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Background The aim of this study was to review, systematically, evidence concerning the link between the ACTN3 R577X polymorphism and the rates and severity of non-contact injuries and exercise-induced muscle damage in athletes and individuals enrolled in exercise training programs. Methods A computerized literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus, from inception until November 2020. All included studies compared the epidemiological characteristics of non-contact injury between the different genotypes of the ACTN3 R577X polymorphism. Results Our search identified 492 records. After the screening of titles, abstracts, and full texts, 13 studies examining the association between the ACTN3 genotypes and the rate and severity of non-contact injury were included in the analysis. These studies were performed in 6 different countries (Spain, Japan, Brazil, China, Republic of Korea, and Italy) and involved a total participant pool of 1093 participants. Of the studies, 2 studies involved only women, 5 studies involved only men, and 6 studies involved both men and women. All the studies included were classified as high-quality studies (≥6 points in the Physiotherapy Evidence Database (PEDro) scale score). Overall, evidence suggests there is an association between the ACTN3 R577X genotype and non-contact injury in 12 investigations. Six studies observed a significant association between ACTN3 R577X polymorphism and exercise induced muscle damage: two with non-contact ankle injury, three with non-contact muscle injury, and one with overall non-contact injury. Conclusion The present findings support the premise that possessing the ACTN3 XX genotype may predispose athletes to a higher probability of some non-contact injuries, such as muscle injury, ankle sprains, and higher levels of exercise-induced muscle damage.

Purpose: During Ramadan month, Muslims often continue training to maintain their muscle performance. However, trainers should stress the importance of the time of day chosen for practicing resistance training (RT) during Ramadan fasting to avoid health and performance alteration. Thus, this study aimed to investigate the effects of the timing of RT during Ramadan intermittent fasting (RIF) on muscle strength and hypertrophy in healthy male adults. Methods: Forty men were randomly allocated to 2 matched groups: 20 practicing whole-body RT in the late afternoon in a fasted state and 20 training in the late evening in a fed state (FED). Both groups performed 4 days per week of whole-body RT (∼75%–85% 1-repetition maximum, 12 repetitions/3–4 sets) during RIF. Anthropometric measurements and 1-repetition-maximum test for the squats, deadlift, and bench press were measured. A cross-sectional area of the quadriceps and biceps brachii was examined using ultrasound scans. All measurements were taken at 4 time points: 24 hours before the start of Ramadan, on the 15th day of Ramadan, on the 29th day of Ramadan, and 21 days after Ramadan. Results: Post hoc tests indicated significant preimprovement to postimprovement in FED at the 29th day of Ramadan for the 1-repetition-maximum test for the squats (P = .02; effect size = 0.21) and deadlift (P = .03; effect size = 0.24) when compared to 24 hours before the start of Ramadan. No significant changes were observed in the fasted-state group or for cross-sectional area for both groups. Conclusions: Practicing RT during RIF appears not to have adverse effects on muscle hypertrophy and strength no matter whether it is practiced in FED or fasted state. However, RT had greater effects on muscle strength when applied in FED. Our findings suggest that training sessions should be scheduled after breaking the fast during Ramadan.

The authors present opinions based on their applied experiences of working with female athletes in combination with the existing evidence-based literature. Most of the existing menstrual cycle research focuses on a few steady-state time points within the pre-defined menstrual cycle phases, yet this disregards the day-to-day hormonal changes that women have to accommodate to perform optimally and consistently. The traditional research models are inadequate for studying symptoms and symptom management, and ultimately for supporting athletes to perform well throughout the entirety of their cycle. As such, the monitoring of the day-to-day variation, particularly during the transitions between menstrual cycle phases appears to be an important “overlooked” consideration. This is particularly pertinent considering the known intra-individual and inter-individual variation in menstrual cycle characteristics. Anecdotal and research evidence supports the idea that athletes can use non-pharmacological solutions to mitigate negative menstrual cycle symptoms and do not need to “grit their teeth and roll with it”. However, further research (including case studies) is needed in this important research area. Such knowledge should be and needs to be widespread amongst practitioners and athletes as they should not have to figure this out alone. As such, researchers and practitioners need to put more work into understanding symptom aetiology, symptom clusters and their relationship with hormonal changes, menstrual cycle phases and transitions, with potential for a profound impact on individual athlete health and well-being. In so doing, those working with female athletes need to continue building on the recent progress made in educating athletes and practitioners; for example, normalising the discussion of and about the menstrual cycle and all of its implications.

Purpose: Most women during their lifetime experience a combination of premenstrual syndrome (PMS) symptoms (eg, menstrual cramps) before and often to the end of menstruation. However, the impact of these symptoms on sport routines (eg, performance, training absence) during phases around menstruation is still unclear. Therefore, we investigated the impact of PMS symptoms on sport routines among nonelite athletes over 3 phases related to menstruation. Methods: An online questionnaire was developed to recruit nonelite female athletes who participate in summer Olympic sports. Participants were allocated into 2 groups: those who experienced mild to moderate PMS symptoms (no-PMS) and those with severe PMS symptoms (p-PMS). Two hundred thirty-four responses from eumenorrheic women (p-PMS = 78%) were considered valid. An unpaired Student t test was conducted to compare demographic characteristics between groups and chi-square test to evaluate the impact of PMS status on sport routines between groups. Results: A significant (P P = .01) and competitive (P P Conclusion: The presence of PMS symptoms reduces training and competitive performance, primarily during and before menstruation, respectively. Severity of PMS symptoms was significantly associated with alterations in training schedule but not with competitive schedule.

The aim of this systematic review was to summarize the evidence on the acute and long-term effects of exercise training on PV, in both trained and untrained individuals and to examine associations between changes in %PVV and change in physical/physiological performance. Despite the status of participants and the exercise duration or intensity, all the acute studies reported a significant decrease of PV (effect size: 0.85

PURPOSE This study examined and compared select Triad-RED-S components/risk factors in high-level Kenyan male and female distance runners to corresponding control groups; focusing on examining energy intake (EI), bone indices, and hormonal markers. METHODS A cross-sectional, observational design was used in which Kenyan male and female (n = 30 and n = 26, respectively) middle- and long-distance runners and corresponding male and female control groups (n = 29 and n = 29, respectively) were examined. The participant's bone mineral density (BMD) at the lumbar spine, right femur, and total body were measured using a dual-energy X-ray absorptiometry analysis. Complete blood counts (CBC) were done on the whole blood specimens and hormonal measurements were performed on plasma specimens. In addition, athletes completed metabolic testing to determine maximal oxygen uptakes and 7-day dietary diaries. RESULTS Overall daily EI across runners and controls within each sex were low, but not significantly different (p > 0.05). Prevalence of low BMD values (Z score 0.05). CBC measures suggested that both runners and controls were healthy. Finally, slight hormonal differences between runners and their respective controls existed (p

International audience; Background Knowledge of the long-term effects of soccer training on hematological, hormonal, inflammatory, and muscle damage markers and physical performance may help to better design strength and conditioning programs for performance development and injury prevention for the individual player and the team. Objectives The aim of this systematic review was to summarize and discuss evidence on the long-term effects of soccer training on selected hematological, hormonal, inflammatory, and muscle damage markers and physical performance in elite and professional soccer players. A second goal was to investigate associations between selected physiological markers and measures of performance. Methods Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic literature search was conducted in four electronic databases (PubMed, ISI Web of Knowledge, Web of Science, and SPORTDiscus) from inception until August 2020 to identify articles related to soccer training effects. To be included in this systematic review, studies had to examine male elite (national level) and/or professional (international level) soccer players aged > 17 years and a soccer training period > 4 weeks, and report outcomes related to hematological, hormonal, inflammatory, muscle damage, and performance markers. Results The search syntax initially identified 2420 records. After screening titles, abstracts, and full texts, 20 eligible studies were included in this systematic review, with training durations lasting between 4 and 18 weeks in 15 studies, around 6 months in four studies, and around 1 year in one study. Effects of long-term soccer training revealed parameter-specific increases or decreases in hematological, hormonal, inflammatory, and muscle damage markers and physical performance. Two studies showed a moderate increase in hematological markers such as hemoglobin (effect size [ES] = 0.67-0.93). Parameter-specific changes were noted for hormonal markers in the form of increases for total testosterone (ES = 0.20-0.67) and free testosterone (FT) (ES = 0.20-0.65) and decreases for cortisol (ES = - 0.28 to - 1.31). Finally, moderate to very large increases were found for muscle damage markers such as creatine kinase (ES = 0.94-6.80) and physical performance such as countermovement jump (CMJ) height (ES = 0.50-1.11) and squat jump (SJ) height (ES = 0.65-1.28). After long-term periods of soccer training, significant positive correlations were found between percentage change (Delta%) in FT and Delta% in CMJ height (r = 0.94; p = 0.04) and between Delta% in total testosterone/cortisol (TT/C) ratio and Delta% in SJ (r = 0.89; p = 0.03). Conclusions Findings suggest that long-term soccer training induces increases/decreases in hematological, hormonal, inflammatory, and muscle damage markers and physical performance in male elite and professional soccer players. These fluctuations can be explained by different contextual factors (e.g., training load, duration of training, psychological factors, mood state). Interestingly, the observed changes in hormonal parameters (FT and TT/C) were related to vertical jump performance changes (e.g., CMJ and SJ). Anabolic hormones and TT/C can possibly be used as a tool to identify physical performance alteration after long-term soccer training.

This study aimed to examine the effects of two high-intensity interval training programs (HIIT) on maximal aerobic velocity (MAV), hematological variations and muscle damage markers in young healthy adults. Twenty-nine male physical education students, aged 20.3 ± 3.3 years, volunteered to participate in this study, and were randomly assigned to a control group (CG, n = 9) or two intervention groups (group 1 or 2). Intervention group 1 (n = 10) exercised at 100% of their MAV (EG100) while group 2 (n = 10) exercised at 110% MAV (EG110). Before and after the eight week training program, blood samples were drawn at rest, before, and after an intermittent exercise. Aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), C reactive protein (CRP), creatine kinase (CK) concentrations and hematological parameters (white blood cells [WBC], monocytes [MO], lymphocytes [LY], neutrophil [NE]) and lactate dehydrogenase (LDH) were measured. Post-hoc tests showed that MAV was significantly higher in EG110 compared to EG100 after HIIT (p p2 = 0.05), whilst ALAT, ASAT, and CPR were significantly lower (p p2 110 compared to EG100. Moreover, post-hoc tests indicated that LY decreased significantly (p p2 = 0.21) only for EG110. Furthermore, there were significant positive correlations for both EG100 and EG110 between MAV and ALAT (r = 0.66, p = 0.044 and r = 0.64, p = 0.041 respectively), CK (r = 0.67, p = 0.031 and r = 0.86, p = 0.030, respectively), LDH (r = 0.74, p = 0.014, and r = 0.071, p = 0.021, respectively). In addition, there was a significant positive correlation for both, EG100 and EG110 between MAV and LY (r = 0.79, p p p 110. Findings from this study revealed that HIIT at 110% MAV was more efficient to improve MAV and reduce muscle damage. In addition, we observed significant associations between performance improvements (MAV) and markers of muscle damage.

Mooses, M, Haile, DW, Ojiambo, R, Sang, M, Mooses, K, Lane, AR, and Hackney, AC. Shorter ground contact time and better running economy: evidence from female Kenyan runners. J Strength Cond Res 35(2): 481-486, 2021-Previously, it has been concluded that the improvement in running economy (RE) might be considered as a key to the continued improvement in performance when no further increase in V̇o2max is observed. To date, RE has been extensively studied among male East African distance runners. By contrast, there is a paucity of data on the RE of female East African runners. A total of 10 female Kenyan runners performed 3 × 1,600-m steady-state run trials on a flat outdoor clay track (400-m lap) at the intensities that corresponded to their everyday training intensities for easy, moderate, and fast running. Running economy together with gait characteristics was determined. Subjects showed moderate to very good RE at the first (202 ± 26 ml·kg-1·km-1) and second (188 ± 12 ml·kg-1·km-1) run trials, respectively. Correlation analysis revealed significant relationship between ground contact time (GCT) and RE at the second run (r = 0.782; p = 0.022), which represented the intensity of anaerobic threshold. This study is the first to report the RE and gait characteristics of East African female athletes measured under everyday training settings. We provided the evidence that GCT is associated with the superior RE of the female Kenyan runners.

Context Field-based, portable motion-capture systems can be used to help identify individuals at greater risk of lower extremity injury. Microsoft Kinect-based markerless motion-capture systems meet these requirements; however, until recently, these systems were generally not automated, required substantial data postprocessing, and were not commercially available. Objective To validate the kinematic measures of a commercially available markerless motion-capture system. Design Descriptive laboratory study. Setting Laboratory. Patients or Other Participants A total of 20 healthy, physically active university students (10 males, 10 females; age = 20.50 ± 2.78 years, height = 170.36 ± 9.82 cm, mass = 68.38 ± 10.07 kg, body mass index = 23.50 ± 2.40 kg/m2). Intervention(s) Participants completed 5 jump-landing trials. Kinematic data were simultaneously recorded using Kinect-based markerless and stereophotogrammetric motion-capture systems. Main Outcome Measure(s) Sagittal- and frontal-plane trunk, hip-joint, and knee-joint angles were identified at initial ground contact of the jump landing (IC), for the maximum joint angle during the landing phase of the initial landing (MAX), and for the joint-angle displacement from IC to MAX (DSP). Outliers were removed, and data were averaged across trials. We used intraclass correlation coefficients (ICCs [2,1]) to assess intersystem reliability and the paired-samples t test to examine mean differences (α ≤ .05). Results Agreement existed between the systems (ICC range = −1.52 to 0.96; ICC average = 0.58), with 75.00% (n = 24/32) of the measures being validated (P ≤ .05). Agreement was better for sagittal- (ICC average = 0.84) than frontal- (ICC average = 0.35) plane measures. Agreement was best for MAX (ICC average = 0.77) compared with IC (ICC average = 0.56) and DSP (ICC average = 0.41) measures. Pairwise comparisons identified differences for 18.75% (6/32) of the measures. Fewer differences were observed for sagittal- (0.00%; 0/15) than for frontal- (35.29%; 6/17) plane measures. Between-systems differences were equivalent for MAX (18.18%; 2/11), DSP (18.18%; 2/11), and IC (20.00%; 2/10) measures. The markerless system underestimated sagittal-plane measures (86.67%; 13/15) and overestimated frontal-plane measures (76.47%; 13/17). No trends were observed for overestimating or underestimating IC, MAX, or DSP measures. Conclusions Moderate agreement existed between markerless and stereophotogrammetric motion-capture systems. Better agreement existed for larger (eg, sagittal-plane, MAX) than for smaller (eg, frontal-plane, IC) joint angles. The DSP angles had the worst agreement. Markerless motion-capture systems may help clinicians identify individuals at greater risk of lower extremity injury.

The purpose of this study was to compare three types of resistance training including traditional, circular and interval in non-athletic men with obesity in comparison to a control group for neuregulin 4, adiponectin and leptin responses.The sample of the study included 44 non-athletic men with obesity, who were randomly divided into the 4 equal groups (10 per each group): traditional, circular, and interval resistance training as well as a control group. Neuregulin 4, leptin and adiponectin were analyzed using ELISA commercial kits.The results of mixed-design ANOVA with repeated measures showed that there was a significant interaction between the type of resistance training used and time on neuregulin 4 (F (3, 40) = 80.22, P= 0.005, ES = 0.85), leptin (F (3, 40) = 27.53, P= 0.005, ES = 0.67) and adiponectin (F (3, 40) = 12.44, P= 0.005, ES = 0.48). Considering the main effect of groups, results indicated that there was a significant difference between types of resistance training and control group in neuregulin 4 (F (1, 40) =41.31, P=0.005, ES = 0.75), adiponectin (F (1, 40) =15.08, P=0.005, ES = 0.53) and leptin (F (1, 40) =32.05, P = 0.005, ES = 0.70).Findings suggest that resistance training, especially interval resistance training can lead to increase the plasma level of neuregulin 4, adiponectin and decrease leptin in non-athletic men with obesity. Interval training showed superior effects on all study outcomes followed by circular and traditional training, respectively.El propósito de este estudio fue comparar tres tipos de entrenamiento de resistencia, incluido el tradicional, el circular y el intervalo en hombres no atléticos con obesidad, en comparación con un grupo de control para las respuestas de neuregulin 4, adiponectin y leptin.La muestra del estudio incluyó a 44 hombres no deportistas con obesidad, que fueron divididos alea-toriamente en 4 grupos iguales (10 por cada grupo): entrenamiento de resistencia tradicional, circular e intervalado, así como un grupo de control. Se analizaron neuregulin 4, leptin y adiponectin utilizando kits comerciales de ELISA.Los resultados del ANOVA de diseño mixto con medidas repetidas mostraron que hubo una interacción significativa entre el tipo de entrenamiento de resistencia utilizado y el tiempo con neuregulin 4 (F (3, 40) = 80,22, p = 0,005, ES = 0,85), leptin (F (3, 40) = 27,53, p = 0,005, ES = 0,67) y adiponectin (F (3, 40) = 12,44, p = 0,005, ES = 0,48). Considerando el efecto principal de los grupos, los resultados indicaron que hubo una diferencia significativa entre los tipos de entrenamiento de resistencia y el grupo de control en neuregulin 4 (F (1, 40) = 41,31, p = 0,005, ES = 0,75), adiponectin (F (1, 40) = 15,08, p = 0,005, ES = 0,53) y leptin (F (1, 40) = 32,05, p = 0,005, ES = 0,70).Los resultados sugieren que el entrenamiento de resistencia, especialmente el entrenamiento de resistencia a intervalos, puede aumentar el nivel plasmático de neuregulin 4, adiponectin y disminuir leptin en hombres obesos no atléticos. El entrenamiento por intervalos mostró efectos superiores en todos los resultados del estudio seguido del entrenamiento circular y tradicional, respectivamente.

Context Gait biomechanics are linked to biochemical changes that contribute to the development of posttraumatic knee osteoarthritis in individuals with anterior cruciate ligament reconstruction (ACLR). It remains unknown if modifying peak loading during gait using real-time biofeedback will result in acute biochemical changes related to cartilage metabolism. Objective To determine if acutely manipulating peak vertical ground reaction force (vGRF) during gait influences acute changes in serum cartilage oligomeric matrix protein concentration (sCOMP) among individuals with ACLR. Design Crossover study. Patients or Other Participants Thirty individuals with unilateral ACLR participated (70% female, age = 20.43 ± 2.91 years old, body mass index = 24.42 ± 4.25, months post-ACLR = 47.83 ± 26.97). Additionally, we identified a subgroup of participants who demonstrated an increase in sCOMP after the control or natural loading condition (sCOMPCHANGE > 0 ng/mL, n = 22, 70% female, age = 20.32 ± 3.00 years old, body mass index = 24.73 ± 4.33, months post-ACLR = 47.27 ± 29.32). Main Outcome Measure(s) Serum was collected both prior to and immediately after each condition to determine sCOMPchange. Intervention(s) All participants attended 4 sessions that involved 20 minutes of walking on a force-measuring treadmill consisting of a control condition (natural loading) followed by random ordering of 3 loading conditions with real-time biofeedback: (1) symmetric vGRF between limbs, (2) a 5% increase in vGRF (high loading) and (3) a 5% decrease in vGRF (low loading). A general linear mixed model was used to determine differences in sCOMPCHANGE between altered loading conditions and the control group in the entire cohort and the subgroup. Results The sCOMPCHANGE was not different across loading conditions for the entire cohort (F3,29 = 1.34, P = .282). Within the subgroup, sCOMPCHANGE was less during high loading (1.95 ± 24.22 ng/mL, t21 = −3.53, P = .005) and symmetric loading (9.93 ± 21.45 ng/mL, t21 = −2.86, P = .025) compared with the control condition (25.79 ± 21.40 ng/mL). Conclusions Increasing peak vGRF during gait decreased sCOMP in individuals with ACLR who naturally demonstrated an increase in sCOMP after 20 minutes of walking. Trial Registry ClinicalTrials.gov (NCT03035994)

Context Military service members commonly sustain lower extremity stress fractures (SFx). How SFx risk factors influence bone metabolism is unknown. Understanding how SFx risk factors influence bone metabolism may help to optimize risk-mitigation strategies. Objective To determine how SFx risk factors influence bone metabolism. Design Cross-sectional study. Setting Military service academy. Patients or Other Participants Forty-five men (agepre = 18.56 ± 1.39 years, heightpre = 176.95 ± 7.29 cm, masspre = 77.20 ± 9.40 kg; body mass indexpre = 24.68 ± 2.87) who completed Cadet Basic Training (CBT). Individuals with neurologic or metabolic disorders were excluded. Intervention(s) We assessed SFx risk factors (independent variables) with (1) the Landing Error Scoring System (LESS), (2) self-reported injury and physical activity questionnaires, and (3) physical fitness tests. We assessed bone biomarkers (dependent variables; procollagen type I amino-terminal propeptide [PINP] and cross-linked collagen telopeptide [CTx-1]) via serum. Main Outcome Measure(s) A markerless motion-capture system was used to analyze trunk and lower extremity biomechanics via the LESS. Serum samples were collected post-CBT; enzyme-linked immunosorbent assays determined PINP and CTx-1 concentrations, and PINP : CTx-1 ratios were calculated. Linear regression models demonstrated associations between SFx risk factors and PINP and CTx-1 concentrations and PINP : CTx-1 ratio. Biomarker concentration mean differences with 95% confidence intervals were calculated. Significance was set a priori using α ≤ .10 for simple and α ≤ .05 for multiple regression analyses. Results The multiple regression models incorporating LESS and SFx risk factor data predicted the PINP concentration (R2 = 0.47, P = .02) and PINP : CTx-1 ratio (R2 = 0.66, P = .01). The PINP concentration was increased by foot internal rotation, trunk flexion, CBT injury, sit-up score, and pre- to post-CBT mass changes. The CTx-1 concentration was increased by heel-to-toe landing and post-CBT mass. The PINP : CTx-1 ratio was increased by foot internal rotation, lower extremity sagittal-plane displacement (inversely), CBT injury, sit-up score, and pre- to post-CBT mass changes. Conclusions Stress fracture risk factors accounted for 66% of the PINP : CTx-1 ratio variability, a potential surrogate for bone health. Our findings provide insight into how SFx risk factors influence bone health. This information can help guide SFx risk-mitigation strategies.

Context: Individuals who undergo anterior cruciate ligament reconstruction (ACLR) are at higher risk of posttraumatic osteoarthritis (PTOA). Altered joint tissue loading caused by aberrant gait biomechanics leads to deleterious changes in joint health linked to PTOA onset. Knee braces have been used to modify joint tissue loading in individuals with joint injury; yet, the effects of walking with a brace following ACLR on biomechanical, biological, and structural cartilage outcomes are unknown. Objective: To compare biomechanical, biochemical, and structural outcomes between braced and non-braced walking in ACLR individuals. Design: Cross-over study. Setting: Research laboratory. Participants: 34 individuals with unilateral ACLR (time since ACLR = 50±37 months; 18 females, 16 males). Interventions: Gait bioemchanics were assessed during braced (Rebound Cartilage; Ossur, Reykavik, Iceland) and unbraced conditions on separate days. Main Outcome Measures: Vertical ground reaction force (vGRF), knee flexion angle (KFA), and internal knee extension moment (KEM) waveforms were evaluated throughout the stance phase and compared between conditions. Percent changes of serum cartilage oligomeric matrix protein (%ΔCOMP) and femoral cartilage cross sectional area (%ΔCSA) measured via ultrasound were calculated following a 3000-step walking protocol. Results: Braced walking increased KFA (largest difference: 3.56°; effect size: d=1.72) and increased KEM (largest difference: 0.48 %Body Weight×Height; effect size: d=1.14) compared to non-braced walking but did not influence vGRF. While there was no significant difference (p=0.196) in %ΔCOMP between the braced and non-braced conditions in the entire cohort(n=30), there was a larger increase (p=0.036) in %ΔCOMP during non-braced compared to braced walking in individuals who demonstrated increased COMP during non-braced walking. There was no difference (p=0.86) in %ΔCSA between the braced and non-braced conditions. Conclusions: Braced walking may improve sagittal plane gait biomechanics and %ΔCOMP in a subset of individuals who demonstrate a typical increased COMP response to load (i.e., increase in COMP) following non-braced walking.

The energy costs of athletic training can be substantial, and deficits arising from costs unmet by adequate energy intake, leading to a state of low energy availability, may adversely impact athlete health and performance. Life history theory is a branch of evolutionary theory that recognizes that the way the body uses energy—and responds to low energy availability—is an evolved trait. Energy is a finite resource that must be distributed throughout the body to simultaneously fuel all biological processes. When energy availability is low, insufficient energy may be available to equally support all processes. As energy used for one function cannot be used for others, energetic “trade-offs” will arise. Biological processes offering the greatest immediate survival value will be protected, even if this results in energy being diverted away from others, potentially leading to their downregulation. Athletes with low energy availability provide a useful model for anthropologists investigating the biological trade-offs that occur when energy is scarce, while the broader conceptual framework provided by life history theory may be useful to sport and exercise researchers who investigate the influence of low energy availability on athlete health and performance. The goals of this review are: (1) to describe the core tenets of life history theory; (2) consider trade-offs that might occur in athletes with low energy availability in the context of four broad biological areas: reproduction, somatic maintenance, growth, and immunity; and (3) use this evolutionary perspective to consider potential directions for future research.

Purpose: To determine the relationship between gastrointestinal hormones (leptin, glucagon-like peptide-1), ghrelin, cholecystokinin, peptide YY, morphological characteristics, and physical performances in elite soccer players. Methods: Q2 Twenty-two elite male soccer players (age = 23.1 [2.7] y, height = 177.0 [0.1] cm, weight = 70.2 [2.9] kg, body mass index = 22.1 [1.8] kg/m2) completed 3-day food records each week during the 5-week training period. Blood samples were drawn after an overnight fast before and after preseason training to assess gastrointestinal hormones (leptin, glucagon-like peptide-1, ghrelin, cholecystokinin, and peptide YY). Continuous analysis of the training load was used during the training period. Preintervention and postintervention tests assessed jumping (countermovement jump), sprinting (10, 20, and 30 m), and endurance fitness (the Yo-Yo Intermittent Recovery Test Level 1 [YYIRT1]) levels. Results: Preseason training decreased body mass index (P = .001; effect size [ES] = 0.183) and body fat percentage (P = .001; ES = 0.516). There were increases in countermovement jump (P = .032; ES = 0.215), 20- (P = .016; ES = 0.195) and 30-m sprints (P = .001; ES = 0.188), and YYIRT1 performance (P = .001; ES = 0.9). Levels of cholecystokinin, peptide YY, and ghrelin did not change during preseason training, although changes in leptin (P = .001; ES = 0.41) and glucagon-like peptide-1 levels (P = .039; ES = 0.606) were recorded. Leptinemia correlated with anthropometric parameters (body mass index, r = .77, P = .001; percentage of body fat,r = .67, P = .006) and the total distance covered during the YYIRT1 (r = −.54; P = .03). Conclusion: Changes in morphological parameters and physical performance in elite-level male soccer players are related to variations in selected gastrointestinal hormones.

Aberrant joint loading contributes to the development of posttraumatic knee osteoarthritis (PTOA) following anterior cruciate ligament reconstruction (ACLR); yet little is known about the association between joint loading due to daily walking and cartilage health post-ACLR. Accelerometer-based measures of daily steps and cadence (i.e., rate of steps/min) provide information regarding daily walking in a real-world setting. The purpose of this study was to determine the association between changes in serum cartilage oligomeric matrix protein (COMP; %∆COMP), a mechanosensitive biomarker that is associated with osteoarthritis progression, following a standardized walking protocol and daily walking in individuals with ACLR and uninjured controls. Daily walking was assessed over 7 days using an accelerometer worn on the right hip in 31 individuals with ACLR and 21 controls and quantified as mean steps/day and time spent in ≥100 steps/min. Serum COMP was measured before and following a 3000-step walking protocol at a preferred speed. %∆COMP was calculated as a change in COMP relative to the prewalking value. Linear regressions were used to examine associations between daily walking and %∆COMP after adjusting for preferred speed. Fewer daily steps (ΔR

Context Better knee function is linked to psychological readiness to return to sport after anterior cruciate ligament reconstruction (ACLR). Individuals with ACLR participate in less physical activity than matched uninjured control individuals, yet the association between knee function and physical activity post–ACLR remains unclear. Objective To determine the associations between (1) patient-reported knee function measured using the Knee Injury and Osteoarthritis Outcome Score Knee-Related Quality of Life (KOOS-QOL), daily steps, and minutes spent in moderate-to-vigorous physical activity (MVPA) of individuals with ACLR and (2) KOOS-QOL and daily steps and MVPA in individuals with ACLR who presented with (ie, symptomatic) or without (ie, asymptomatic) clinically meaningful knee-related symptoms. Design Cross-sectional study. Setting Laboratory, free-living conditions. Patients or Other Participants A total of 66 individuals with primary unilateral ACLR (36 women, 30 men; age = 22 ± 4 years, height = 1.71 ± 0.1 m, mass = 71.3 ± 12.6 kg, body mass index = 24.2 ± 2.9, time post–ACLR = 28 ± 33 months). Main Outcome Measure(s) We collected KOOS data and retrospectively stratified participants into those with (symptomatic group, n = 30) or without (asymptomatic group, n = 36) clinically meaningful knee-related symptoms based on previously defined KOOS cutoffs. We assessed daily steps and MVPA using accelerometers that participants wore on the right hip for 7 days. We conducted linear regressions to determine associations between KOOS-QOL and daily steps and MVPA. Results In the entire sample, no associations existed between KOOS-QOL and daily steps (ΔR2 = 0.01, P = .50) or MVPA (ΔR2 = 0.01, P = .36). In the symptomatic group, a greater KOOS-QOL was associated with more time in MVPA (ΔR2 = 0.12, P = .05). In the asymptomatic group, no associations were identified between the KOOS-QOL and daily steps and MVPA. Conclusions Individuals with symptoms post–ACLR who spent more time in MVPA reported higher QOL.

We investigated the effects of 12 weeks of high-intensity interval training (HIIT) on selected circulating adipokines and other cardiovascular diseases risks factors in men with obesity. Thirty men with obesity (age: 24.96±3.11 year, BMI: 30.92±1.04 kg/m2) were randomly assigned to HIIT and control groups. The HIIT group participated in a 12-week HIIT program (5×2 min interval bout at an intensity of 85–95% HRmax interspersed by 1 min passive recovery, three times per week), while the control group maintained their usual lifestyles. Blood lipids, insulin resistance, and select serum adipokines were assessed before and after 12 weeks of the intervention period. HIIT improved body composition and lipid profiles (p

Beta-alanine, caffeine, and nitrate are dietary supplements generally recognized by the sport and exercise science community as evidence-based ergogenic performance aids. Evidence supporting the efficacy of these supplements, however, is greatly skewed due to research being conducted primarily in men. The physiological differences between men and women, most notably in sex hormones and menstrual cycle fluctuations, make generalizing male data to the female athlete inappropriate, and potentially harmful to women. This narrative review outlines the studies conducted in women regarding the efficacy of beta-alanine, caffeine, and nitrate supplementation for performance enhancement. Only nine studies on beta-alanine, 15 on caffeine, and 10 on nitrate in healthy women under the age of 40 years conducted in normoxia conditions were identified as relevant to this research question. Evidence suggests that beta-alanine may lower the rate of perceived exertion and extend training bouts in women, leading to greater functional adaptations. Studies of caffeine in women suggest the physiological responder status and caffeine habituation may contribute to caffeine’s efficacy, with a potential plateau in the dose–response relationship of performance enhancement. Nitrate appears to vary in influence based on activity type and primary muscle group examined. However, the results summarized in the limited literature for each of these three supplements provide no consensus on dosage, timing, or efficacy for women. Furthermore, the literature lacks considerations for hormonal status and its role in metabolism. This gap in sex-based knowledge necessitates further research on these ergogenic supplements in women with greater considerations for the effects of hormonal status.

Objectives The influence of hormonal contraceptives (HC) on inflammation and body composition after high-intensity combined strength and endurance training was investigated. Design Active healthy women formed two training groups: HC users (HCU, n = 9) and those who had never used HC (NHC, n = 9). Training included two strength training sessions and two high-intensity interval training sessions per week for 10 weeks. Methods Before (PRE) and after (POST) the training intervention, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) concentrations were measured. Dual-energy X-ray absorptiometry was used to estimate fat mass (FM), abdominal fat mass (aFM), and lean mass (LM). Results Circulating concentrations of hs-CRP decreased significantly in the NHC from pre to post with −0.46 mg l−1 (95% CI: −0.78, −0.14, p = 0.009, ES = 0.434), whereas a significant increase was observed in HCU from pre to post with 0.89 mg l−1 (95% CI: 1.66, 0.12, p = 0.048, ES = 1.988) with a significant between-group difference (p = 0.015). In addition, hs-CRP concentration was significantly higher in HCU than in NHC after training (p = 0.036) at post. Lean mass increased significantly more in NHC than in HCU (p = 0.049). Conclusions High-intensity combined strength and endurance training can modify inflammation and body composition of women. The present study showed that inflammation, in terms of hs-CRP was higher post training in HCU than NHC, which may be associated with smaller gains in lean mass in response to training.

Context Individuals with an anterior cruciate ligament reconstruction (ACLR) are at an increased risk of developing posttraumatic osteoarthritis. How osteoarthritis risk factors, such as increased body mass index (BMI), may influence early changes in joint tissue metabolism is unknown. Objective To determine the association between BMI and type 2 cartilage turnover in individuals with an ACLR. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants Forty-five individuals (31 women, 14 men) with unilateral ACLR at least 6 months earlier who were cleared for unrestricted physical activity. Main Outcome Measure(s) Body mass index (kg/m2) and type 2 collagen turnover were the primary outcomes. Body mass index was calculated from objectively measured height and mass. Serum was obtained to measure type 2 collagen turnover, quantified as the ratio of degradation (collagen type 2 cleavage product [C2C]) to synthesis (collagen type 2 C-propeptide [CP2]; C2C : CP2). Covariate measures were physical activity level before ACLR (Tegner score) and current level of disability (International Knee Documentation Committee Index score). Associations of primary outcomes were analyzed for the group as a whole and then separately for males and females. Results Overall, greater BMI was associated with greater C2C : CP2 (r = 0.32, P = .030). After controlling for covariates (Tegner and International Knee Documentation Committee Index scores), we identified a similar association between BMI and C2C : CP2 (partial r = 0.42, P = .009). Among women, greater BMI was associated with greater C2C : CP2 before (r = 0.47, P = .008) and after (partial r = 0.50, P = .008) controlling for covariates. No such association occurred in men. Conclusions Greater BMI may influence greater type 2 collagen turnover in those with ACLR. Individuals, especially women, who maintain or reduce BMI may be less likely to demonstrate greater type 2 collagen turnover ratios after ACLR.

Coronavirus-disease 19 (COVID-19) has rapidly become a global public health issue, and there is a desperate need for strategies of prevention, reduction, and treatment to halt the epidemic The coronavirus affects the immune system, and individuals with a compromised immune system, such as those with diabetes, hypertension, obesity, are more susceptible to this virus Lifestyle-related variables such as physical activity and nutritional supplements can decrease inflammatory markers, increase anti-inflammatory and antioxidant status, and improve the immune system Lifestyle-related variables play preventive roles against various infectious diseases including COVID-19 This review highlights the effects of physical activity and nutrients supplements on the immune system and their possible benefits in combating the harms caused by infection with the COVID-19 virus © 2021

Until recently, there has been less demand for and interest in female-specific sport and exercise science data. As a result, the vast majority of high-quality sport and exercise science data have been derived from studies with men as participants, which reduces the application of these data due to the known physiological differences between the sexes, specifically with regard to reproductive endocrinology. Furthermore, a shortage of specialist knowledge on female physiology in the sport science community, coupled with a reluctance to effectively adapt experimental designs to incorporate female-specific considerations, such as the menstrual cycle, hormonal contraceptive use, pregnancy and the menopause, has slowed the pursuit of knowledge in this field of research. In addition, a lack of agreement on the terminology and methodological approaches (i.e., gold-standard techniques) used within this research area has further hindered the ability of researchers to adequately develop evidenced-based guidelines for female exercisers. The purpose of this paper was to highlight the specific considerations needed when employing women (i.e., from athletes to non-athletes) as participants in sport and exercise science-based research. These considerations relate to participant selection criteria and adaptations for experimental design and address the diversity and complexities associated with female reproductive endocrinology across the lifespan. This statement intends to promote an increase in the inclusion of women as participants in studies related to sport and exercise science and an enhanced execution of these studies resulting in more high-quality female-specific data.

International audience; The objective of present study is to investigate the effects of walk training with and without blood flow restriction (BFR and no-BFR) on lipid profiles, inflammatory and haematological factors in over-weighed men. Participants were divided into BFR (n = 9) or no-BFR (n = 9) groups. Both groups were exposed to 8-week walk training on a treadmill: 3 sessions/week at a speed of 50 m/min, 5 sets × 2 min/session. There were differences in pre- to post-levels of (TG) and fibrinogen in the BFR group (p ≤ 0.05) that were accompanied by changes in red blood cells (RBC), haemoglobin (HGB) and haematocrit (HCT) levels (p ≤ 0.05). RBC levels were increased in the BFR group (p ≤ 0.05). The groups differed in their mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). These findings suggest the efficiency of BFR walk training in individuals exposed to chronic diseases associated with overweight, such as metabolic syndrome.

Umlauff, L, Weil, P, Zimmer, P, Hackney, AC, Bloch, W, and Schumann, M. Oral contraceptives do not affect physiological responses to strength exercise. J Strength Cond Res 35(4): 894-901, 2021-This study investigated the effect of oral contraceptive (OC) use on acute changes in steroid hormone concentrations and tryptophan (TRP) metabolites in response to strength exercise. Twenty-one women (age: 23 ± 3 years), 8 combined OC users (OC group) and 13 naturally cycling women (menstrual cycle [MC] group), participated. Testing was performed during the pill-free interval for the OC group and the follicular phase for the MC group. Subjects completed an intense strength exercise protocol (4 × 10 repetitions back squat). Blood samples were taken at baseline (T0), post-exercise (T1), and after 24 hours (T2) to determine serum concentrations of cortisol, estradiol, testosterone, TRP, and kynurenine (KYN). Statistical significance was defined as p ≤ 0.05. At T0, the OC group showed higher cortisol (OC: 493.7 ± 47.1 ng·mL-1, MC: 299.1 ± 62.7 ng·mL-1, p0.001) and blood lactate (OC: 1.81 ± 0.61 mmol·L-1, MC: 1.06 ± 0.30 mmol·L-1, p = 0.001) and lower estradiol (OC: 31.12 ± 4.24 pg·mL-1, MC: 38.34 ± 7.50 pg·mL-1, p = 0.023) and KYN (OC: 1.15 ± 0.23 µmol·L-1, MC: 1.75 ± 0.50 µmol·L-1, p = 0.005). No significant interactions (group × time, p0.05) were found for the hormones and TRP metabolites assessed. Oral contraceptive use did not affect the physiological response of steroid hormones and TRP metabolites to acute strength exercise during the low hormone phase of the contraceptive or MC in healthy young women, even when some baseline concentrations differed between groups. Consequently, these findings provide important implications for practitioners testing heterogeneous groups of female athletes.

The effects of acute consumption of L-Arginine (L-Arg) in healthy young individuals are not clearly defined, and no studies on the effects of L-Arg in individuals with abnormal body mass index undertaking strenuous exercise exist. Thus, we examined whether supplementation with L-Arg diminishes cardiopulmonary exercise testing responses, such as ventilation (VE), VE/VCO2, oxygen uptake (VO2), and heart rate, in response to an acute session of high-intensity interval exercise (HIIE) in overweight men. A double-blind, randomized crossover design was used to study 30 overweight men (age, 26.5 ± 2.2 years; body weight, 88.2 ± 5.3 kilogram; body mass index, 28.0 ± 1.4 kg/m2). Participants first completed a ramped-treadmill exercise protocol to determine VO2max velocity (vVO2max), after which they participated in two sessions of HIIE. Participants were randomly assigned to receive either 6 g of L-Arg or placebo supplements. The HIIE treadmill running protocol consisted of 12 trials, including exercise at 100% of vVO2max for 1 min interspersed with recovery intervals of 40% of vVO2max for 2 min. Measurements of VO2 (ml·kg−1·min−1), VE (L/min), heart rate (beat per min), and VE/VCO2 were obtained. Supplementation with L-Arg significantly decreased all cardiorespiratory responses during HIIE (placebo+HIIE vs. L-Arg+HIIE for each measurement: VE [80.9 ± 4.3 L/min vs. 74.6 ± 3.5 L/min, p 2 [26.4 ± 1.3 vs. 24.4 ± 1.0, p 2 [26.4 ± 0.8 ml·kg−1·min−1 vs. 24.4 ± 0.9 ml·kg−1·min−1, p p d = 0.89]). The authors conclude consuming L-Arg before HIIE can alleviate the excessive physiological strain resulting from HIIE and help to increase exercise tolerance in participants with a higher body mass index who may need to exercise on a regular basis for extended periods to improve their health.

Myllyaho, MM, Ihalainen, JK, Hackney, AC, Valtonen, M, Nummela, A, Vaara, E, Häkkinen, K, Kyröläinen, H, and Taipale, RS. Hormonal contraceptive use does not affect strength, endurance, or body composition adaptations to combined strength and endurance training in women. J Strength Cond Res 35(2): 449-457, 2021-This study examined the effects of a 10-week period of high-intensity combined strength and endurance training on strength, endurance, body composition, and serum hormone concentrations in physically active women using hormonal contraceptives (HCs, n = 9) compared with those who had never used hormonal contraceptives (NHCs, n = 9). Training consisted of 2 strength training sessions and 2 high-intensity running interval sessions per week. Maximal bilateral isometric leg press (Isom), maximal bilateral dynamic leg press (one repetition maximum [1RM]), countermovement jump (CMJ), a 3,000-m running test (3,000 m), body composition, and serum hormone levels were measured before and after training between days 1-5 of each subject's menstrual cycle. Both groups increased 1RM and CMJ: HC = 13.2% (p0.001) and 9.6% (p0.05), and NHC = 8.3% (p0.01) and 8.5% (p0.001). Hormonal contraceptive improved 3,000 m by 3.5% (p0.05) and NHC by 1% (n.s.). Never used hormonal contraceptive increased lean mass by 2.1% (p0.001), whereas body fat percentage decreased from 23.9 ± 6.7 to 22.4 ± 6.0 (-6.0%, p0.05). No significant changes were observed in body composition in HC. No significant between-group differences were observed in any of the performance variables. Luteinizing hormone concentrations decreased significantly (p0.05) over 10 weeks in NHC, whereas other hormone levels remained statistically unaltered in both groups. It seems that the present training is equally appropriate for improving strength, endurance, and body composition in women using HC as those not using HC without disrupting hypothalamic-pituitary-gonadal axis function.

Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined. Methods: Altogether 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study. Results: ATH had significantly lower body mass (P P P P P P r P Conclusions: More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.

Purpose: To examine the potential impact of fluctuations in sex steroid hormones across the menstrual cycle (MC) on marathon running performance of recreational female athletes. Methods: A survey questionnaire was administered to recreational, nonelite runners who had completed multiple marathons within the last 18 months. Results: A total of 599 questionnaires were returned and deemed viable for review. From these, 185 survey participants were found to have complete information and eligibility to have their surveys used in the statistical analysis. A total of 106 women had their best marathon performance in the luteal phase (high sex steroid hormones) of the MC, and 79 had their best performance in the follicular phase (low sex steroid hormones) of the MC (responses were significantly different; z-score value = 1.11; P Conclusion: Recreational female runners have varying performances in the marathon across their MC phases, specifically performing better in the luteal phase of the cycle.

Performance enhancing substances are becoming increasingly popular amongst bodybuilders and people who want to enhance their physiques. However, due to the rise of the Internet and laws prohibiting sales of these substances without prescription, the route of procurement and administration practices have become more and more dangerous. Prior to the mid-1970's, anabolic steroids were not regulated and easily available from physicians and pharmacies in several countries. In 1990, the United States enacted the Anabolic Steroid Control Act, leading to the proliferation of black markets and underground laboratories. The shift from pharmacy to underground online sites for the procurement of anabolic steroids led to an increase of fake products with low purity and the ability to potentially endanger the health of anabolic steroid users. Underground laboratories emerged both locally and in countries with lax legal regulations. 'Anabolic steroid tourism' and large networks of online resellers emerged, leading to the banalisation of the illegal procurement of anabolic steroids. Furthermore, the increase of anecdotal information spreading on the internet among anabolic steroid user forums nourishes the rampant misinformation and dangerous practices that currently exist. The dosages and ways of administration recommended on these forums can be false and misleading to those who lack a medical background and cannot go to their physician to seek advice because of the fear of repercussions. This review aims to elucidate and describe current practices of the anabolic-androgenic steroids black market and draw attention to potential dangers for users.

The cortisol awakening response (CAR) is commonly used as a marker of psychological stress; however, it is unknown whether CAR is affected by regular physical-exercise-induced stress. Purpose: To assess the relationship between training load and CAR. Methods: Recreational endurance athletes were recruited from local running clubs. Subjects (n = 15) completed training logs for 2 wk, with various training loads, including psychometric analysis (Recovery-Stress Questionnaire for Athletes). Subjects provided saliva samples each day immediately after waking and 30 min postwaking. Samples were analyzed for cortisol concentration via enzyme-linked immunosorbent assay and subsequently were analyzed for CAR and CAR%. Daily training load was calculated and analyzed as training impulse. Simple linear regression was used to assess the relationship between CAR and training impulse. Results: CAR (r2 = .352, P = .025) and CAR% (r2 = .373, P = .012) both showed a significant negative relationship with training load. Conclusions: These results suggest that CAR is affected by regular exercise training loads in recreational athletes. It is recommended that future CAR research control for fitness level and exercise training load in physically active populations.

INTRODUCTION An in-depth understanding of the healthy cartilage response to activities of daily living is needed to better understand the complex relationship between cartilage health and loading. The purpose was to assess the role of loading on the acute serum cartilage oligomeric matrix protein (COMP) response in recreationally active individuals. METHODS Forty individuals without previous lower extremity injury participated in this repeated-measures study in which each participant completed all conditions during independent data collection sessions separated by at least 1 wk. An antecubital blood draw was performed before and after walking, drop-landing, and control (i.e., sitting) conditions. Commercially available enzyme-linked immunosorbent assays measured COMP concentration. The acute COMP response was quantified as the percent change of COMP concentration from before to after each condition. A one-way, repeated-measures ANOVA compared the acute COMP response between conditions. Post hoc Pearson product-moment correlation and chi-square analysis determined the relationship between the walking and drop-landing acute COMP response within individuals. RESULTS Acute COMP response was greater after walking (+4.2, P = 0.008) and drop landing (+4.6%, P = 0.002) compared with control (-2.3%), but did not differ between the walking and drop-landing conditions (P = 0.596). The magnitudes of the acute COMP response during walking and drop landing were correlated (r = 0.56, P < 0.001). However, the direction (i.e., either increase or decrease) of COMP was not the same after the walking and drop-landing conditions (χ1 = 0.870, P = 0.351). CONCLUSIONS Walking and drop landing produced a greater acute COMP response when compared with a control condition in healthy individuals, but the acute COMP response was similar between the two physical activity conditions, although the conditions differed in magnitude and frequency of loading.

Individuals with anterior cruciate ligament reconstruction (ACLR) often exhibit a "stiffened knee strategy" or an excessively extended knee during gait, characterized by lesser knee flexion excursion and peak internal knee extension moment (KEM). The purpose of this study was to determine the effect of real-time biofeedback (RTBF) cuing an acute change in peak vertical ground reaction force (vGRF) during the first 50% of the stance phase of walking gait on: (1) root mean square error (RMSE) between actual vGRF and RTBF target vGRF; (2) perceived difficulty; and (3) knee biomechanics. Acquisition and short-term recall of these outcomes were evaluated. Thirty individuals with unilateral ACLR completed 4 separate walking sessions on a force-measuring treadmill that consisted of a control (no RTBF) and 3 experimental loading conditions using RTBF including: (1) 5% vGRF increase (high-loading), (2) 5% vGRF decrease (low-loading) and (3) symmetric vGRF between limbs. Bilateral biomechanical outcomes were analyzed during the first 50% of the stance phase, and included KEM, knee flexion excursion, peak vGRF, and instantaneous vGRF loading rate (vGRF-LR) for each loading condition. Peak vGRF significantly increased and decreased during high-loading and low-loading, respectively compared to control loading. Instantaneous vGRF-LR, peak KEM and knee flexion excursion significantly increased during the high-loading condition compared to low-loading. Perceived difficultly and RMSE were lower during the symmetrical loading condition compared to the low-loading condition. Cuing an increase in peak vGRF may be beneficial for increasing KEM, knee flexion excursion, peak vGRF, and vGRF-LR in individuals with ACLR. Clinical Trials Number: NCT03035994.

Summary Study aim: Evidence supports female sex hormones have an influencing effect on amultitude of physiological and psychological systems related to exercise. Little is known, however, whether is effect persist into the recovery from exercise. Our objective was to examine aspects of muscle damage/inflammation process during recovery in healthy, exercise-trained women following endurance activity at the mid-follicular (MF; low sex hormone level) and mid-luteal (ML; elevated sex hormone levels) phases of their menstrual cycle. Material and methods: The MF and ML exercise sessions consisted of running for 90 minutes at 70% VO2max on atreadmill in a controlled laboratory environment. Menstrual cycle phase was hormonally confirmed, diet and physical activity was control throughout the study. Outcome measures were: blood creatine kinase (CK) and interleukin-6 (IL-6) assessed at immediate-post exercise (IP), 24-hour and 72-hour into recovery. Statistics involved ANOVA procedures. Results: At 24-hours and 72-hour into recovery CK activity was greater in MF than ML (p < 0.05) while for IL-6 at IP, 24-hour and 72-hour responses were significantly greater at MF than at ML (p < 0.05). Conclusions: Amore robust recovery CK and IL-6 response occur in the MF of the menstrual cycle when female sex hormones are reduced. This finding suggests female sex hormone changes due to menstrual cycle phase affect the physiologic responses during the extended recovery period from intensive exercise in eumenorrheic women.

Male athletes in general are subjected to the same causes of infertility as the general population, but sports practice itself may be possibly an additional infertility factor or, at least an aggravating factor for a previously existing fertility condition; on the contrary, being physically active has been hypothesized to favor hormonal and seminological processes and could be beneficial for fertility. In this relationship, the different inherent parameters of physical activity-exercise (training volume, intensity, objective, organization and frequency) are of paramount importance. Therefore, this review discusses both the negative and positive impact of physical exercise on the male reproductive potential. Clear knowledge is lacking on this topic as incongruences exist due to the fact that studies lack standardization in assessment tools or research protocols. So that future studies can reveal more information regarding exercising male fertility, we introduce a unique questionnaire developed with the intent to help standardize future studies on male fertility and exercise.

International audience

Summary Purpose Menopause is a normal condition that all women experience as they age. The aim of this study was to assess the effects of circuit resistance exercise training with Zataria multiflora (Avishan-e-Shirazi) dietary supplementation on plasma apelin, glucose, insulin, insulin sensitivity and insulin resistance. Methods Ninety-six volunteer postmenopausal women were allocated into 8 groups. Resistance training consisted of 12 stations had been done for 8 weeks. Blood samples were collected at pre- and -post intervention. Results Circuit RT increases apelin and decreases both insulin and blood glucose, whereas Zataria multiflora has no independent effect on apelin but does decrease blood glucose and is likely to be in some means synergistic with circuit RT effects. Conclusion These results suggest that circuit resistance training augments plasma apelin and decreases both insulin and blood glucose. However, Zataria multiflora has no independent effect on apelin but does decrease blood glucose which is likely to be to some extent synergistic with training effects.

PURPOSE: Zataria is a plant with anti-inflammatory properties, which has been used for the treatment of many diseases. This study investigated the effect of different intensities of circuit resistance training and Zataria supplementation on plasma retinol-binding protein-4 (RBP-4) and tumor necrosis factor-α (TNF-α) in postmenopausal women. METHODS: Seventy-two postmenopausal women were divided on randomized order into six groups: Control (McGinley and Bishop in J Appl Physiol 121(6):1290–1305, 2016), Training 35% (T35%), Training 55% (T55%), Zataria (Özgünen et al. in Scand J Med Sci Sports 20:140–147, 2010), Zataria/Training 35% (ZT35%), and Zataria/Training 55% (ZT55%). Resist-ance training program included 12 exercise stations (each: 30 s, intensity: 35% and 55% of 1-RM) for 8 weeks (3 sessions/week). Daily (500 mg) Zataria was used after breakfast by participants in ZG, ZT35%, and ZT55% groups. Blood samples were taken 48 h before and after the first and last sessions of training. RESULTS: After the training period the percentage of body fat decreased significantly (P < 0.001) in all trained groups, whereas muscle mass increased significantly (P < 0.01) only in T55% and ZT55% groups. A significant decrease was observed for RBP-4 values (P < 0.05) after training in all groups except for ZG and CG. Also, RBP-4 was significantly lower (P < 0.05) in all groups as compared to CG at the post-test except for ZG. Moreover, significantly lower values (P < 0.05) were found in T55%, ZT35%, and ZT55% as compared to ZG in post-intervention. TNF-α values decreased significantly (P < 0.05) at the post-test as compared to pre-intervention in ZT35% and ZT55%. Also, TNF-α was significantly lower (P < 0.05) in ZT55% compared to CG and T35% in post-test CONCLUSIONS: The results demonstrate clearly that in postmenopausal women, circuit resistance training both at low and moderate intensities cause a greater reduction in RBP-4 and TNF-α when Zataria is supplemented in the diet during training.

This is an Editoril article and has not Abstract.

The aim of this study was to explore the effect of one bout of aerobic exercise on epinephrine, norepinephrine, cortisol, glucose, lactate, and free fatty acid (FFA) responses in breast cancer survivors and healthy controls. 9 female breast cancer survivors and 9 women without a history of cancer completed 30 min of cycle ergometry exercise at 60 % of VO2peak. Blood samples were taken pre-exercise, immediately post-exercise, and 2 h post-exercise from which plasma concentrations of study variables were measured. Immediately and 2 h post-exercise, increases were observed in epinephrine (control group only) norepinephrine (both groups), lactate (both groups), and FFA (both groups immediately post-exercise; breast cancer survivor group only at 2 h post-exercise) (p < 0.05). Cortisol decreased immediately and 2 h post-exercise in the control group while glucose decreased immediately post-exercise in the breast cancer survivor group (p < 0.05). In conclusion, breast cancer survivors appeared to display attenuated epinephrine, cortisol, and lactate responses while displaying larger magnitude changes in glucose and FFA responses compared to controls. These preliminary findings may have implications for the regulation of metabolism during exercise in breast cancer survivors.

Background: Individuals who have sustained an anterior cruciate ligament (ACL) injury and undergo ACL reconstruction (ACLR) are at higher risk of developing knee osteoarthritis. It is hypothesized that altered knee loading may influence the underlying joint metabolism and hasten development of posttraumatic knee osteoarthritis. Purpose: To explore the associations between serum biomarkers of cartilage metabolism and peak vertical ground-reaction force (vGRF) and vGRF loading rate in the injured and uninjured limbs of individuals with ACLR. Study Design: Descriptive laboratory study. Methods: Patients with a history of a primary unilateral ACLR who had returned to unrestricted physical activity (N = 19) participated in the study. Resting blood was collected from each participant before completing 5 walking gait trials at a self-selected comfortable speed. Peak vGRF was extracted for both limbs during the first 50% of the stance phase of gait, and the linear vGRF loading rate was determined between heel strike and peak vGRF. Sera were assessed for collagen breakdown (collagen type II cleavage product [C2C]) and synthesis (collagen type II C-propeptide [CPII]), as well as aggrecan concentrations, via commercially available specific enzyme-linked immunosorbent assays. Pearson product-moment correlations ( r) and Spearman rank-order correlations (ρ) were used to evaluate associations between loading characteristics and biomarkers of cartilage metabolism. Results: Lower C2C:CPII ratios were associated with higher peak vGRF in the injured limb (ρ = −0.59, uncorrected P = .007). There were no significant associations between peak vGRF or linear vGRF loading rate and CPII, C2C, or aggrecan serum concentrations. Conclusion: Lower C2C:CPII ratios were associated with higher peak vGRF in the ACLR limb during gait, suggesting that higher peak loading in the ACLR limb is related to lower type II collagen breakdown relative to type II collagen synthesis. Clinical Relevance: These data suggest that type II collagen synthesis may be higher relative to the amount of type II collagen breakdown in the ACLR limb with higher lower extremity loading. Future study should determine if metabolic compensations to increase collagen synthesis may affect the risk of developing osteoarthritis after ACLR.