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Objective. Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2DM) commonly coexist and act synergistically to drive adverse clinical outcomes. This study is aimed at investigating the effects of exercise intervention and oral hypoglycaemic drug of metformin (MET) alone or combined on hepatic lipid accumulation. To investigate if oxidative stress and endoplasmic reticulum stress (ERS) are involved in lipotoxicity-induced hepatocyte apoptosis in diabetic mice and whether exercise and/or MET alleviated oxidative stress or ERS-apoptosis by AMPK-Nrf2-HO-1 signaling pathway. Methods. Forty db/db mice with diabetes ( random blood glucose ≥ 250 mg / dL ) were randomly allocated into four groups: control (CON), exercise training alone (EX), metformin treatment alone (MET), and exercise combined with metformin (EM) groups. Hematoxylin-eosin and oil red O staining were carried out to observe hepatic lipid accumulation. Immunohistochemical and TUNEL methods were used to detect the protein expression of the binding immunoglobulin protein (BiP) and superoxide dismutase-1 (SOD1) and the apoptosis level of hepatocytes. ERS-related gene expression and the AMPK-Nrf2-HO-1 signaling pathway were tested by western blotting. Results. Our data showed that db/db mice exhibited increased liver lipid accumulation, which induced oxidative and ER stress of the PERK-eIF2α-ATF4 pathway, and hepatocyte apoptosis. MET combined with exercise training significantly alleviated hepatic lipid accumulation by suppressing BiP expression, the central regulator of ER homeostasis, and its downstream PERK-eIF2α-ATF4 pathway, as well as upregulated the AMPK-Nrf2-HO-1 signaling pathway. Moreover, the combination of exercise and MET displayed protective effects on hepatocyte apoptosis by downregulating Bax expression and TUNEL-positive staining, restoring the balance of cleaved-caspase-3 and caspase-3, and improving the antioxidant defense system to prevent oxidative damage in db/db mice. Conclusion. Compared to MET or exercise intervention alone, the combined exercise and metformin exhibited significant effect on ameliorating hepatic steatosis, inhibiting oxidative and ER stress-induced hepatocyte apoptosis via improving the capacity of the antioxidant defense system and suppression of the PERK-eIF2α-ATF4 pathway. Furthermore, upregulation of AMPK-Nrf2-HO-1 signaling pathway might be a key crosstalk between MET and exercise, which may have additive effects on alleviating hepatic lipid accumulation.

This research was partly funded by Huawei Technologies Oy (Finland) Co. Ltd. A limited liability company headquartered in Helsinki, Finland., Background Technological advances have recently made possible the estimation of maximal oxygen consumption (VO2max) by consumer wearables. However, the validity of such estimations has not been systematically summarized using metaanalytic methods and there are no standards guiding the validation protocols. Objective The aim was to (1) quantitatively summarize previous studies investigating the validity of the VO2max estimated by consumer wearables and (2) provide best-practice recommendations for future validation studies. Methods First, we conducted a systematic review and meta-analysis of studies validating the estimation of VO2max by wearables. Second, based on the state of knowledge (derived from the systematic review) combined with the expert discussion between the members of the Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) consortium, we provided a set of best-practice recommendations for validation protocols. Results Fourteen validation studies were included in the systematic review and meta-analysis. Meta-analysis results revealed that wearables using resting condition information in their algorithms significantly overestimated VO2max (bias 2.17 ml·kg−1·min−1; limits of agreement − 13.07 to 17.41 ml·kg−1·min−1), while devices using exercise-based information in their algorithms showed a lower systematic and random error (bias − 0.09 ml·kg−1·min−1; limits of agreement − 9.92 to 9.74 ml·kg−1·min−1). The INTERLIVE consortium proposed six key domains to be considered for validating wearable devices estimating VO2max, concerning the following: the target population, reference standard, index measure, testing conditions, data processing, and statistical analysis. Conclusions Our meta-analysis suggests that the estimations of VO2max by wearables that use exercise-based algorithms provide higher accuracy than those based on resting conditions. The exercise-based estimation seems to be optimal for measuring VO2max at the population level, yet the estimation error at the individual level is large, and, therefore, for sport/ clinical purposes these methods still need improvement. The INTERLIVE network hereby provides best-practice recommendations to be used in future protocols to move towards a more accurate, transparent and comparable validation of VO2max derived from wearables., Huawei Technologies

ContextIt remains uncertain whether aging before late adulthood and menopause are associated with fat-free mass and fat mass–adjusted resting energy expenditure (REEadj).ObjectivesWe investigated whether REEadjdiffers between middle-aged and younger women and between middle-aged women with different menopausal statuses. We repeated the age group comparison between middle-aged mothers and their daughters to partially control for genotype. We also explored whether serum estradiol and follicle-stimulating hormone concentrations explain REEadjin midlife.MethodsWe divided 120 women, including 16 mother–daughter pairs, into age groups; group I (n= 26) consisted of participants aged 17–21, group II (n= 35) of those aged 22–38 and group III (n= 59) of those aged 41–58 years. The women in group III were further categorized as pre- or perimenopausal (n= 19), postmenopausal (n= 30) or postmenopausal hormone therapy users (n= 10). REE was assessed using indirect calorimetry, body composition using dual-energy X-ray absorptiometry and hormones using immunoassays.ResultsThe REEadjof group I was 126 kcal/d (95% CI: 93–160) higher than that of group III, and the REEadjof group II was 88 kcal/d (95% CI: 49–127) higher. Furthermore, daughters had a 100 kcal/d (95% CI: 63–138 kcal/d) higher REEadjthan their middle-aged mothers (allP< 0.001). In group III, REEadjwas not lower in postmenopausal women and did not vary by sex hormone concentrations.ConclusionsWe demonstrated that REEadjdeclines with age in women before late adulthood, also when controlling partially for genetic background, and that menopause may not contribute to this decline.

Impact loading has been associated with running-related injuries, and gait retraining has been suggested as a means of reducing impact loading and lowering the risk of injury. However, gait retraining can lead to increased perceived awkwardness and effort. The influence of specifically trained and self-selected running gait modifications on acute impact loading, perceived awkwardness and effort is currently unclear. Sixteen habitual rearfoot/midfoot runners performed forefoot strike pattern, increased step rate, anterior trunk lean and self-selected running gait modifications on an instrumented treadmill based on real-time biofeedback. Impact loading, perceived awkwardness and effort scores were compared among the four gait retraining conditions. Self-selected gait modification reduced vertical average loading rate (VALR) by 25.3%, vertical instantaneous loading rate (VILR) by 27.0%, vertical impact peak (VIP) by 16.8% as compared with baseline. Forefoot strike pattern reduced VALR, VILR and peak tibial acceleration. Increased step rate reduced VALR. Anterior trunk lean did not reduce any impact loading. Self-selected gait modification was perceived as less awkward and require less effort than the specifically trained gait modification (

Translational Medicine and Exercise Prescription (TMEP): Advancing the Era of Exercise Medicine Sulin Cheng1,2,3,4, Moritz Schumann()2,4 and Wilhelm Bloch4 1Exercise, Health and Technology Center, Department of Physical Education, Shanghai Jiao Tong University, Shanghai, China 2Exercise Translational Medicine Center, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China 3Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland 4Department of Molecular and Cellular Sport Medicine, German Sport University, Cologne, Germany © The Authors "Exercise is medicine" has gained popularity worldwide after the American Medical Association and the American College of Sports Medicine co-launched their ground-breaking health initiative in 20071 . This initiative was aimed at improving population health and well-being, mainly by raising the awareness of healthcare providers to regard performing physical activity (PA) as one of the vital signs. Ever since, this concept has spread worldwide and PA has been proposed as an essential part of treatment for chronic diseases2 . In their pioneering work, Pedersen and Saltin provided compelling evidence for the role of exercise as the first- or second-line therapy for at least 26 diseases2 . These findings are further corroborated by meta-epidemiological data, indicating exercise interventions to be as effective as drug interventions, such as during rehabilitation after stroke and for the treatment of heart failure3 . However, the overall effect appears to be strongly correlated with important determinants of the exercise program performed (i.e. dose of training [frequency, volume, intensity], type of exercise and adherence to the training program) and disease-related specifics4 , thus requiring not only clinical expertise but also an in-depth understanding of exercise physiology and biology. In this new journal-Translational Medicine and Exercise Prescription (TMEP), we are aiming to bring together the fields of exercise physiology and biology, sports medicine and the science of physical training and testing to bridge the gap between mechanistic research and clinical practice. The journal covers nine sections, including obesity, diabetes, cancer, cardiovascular diseases, neurological and psychiatric diseases, pulmonary diseases, musculoskeletal diseases, endocrine disorders as well as advanced exercise prescription and health maintenance. In this first issue of TMEP, we are delighted to present seven papers from different areas of translational research performed in humans on specific themes related to the treatment and prevention of chronic diseases. Appropriate selection of primary and secondary endpoints is critical for successfully designing translational studies. In the first paper of this issue, TMEP Section Editor, Jörn Rittweger provides his thoughts on "What Are Good Muscle Endpoints for Translational Studies?". In his important work, he highlights the importance of muscles for our health because of their size, their involvement in energy metabolism and their relevance for locomotion. He further suggests that at least eight different muscle functions are important to health. Well accepted methods exist for three relevant muscular endpoints, namely for power, strength and muscle mass, and these endpoints are utilized in clinical studies. However, such validated methods lack a number of additional muscle functions that are not yet fully scientifically explored. This applies foremost to not only the metabolic functions of muscles, but also to their role in storage and dissipation of mechanical energy. His work concludes by emphasizing how physiological knowledge can be an important base for the guidance of clinical diagnostics. Following this important message, the group of TMEP Section Editor Pieter de Lange shares their work entitled "Exercise with Energy Restriction as a Means of Losing Body Mass While Preserving Muscle Quality and Ameliorating Comorbidities: Towards A Therapy for Obesity?". Obesity and related comorbidities have reached pandemic proportions worldwide, particularly during the past decade. Therefore, finding effective intervention strategies not only requires scientific focus but these strategies are also of public interest. Based on both human and animal studies, this narrative review summarizes the effects of dietary and exercise-based programs on loss of different body mass components. Furthermore, both the gain and lack of loss of lean mass in view of muscle quality maintenance are discussed and data related to the mechanisms underlying the conservation of functional muscle mass provided. They also provide evidence of the interaction between energy restriction by diet and exercise-induced metabolic demands at the molecular level. This insight into the mechanisms underlines the relevance of translational considerations for personalized exercise prescription. Obesity and an unhealthy lifestyle are also known to be among the risk factors for type 2 diabetes (T2DM). The research group of TMEP Section Editor Thomas Yates highlights research opportunities and challenges for combining exercise and medical therapies by means of a narrative review entitled "Exercise, Pharmaceutical Therapies and Type 2 Diabetes: Looking beyond Glycemic Control to Whole Body Health and Function". The authors provide evidence on newer generations of glucose-lowering therapies that also induce concomitant weight loss, particularly on glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2is). Based on current knowledge, they stress the importance of investigating the interaction or synergy between exercise and other glucose-lowering or weight loss therapies, to make exercise a tailored therapy rather than a generic treatment in the management of T2DM. This review, therefore, clearly highlights the need of precise exercise prescription, originating from an in-depth mechanistic understanding of the effects of exercise. Cancer is another important metabolic and chronic inflammatory disease that may also be associated with obesity. TMEP Section Editor Jesper F Christensen and Associate Editor Ciaran M Fairman provide a very interesting viewpoint in their article,"Targeted Exercise Training for Cancer Patients: Moving beyond Generic Exercise Guidelines in Clinical Oncology". This paper aims to update the current knowledge and the clinical rationale for targeted exercise interventions in exercise oncology. Moreover, a framework for systematic guidance of the design and execution of targeted exercise interventions in oncology is presented. The authors hope that their framework can encourage further research into targeted exercise interventions in oncology and may also be used as a guideline for the design of future trials to increase quality and impact. The group of TMEP Section Editor Helen Dawes, shares their original data in the context of neurological and psychiatric diseases in the article entitled "Physical Activity and Fatigue in Multiple Sclerosis: Secondary Outcomes from a Double-blinded Randomized Controlled Trial of Cocoa Flavonoid Drinks". In this study, they performed intensive phenotyping of the inter-relationships of the time of day, physical activity levels and fatigue to determine exercise prescription in a group of people with multiple sclerosis (MS) participating in a six-week randomized controlled trial of morning flavonoid intake. It was found that fatigue levels increased during the day and higher levels of fatigue reduced physical activity; yet physical activity itself did not lead to increased fatigue. Additionally, morning cocoa intake reduced daytime fatigue and fatigue related to subsequent physical activity. Therefore, combined prescription of morning exercise and dietary flavonoids may optimize the exercise and physical activity potential in people with MS. This study nicely demonstrates the importance of understanding and considering possible covariants such as nutrition and chronobiology to determine an optimal exercise prescription model. TMEP Section Editor Jonathan Myers and colleague Baruch Vainshelboim present a narrative review on "Resistance Training for Rehabilitation of Patients with Idiopathic Pulmonary Fibrosis". In this paper, the pathophysiology and clinical manifestations of Idiopathic Pulmonary Fibrosis (IPF) are summarized with an emphasis on the numerous health and clinical benefits of resistance training among older adults and patients with this respiratory disease. This article effectively explores the potential mechanisms by which systematic resistance training may help overcome exercise limitations in IPF, providing a therapeutic opportunity for rehabilitation. Furthermore, the authors provide important recommendations for pulmonary rehabilitation programs that are based on resistance training for patients with IPF. With this paper, the authors highlight that disease-adapted exercise prescription requires a pathophysiological understanding to justify the inclusion of specific exercise regimens. In the final paper of this special issue, the research group of Section Editor Anthony C Hackney shares their original data on the "Energy Availability and RED-S Risk Factors in Competitive, Non-elite Male Endurance Athletes". This paper particularly emphasizes the entire spectrum of TMEP, that is more than just the most common types of non-communicable diseases, but also includes chronic conditions that may be for example induced by athletic training. In this study, the authors assessed the associations of energy availability and risk factors of relative energy deficiency in sport (RED-S) in 60 competitive, recreationally trained male endurance athletes. They found that hormonal and bone biomarkers were within normal clinical ranges, even when the energy availability was low. The authors further state that athletes are considered at a high risk for RED-S if their energy availability is low (

Accumulating evidence show that exercise and diet interventions are associated with improved sleep quality. Studies investigating the effects of exercise and dieting on circulating metabolomics in people with sleep disorders, particularly insomnia, are scarce. This 6-month randomized study aimed to assess the effects of exercise and dietary interventions on serum metabolites in men with insomnia symptoms. Seventy-two Finnish men (age: 51.6 ± 10.1 years) with chronic insomnia symptoms who were assigned to different intervention groups completed this study (exercise, n = 24; diet, n = 27; and control, n = 21). The Shapiro-Wilk W-test, Levene test, Spearman correlation analysis, and analysis of variance were used for data analysis. We found that exercise and diet intervention were associated with improved sleep quality and with a number of metabolites across different biochemical pathways. Although we could not show causality, our findings provide new insight into the biological mechanisms underlying the health effects of physical activity, diet, and sleep quality. Further investigation is needed to better understand the link among lifestyle, sleep quality, and metabolic health.

Feuerbacher, JF, Jacobs, MW, Dragutinovic, B, Goldmann, J-P, Cheng, S, and Schumann, M. Validity and test-retest reliability of the Vmaxpro sensor for evaluation of movement velocity in the deep squat. J Strength Cond Res 37(1): 35-40, 2023-We aimed at assessing the validity and test-retest reliability of the inertial measurement unit-based Vmaxpro sensor compared with a Vicon 3D motion capture system and the T-Force sensor during an incremental 1-repetition maximum (1RM) test and at submaximal loads. Nineteen subjects reported to the laboratory for the 1RM test sessions, whereas 15 subjects carried out another 3 sessions consisting of 3 repetitions with 4 different intensities (30, 50, 70, and 90% of 1RM) to determine the intra- and interday reliability. The Vmaxpro sensor showed high validity (Vicon: R2 = 0.935; T-Force: R2 = 0.968) but an overestimation of the mean velocities (MVs) of 0.06 ± 0.08 m·s-1 and 0.06 ± 0.06 m·s-1 compared with Vicon and T-Force, respectively. Regression analysis indicated a systematic bias that is increasing with higher MVs. The intraclass correlation coefficients (ICCs) for Vmaxpro were moderate to high for intraday (ICC: 0.662-0.938; p ≤ 0.05) and for interday (ICC: 0.568-0.837; p ≤ 0.05) reliability, respectively. The Vmaxpro is a valid and reliable measurement device that can be used to monitor movement velocities within a training session. However, practitioners should be cautious when assessing movement velocities on separate days because of the moderate interday reliability.

Open Access funding provided by the IReL Consortium. This research was partly funded by Huawei Technologies, Finland. RA and BC are partly funded by Science Foundation Ireland (12/RC/2289_P2). PMG and FBO are supported by grants from the MINECO/FEDER (DEP2016-79512-R) and from the University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Scientific Excellence Unit on Exercise and Health (UCEES); Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades and European Regional Development Funds (ref. SOMM17/6107/UGR). JT and JS are partly funded by the Research Council of Norway (249932/F20). AG is supported by a European Research Council Grant (grant number 716657)., Background Consumer wearables and smartphone devices commonly offer an estimate of energy expenditure (EE) to assist in the objective monitoring of physical activity to the general population. Alongside consumers, healthcare professionals and researchers are seeking to utilise these devices for the monitoring of training and improving human health. However, the methods of validation and reporting of EE estimation in these devices lacks rigour, negatively impacting on the ability to make comparisons between devices and provide transparent accuracy. Objectives The Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The network was founded in 2019 and strives towards developing best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice validation protocol for consumer wearables and smartphones in the estimation of EE. Methods The recommendations were developed through (1) a systematic literature review; (2) an unstructured review of the wider literature discussing the potential factors that may introduce bias during validation studies; and (3) evidence-informed expert opinions from members of the INTERLIVE network. Results The systematic literature review process identified 1645 potential articles, of which 62 were deemed eligible for the final dataset. Based on these studies and the wider literature search, a validation framework is proposed encompassing six key domains for validation: the target population, criterion measure, index measure, testing conditions, data processing and the statistical analysis. Conclusions The INTERLIVE network recommends that the proposed protocol, and checklists provided, are used to standardise the testing and reporting of the validation of any consumer wearable or smartphone device to estimate EE. This in turn will maximise the potential utility of these technologies for clinicians, researchers, consumers, and manufacturers/ developers, while ensuring transparency, comparability, and replicability in validation., IReL Consortium, Huawei Technologies, Science Foundation Ireland, European Commission 12/RC/2289_P2, Spanish Government DEP2016-79512-R, University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Scientific Excellence Unit on Exercise and Health (UCEES), Junta de Andalucia, European Commission SOMM17/6107/UGR, Research Council of Norway 249932/F20, European Research Council (ERC) 716657

(1) Background: Evidence suggests that aerobic exercise and high-intensity interval training (HIIT) might increase fat oxidation and reduce fat. However, limited research has examined the effects of combining progressive aerobic exercise and HIIT interventions in sedentary adults with overweight and obesity, and differences in its effects between men and women remain unclear. The purpose of this study was to investigate the effects of combined progressive aerobic exercise and HIIT (CAEH) on fat oxidation and fat reduction in sedentary Chinese adults and compare sex differences in sedentary adults after seven weeks. (2) Methods: Eighty-four sedentary obese adults were enrolled and allocated to two groups in baseline (experimental (EXP) group:42; control (CON) group:42), and fifty-six subjects (EXP:31; CON:25) completed the experiments and were included in the final analysis. Subjects in the EXP group performed CAEH three times per week for seven weeks. Subjects in the CON group were advised to continue with their normal daily activities. Anthropometric, lipid profile, cardiorespiratory fitness, and fat oxidation outcomes were assessed before and after the intervention. (3) Results: After seven weeks of the CAEH intervention, compared with the CON group, the EXP group showed significant increases in fat oxidation at rest (FO_rest) (+0.03 g/min, p < 0.01), maximal fat oxidation (MFO) (+0.05 g/min, p < 0.01), and maximal oxygen intake (VO2max) (+3.2 mL/kg/min, p < 0.01). The changes in the percentages of the FO_rest (+57%) and the VO2max (+16%) were significantly greater (+20%, +6%) in males than in females (p < 0.05, p < 0.05). The body mass index (BMI) (−1.2 kg/m2, p < 0.01), body fat percentage (−3.2%, p < 0.001), visceral fat area (−12.8 cm2, p < 0.001), and total cholesterol (TC) levels (−0.4 mmol/L, p < 0.05) were significantly decreased in the EXP group. (4) Conclusions: Seven weeks of the CAEH intervention effectively improved FO_rest, MFO, and VO2max in sedentary obese adults, and the improvements in FO_rest and VO2max were more pronounced in males than in females. CAEH also improved body composition and TC levels in sedentary obese adults.

This study investigated the factors that are associated with sleep disturbances among Chinese athletes. Sleep quality and associated factors were assessed by the Athlete Sleep Screening Questionnaire (ASSQ, n ​= ​394, aged 18–32 years, 47.6% female). Sleep difficulty score (SDS) and level of sleep problem (none, mild, moderate, or severe) were used to classify participants' sleep quality. Categorical variables were analyzed by Chi-square or fisher's exact tests. An ordinal logistic regression analysis was used to explore factors with poor sleep (SDS ≥8). Approximately 14.2% of participants had moderate to severe sleep problem (SDS ≥8). Fifty-nine percent of the athletes reported sleep disturbance during travel, while 43.3% experienced daytime dysfunction when travelling for competition. No significant difference was found in the SDS category between gender, sports level and events. Athletes with evening chronotype were more likely to report worse sleep than athletes with morning and intermediate chronotype (OR, 2.25; 95%CI, 1.44–3.52; p ​< ​0.001). For each additional year of age, there was an increase of odds ratio for poor sleep quality (OR, 1.15; 95%CI, 1.04–1.26; p ​= ​0.004), while each additional year of training reduced the odds ratio (OR, 0.95; 95%CI, 0.91–0.99; p ​= ​0.044). To improve sleep health in athletes, chronotype, travel-related issues, age and years of training should be taken into consideration. peerReviewed

Aerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging and their interaction on metabolism, we utilized rat models of low and high intrinsic aerobic capacity (LCRs/HCRs) and assessed the metabolomics of serum, muscle, and white adipose tissue (WAT). We compared LCRs and HCRs at two time points: Young rats were sacrificed at 9 months, and old rats were sacrificed at 21 months. Targeted and semi-quantitative metabolomics analysis was performed on ultra-pressure Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS) platform. Interaction of aerobic capacity and aging was studied via regression analysis. Our results showed at young age, metabolites linked to amino acid metabolism differed in serum and muscle with aerobic capacity, whereas no difference were observed in WAT. In aged animals, most prominent changes in metabolites occurred in WAT. Aerobic capacity and aging interactively affected seven metabolites linked to energy metabolism. Our results support previous findings that high aerobic capacity is associated with more efficient amino acid metabolism in muscle. While impaired branched chain amino acids (BCAAs) and fatty acid metabolism in the muscle may associate to the high risk of metabolic disorders and shorter lifespan previously observed in LCRs. The interactive effects of aging and aerobic capacity on energy metabolism-related metabolites were largely driven by HCRs, reflecting the importance of inherited aerobic capacity in the aging process. Our results highlight that dysfunctional mitochondrial β-oxidation in WAT may be one key mechanism related to aging.

A low-carbohydrate, high-fat (LCHF) diet has been proposed to enhance the fat utilization of muscle and the aerobic capacity of endurance athletes, thereby improving their exercise performance. However, it remains uncertain how the macronutrient intake shift from carbohydrate to fat affects endurance exercise training and performance. This study performed a systematic review and meta-analysis to explore the effects of a ketogenic low-carbohydrate, high-fat (K-LCHF) diet on aerobic capacity and exercise performance among endurance athletes. Searches were carried out in five electronic databases, and we followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The search included studies using an LCHF diet as an intervention protocol and compared data on factors such as maximum oxygen uptake (VO2max) and rating of perceived exertion (RPE) from the graded exercise test. In this case, 10 studies met the criteria and were included in the meta-analysis. We did not find a significant effect of K-LCHF diet interventions on VO2max, time to exhaustion, HRmax or RPE. However, a significant overall effect in the substrate oxidation response to respiratory exchange rate was observed. The meta-analysis showed that K-LCHF diets did not affect aerobic capacity and exercise performance. Therefore, high-quality interventions of a K-LCHF diet are needed to illustrate its effect on various endurance training programs.

Background The directional influences between serum sex hormone-binding globulin (SHBG), adiposity and insulin resistance during pubertal growth remain unclear. The aim of this study was to investigate bidirectional associations between SHBG and insulin resistance (HOMA-IR) and adiposity from childhood to early adulthood. Methods Participants were 396 healthy girls measured at baseline (age 11.2 years) and at 1, 2, 4 and 7.5 years. Serum concentrations of estradiol, testosterone and SHBG were determined by ELISA, glucose and insulin by enzymatic photometry, insulin-like growth factor 1 (IGF-1) by time-resolved fluoroimmunoassays, whole-body fat mass by dual-energy X-ray absorptiometry and HOMA-IR were determined by homeostatic model assessment. The associations were examined using cross-lagged path models. Results In a cross-lagged path model, SHBG predicted HOMA-IR before menarche β = −0.320 (95% CI: −0.552 to −0.089), P = 0.007, independent of adiposity and IGF-1. After menarche, no directional effect was found between SHBG and insulin resistance or adiposity. Conclusions Our results suggest that in early puberty, decline in SHBG predicts development of insulin resistance, independent of adiposity. However, after menarche, no directional influences between SHBG, adiposity and insulin resistance were found, suggesting that observational associations between SHBG, adiposity and insulin resistance in pubertal children may be subject to confounding. Further research is needed to understand the underlying mechanisms of the associations between SHBG and cardiometabolic risk markers in peripubertal children.

Elevated impact loading can be detrimental to runners as it has been linked to the increased risk of tibial stress fracture and plantar fasciitis. The objective of this study was to investigate the combined effects of foot strike pattern, step rate, and anterior trunk lean gait modifications on impact loading in runners. Nineteen healthy runners performed 12 separate gait modification trials involving: three foot strike patterns (rearfoot, midfoot, and forefoot strike), two step rates (natural and 10% increased), and two anterior trunk lean postures (natural and 10-degree increased flexion). Overall, forefoot strike combined with increased step rate led to the lowest impact loading rates, and rearfoot strike combined with anterior trunk lean led to the highest impact loading rates. In addition, there were interaction effects between foot strike pattern and step rate on awkwardness and effort, such that it was both more natural and easier to transition to a combined gait modification involving forefoot strike and increased step rate than to an isolated gait modification involving either forefoot strike or increased step rate. These findings could help to inform gait modifications for runners to reduce impact loading and associated injury risks. peerReviewed

Background The primary aim of this study was to examine the associations of normal weight obesity (NWO) with physical fitness in Chinese university students. As a secondary aim, we assessed whether possible differences in physical fitness between students classified as NWO and normal weight non-obese (NWNO) were mediated by skeletal muscles mass. Methods A total of 383 students (205 males and 178 females, aged 18–24 years) from two universities volunteered to participate in this study. Body height and weight were measured by standard procedures and body composition was assessed by bio-impedance analysis (InBody 720). NWO was defined by a BMI of 18.5–23.9 kg/m2 and a body fat percentage of > 20% or > 30% in male and female students, respectively. Physical fitness was measured using a 10-min intermittent endurance running test (Andersen test), countermovement jumps (CMJ) and a 5 × 5 m shuttle run test (5mSR). The level of leisure time physical activity (PA) was assessed by a questionnaire. Results 13.7% of male and 27.5% of female students were classified as NWO. Compared to NWNO, students classified as NWO showed a significantly poorer performance in the Andersen test (males: 1146 ± 70 m vs. 1046 ± 95 m, females: 968 ± 61 m vs. 907 ± 67 m, p

This study assessed the associations of maximal isometric strength and movement economy in 126 recreationally active men and women. Oxygen consumption was assessed through a graded treadmill test with 4-minute increments (4-12 km∙h

Background: How bone properties would change after exercise intervention in patients with comorbidities are largely unknown. This study investigated the impact of Nordic walking on bone properties in postmenopausal women with pre-diabetes and non-alcohol fatty liver disease (NAFLD).Methods: The study is a part of a large randomized controlled trial. Of the eligible participants, 63 postmenopausal women (aged 50-65 years) with prediabetes and NAFLD participated in either a progressive supervised Nordic walking training (60-75% VO2max intensity), 2-3 times/week, 30-60 min/sessions for 8.6-month (AEx, n=33), or maintained their daily lifestyle during intervention (Con, n=30). Bone mineral content (BMC) and density (BMD) of the whole body (WB), total femur (TF), femoral neck (FN) and lumbar spine (L2-4) were assessed by a dual-energy X-ray absorptiometry. Venous blood samples were analyzed for serum osteocalcin, pentosidine and receptor activator of nuclear factor kappa-B ligand (RANKL) levels by ELISA assay. Results: After 8.6-month intervention, the AEx group maintained their BMCTF, BMDTF, BMCL2-4 and BMDL2-4, and increased their BMCFN (pTF (pTF (pL2-4 (pL2-4 (p=0.013). Decreased pentosidine was correlated with increased BMCWB (=-0.352, p=0.019). The intervention has no significant effect on osteocalcin and RANKL. Conclusions: Our results suggest that Nordic walking is effective in preventing bone loss among postmenopausal women with pre-diabetes and NAFLD. Changing of bone mass is associated with changing of pentosidine. However, this effect is not associated with osteocalcin and RANKL.Trial registration: ISRCTN registry, ISRCTN 42622771, registered 23 April 2013, https://www.isrctn.com/