-km mountain ultra-marathon (MUM) with 9500 m of positive and negative elevation change. For this purpose, (i) the fatigue induced by the MUM and (ii) the recovery processes over two weeks were assessed. Evaluation of neuromuscular function (NMF) and blood markers of muscle damage and inflammation were performed before and immediately following (n = 22), and 2, 5, 9 and 16 days after the MUM (n = 11) in experienced ultra-marathon runners. Large maximal voluntary contraction decreases occurred after MUM (-35% [95% CI: -28 to -42%] and -39% [95% CI: -32 to -46%] for KE and PF, respectively), with alteration of maximal voluntary activation, mainly for KE (-19% [95% CI: -7 to -32%]). Significant modifications in markers of muscle damage and inflammation were observed after the MUM as suggested by the large changes in creatine kinase (from 144 ± 94 to 13,633 ± 12,626 UI L(-1)), myoglobin (from 32 ± 22 to 1,432 ± 1,209 µg L(-1)), and C-Reactive Protein (from <2.0 to 37.7 ± 26.5 mg L(-1)). Moderate to large reductions in maximal compound muscle action potential amplitude, high-frequency doublet force, and low frequency fatigue (index of excitation-contraction coupling alteration) were also observed for both muscle groups. Sixteen days after MUM, NMF had returned to initial values, with most of the recovery process occurring within 9 days of the race. These findings suggest that the large alterations in NMF after an ultra-marathon race are multi-factorial, including failure of excitation-contraction coupling, which has never been described after prolonged running. It is also concluded that as early as two weeks after such an extreme running exercise, maximal force capacities have returned to baseline.

Visual pathways for object-oriented action and object recognition: functional anatomy with PET
Isabelle Faillenot
1997· Cerebral Cortex221doi:10.1093/cercor/7.1.77

The purpose of this study was to identify the functional anatomy of the mechanisms involved in visually guided prehension and in object recognition in humans. The cerebral blood flow of seven subjects was investigated by positron emission tomography. Three conditions were performed using the same set of stimuli. In the 'grasping' condition, subjects were instructed to accurately grasp the objects. In the 'matching' condition, subjects were requested to compare the shape of the presented object with that of the previous one. In the 'pointing' condition (control), subjects pointed towards the objects. The comparison between grasping and pointing showed a regional cerebral blood flow (rCBF) increase in the anterior part of the inferior parietal cortex and part of the posterior parietal cortex. The comparison between grasping and matching showed an rCBF increase in the cerebellum, the left frontal cortex around the central sulcus, the mesial frontal cortex and the left inferior parietal cortex. Finally, the comparison between matching and pointing showed an rCBF increase in the right temporal cortex and the right posterior parietal cortex. Thus object-oriented action and object recognition activate a common posterior parietal area, suggesting that some kind of within-object spatial analysis was processed by this area whatever the goal of the task.

Personalized alignment in total knee arthroplasty: current concepts
Sébastien Lustıg, Elliot Sappey‐Marinier, Camdon Fary, Elvire Servıen +2 more
2021· SICOT-J199doi:10.1051/sicotj/2021021

Traditionally in total knee arthroplasty (TKA), a post-operative neutral alignment was the gold standard. This principle has been contested as functional outcomes were found to be inconsistent. Analysis of limb alignment in the non-osteoarthritic population reveals variations from neutral alignment and consideration of a personalized or patient-specific alignment in TKA is challenging previous concepts. The aim of this review was to clarify the variations of current personalized alignments and to report their results. Current personalized approaches of alignment reported are: kinematic, inverse kinematic, restricted kinematic, and functional. The principle of "kinematic alignment" is knee resurfacing with restitution of pre-arthritic anatomy. The aim is to resurface the femur maintaining the native femoral joint line obliquity. The flexion and extension gaps are balanced with the tibial resection. The principle of the "inverse kinematic alignment" is to resurface the tibia with similar medial and lateral bone resections in order to keep the native tibial joint line obliquity. Gap balancing is performed by adjusting the femoral resections. To avoid reproducing extreme anatomical alignments there is "restricted kinematic alignment" which is a compromise between mechanical alignment and true kinematic alignment with a defined safe zone of alignment. Finally, there is the concept of "functional alignment" which is an evolution of kinematic alignment as enabling technology has progressed. This is obtained by manipulating alignment, bone resections, soft tissue releases, and/or implant positioning with a robotic-assisted system to optimize TKA function for a patient's specific alignment, bone morphology, and soft tissue envelope. The aim of personalizing alignment is to restore native knee kinematics and improve functional outcomes after TKA. A long-term follow-up remains crucial to assess both outcomes and implant survivorship of these current concepts.

Redox Control of Skeletal Muscle Regeneration
Emméran Le Moal, Vincent Pialoux, Gaëtan Juban, Carole Groussard +3 more
2016· Antioxidants and Redox Signaling191doi:10.1089/ars.2016.6782

Skeletal muscle shows high plasticity in response to external demand. Moreover, adult skeletal muscle is capable of complete regeneration after injury, due to the properties of muscle stem cells (MuSCs), the satellite cells, which follow a tightly regulated myogenic program to generate both new myofibers and new MuSCs for further needs. Although reactive oxygen species (ROS) and reactive nitrogen species (RNS) have long been associated with skeletal muscle physiology, their implication in the cell and molecular processes at work during muscle regeneration is more recent. This review focuses on redox regulation during skeletal muscle regeneration. An overview of the basics of ROS/RNS and antioxidant chemistry and biology occurring in skeletal muscle is first provided. Then, the comprehensive knowledge on redox regulation of MuSCs and their surrounding cell partners (macrophages, endothelial cells) during skeletal muscle regeneration is presented in normal muscle and in specific physiological (exercise-induced muscle damage, aging) and pathological (muscular dystrophies) contexts. Recent advances in the comprehension of these processes has led to the development of therapeutic assays using antioxidant supplementation, which result in inconsistent efficiency, underlying the need for new tools that are aimed at precisely deciphering and targeting ROS networks. This review should provide an overall insight of the redox regulation of skeletal muscle regeneration while highlighting the limits of the use of nonspecific antioxidants to improve muscle function. Antioxid. Redox Signal. 27, 276-310.

Point: Counterpoint: Hypobaric hypoxia induces/does not induce different responses from normobaric hypoxia
Grégoire P. Millet, Raphaël Faiss, Vincent Pialoux
2012· Journal of Applied Physiology184doi:10.1152/japplphysiol.00067.2012

International audience

The Red Blood Cell—Inflammation Vicious Circle in Sickle Cell Disease
Élie Nader, Marc Romana, Philippe Connes
2020· Frontiers in Immunology178doi:10.3389/fimmu.2020.00454

Sickle cell disease (SCD) is a genetic disease caused by a single mutation in the β-globin gene, leading to the production of an abnormal hemoglobin called hemoglobin S (HbS), which polymerizes under deoxygenation, and induces the sickling of red blood cells (RBCs). Sickled RBCs are very fragile and rigid, and patients consequently become anemic and develop frequent and recurrent vaso-occlusive crises. However, it is now evident that SCD is not only a RBC rheological disease. Accumulating evidence shows that SCD is also characterized by the presence of chronic inflammation and oxidative stress, participating in the development of chronic vasculopathy and several chronic complications. The accumulation of hemoglobin and heme in the plasma, as a consequence of enhanced intravascular hemolysis, decreases nitric oxide bioavailability and enhances the production of reactive oxygen species (ROS). Heme and hemoglobin also represent erythrocytic danger-associated molecular pattern molecules (eDAMPs), which may activate endothelial inflammation through TLR-4 signaling and promote the development of complications, such as acute chest syndrome. It is also suspected that heme may activate the innate immune complement system and stimulate neutrophils to release neutrophil extracellular traps. A large amount of microparticles (MPs) from various cellular origins (platelets, RBCs, white blood cells, endothelial cells) is also released into the plasma of SCD patients and participate in the inflammation and oxidative stress in SCD. In turn, this pro-inflammatory and oxidative stress environment further alters the RBC properties. Increased pro-inflammatory cytokine concentrations promote the activation of RBC NADPH oxidase and, thus, raise the production of intra-erythrocyte ROS. Such enhanced oxidative stress causes deleterious damage to the RBC membrane and further alters the deformability of the cells, modifying their aggregation properties. These RBC rheological alterations have been shown to be associated to specific SCD complications, such as leg ulcers, priapism, and glomerulopathy. Moreover, RBCs positive for the Duffy antigen receptor for chemokines may be very sensitive to various inflammatory molecules that promote RBC dehydration and increase RBC adhesiveness to the vascular wall. In summary, SCD is characterized by a vicious circle between abnormal RBC rheology and inflammation, which modulates the clinical severity of patients.

Effects of Exposure to Intermittent Hypoxia on Oxidative Stress and Acute Hypoxic Ventilatory Response in Humans
Vincent Pialoux, Patrick J. Hanly, Glen E. Foster, Julien V. Brugniaux +4 more
2009· American Journal of Respiratory and Critical Care Medicine175doi:10.1164/rccm.200905-0671oc

RATIONALE: Periodic occlusion of the upper airway in patients with obstructive sleep apnea leads to chronic intermittent hypoxia, which increases the acute hypoxic ventilatory response (AHVR). Animal studies suggest that oxidative stress may modulate AHVR by increasing carotid body sensitivity to hypoxia. This has not been shown in humans. OBJECTIVES: To determine whether 4 days of exposure to chronic intermittent hypoxia increases AHVR and oxidative stress and to determine the strength of the association between oxidative stress and AHVR. METHODS: After two normoxic control days (Day -4 and Day 0), 10 young healthy men were exposed awake to 4 days (Days 1-4) of intermittent hypoxia for 6 hours per day. MEASUREMENTS AND MAIN RESULTS: AHVR, assessed using an isocapnic hypoxia protocol, was determined as the slope of the linear regression between ventilation and oxygen desaturation. Oxidative stress was evaluated by measuring plasma DNA, lipid and protein oxidation, uric acid and antioxidant status by measuring alpha-tocopherol, total vitamin C, and antioxidant enzymatic activities. Between baseline and Day 4, there were significant increases in AHVR, DNA oxidation, uric acid, and vitamin C, whereas antioxidant enzymatic activities and alpha-tocopherol were unchanged. There were strong correlations between the changes in AHVR and DNA oxidation (r = 0.88; P = 0.002). CONCLUSIONS: Chronic intermittent hypoxia increases oxidative stress by increasing production of reactive oxygen species without a compensatory increase in antioxidant activity. This human study shows that reactive oxygen species overproduction modulates increased AHVR. These mechanisms may be responsible for increased AHVR in patients with obstructive sleep apnea.

Linking zooplankton communities to ecosystem functioning: toward an effect-trait framework
Marie‐Pier Hébert, Beatrix E. Beisner, Roxane Maranger
2016· Journal of Plankton Research175doi:10.1093/plankt/fbw068

The renewed interest in trait-based approaches has offered a stimulating, conceptual framework for predicting species distributions, assessing community composition and determining biodiversity-ecosystem linkages. However, despite previous attempts to clarify trait terminology and its application, selecting ecologically meaningful traits that mechanistically link levels of biological organization remains a challenge in aquatic ecology. Response traits can be used to capture community assembly processes along environmental gradients, while effect traits hold the potential to predict ecosystem functions. Although effect traits related to organismal physiology and body composition best allow for extrapolation from individuals to ecosystem processes, such traits are still rarely incorporated within plankton functional approaches or classifications for numerous reasons. Synthesizing current knowledge on effect traits in zooplankton, we call for a better implementation of such metrics as descriptors of community structure. We then capitalize on concepts of bioenergetics and ecosystem ecology to propose a hierarchical framework for zooplankton trait classification, identifying key traits fulfilling organismal functions and linking these to ecosystem processes likely to be influenced. Our framework provides insight regarding trait trade-offs, with implications for feedbacks to ecosystems, aiming to bridge the gap between plankton community ecology and aquatic biogeochemistry.

Very-Heavy Sled Training for Improving Horizontal-Force Output in Soccer Players
Jean-Benoı̂t Morin, George Petrakos, Pedro Jiménez‐Reyes, Scott R. Brown +2 more
2016· International Journal of Sports Physiology and Performance169doi:10.1123/ijspp.2016-0444

BACKGROUND: Sprint running acceleration is a key feature of physical performance in team sports, and recent literature shows that the ability to generate large magnitudes of horizontal ground-reaction force and mechanical effectiveness of force application are paramount. The authors tested the hypothesis that very-heavy loaded sled sprint training would induce an improvement in horizontal-force production, via an increased effectiveness of application. METHODS: Training-induced changes in sprint performance and mechanical outputs were computed using a field method based on velocity-time data, before and after an 8-wk protocol (16 sessions of 10- × 20-m sprints). Sixteen male amateur soccer players were assigned to either a very-heavy sled (80% body mass sled load) or a control group (unresisted sprints). RESULTS: The main outcome of this pilot study is that very-heavy sled-resisted sprint training, using much greater loads than traditionally recommended, clearly increased maximal horizontal-force production compared with standard unloaded sprint training (effect size of 0.80 vs 0.20 for controls, unclear between-groups difference) and mechanical effectiveness (ie, more horizontally applied force; effect size of 0.95 vs -0.11, moderate between-groups difference). In addition, 5-m and 20-m sprint performance improvements were moderate and small for the very-heavy sled group and small and trivial for the control group, respectively. Practical Applications: This brief report highlights the usefulness of very-heavy sled (80% body mass) training, which may suggest value for practical improvement of mechanical effectiveness and maximal horizontal-force capabilities in soccer players and other team-sport athletes. RESULTS: This study may encourage further research to confirm the usefulness of very-heavy sled in this context.

Relationship between vertical and horizontal force-velocity-power profiles in various sports and levels of practice
Pedro Jiménez‐Reyes, Pierre Samozino, Amador García‐Ramos, Víctor Cuadrado‐Peñafiel +2 more
2018· PeerJ167doi:10.7717/peerj.5937

This study aimed (i) to explore the relationship between vertical (jumping) and horizontal (sprinting) force–velocity–power (FVP) mechanical profiles in a large range of sports and levels of practice, and (ii) to provide a large database to serve as a reference of the FVP profile for all sports and levels tested. A total of 553 participants (333 men, 220 women) from 14 sport disciplines and all levels of practice participated in this study. Participants performed squat jumps (SJ) against multiple external loads (vertical) and linear 30–40 m sprints (horizontal). The vertical and horizontal FVP profile (i.e., theoretical maximal values of force ( F 0 ), velocity ( v 0 ), and power ( P max )) as well as main performance variables (unloaded SJ height in jumping and 20-m sprint time) were measured. Correlations coefficient between the same mechanical variables obtained from the vertical and horizontal modalities ranged from −0.12 to 0.58 for F 0 , −0.31 to 0.71 for v 0 , −0.10 to 0.67 for P max , and −0.92 to −0.23 for the performance variables (i.e, SJ height and sprint time). Overall, results showed a decrease in the magnitude of the correlations for higher-level athletes. The low correlations generally observed between jumping and sprinting mechanical outputs suggest that both tasks provide distinctive information regarding the FVP profile of lower-body muscles. Therefore, we recommend the assessment of the FVP profile both in jumping and sprinting to gain a deeper insight into the maximal mechanical capacities of lower-body muscles, especially at high and elite levels.

Muscle injury is the principal injury type and hamstring muscle injury is the first injury diagnosis during top-level international athletics championships between 2007 and 2015
Pascal Édouard, Pedro Branco, Juan Manuel Alonso
2016· British Journal of Sports Medicine165doi:10.1136/bjsports-2015-095559

BACKGROUND: During top-level international athletics championships, muscle injuries are frequent. OBJECTIVE: To analyse the incidence and characteristics of muscle injuries and hamstring muscle injuries (hamstring injuries) occurring during top-level international athletics championships. METHODS: During 16 international championships held between 2007 and 2015, national medical team and local organising committee physicians reported daily all injuries on a standardised injury report form. Only muscle injuries (muscle tears and muscle cramps) and hamstring injuries have been analysed. RESULTS: 40.9% of all recorded injuries (n=720) were muscle injuries, with 57.5% of them resulting in time loss. The overall incidence of muscle injuries was higher in male athletes than female athletes (51.9±6.0 vs 30.3±5.0 injuries per 1000 registered athletes, respectively; RR=1.71; 95% CI 1.45 to 2.01). Muscle injuries mainly affected the thigh (52.9%) and lower leg (20.1%), and were mostly caused by overuse with sudden onset (38.2%) and non-contact trauma (24.6%). Muscle injury risk varied according to the event groups. Hamstring injuries represented 17.1% of all injuries, with a higher risk in male compared to female athletes (22.4±3.4 vs 11.5±2.6 injuries per 1000 registered athletes, respectively; RR=1.94; 95% CI 1.42 to 2.66). CONCLUSIONS: During international athletics championships, muscle injury is the principal type of injury, and among those, the hamstring is the most commonly affected, with a two times higher risk in male than female athletes. Athletes in explosive power events, male athletes and older male athletes, in specific were more at risk of muscle injuries and hamstring injuries. Injury prevention strategies should be sex-specific.

Criteria for return to running after anterior cruciate ligament reconstruction: a scoping review
Alexandre Rambaud, Clare L. Ardern, Patricia Thoreux, Jean-Philippe Régnaux +1 more
2018· British Journal of Sports Medicine165doi:10.1136/bjsports-2017-098602

OBJECTIVE: To describe the criteria used to guide clinical decision-making regarding when a patient is ready to return to running (RTR) after ACL reconstruction. DESIGN: Scoping review. DATA SOURCES: The MEDLINE (PubMed), EMBASE, Web of Science, PEDro, SPORTDiscus and Cochrane Library electronic databases. We also screened the reference lists of included studies and conducted forward citation tracking. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Reported at least one criterion for permitting adult patients with primary ACL reconstruction to commence running postoperatively. RESULTS: 201 studies fulfilled the inclusion criteria and reported 205 time-based criteria for RTR. The median time from when RTR was permitted was 12 postoperative weeks (IQR=3.3, range 5-39 weeks). Fewer than one in five studies used additional clinical, strength or performance-based criteria for decision-making regarding RTR. Aside from time, the most frequently reported criteria for RTR were: full knee range of motion or >95% of the non-injured knee plus no pain or pain <2 on visual analogue scale; isometric extensor limb symmetry index (LSI)>70% plus extensor and flexor LSI>70%; and hop test LSI>70%. CONCLUSIONS: Fewer than one in five studies reported clinical, strength or performance-based criteria for RTR even though best evidence recommends performance-based criteria combined with time-based criteria to commence running activities following ACL reconstruction.

The knowns and unknowns of neural adaptations to resistance training
Jakob Škarabot, Callum G. Brownstein, Andrea Casolo, Alessandro Del Vecchio +1 more
2020· European Journal of Applied Physiology164doi:10.1007/s00421-020-04567-3

Abstract The initial increases in force production with resistance training are thought to be primarily underpinned by neural adaptations. This notion is firmly supported by evidence displaying motor unit adaptations following resistance training; however, the precise locus of neural adaptation remains elusive. The purpose of this review is to clarify and critically discuss the literature concerning the site(s) of putative neural adaptations to short-term resistance training. The proliferation of studies employing non-invasive stimulation techniques to investigate evoked responses have yielded variable results, but generally support the notion that resistance training alters intracortical inhibition. Nevertheless, methodological inconsistencies and the limitations of techniques, e.g. limited relation to behavioural outcomes and the inability to measure volitional muscle activity, preclude firm conclusions. Much of the literature has focused on the corticospinal tract; however, preliminary research in non-human primates suggests reticulospinal tract is a potential substrate for neural adaptations to resistance training, though human data is lacking due to methodological constraints. Recent advances in technology have provided substantial evidence of adaptations within a large motor unit population following resistance training. However, their activity represents the transformation of afferent and efferent inputs, making it challenging to establish the source of adaptation. Whilst much has been learned about the nature of neural adaptations to resistance training, the puzzle remains to be solved. Additional analyses of motoneuron firing during different training regimes or coupling with other methodologies (e.g., electroencephalography) may facilitate the estimation of the site(s) of neural adaptations to resistance training in the future.

A Multifactorial, Criteria-based Progressive Algorithm for Hamstring Injury Treatment
Jurdan Mendiguchía, Enrique Martínez-Ruiz, Pascal Édouard, Jean‐Benoît Morin +3 more
2017· Medicine & Science in Sports & Exercise160doi:10.1249/mss.0000000000001241

INTRODUCTION: Given the prevalence of hamstring injuries in football, a rehabilitation program that effectively promotes muscle tissue repair and functional recovery is paramount to minimize reinjury risk and optimize player performance and availability. PURPOSE: This study aimed to assess the concurrent effectiveness of administering an individualized and multifactorial criteria-based algorithm (rehabilitation algorithm [RA]) on hamstring injury rehabilitation in comparison with using a general rehabilitation protocol (RP). METHODS: Implementing a double-blind randomized controlled trial approach, two equal groups of 24 football players (48 total) completed either an RA group or a validated RP group 5 d after an acute hamstring injury. RESULTS: Within 6 months after return to sport, six hamstring reinjuries occurred in RP versus one injury in RA (relative risk = 6, 90% confidence interval = 1-35; clinical inference: very likely beneficial effect). The average duration of return to sport was possibly quicker (effect size = 0.34 ± 0.42) in RP (23.2 ± 11.7 d) compared with RA (25.5 ± 7.8 d) (-13.8%, 90% confidence interval = -34.0% to 3.4%; clinical inference: possibly small effect). At the time to return to sport, RA players showed substantially better 10-m time, maximal sprinting speed, and greater mechanical variables related to speed (i.e., maximum theoretical speed and maximal horizontal power) than the RP. CONCLUSIONS: Although return to sport was slower, male football players who underwent an individualized, multifactorial, criteria-based algorithm with a performance- and primary risk factor-oriented training program from the early stages of the process markedly decreased the risk of reinjury compared with a general protocol where long-length strength training exercises were prioritized.

Olfactory learning modifies the expression of odour‐induced oscillatory responses in the gamma (60–90 Hz) and beta (15–40 Hz) bands in the rat olfactory bulb
Nadine Ravel, Pascal Chabaud, Claire Martin, Valérie Gaveau +4 more
2003· European Journal of Neuroscience156doi:10.1046/j.1460-9568.2003.02445.x

This study addressed the question of the possible functional relevance of two different oscillatory activities, beta and gamma (15-40 and 60-90 Hz, respectively) for perception and memory processes in olfactory areas of mammals. Local field potentials were recorded near relay olfactory bulb neurons while rats performed an olfactory discrimination task. Signals reflected the mass activity from this region and characteristics of oscillatory activities were used as an index of local synchrony. Beta and gamma oscillatory activities were quantified by time-frequency methods before during and after odour sampling. In rats early in their training, olfactory sampling was associated with a significant decrease in power in the gamma band in parallel with a weak but significant increase in the beta band (centred on 27 Hz). Several days later, in well-trained rats, the gamma oscillatory depression was significantly enhanced both in duration and amplitude. It appeared within the 500 ms time period preceding odour onset and was further reduced during the odour period. Concurrently the beta oscillatory response (now centred on 24 Hz) during odour sampling was amplified by a twofold factor. The beta band response was modulated according to the chemical nature of the stimuli and rat's behavioural response. This study showed for the first time that odour sampling in behaving animals is associated with a clear shift in the olfactory bulb neuronal activity from a gamma to a beta oscillatory regime. Moreover, the data stress the importance of studying the odour-induced beta activity and its relation to perception and memory.

Polyphenols in Metabolic Diseases
Amin Gasmi, Pavan Kumar Mujawdiya, Sàdaf Noor, Roman Lysiuk +4 more
2022· Molecules151doi:10.3390/molecules27196280

Polyphenols (PPs) are a large group of phytochemicals containing phenolic rings with two or more hydroxyl groups. They possess powerful antioxidant properties, multiple therapeutic effects, and possible health benefits in vivo and in vitro, as well as reported clinical studies. Considering their free-radical scavenging and anti-inflammatory properties, these substances can be used to treat different kinds of conditions associated with metabolic disorders. Many symptoms of metabolic syndrome (MtS), including obesity, dyslipidemia, atherosclerosis, elevated blood sugar, accelerating aging, liver intoxication, hypertension, as well as cancer and neurodegenerative disorders, are substantially relieved by dietary PPs. The present study explores the bioprotective properties and associated underlying mechanisms of PPs. A detailed understanding of these natural compounds will open up new opportunities for producing unique natural PP-rich dietary and medicinal plans, ultimately affirming their health benefits.

Exercise and colorectal cancer: a systematic review and meta-analysis of exercise safety, feasibility and effectiveness
Ben Singh, Sandra C. Hayes, Rosalind R. Spence, Megan L. Steele +2 more
2020· International Journal of Behavioral Nutrition and Physical Activity148doi:10.1186/s12966-020-01021-7

BACKGROUND: This meta-analysis evaluated the safety, feasibility and effect of exercise among individuals with colorectal cancer. METHODS: A database search (CINAHL, Ebscohost, MEDLINE, Pubmed, ProQuest Health and Medical Complete, ProQuest Nursing, Science Direct) for randomised, controlled, exercise trials involving individuals with colorectal cancer, published before January 1, 2020 was undertaken. Safety (adverse events), feasibility (withdrawal and adherence rates) and effect data (health outcomes including quality of life, QoL) were abstracted. Risk difference (RD) and standardised mean differences (SMD) were calculated to compare safety and effects between exercise and usual care (UC). Subgroup analyses were conducted to assess whether outcomes differed by exercise mode, duration, supervision and treatment. Risk of bias was assessed using the Physiotherapy Evidence Database tool. RESULTS: For the 19 trials included, there was no difference in adverse event risk between exercise and UC (RD = 0.00; 95% CI:-0.01, 0.01, p = 0.92). Median withdrawal rate was 12% (0-22%) and adherence was 86% (42-91%). Significant effects of exercise compared to UC were observed for QoL, fatigue, aerobic fitness, upper-body strength, depression, sleep and reduced body fat (SMD = 0.21-0.66, p < 0.05). Subgroup analyses suggested larger benefits (p < 0.05) for QoL and fatigue for supervised interventions; for QoL, aerobic fitness and reduced body fat for ≥12-week interventions; and for aerobic fitness when interventions were during chemotherapy. CONCLUSION: Although reporting of safety and compliance data was lacking in most trials, findings support that exercise is safe and feasible in colorectal cancer. Further, participation in mixed-mode exercise, including unsupervised exercise, leads to improvements in various health-related outcomes.