The effects of a 20-week exercise program on blood-circulating biomarkers related to brain health in overweight or obese children:The ActiveBrains project

Background:Emerging research supports the idea that exercise positively affects neurodevelopment.However,the mechanisms linking exercise with brain health are largely unknown.We aimed to investigate the effect of exercise on(a)blood biomarkers selected based on previous evidence(brainderived neurotrophic factor,β-hydroxybutyrate(BHB),cathepsin B(CTSB),kynurenine,fibroblast growth factor 21(FGF21),soluble vascular cell adhesion molecule-1(sVCAM-1));and(b)a panel of 92 neurology-related proteins(discovery analysis).We also investigated whether changes in these biomarkers mediate the effects of exercise on brain health(hippocampal structure and function,cognitive performance,and mental health).Methods:We randomized 81 overweight/obese children(10.1±1.1 years,41%girls)into 2 groups:either 20 weeks of aerobic plus resistance exercise or control.Candidate biomarkers were assessed using enzyme-linked immunosorbent assay(ELISA)for kynurenine,FGF21,and CTSB;colorimetry forβ-hydroxybutyrate;and XMap for brain-derived neurotrophic factor and soluble vascular cell adhesion molecule-1.The92 neurology-related proteins were analyzed by an antibody-based proteomic analysis.Results:Our intervention had no significant effect on candidate biomarkers(all p>0.05).In the discovery analysis,a reduction in circulating macrophage scavenger receptor type-I was observed(standardized differences between groups=-0.3,p=0.001).This effect was validated using ELISA methods(standardized difference=-0.3,p=0.01).None of the biomarkers mediated the effects of exercise on brain health.Conclusions:Our study does not support a chronic effect of exercise on candidate biomarkers.We observed that while chronic exercise reduced the levels of macrophage scavenger receptor type-Ⅰ,it did not mediate the effects of exercise on brain health.Future studies should explore the implications of this novel biomarker for overall health.

Longitudinal associations of physical activity and pubertal development with academic achievement in adolescents

Objective: We sought to investigate the longitudinal associations of moderate-to-vigorous physical activity(MVPA) and pubertal development with academic achievement in adolescents.Methods: A total of 635 adolescents(283 boys, 352 girls) aged 11-13 years participated in the study. MVPA was assessed by the Health Behaviour in School-aged Children study questionnaire, and pubertal development was assessed by the Pubertal Development Scale at beginning of the 6 th grade(baseline) and end of the 7 th grade(follow-up). Grade point average(GPA) at the end of Grades 5 and 7 was computed from data acquired from the school registers. The data were analyzed using linear regression and analyses of covariance.Results: In boys, MVPA was positively associated with GPA at baseline after adjustment for age(b = 0.144, 95% confidence interval(CI):0.028-0.260, p = 0.028). In girls, the Pubertal Development Scale was positively associated with GPA at baseline(b = 0.104, 95%CI: -0.004 to0.211, p = 0.058) and follow-up(b = 0.104, 95%CI: -0.002 to 0.211, p = 0.055) after adjustment for age, and these associations strengthened after further adjustment for MVPA(p < 0.05). Adolescents who were inactive at baseline or at baseline and follow-up had lower GPA during followup than their continuously highly active peers(mean difference = -0.301, 95%CI: -0.543 to -0.058, p = 0.009) and all other adolescents(mean difference = -0.247, 95%CI: -0.475 to -0.019, p = 0.029). These differences were greater in girls than in boys.Conclusion: Lower levels of MVPA were associated with lower GPA in boys at baseline. Girls who were continuously inactive had lower GPA over the follow-up period than those who were continuously active. Finally, earlier pubertal development was associated with better academic achievement in girls.

The roles of microRNA in redox metabolism and exercise-mediated adaptation

MicroRNAs(miRs)are small regulatory RNA transcripts capable of post-transcriptional silencing of mRNA messages by entering a cellular bimolecular apparatus called RNA-induced silencing complex.miRs are involved in the regulation of cellular processes producing,eliminating or repairing the damage caused by reactive oxygen species,and they are active players in redox homeostasis.Increased mitochondrial biogenesis,function and hypertrophy of skeletal muscle are important adaptive responses to regular exercise.In the present review,we highlight some of the redox-sensitive regulatory roles of miRs.

Cold dialysis and its impact on renal patients' health:An evidence-based mini review

Chronic renal disease is associated with advanced age,diabetes,hypertension,obesity,musculoskeletal problems and cardiovascular disease,the latter being the main cause of mortality in patients receiving haemodialysis(HD).Cooled dialysate(35 ℃-36 ℃) is recently employed to reduce the incidence of intradialytic hypotension in patients on chronic HD.The studies to date that have evaluated cooled dialysate are limited,however,data suggest that cooled dialysate improves hemodynamic tolerability of dialysis,minimizes hypotension and exerts a protective effect over major organs including the heart and brain.The current evidence-based review is dealing with the protective effect of cold dialysis and the benefits of it in aspects affecting patients' quality of care and life.There is evidence to suggest that cold dialysis can reduce cardiovascular mortality.However,large multicentre randomized clinical trials are urgently needed to provide further supporting evidence in order to incorporate cold dialysis in routine clinical practice.

Validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese office workers

Background:As sedentary behavior is a global health issue,there is a need for methods of self-reported sitting assessment.The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts.This study examined the validity of longterm and short-term recall of occupational sitting time in Finnish and Chinese subgroups.Methods:Two cohort groups of office-based workers(58.6%female,age range 22
67 years)participated:a Finnish group(FIN,n=34)and a Chinese group(CHI,n=36).Long-term(past 3-month sitting)and short-term(daily sitting assessed on 5 consecutive days)single-item measures were used to assess self-reported occupational sitting time.Values from each participant were compared to objectively measured occupational sitting time assessed via thigh-mounted accelerometers,with Spearman’s rho(r)used to assess validity and the Bland-Altman method used to evaluate agreement.Coefficients of variation depicted day-to-day variability of time spent on sitting at work.Results:In the total study sample,the results showed that both long-term and short-term recall correlated with accelerometer-derived sitting time(r=0.532,95%confidence intervals(CI):0.336
0.684,p<0.001;r=0.533,95%CI:0.449
0.607,p<0.001,respectively).Compared to objectively measured sitting time,self-reported occupational sitting time was 2.4%(95%CI:
0.5%to 5.3%,p=0.091)and 2.2%(95%CI:0.7%
3.6%,p=0.005)greater for long-term and short-term recall,respectively.The agreement level was within the range
21.2%to 25.9%for long-term recall,and
24.2%to 28.5%for short-term recall.During a 5-day work week,day-to-day variation of sitting time was 9.4%§11.4%according to short-term recall and 10.4%§8.4%according to accelerometry-derived occupational sitting time.Conclusion:Overall,both long-term and short-term self-reported instruments provide acceptable measures of occupational sitting time in an office-based workplace,but their utility at the individual level is limited due to large variability.

Restless legs syndrome is contributing to fatigue and low quality of life levels in hemodialysis patients

AIM To examine whether hemodialysis(HD) patients with restless legs syndrome(RLS) are subjects of greater fatigue and impaired quality of life(QoL) compared to HD patients without RLS.METHODS Eighty five stable HD patients participated in this study. According to their RLS status, the patients were dividedinto the RLS group(n = 23) and the non-RLS group(n = 62). QoL, fatigue, sleep quality, daily sleepiness and depression symptoms were assessed by using various questionnaires. Finally, biochemical parameters including iron, ferritin, hemoglobin, hematocrit and parathormone were assessed. RESULTS The HD patients with RLS scored worse in all the questionnaires used in the study(P < 0.05). The patients with RLS were more likely to receive the HD therapy on the morning shift, whilst 43.5% of the RLS patients reported to experience the RLS symptoms also during HD. The severity of RLS was correlated with fatigue, depression score and sleep quality(P < 0.05). CONCLUSION HD patients with RLS are subject to lower QoL related parameters and greater fatigue compared to HD patients without RLS. RLS should be successfully managed in order to improve the QoL of the sufferers.

Process and outcome evaluation of the “No more smoking! It's time for physical activity” program

Purpose:The aim of this study was to evaluate the program"No more smoking!It’s time for physical activity",with a mixed methods design,in order to collect information to improve the program for future applications.Methods:Forty patients across five anti-smoking clinics in Central Greece completed the program.Counselors’records and participants’questionnaires and interviews were used as data in order to evaluate the programs’process and outcome.Results:Quantitative measures before and after the program revealed significant differences on smoking behavior,physical activity(PA)behavior,self-efficacy,and smoking habit measures.Qualitative data implied that the promotion of PA as a cessation aid was perceived as positive by the participants and both participants’and counselors’statements were encouraging for the effectiveness of PA promotion during the program as a cessation-aid technique.Conclusion:Evaluation of the"No more smoking!It’s time for physical activity"program showed encouraging results.People who try to quit smoking can become more physically active through targeted intervention and they regard PA as a significant aid in their efforts to quit smoking.

Exercise cardiac power and the risk of heart failure in men:A population-based follow-up study

Background:Little is known about exercise cardiac power(ECP),defined as the ratio of directly measured maximal oxygen uptake with peak systolic blood pressure during exercise,on heart failure(HF)risk.We examined the association of ECP and the risk of HF.Methods:This was a population-based cohort study of 2351 men from eastern Finland.The average time to follow-up was 25 years.Participants participated at baseline in an exercise stress test.A total of 313 cases of HF occurred.Results:Men with low ECP(<9.84 mL/mmHg,the lowest quartile)had a 2.37-fold(95%confidence interval(95%CI):1.68-3.35,p<0.0001)hazards ratio of HF as compared with men with high ECP(>13.92 mL/mmHg,the highest quartile),after adjusting for age.Low ECP was associated with a 1.96-fold risk(95%CI:1.38-2.78,p<0.001)of HF after additional adjustment for conventional risk factors.After further adjustment for left ventricular hypertrophy,the results hardly changed(hazards ratio=1.87,95%CI:1.31-2.66,p<0.001).One SD increase in ECP(3.16 mL/mmHg)was associated with a decreased risk of HF by 28%(95%CI:17%-37%).Conclusion:ECP provides a noninvasive and easily available measure from cardiopulmonary exercise tests in predicting HF.However,ECP did not provide additional value over maximal oxygen uptake.

Relationship between peak oxygen uptake and regional body composition in Japanese subjects

Purpose： To investigate the link between peak oxygen uptake and regional body composition by dual energy X-ray absorptiometry （DEXA） in Japanese subjects. Methods： A total of 93 men （42.2 ± 12.3 years old） and 106 women （43.5 ± 12.3 years old） were enrolled in this cross-sectional investigation study. Peak oxygen uptake was measured by the breath-by-breath method. Regional body composition i.e., body fat mass, lean body mass, and body fat percentage was evaluated using DEXA. In addition, metabolic risk parameters were also evaluated. Results： Peak oxygen uptake was 37.6± 8.7 mL/kg/min in men and 31.1 ± 6.4 mL/kg/min in women, and decreased with age in both genders. Peak oxygen uptake was significantly correlated with total body fat percentage （men： r = -0.684, p 〈 0.0001; women： r = -0.681, p 〈 0.0001）. These associations remained even after adjusting for age and total lean body mass. However, peak work rate was positively and significantly correlated with leg lean body mass. Conclusion： Peak oxygen uptake was closely correlated with total body fat percentage in both genders. Aerobic exercise as well as leg resistance training might be useful for improving peak oxygen uptake in Japanese subjects. Copyright

Oxygen uptake during the last bouts of exercise incorporated into high-intensity intermittent cross-exercise exceeds the V_ O2max of the same exercise mode

Oxygen uptake(V O_(2))was measured during a non-exhaustive high-intensity intermittent cross-exercise(HIICE)protocol consisting of four alternating bouts of 20 s running(R)and three bouts of bicycle exercise(BE)at~160%and~170%maximal oxygen uptake(V O_(2)max),respectively,with 10 s between-bout rests(sequence R-BE-R-BER-BE-R).The V O_(2) during the last BE([52.2±5.0]mL⋅kg^(-1)⋅min^(-1))was significantly higher than the V O_(2)max of the BE([48.0±5.4]mL⋅kg^(-1)⋅min^(-1),n=30)and similar to that of running.For clarifying the underlying mechanisms,a corresponding HIICE-protocol with BE and arm cranking ergometer exercise(AC)was used(sequence AC-AC-BE-AC-BE-AC-AC-BE).In some experiments,thigh blood flow was occluded by a cuff around the upper thigh.Without occlusion,the V O_(2) during the AC([39.2±7.1]mL⋅kg^(-1)⋅min^(-1)[6th bout])was significantly higher than the V O_(2)max of AC([30.2±4.4]mL⋅kg^(-1)⋅min^(-1),n=7).With occlusion,the corresponding V O_(2)([29.8±3.9]mL⋅kg^(-1)⋅min^(-1))was reduced to that of the V O_(2)max of AC and significantly less than the V O_(2) without occlusion.These findings suggest that during the last bouts of HIICE may exceed the of the specific exercise,probably because it is a summation of the V O_(2) for the ongoing exercise plus excess post-oxygen consumption(EPOC)produced by the previous exercise with a higher V O_(2)max.

High intensity interval training and molecular adaptive response of skeletal muscle

Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and endurance capacity for top athletes and for the general public as well.Because of the high intensity of this type of training,the adaptive response is not restricted to Type I fibers,as found for moderate intensity exercise of long duration.Even with a short exercise duration,HIIT can induce activation of AMPK,PGC-1α,SIRT1 and ROS pathway as well as by the modulation of Ca^(2+)homeostasis,leading to enhanced mitochondrial biogenesis,and angiogenesis.The present review summarizes the current knowledge of the adaptive response of HIIT.

MUSCLE RESEARCH WORK WITH BRITTON CHANCE FROM IN VIVO MAGNETIC RESONANCE SPECTROSCOPY TO NEAR-INFRARED SPECTROSCOPY

Britton Chance has pioneered magnetic resonance spectroscopy(MRS)and near-infrared(NIR)spectroscopy(NIRS)as noninvasive methods for measuring muscle metabolism in vivo from the late 1970s.This review honoring Britton Chance will highlight the progress that has been made in developing and utilizing MRS and NIRS technologies for evaluating skeletal muscle O_(2) dynamics and energetics.Adaptation of MRS and NIRS technology has focused on the validity and reliability of the measurements and extending the methods in physiological and clinical research.Britton Chance has conducted MRS and NIRS research on elite athletes and a number of chronic health conditions,including patients with chronic heart failure,peripheral vascular disease,and neuromuscular myopathies.As MRS and NIRS technologies are practical and useful for measuring human muscle metabolism,we will strive to continue Chance's legacy by advancing muscle MRS and NIRS studies.

An fNIRS-Based Study on Prefrontal Cortex Activity during a Virtual Shopping Test with Different Task Difficulties in Brain-Damaged Patients

We developed a Virtual Shopping Test with three different task levels for assessment of daily cognitive function using virtual reality technology. The objective of present study was to investigate the difference on task performance, brain activation and subjective assessment in relation to the difficulty levels of the tasks. Subjects were asked to buy specific 2 items in Task 1, 4 items in Task 2, and 6 items in Task 3 at a virtual mall. The tasks and questionnaires were conducted on 10 convalescent brain-damaged patients and 6 healthy young adults. Hemodynamic changes in the prefrontal cortex (PFC) during activation due to the tasks were examined using functional near-infrared spectroscopy. As the result, the mean total time was significantly longer for the patients than for healthy subjects. PFC showed a greater response for related Task 2 than Task 1 in shopping and moving phase in patient group. The patients evaluated Tasks 1 and 2 are more difficult and bring more psychological load than healthy adults subjectively. That is, although the healthy adults did not show large difference in their task performances as well as PFC responses, they can evaluate the differences between three task levels, subjectively, while which could not be for the patients means that patients could not distinguish the difference of the tasks, subjectively. The results suggest that 4-item shopping task might be enough difficulty level that causes brain activation for the brain-damaged patients.

Effects of exercise and dietary interventions on serum metabolites in men with insomnia symptoms:A 6-month randomized controlled trial

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.

Landing in Ski Jumping: A Review About its Biomechanics and the Connected Injuries

The present review deals with the current scientific knowledge related with ski jump landing.A specific focus is given on the landing biomechanics,the methods utilized for its analysis and the injuries connected to the landing phase.Despite the demonstrated importance for the safety and the performance of ski jumpers,the landing and its preparation are rarely inves-tigated.In this paper,after having firstly described the execution of landing and its preparation and the reason why is impor-tant to analyze it,an overview of the current status of the research related to the landing biomechanics is reported(kinetics,kinematics,electromyographic activation,aerodynamics,computer simulation).The third part describes the methods and technologies utilized in literature to analyze the landing and its preparation(video cameras,inertial sensors,force insoles,wind tunnel and computer simulation).After that,an overview of the injuries related to landing is reported.The final section proposes future research in the field of biomechanics of ski jump landing in different fields,such as computer simulations,kinematic analysis,equipment development and biomechanics of female athletes.

Force Generation Profiles of Para-Nordic Sit-Skiers Representing Different Physical Impairments

Purpose To biomechanically profile force generation connected to the complex role of the trunk in double poling in a rep-resentative sample of Para-Nordic sit-skiers.Methods Twelve male World Cup Para-Nordic sit-skiers(sport classes:LW10-12)were skiing on flat snow terrain at submaximal speed of 4.5 m/s(~73% max imum speed).2D video(50 Hz)and pole force analyses(1000 Hz)were performed synchronously,examining angle,force and cycle characteristics to analyse the role of the trunk in generating propulsion.Results LW10-11.5 skiers lost between 21%and 4%propulsive force versus LW12 athletes only due to different geomet-rics of the trunk and pole angle at an equal axial pole force.While LW10-11 skiers indicated trunk extension or position maintenance during pole thrust,LW11.5-12 skiers showed strong trunk flexion combined with smaller pole angles to the ground.Hence,LW11.5-12 skiers could create larger propulsive forces and therefore greater cycle lengths at lower cycle rates at the same speed.Maximum speed increased from LW10 to LW12 and was significantly correlated to trunk flexion range of motion(r=0.63)and cycle length(r=0.59).Trunk flexion ROM showed a significant relationship to the impulse of propulsive force(r=0.63)and pole angle to the ground(r=−0.76)(all P<0.05).Conclusion The impact of impairment on the force production profiles and its physiological-biomechanical consequences need further investigation also in other terrains and at wider spectrums of skiing speeds.The evident problem of low numbers of LW10-11 skiers in World Cup needs creative future solutions for research.

Assessment of sleep disturbances with the athlete sleep screening questionnaire in Chinese athletes

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(SDS8).Approximately 14.2%of participants had moderate to severe sleep problem(SDS8).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.

Inflammatory Biomarkers in Elite Cross-Country Skiers After a Competition Season:A Case-Control Study

Purpose Whether elite athletes,who have been exposed to vigorous-intensity exercise combined with other stressors,have elevated systemic low-grade inflammation,remains largely unclear.To address this question,we studied the levels of six inflammatory cytokines as potential biomarkers of a low-grade inflammatory state in elite athletes after an 11-month train-ing and competition season.Methods We collected sera from 27 Finnish elite cross-country skiers and 27 gender-and age-matched,moderately-exer-cising controls.The serum concentrations of C-reactive protein(CRP),interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),glycoprotein acetyls(GlycA),interleukin 10(IL-10),and interferon gamma(IFN-γ)cytokines were quantified as surrogate markers of low-grade inflammation.Results The athletes were found to have significantly lower concentrations of CRP(P=0.0232)and higher concentrations of IL-10,TNF-α,and IFN-γ(P=0.0097,P=0.0256,and P=0.0185,respectively)than the controls.No significant differences between athletes and controls were detected in the concentrations of IL-6 and GlycA.The inflammatory score(IS)did not differ significantly between athletes and controls.Conclusion The results of this study argued against the hypothesis of a significant chronic low-grade inflammation in response to prolonged high-performance exercise among elite endurance athletes.

Exercise precision medicine for type 2 diabetes:Targeted benefit or risk?

Concurrent exercise and metformin administration may reduce the acute and chronic effects of exercise on glucose metabolism in the patients with type 2 diabetes(T2D).However,several studies suggest that combing metformin and exercise treatment may have neither additive effect nor even cause adverse effects in T2D patients.This case report aimed to highlight the challenges associated with prescribing exercise to type 2 diabetes patients undergoing metformin treatment.A 67-years old woman was followed-up for five months,including assessment of the acute and chronic glucose and lactate metabolism induced by concomitant exercise and metformin.The findings were four-fold:1)During a high-intensity interval training bout,blood glucose systematically decreased,while blood lactate concentrations fluctuated randomly;2)Basal blood lactate levels were well above 2 mmol/L on days with medication only;3)Combined exercise and metformin administration induced additive effects on the normalization of glucose and 4)high levels of physical activity had a positive impact on the continuous glucose fluctuations,while decreased levels of physical activity induced a large fluctuation of glucose due to home confinement of an infectious disease caused by the SARS-CoV-2 virus.Our findings showed that when combined with exercise and metformin treatment for T2D patients,exercise may contribute to improving glycemic control while metformin may elevate lactate levels in the long term.The observed results underline the need to prescribe exercise and monitor lactate levels for reducing possible risks associated with metformin treatment and reinforce the importance of tailoring exercise therapy.

Editorial

Welcome to the Special Issue of the Journal of Science in Sport and Exercise(SSEJ)focusing on Winter Sports and in particular Nordic and alpine skiing.The 2022 Winter Olympics are approaching and the research community is assisting athletes and coaches to achieve peak per-formances in 2022.