Relationship of Testosterone, LH, Estradiol, IGF-1, and SHBG with Physical Performance of Master Athletes.

Purpose: The aim of this study was to investigate and compare the levels of luteinizing hormone (LH), testosterone (T), estradiol (ES), sex hormone-binding globulin (SHBG), and insulin-like growth factor 1 (IGF-1) in master sprint (MS) and master endurance (ME) athletes. Additionally, the possible associations between these hormones, body composition, and lipid profile with athletic performance (% of performance in relation to the current world record) were analyzed. Materials and Methods: The participants were all men: (i) 34 MS (51.0 ± 6.8 years); and (ii) 32 ME (51.7 ± 9.4 years). Student's t-tests for independent samples were performed to compare all variables between groups. Results: MS had a significantly higher (p = .008) average IGF-1 (154.78 ± 29.85 ng/mL) when compared to ME (129.92 ± 25.48 ng/mL). Performance was significantly correlated with IGF-1 (r = 0.424). The MS group had a moderately lower body fat than ME athletes (MS 12.54 ± 4.07 vs. ME 14.60 ± 4.12; p = .078; d = 0.503). Conclusions: Thus, strength/power training exercise/sport seems to be more beneficial for obtaining a higher IGF-1 compared to aerobic/distance exercise/sport. In addition, LH, T, ES, and SHBG were similar between the two groups of athletes and were comparable to the reference values of younger adults.

Morphological and phylogenetic investigations shed light on evolutionary relationships of the enigmatic genus Copemetopus (Ciliophora, Alveolata), with the proposal of Copemetopus verae sp. nov.

Copemetopus Villeneuve-Brachon, 1940 is a rare, poorly known sapropelic ciliate genus composed of only two valid nominal species. Over time, Copemetopus was taxonomically assigned to Heterotrichea and Armophorea classes, but its phylogenetic affinities remained unknown. Until the present study, there were no molecular data available for Copemetopus representatives. Here, we present the 18S and 28S-rDNA sequences and the phylogenetic position of Copemetopus verae sp. nov., as well as its detailed morphological description based on live observations, protargol impregnation, and scanning electron microscopy. Transmission electron micrographs of the type species C. subsalsus Villeneuve-Brachon, 1940 reveal new morphological traits and a unique somatic ciliature pattern of Copemetopus, composed by short segments of dikinetids with one or two supplementary kinetosomes. The phylogenetic trees recovered Copemetopus as the sister group of the genus Protocruzia, both constituting early-divergent lineages that split first from a common ancestor of Intramacronucleta. Morphological and molecular evidence suggest that Copemetopus is neither a heterotrichean nor an armophorean ciliate, but a distinct clade related to Protocruzia.

Prevalence of Temporomandibular Joint Disorders in Patients with Ankylosing Spondylitis: A Cross-Sectional Study.

BACKGROUND: This study sought to investigate which temporomandibular disorders (TMD) can be expected in patients with ankylosing spondylitis (AS) and to determine the combined impact of these conditions on the psychological status, chronic pain, and functional disability. MATERIAL AND METHODS: A cross-sectional study composed of 30 patients between 18 and 65 years with ankylosing spondylitis was performed. The research protocol considered the evaluation of outcomes related to the ankylosing spondylitis (HLA-B27 antigen, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Health Assessment Questionnaire - Spondylitis (HAQ-S)) and temporomandibular disorders (axis I and II of the Research Diagnostic Criteria for Temporomandibular Disorders - RDC/TMD). Descriptive analyses were applied to express the results. RESULTS: The sample presented both AS and TMD, most of them (24) were diagnosed with conventional AS (HLA-B27 positive). The BASDAI was scored as 7.70 (2.30) (high activity of AS disease). Functional disability represented by high scores of BASFI [7.00 (2.63)] and HAQ-S [1.79 (0.62)] demonstrates the severe impact of the disease on the daily routine and quality of life. According to RDC/TMD diagnostic criteria, 17 (57%) share the three groups of TMD, and 9 (30%) share two groups of TMD (Group I and III). Over 73% of the volunteers scored high levels of chronic pain (Grade III and IV) associated with a high depression scale score. The sample scored the somatization scale (with and without pain) as severe. CONCLUSION: Patients with ankylosing spondylitis presented a high prevalence of temporomandibular disorder, most of them having the degenerative forms of TMJ disease. AS and TMD cause moderate to severe chronic pain and a negative impact on psychological status and functional capacities.

Influência de diferentes materiais obturadores endodônticos em imagens de TCFC: uma avaliação in vitro / Influence of different root canal obturation materials in CBCT imaging: an in vitro evaluation

Objetivo: O presente estudo avaliou a influência de materiais obturadores endodônticos na produção de artefato de imagens de tomografia computadorizada de feixe cônico (TCFC), por meio da análise de densidade de imagem em incisivos centrais e dentes pré-molares unirradiculares. Métodos: Os dentes foram submetidos a instrumentação endodôntica e divididos em cinco grupos: um grupo controle (sem preenchimento endodôntico) e quatro grupos teste, cada um preenchido por um material obturador endodôntico diferente (PulpCanal Sealer, AHPlus, Sealer26 e BCSealer). Após a aquisição da TCFC, as imagens foram avaliadas para determinar variações de tons de cinza nos três terços da raiz (análise objetiva). A segunda análise (subjetiva) comparou o grupo controle com dois dos grupos teste, em um processo randomizado. Resultados: Na análise objetiva, o Sealer26 e o BCSealer mostraram diferença estatística para valores mínimos, em comparação com outros materiais obturadores endodônticos, para dentes anteriores e posteriores. Para valores máximos, apenas o grupo controle diferiu estatisticamente dos grupos teste. Ao comparar os valores dos pré-molares e dos incisivos centrais em tons cinza pelo teste de Kruskal-Wallis, foi encontrada diferença estatisticamente significativa para os valores mínimos. Na análise subjetiva, para dentes anteriores e posteriores, o PulpCanal Sealer foi o material mais frequentemente apontado pelos observadores como aquele que produziu mais interferência de artefato. Conclusões: Os materiais obturadores endodônticos nos dentes posteriores apresentaram comportamento semelhante; somente o PulpCanal Sealer no terço apical apresentou diferenças estatísticas em relação aos demais grupos. Para os dentes anteriores, o BCSealer apresentou valores mínimos maiores em relação aos outros materiais obturadores endodônticos, o que poderia representar maior interferência do artefato (AU).

Objective: This study evaluated the influence of canal obturation materials in the production of cone beam computed tomography (CBCT) images artifact, by means of image density analysis and comparison between four materials in central incisors and monoradicular premolar teeth. Materials and Methods: The teeth were submitted to endodontic instrumentation and divided into 5 groups: one control group (no endodontic filling) and four test groups each one filled by a different endodontic sealer (PulpCanal Sealer, AHPlus, Sealer26 and BCSealer). After CBCT scanning, the images were assessed to determine grayscale variations in three root thirds (objective analysis). The second (subjective) analysis compared the control group with two of the test groups in a randomized process. Results: In the objective analysis, Sealer26 and BCSealer showed statistical difference for minimum values, in comparison with another sealers, for both anterior and posterior teeth. For maximum values, only control group differed statistically from test groups. When comparing premolars and central incisors grayscale values by ANOVA analysis, a statistically significant difference was found mainly for minimum values. At the subjective analysis, for both anterior and posterior teeth, PulpCanal Sealer was the filling most frequently appointed by the observers as the one that produced more artifact interference. Conclusion: Endodontic fillings at posterior teeth performed similar behavior. Only PulpCanal Sealer on apical third presented higher maximum values in relation to others groups, which could represent more white brands. For anterior teeth, BC Sealer performed higher minimum values in relation to other endodontic fillings, which could represent more dark bands (AU).

Is there an association between rheumatoid arthritis and bone changes in the temporomandibular joint diagnosed by cone-beam computed tomography? A systematic review and meta-analysis.

OBJECTIVES: Evaluate the relation of rheumatoid arthritis (RA) and bone changes in the temporomandibular joint diagnosed by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This systematic review and meta-analysis were recorded in the PROSPERO database, using the CRD42020153246 protocol. The electronic searches were performed in the following databases: Pubmed, Scopus, Web of Science, Lilacs, Cochrane, and Open Grey. Cross-sectional studies that evaluated patients with RA with bone changes in the temporomandibular joint diagnosed by CBCT, without language restriction or publication date, were included. Meta-analysis was performed in Stata Software (StataCorp, TX, USA, version 12.0), using the metan, and a random effects model, and the risk of different bone alterations occurring in adults with and without arthritis was estimated using odds ratios (ORs) as a pooled measure of effect. Forest plots were used to present the isolated and the pooled effects (ORs and 95% CI). RESULTS: Six studies were used for qualitative synthesis and 2 studies for quantitative synthesis. All studies diagnosed higher prevalence changes in the bone structures of the TMJ of RA patients, described as erosion, flattening, sclerosis, and osteophytes. Meta-analysis showed that the chance of bone changes occurring in components of the TMJ is greater in individuals who have RA. CONCLUSION: There is an association between RA and bone changes in TMJ structures diagnosed through CBCT, as RA patients were more likely to have osteoarthritic changes in this joint. CLINICAL RELEVANCE: Understanding the existence of an association between bone alterations in TMJ and RA can assist in the management of patients.

Association between dynapenic abdominal obesity and inflammatory profile in diabetic older community-dwelling patients with end-stage renal disease.

BACKGROUND: Obesity and poor strength impose higher risk factor for end-stage renal disease (ESRD) patients. It is expected that the combination of both conditions might be critically associated with the inflammatory profile in this population, especially in community-dwelling elderly. So, diagnosis of dynapenic obesity and inflammation is an important tool in the management of chronic kidney disease patients at imminent risk of hospitalization. PURPOSE: To investigate the association between dynapenic abdominal obesity and inflammatory markers in community-swelling elderly with ESRD. METHODS: Two hundred and forty-seven community-dwelling older patients (66.74 ± 3.20 years; n = 150, 60.73%, males) undergoing maintenance phase hemodialysis volunteered for this study. The study sample was categorized into four groups according to handgrip strength and waist circumference as follows: control, dynapenia (low strength alone), abdominal obesity (high waist circumference alone), and dynapenic obesity (D/AO) (the combination of low strength and high waist circumference). Blood samples were collected for tumor necrosis factor alpha (TNF-α), interleukin (IL)- 6 and IL- 10. Results were considered significant at P < 0.05. RESULTS: Proportions for control, abdominal obesity, dynapenic, and D/AO were 38.5%, 15.8%, 25.9%, and 19.8%, respectively. Higher concentrations of TNF-α were found in the D/AO group (P < 0.0001). This group also displayed lower levels of IL-10 (P < 0.0001). Further, the D/AO traits were strongly associated with TNF-α and IL-10 (P < 0.0001). CONCLUSION: The closely relation between D/AO and inflammatory profile provides evidence that the pooled information of low muscle strength and abdominal obesity may be clinically relevant for the management of ESRD patients.

Cut-Off Values in the Prediction of Success in Olympic Distance Triathlon.

Cut-off points and performance-related tools are needed for the development of the Olympic distance triathlon. The purposes of the present study were (i) to determine cut-off values to reach the top three positions in an Olympic distance triathlon; (ii) to identify which discipline present the highest influence on overall race performance and if it has changed over the decades. Data from 1989 to 2019 (n = 52,027) from all who have competed in an official Olympic distance triathlon events (World Triathlon Series and Olympics) were included. The cut-off value to achieve a top three position was calculated. Linear regressions were applied for performance trends overall and for the top three positions of each race. Men had cut-off values of: swimming = 19.5 min; cycling = 60.7 min; running = 34.1 min. Women's cut-off values were: swimming = 20.7 min; cycling = 71.6 min; running = 38.1 min. The running split seemed to be the most influential in overall race time regardless of rank position or sex. In conclusion, cut-offs were established, which can increase the chances of achieving a successful rank position in an Olympic triathlon. Cycling is the discipline with the least influence on overall performance for both men and women in the Olympic distance triathlon. This influence pattern has not changed in the last three decades.

Breaking the athletics world record in the 100 and 400 meters: an alternative method for assessment.

BACKGROUND: The top 10 athletes in the International Association of Athletic Federations in 100-m and 400-m ranking for each sex were assessed for their history of race times before achieving their personal record (PR). The main goal of this study was to create a new method for optimal performance improvement rate assessment for coaches and athletes aiming the World Record. METHODS: The difference between PR ('current' season) and the best race time in the last season was defined as the first season improvement rate (1-SIR), whereas the average improvement rate in the last and preceding seasons was the multi-season improvement rate (M-SIR). 1-SIR and M-SIR were calculated for each athlete. RESULTS: The sex comparison for the 100 m event showed a significant difference in the M-SIR in favor of women. No statistical differences were identified for the 400 m event, with a trivial effect in both 1-SIR and M-SIR. CONCLUSIONS: As a practical applicability, graph plots were designed to help verifying the improvement rate of athletes and to evaluate whether a long-term training strategy induced an acceptable performance improvement or whether some adjustments needed and check within the plots if the improvement rate is within the average of the top-10 athletes of their event.

Oxidative stress, inflammatory cytokines and body composition of master athletes: The interplay.

Unhealthy aging is associated with increased adiposity, inflammation and oxidative stress (OS), but the interactions between them have been poorly investigated in people growing old under vigorous lifelong exercise regimens. Therefore, we compared and analyzed the relationships between markers of inflammation, OS and adiposity in master athletes (MA), young (YC) and middle-aged controls (MC). Fifty-nine participants (MA, n = 30, 51.56 ± 8.61 yrs, minimum of 20 yrs of training; YC, n = 17, 22.70 ± 3.92 yrs; MC, n = 12, 45.54 ± 9.86 yrs) underwent body composition measurements, blood sampling for inflammation and OS measurements, and provided information regarding general health and training status. The MA and YC demonstrated higher catalase (CAT) and superoxide dismutase (SOD) activity, and higher CAT/TBARS (TBARS: thiobarbituric acid reactive substances) and SOD/TBARS ratios. The cytokines TNF-α and IL-6, and their soluble receptors sTNF-RI and sIL-6R were lower in YC compared to MC and MA (p < 0.05). Moreover, MA showed lower levels of sTNF-RI, IL-6 and sIL-6R and higher IL-10 and IL-10/IL-6 ratio compared to MC (p < 0.05). The body fat was negatively associated with antioxidant enzymes (CAT: r = -0.448 and SOD: r = -0.413) and IL-10 (r = -0.585) and positively correlated with pro-inflammatory cytokines (TNF-α: r = 0.278; sTNF-RI: r = 0.709; IL-6: r = 0.720: sIL-6R: r = 0.430) (p < 0.05). Further, CAT and SOD activities were inversely associated with inflammatory parameters (sTNF-RI, IL-6 and sIL-6R; p < 0.05). In conclusion, markers of OS and inflammation did not differ between MA and YC and were associated with adiposity. Moreover, MA were leaner than MC, similarly to YC. Thus, lifelong training clearly attenuates inflammation, OS, and adiposity, supporting an attenuated and healthy aging.

Celebrating 40 Years of Ironman: How the Champions Perform.

We aimed to determine which discipline had the greater performance improvements in the history of Ironman triathlon in Hawaii and also which discipline had the greater influence in overall race time. Data from 1983 to 2018 of the top three women and men of each year who competed in the Ironman World Championship were included. In addition to exploratory data analyses, linear regressions between split times and years of achievement were performed. Further, a stepwise multiple linear regression was applied using total race time as the dependent variable and split times as the independent variables. Both women and men significantly improved their performances from 1983 to 2018 in the Ironman World Championship. Swimming had the largest difference in improvements between men and women (3.0% versus 12.1%, respectively). A negative and significant decrease in each discipline was identified for both women and men, with cycling being the discipline with the greatest reduction. The results from the stepwise multiple regression indicated that cycling was the discipline with the highest influence on overall race time for both sexes. Based on the findings of this study, cycling seems to be the Ironman triathlon discipline that most improved overall race times and is also the discipline with the greatest influence on the overall race time of elite men and women in the Ironman World Championship.

Heart rate cost of running in track estimates velocity associated with maximal oxygen uptake.

BACKGROUND: Running velocity associated with VO2max (vVO2max) is a parameter widely used for exercise prescription and is related to endurance performance. However, the vVO2max determination usually requires a maximal effort test and equipped laboratory for expired gas analysis, what make difficulty its assessment. OBJECTIVE: We aimed to test the validity of a simple method of vVO2max prediction through the heart rate cost of running (HRC) in a submaximal 6-min running test, both in treadmill and in a 400-meter track. METHODS: Male recreational runners (n = 16; 30.3 ±â€¯8.0 years; VO2max of 46.2 ±â€¯3.2 ml·kg-1·min-1) randomly underwent an incremental test in treadmill with gas analysis, and a 3000-m time trial in a track, to determine vVO2max. Before every maximal test, participants also performed a submaximal 6-min running (~85% HRmax), both in the treadmill and in a track, to assess HRC (bpm-1m·min-1) by dividing the submaximal running velocity by its respective HR. The vVO2max (km·h-1) was predicted by dividing the HRmax (bpm)/HRC (bpm-1m·min-1). RESULTS: No differences were verified (p > .05) among vVO2max determined both in the treadmill (13.8 ±â€¯0.9 km·h-1) and track (13.6 ±â€¯0.9 km·h-1) to those predicted by the HRC method both in treadmill (13.5 ±â€¯0.8 km·h-1) and track (13.6 ±â€¯1.0 km·h-1). The vVO2max measured directly with expired gas analysis was highly correlated with vVO2max estimated through HRC in treadmill and track (p < .05). Additionally, the intraclass correlation coefficient (ICC) and Bland-Altman technique revealed good agreement and reliability classified with substantial agreement [ICC = 0.673 (95% CI 0.064-0.886; p = .019)] and almost perfect agreement [ICC = 0.870 (95% CI 0.628-0.955 p = .0001)] between methods to identify vVO2max, respectively. CONCLUSION: A submaximal 6-min exercise test protocol to assess HRC of running was considered valid to estimate vVO2max of recreational runners both in treadmill and outdoor track.

Cycling as the Best Sub-8-Hour Performance Predictor in Full Distance Triathlon.

For any triathlon distance (short, Olympic, half-distance and full-distance), competitors spend more time cycling than swimming or running, but running has emerged as the discipline with the greatest influence on overall performance at the Olympic distance. However, there is a lack of evidence on which discipline has the greatest influence on performance in the overall full-distance triathlon (3.8 km swimming/180 km cycling/42.195 km running), especially for the fastest performing athletes of all time. The total race times of 51 fastest triathletes (sub-8-hour) were studied, while for the split times, a sample of 44 participants was considered. The discipline that seemed to better predict total race time was cycling (coefficient = 0.828; p < 0.001), followed by running (coefficient = 0.726; p < 0.001) and swimming (coefficient = 0.476; p < 0.001). Furthermore, cycling was the discipline with the highest performance improvement over the years, whereas running had a slightly decrease. In conclusion, cycling seems to be the discipline with greater influence in final result for the full-distance triathlon.

An integrative perspective of the anaerobic threshold.

The concept of anaerobic threshold (AT) was introduced during the nineteen sixties. Since then, several methods to identify the anaerobic threshold (AT) have been studied and suggested as novel 'thresholds' based upon the variable used for its detection (i.e. lactate threshold, ventilatory threshold, glucose threshold). These different techniques have brought some confusion about how we should name this parameter, for instance, anaerobic threshold or the physiological measure used (i.e. lactate, ventilation). On the other hand, the modernization of scientific methods and apparatus to detect AT, as well as the body of literature formed in the past decades, could provide a more cohesive understanding over the AT and the multiple physiological systems involved. Thus, the purpose of this review was to provide an integrative perspective of the methods to determine AT.

Hydration Status After an Ironman Triathlon: A Meta-Analysis.

The Ironman is one of the most popular triathlon events in the world. Such a race involves a great number of tactical decisions for a healthy finish and best performance. Dehydration is widely postulated to decrease performance and is known as a cause of dropouts in Ironman. Despite the importance of hydration status after an Ironman triathlon, there is a clear lack of review and especially meta-analysis studies on this topic. Therefore, the objective was to systematically review the literature and carry out a meta-analysis investigating the hydration status after an Ironman triathlon. We conducted a systematic review of the literature up to June 2016 that included the following databases: PubMed, SCOPUS, Science Direct and Web of Science. From the initial 995 references, we included 6 studies in the qualitative analysis and in the meta-analysis. All trials had two measures of hydration status after a full Ironman race. Total body water, blood and urine osmolality, urine specific gravity and sodium plasma concentration were considered as hydration markers. Three investigators independently abstracted data on the study design, sample size, participants' and race characteristics, outcomes, and quantitative data for the meta-analysis. In the pooled analysis, it seems that the Ironman event led to a moderate state of dehydration in comparison to baseline values (SMD 0.494; 95% CI 0.220 to 0.767; p = 0.001). Some evidence of heterogeneity and consistency was also observed: Q = 19.6; I2 = 28.5%; τ2 = 2.39. The results suggest that after the race athletes seem to be hypo-hydrated in comparison to baseline values.

Telomere length and redox balance in master endurance runners: The role of nitric oxide.

Leukocyte telomere length (LTL), a biological marker of aging that is associated with age-related diseases, is longer in master endurance runners (ER) than age-matched controls, but the underlying mechanisms are poorly investigated. The LTL, nitric oxide (NO), and redox balance of ER master runners were analyzed and compared to untrained middle-aged and young adults. We hypothesized that NO and redox balance at baseline would be related to longer LTL in ER athletes. Participants (n = 38) were long-term ER runners (n = 10; 51.6 ±â€¯5.2 yrs.; 28.4 ±â€¯9.4 yrs. of experience) and untrained age-matched (n = 17; 46.6 ±â€¯7.1 yrs) and young controls (n = 11; 21.8 ±â€¯4.0 yrs). Volunteers were assessed for anamnesis, anthropometrics, and blood sampling. Measurements of pro-and anti-oxidant status and DNA extraction were performed using commercial kits. Relative LTL was determined with qPCR analyses (T/S). While the middle-aged controls had shorter LTL than the young group, no difference was observed between ER athletes and young participants. A large effect size between the LTL of ER athletes and middle-aged controls (d = 0.85) was also observed. The ER athletes and untrained young group had better redox balance according to antioxidant/pro-oxidant ratios compared to middle-aged untrained participants, which also had lower values for redox parameters (TEAC/TBARS, SOD/TBARS, and CAT/TBARS; all p < 0.05). Furthermore, the NO level of ER athletes (175.2 ±â€¯31.9 µM) was higher (p < 0.05) than middle-aged controls (67.2 ±â€¯23.3 µM) and young participants (129.2 ±â€¯17.3 µM), with a significant correlation with LTL (r = 0.766; p = 0.02). In conclusion, ER runners have longer LTL than age-matched controls, which in turn may be related to better NO bioavailability and redox balance status.

Vertical Jump Is Strongly Associated to Running-Based Anaerobic Sprint Test in Teenage Futsal Male Athletes.

As one of the most popular sport modalities in Brazil, and with an exponential growth in Europe, futsal is characterized by intermittent stimulus of anaerobic high intensity sprints. The running-based anaerobic sprint test (RAST) is one of the most common tests to assess anaerobic power in futsal athletes, however, it presents both time and physical challenges. Therefore, we aimed to correlate RAST with a simpler test, the vertical jump (VJ), in teenage male futsal athletes; Methods: Thirteen volunteers were enrolled and underwent two visits to the laboratory, one for the VJ and the other for the RAST in a randomized order; Results: The association test indicates a strong and significant correlation between VJ and RAST. We conclude that VJ can be used as an alternative to RAST in teenage male futsal athletes.

How much further for the sub-2-hour marathon?

The sub-2-hour marathon is a new barrier in endurance running performance, and it has been widely debated in the scientific community. In this review we present a mathematical model to estimate the possible year when a male could break through the sub-2-hour barrier, and also an estimation of when a female could break Paula Radcliffe's marathon running record. Further, we present several aspects (ie, physiology, nationality, age, biomechanics, pacing, and drafting) that are associated with marathon running performance in elite runners and, finally, the possible characteristics of the male to break the sub-2-hour barrier. In summary, with the results of the developed equations, it is possible that a male athlete can break through the sub-2-hour barrier in the next decade (with Nike® Breaking2 performance 1920-2018 [NBP]: y =0.0417x2-14.18x +3,128; year of 2026; without NBP 1920-2018: y =0.045x2-15.12x +3,194; year of 2027). This marathoner will possibly have a maximal oxygen uptake >85 mL∙kg-1∙min-1 and should perform the race at a pacing higher than 85% of maximal oxygen uptake. In addition, this runner should pay more attention to strength training, endurance strength, speed training, and focus on running training at an intensity above the anaerobic threshold. Most likely, this runner originates from East Africa (especially from Ethiopia) and will have an age of ~27 years. For the females, there is poor evidence regarding the physiological profile of the female marathoner who will break Radcliffe's record, but the available literature suggests that it will not happen any time soon.

Training Performed Above Lactate Threshold Decreases p53 and Shelterin Expression in Mice.

Telomere shortening is associated to sarcopenia leading to functional impairment during aging. There are mechanisms associated with telomere attrition, as well to its protection and repair. Physical training is a factor that attenuates telomere shortening, but little is known about the effects of different exercise intensities on telomere biology. Thus, we evaluated the effects of exercise intensity (moderate vs. high-intensity domain) on gene expression of senescence markers Checkpoint kinase 2 and tumor suppressor (Chk2 and p53, respectively), shelterin telomere repeat binding 1 and 2 (Trf1/Trf2), DNA repair (Xrcc5), telomerase reverse transcriptase (mTERT) and telomere length in middle aged mice. Three groups were studied: a control group (CTL) and two groups submitted to swimming at intensities below the lactate threshold (LI group) and above the lactate threshold (HI group) for 40 and 20 min respectively, for 12 weeks. After training, the HI group showed reduction in p53 expression in the muscle, and decreased shelterin complex expression when compared to LI group. No differences were observed between groups for mTERT expression and telomere length. Thus, exercise training in high-intensity domain was more effective on reducing markers of senescence and apoptosis. The higher intensity exercise training also diminished shelterin expression, with no differences in telomere length and mTERT expression. Such results possibly indicate a more effective DNA protection for the higher-intensity exercise training.

Acute metabolic responses following different resistance exercise protocols.

Resistance exercise (RE) can be an excellent modality for glycemic control. Studies have demonstrated that a single RE session can reduce glycemia in subjects with or without diabetes. Little is known about the dose-response effect of RE on glycemic control. This study aimed to investigate the acute metabolic responses after different RE protocols. Eighty-nine males were separated into six groups that completed RE protocols: 2 sets of 18 repetitions (2 × 18 at 50% of 1-repetition maximum (1RM); n = 19); 3 sets of 12 repetitions (3 × 12 at 70% of 1RM; n = 14); 4 sets of 9 repetitions (4 × 9 at 80% of 1RM; n = 13); 6 sets of 6 repetitions (6 × 6 at 90% of 1RM; n = 19); circuit (2 × 18 at 50% of 1RM; n = 12); and a control session (n = 12). The exercise sequence consisted of 8 exercises. An oral glucose tolerance test was conducted with metabolic measurements immediately after each RE protocol and every 15 min until 120 min of recovery. All groups exhibited significantly lower values (p < 0.05) in the glucose area under the curve (AUC) when compared with control over a 120 min monitoring period. The 6 × 6 group showed a significantly lower glucose AUC versus the 3 × 12 and 4 × 9 groups (p = 0.004; p = 0.001, respectively). As for blood lactate, the control and 6 × 6 groups exhibited lower AUC values versus all other groups (p < 0.05), and AUC for glucose and lactate concentration showed a negative and significant correlation (r = -0.46; p < 0.0001). It appears that a combination of 9-12 repetitions per set and 3-4 sets per muscle group might be optimal for acute postprandial glucose control.