Effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in type 2 diabetes:A systematic review

BACKGROUND Type 2 diabetes mellitus(T2DM)is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction,reduced functional capacity and exercise intolerance.Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases.High intensity interval training(HIIT)seems to be superior than moderate-intensity continuous training(MICT)in cardiovascular diseases by improving brachial artery flow-mediated dilation(FMD)and cardiorespiratory fitness to a greater extent.However,the beneficial effects of HIIT in patients with T2DM still remain under investigation and number of studies is limited.AIM To evaluate the effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in patients with T2DM.METHODS We performed a search on PubMed,PEDro and CINAHL databases,selecting papers published between December 2012 and December 2022 and identified published randomized controlled trials(RCTs)in the English language that included community or outpatient exercise training programs in patients with T2DM.RCTs were assessed for methodological rigor and risk of bias via the Physiotherapy Evidence Database(PEDro).The primary outcome was peak VO_(2 ) and the secondary outcome was endothelial function assessed either by FMD or other indices of microcirculation.RESULTS Twelve studies were included in our systematic review.The 12 RCTs resulted in 661 participants in total.HIIT was performed in 310 patients(46.8%),MICT to 271 and the rest 80 belonged to the control group.Peak VO_(2 ) increased in 10 out of 12 studies after HIIT.Ten studies compared HIIT with other exercise regimens(MICT or strength endurance)and 4 of them demonstrated additional beneficial effects of HIIT over MICT or other exercise regimens.Moreover,4 studies explored the effects of HIIT on endothelial function and FMD in T2DM patients.In 2 of them,HIIT further improved endothelial function compared to MICT and/or the control group while in the rest 2 studies no differences between HIIT and MICT were observed.CONCLUSION Regular aerobic exercise training has beneficial effects on cardiorespiratory fitness and endothelial function in T2DM patients.HIIT may be superior by improving these parameters to a greater extent than MICT.

High-Intensity Interval Training v/s Steady-State Cardio in Rehabilitation of Neurological Patients

Neuropathy is nerve damage that can cause chronic neuropathic pain, which is challenging to cure and has a significant financial burden. Exercise therapies, including High-Intensity Interval Training (HIIT) and steady-state cardio, are being explored as potential treatments for neuropathic pain. This systematic review compares the effectiveness of HIIT and steady-state cardio for improving function in neurological patients. This article provides an overview of the systematic review conducted on the effects of exercise on neuropathic patients, with a focus on high-intensity interval training (HIIT) and steady-state cardio. The authors conducted a comprehensive search of various databases, identified relevant studies based on predetermined inclusion criteria, and used the EPPI automation application to process the data. The final selection of studies was based on validity and relevance, with redundant articles removed. The article reviews four studies that compare high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on various health outcomes. The studies found that HIIT can improve aerobic fitness, cerebral blood flow, and brain function in stroke patients;lower diastolic blood pressure more than MICT and improve insulin sensitivity and skeletal muscle mitochondrial content in obese individuals, potentially helping with the prevention and management of type 2 diabetes. In people with multiple sclerosis, acute exercise can decrease the plasma neurofilament light chain while increasing the flow of the kynurenine pathway. The available clinical and preclinical data suggest that further study on high-intensity interval training (HIIT) and its potential to alleviate neuropathic pain is justified. Randomized controlled trials are needed to investigate the type, intensity, frequency, and duration of exercise, which could lead to consensus and specific HIIT-based advice for patients with neuropathies.

Impact of a single bout of high-intensity interval exercise and short-term interval training on interleukin-6, FNDC5, and METRNL mRNA expression in human skeletal muscle

Background: Exercise promotes numerous phenotypic adaptations in skeletal muscle that contribute to improved function and metabolic capacity. An emerging body of evidence suggests that skeletal muscle also releases a myriad of factors during exercise, termed "myokines". The purpose of this study was to examine the effects of high-intensity interval training(HIIT) on the acute regulation of the mRNA expression of several myokines, including the prototypical myokine interleukin-6(IL-6), and recently identified myokines fibronectin type III domain-containing protein 5(FNDC5)(irisin) and meteorin-like protein(METRNL).Methods: Both before and after a 20-day period of twice-daily high-volume HIIT, 9 healthy males(20.5 ± 1.5 years performed a standardized bout of high-intensity interval exercise(HIIE; 5 × 4 min at ~80% pretraining peak power output) with skeletal muscle biopsy samples(vastus lateralis) obtained at rest, immediately following exercise, and at 3 h recovery.Results: Before training, a single bout of HIIE increased IL-6(p < 0.05) and METRNL(p < 0.05) mRNA expression measured at 3 h recovery when compared to rest. Following 20 days of HIIT, IL-6 and FNDC5 mRNA were increased at 3 h recovery from the standardized HIIE bout when compared to rest(both p < 0.05). Resting METRNL and FNDC5 mRNA expression were higher following training(p < 0.05), and there was an overall increase in FNDC5 mRNA post-training(main effect of training, p < 0.05).Conclusion: In human skeletal muscle(1) an acute bout of HIIE can induce upregulation of skeletal muscle IL-6 mRNA both before and after a period of intensified HIIT;(2) Resting and overall FNDC5 mRNA expression is increased by 20 days of HIIT; and(3) METRNL mRNA expression is responsive to both acute HIIE and short-term intense HIIT. Future studies are needed to confirm these findings at the protein and secretion level in humans.

High-intensity interval training(HIIT) for patients with chronic diseases

Exercise training provides physiological benefits for both improving athletic performance and maintaining good health. Different exercise training modalities and strategies exist. Two common exercise strategies are high-intensity interval training （HIIT） and moderate-intensity continuous exercise training （MCT）. HIIT was first used early in the 20th century and popularized later that century for improving performance of Olympic athletes. The primary premise underlying HIIT is that, compared to energy expenditure-matched MCT, a greater amount of work is performed at a higher intensity during a single exercise session which is achieved by alternating high-intensity exercise intervals with low-intensity exercise or rest intervals. Emerging research suggests that this same training method can provide beneficial effects for patients with a chronic disease and should be included in the comprehensive medical management plan. Accordingly, a major consideration in developing an individual exercise prescription for a patient with a chronic disease is the selection of an appropriate exercise strategy. In order to maximize exercise training benefits, this strategy should be tailored to the individual＇s need. The focus of this paper is to provide a brief summary of the current literature re^ardin~ the use of HIIT to enhance the fimctional capacity of individuals with cardiovascular, pulmonary, and diabetes diseases.

Six high-intensity interval training sessions over 5 days increases maximal oxygen uptake,endurance capacity,and sub-maximal exercise fat oxidation as much as 6 high-intensity interval training sessions over 2 weeks

Background:High-intensity interval training(HIIT)induces similar or even superior adaptations compared to continuous endurance training.Indeed,just 6 HIIT sessions over 2 weeks significantly improves maximal oxygen uptake(VO_(2max)),submaximal exercise fat oxidation,and endurance performance.Whether even faster adaptations can be achieved with HIIT is not known.Thus,we aimed to determine whether 2 sessions of HIIT per day,separated by 3 h,every other day for 5 days(double HIIT(HIIT-D),n=15)could increase VO_(2max),submaximal exercise fat oxidation,and endurance capacity as effectively as 6 sessions of HIIT over 2 weeks(single HIIT(HIIT-S),n=13).Methods:Each training session consisted of 10×60 s of cycling at 100%of VO_(2max)interspersed with 75 s of low-intensity cycling at 60 watt(W).Pre-and post-training assessments included VO_(2max),time to exhaustion at-80%of VO_(2max),and 60-min cycling trials at-67%of VO_(2max).Results:Similar increases(p<0.05)in VO_(2max)(HIIT-D:7.7%vs.HIIT-S:6.0%,p>0.05)and endurance capacity(HIIT-D:80.1%vs.HIIT-S:79.2%,p>0.05)were observed.Submaximal exercise carbohydrate oxidation was reduced in the 2 groups after exercise training(HIIT-D:9.2%,p=0.014 vs.HIIT-S:18.8%,p=0.012)while submaximal exercise fat oxidation was significantly increased in HIIT-D(15.5%,p=0.048)but not in HIIT-S(9.3%,p=0.290).Conclusion:Six HIIT sessions over 5 days was as effective in increasing VO_(2max)and endurance capacity and was more effective in improving submaximal exercise fat oxidation than 6 HIIT sessions over 2 weeks.

Femoral neck stress fracture and medial tibial stress syndrome following high intensity interval training: A case report and review of literature

BACKGROUND Femoral and tibial stress injuries are commonly found in long distance running athletes.Stress fractures have rarely been reported in athletes performing high intensity interval training(HIIT)exercise.The objective of this study was to report a case of a patient who presented with medial tibial stress syndrome and femoral neck stress fracture after performing HIIT exercises.CASE SUMMARY A 26 year old female presented with bilateral medial tibial pain.She had been performing HIIT exercise for 45 min,five times weekly,for a seven month period.Her tibial pain was gradual in onset,and was now severe and worse on exercise,despite six weeks of rest.Magnetic resonance imaging(MRI)revealed bilateral medial tibial stress syndrome.As she was taking norethisterone for birth control,a dual energy X-ray absorbitometry scan was performed which demonstrated normal bone mineral density of her lumbar spine and femoral neck.She was managed conservatively with analgesia and physiotherapy,but continued to exercise against medical advice.She presented again six months later with severe right hip pain.MRI of her right hip demonstrated an incomplete stress fracture of her subtrochanteric region.Her symptoms resolved with strict rest and physiotherapy.CONCLUSION HIIT may cause stress injury of the tibia and femur in young individuals.

Running slow or running fast;that is the question:The merits of high-intensity interval training

In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance adaptations in recreational runners.

The Comparison of the Effects of Two Types of High Intensity Interval Training （HILT） on Body Mass and Physiological Indexes in Inactive Female Students

The aim of this study was to compare the effects of two types of high intensity interval training （HIIT） on body mass and physiological indexes in inactive female students. 27 inactive female students （mean age 24.81 ±0.66 yr, height 162.09 ±0.67 cm, weight 59.41 ±0.33 kg） were voluntarily selected and randomly assigned to three groups （each group = 9 subjects） of high intensity interval training （type I）, high intensity interval training （type 2） and control. HIIT （type 1） （8 seconds of sprint running and 12 seconds of active recovery） was performed for 4 weeks, 3 sessions per week, 6-9 min. per session with above 90% maxHR. HIlT （type 2） （40-m shuttle run test with maximum speed） was performed with above 90% max HR while the control group did not participate in any training. Data analysis with dependent t test showed that HIIT （type 1） and HIlT （type 2） significantly increased VO2max while they decreased fat percentage and BMI. The intergroup data were analyzed by one-way ANOVA at P 〈 0.05. The results showed a significant difference among HIlT （type 1）, HIIT （type 2） and control groups in VO2max, BMI and fat percentage.

High-Intensity Interval Training and Diabetes Mellitus

Background: Diabetes mellitus often develops on the background of insulin resistance. High-intensity interval training (HIIT) is included in the treatment of diabetes mellitus since it increases the sensitivity of tissues to insulin. Objective: This paper aimed to review published articles on the effects of HIIT on insulin resistance in diabetic patients. Method: A narrative literature review was undertaken. This review provides evidence from human studies, which highlights the beneficial effects of HIIT in both T1DM and T2DM patients. Conclusion: HIIT is generally safe and effective for people with diabetes mellitus and warrants further exploration.

Effect of Aerobic High-Intensity Interval Training on VO2max and Anaerobic Power in Cross-Country Skiers

The purpose of this study was to investigate whether eight weeks of aerobic high-intensity interval training with roller ski is effective in cross-country skiers. 10 male （age, 18.28 ± 2.1 years; height, 171.26 ± 4.12 cm; weight 61.39 ± 6.28 kg） and 8 female （age, 16.05 ± 0.3 years; height, 158.3 ± 6.47 cm; weight, 49.34 ± 0.7 kg） junior cross country skiers completed the study. All skiers performed a 2 × 2-kin all-out uphill intervals with roller-skis, 3 times a week, in addition to their traditional training program. Measurements included VO2max （maximal oxygen uptake）, anaerobic power, and also for 2-km roller ski. All values were listed as pre-to post-test mean （± SD）, significant level, and percentage changes （%）. Pre-to post-testing changes in VO2max, anaerobic power, and also 2-kin roller ski performance were significantly higher during all post-test trials in all groups （P 〈 0.005）. With reference to the training effects found in our study, we suggest that the skiers should integrate the roller ski aerobic high-intensity interval uphill models in their training programs for improving performance.

Elevated meteorin-like protein from high-intensity interval training improves heartfunctionviaAMPK/HDAC4pathway

High-intensity interval training(HIlT)has been found to be more effective in relieving heart failure(HF)symptoms,than moderate-intensity continuous aerobic training(MICT).Additionally,higher meteorin-like protein(Metrnl)levels are seen after HIIT versus MICT.We investigated whether Metrnl contributed to post-HF cardiac functional improve-ments,and the signaling pathways involved.50 HF patients underwent MICT,and another 50,HllT,which was followed by cardiac function and serum Metrnl measurements.Metrnl was also measured in both blood and skeletal muscle samples of mice with transverse aortic constriction-induced HF after undergoing HIIT.Afterward,shRNA-containing adenovectors were injected into mice,yielding five groups:control,HF,HF+HIIT+scrambled shRNA,HF+HIIT+shMetrnl,and HF+Metrnl(HF+exogenous Metrnl).Mass spectrometry identified specific signaling pathways associated with increased Metrnl,which was confirmed with biochemical analyses.Glucose metabolism and mitochondrial functioning were evaluated in cardiomyocytes from the five groups.Both HF patients and mice had higher circulating Metrnl levels post-HIIT.Metrnl activated AMPK in cardiomyocytes,subsequently increasing histone deacetylase 4(HDAC4)phosphorylation,leading to its cytosolic sequestration and inactivation via binding with chaperone protein 14-3-3.HDAC4 inactivation removed its repression on glucose transporter type 4,which,along with increased mitochondrial complex I-V expression,yielded improved aerobic glucose respiration and alleviation of mitochondrial dysfunction.All these changes ultimately result in improved post-HF cardiac functioning.HIT increased skeletal muscle Metrnl production,which then operated on HF hearts to alleviate their functional defects,via increasing aerobic glucose metabolism through AMPK-HDAC4 signaling.

Aerobic interval training preconditioning protocols inhibit isoproterenol-induced pathological cardiac remodeling in rats:Implications on oxidative balance,autophagy,and apoptosis

This study aimed to investigate the potential cardioprotective effects of moderate and high-intensity aerobic interval training(MIIT and HIIT)preconditioning.The focus was on histological changes,pro-oxidant-antioxidant balance,autophagy initiation,and apoptosis in myocardial tissue incited by isoproterenol-induced pathological cardiac remodeling(ISO-induced PCR).Male Wistar rats were randomly divided into control(n=6),ISO(n=8),MIIT(n=4),HIIT(n=4),MIIT+ISO(n=8),and HIIT+ISO(n=8)groups.The MIIT and HIIT protocols were administered for 10 weeks,followed by the induction of cardiac remodeling using subcutaneous injection of ISO(100 mg/kg for two consecutive days).Alterations in heart rate(HR),mean arterial pressure(MAP),rate pressure product(RPP),myocardial oxygen consumption(MVO_(2)),cardiac hypertrophy,histopathological changes,prooxidant-antioxidant balance,autophagy biomarkers(Beclin-1,Atg7,p62,LC3Ⅰ/Ⅱ),and apoptotic cell distribution were measured.The findings revealed that the MIIT+ISO and HIIT+ISO groups demonstrated diminished myocardial damage,hemorrhage,immune cell infiltration,edema,necrosis,and apoptosis compared to ISO induced rats.MIIT and HIIT preconditioning mitigated HR,enhanced MAP,and preserved MVO_(2)and RPP.The pro-oxidant-antioxidant balance was sustained in both MIIT+ISO and HIIT+ISO groups,with MIIT primarily inhibiting pro-apoptotic autophagy progression through maintaining pro-oxidant-antioxidant balance,and HIIT promoting pro-survival autophagy.The results demonstrated the beneficial effects of both MIIT and HIIT as AITs preconditioning in ameliorating ISO-induced PCR by improving exercise capacity,hemodynamic parameters,and histopathological changes.Some of these protective effects can be attributed to the modulation of cardiac apoptosis,autophagy,and oxidative stress.

Vitamin C and E supplementation and high intensity interval training induced changes in lipid profile and haematological variables of young males

High intensity interval training(HIIT)causes oxidative stress and haematological alteration.Present study was aimed to evaluate the effect of 8 weeks’supplementation of vitamin C and E on HIIT induced changes in lipid profile parameters and haematological variables.Hundred six male adolescent players were randomly assigned into five age-matched groups,i.e.,Control(no exercise+placebo),HIIT(placebo),HIIT+vitamin-C(1000mg/day),HIIT+vitamin-E 400 IU/day)and combined HIIT+vitamin C and E.Morning and evening sessions(90min)of HIIT included 4 phases(15min each)with 3 sets(4min each).Each 4min HIIT set consisted of 2min intense sprint workout(90%–95%of heart rate maximum[HRmax])followed by 1min active recovery(60%–70%HRmax)followed by 1min of complete rest(1:1 work-rest ratio).Lipid profile parameters,haematological variables,endurance capacity and vertical jump were evaluated by standard protocols.Significant decrease in body weight,fat%,total cholesterol,triglyceride,Total Cholesterol/High Density Lipoprotein-Cholesterol and significant increase in High Density Lipoprotein-Cholesterol,maximal oxygen consumption,vertical jump were observed for all four intervention groups.White blood cell count,red blood cell count,haemoglobin percentage and haematocrit values were significantly decreased while platelet count and platelet-to-leukocyte ratio(PLR)ratio were increased significantly only for HIIT group.Blood level of tocopherol and ascorbic acid was significantly increased(values were within the normal range)in all the respective vitamin supplemented groups.Supplementation of vitamin C and E secures health protection with suppressed haemolysis and improved inflammatory blood variables with enhanced explosive leg strength and lipid profile parameters without any concomitant change in endurance capacity.

Research and Practice of Cardiopulmonary Rehabilitation Training Programs

In today’s society, the incidence of cardiopulmonary diseases is increasing annually, seriously affecting patients’ quality of life. Therefore, developing a scientific and effective rehabilitation training program is of great significance. This study first analyzes the theoretical basis of cardiopulmonary rehabilitation training, including the effects of aerobic exercise, interval training, and strength training on cardiopulmonary function. Based on this, a comprehensive rehabilitation training program is designed, which includes personalized training plans, comprehensive interventions, multidisciplinary collaboration, patient education, and regular follow-up visits. The cardiopulmonary rehabilitation training plan developed in this study has certain scientific practicability, which provides a theoretical basis for cardiopulmonary rehabilitation training, and also provides a reference for medical institutions, rehabilitation centers and communities, which is helpful for promotion and application to a wider range of patients with cardiopulmonary diseases.

Effects of High-Intensity Intermittent Training on Metabolic Parameters and Irisin Levels in High-Fat-Fed Rats

Objective:To investigate the effects of high-intensity intermittent training(HIIT)on preventing significant weight gain and provide scientific theoretical support and practical guidance for reducing the occurrence of obesity.Methods:Twenty-four Sprague-Dawley rats were randomly divided into four groups:the control sedentary group(CS),the high-fat sedentary group(HS),the high-fat continuous exercise group(HE),and the high-fat intermittent exercise group(HI).The HE and HI groups underwent five days of continuous low-intensity exercise and eight weeks of high-intensity intermittent exercise.Weekly monitoring included measurements of food intake and body weight.An automatic biochemical analyzer was used to assess blood lipid and glucose levels,while ELISA kits measured serum insulin and irisin content.H&E staining was used to observe adipocyte size.Results:In the HS group,body weight,blood lipid levels,blood glucose levels,and adipocyte size significantly increased,while the QUICKI index decreased.In the HI group,body weight,blood lipid levels,blood glucose levels,and adipocyte size decreased,and the QUICKI index increased.The effects of high-intensity intermittent exercise were superior to those of continuous low-intensity exercise.In the HI group,serum irisin levels did not change significantly after exercise,while in the HE group,there was a slight upward trend in irisin levels.Conclusion:A high-fat diet induced abnormal metabolism in rats.HIIT effectively prevents metabolic abnormalities induced by a high-fat diet,and its effects are more pronounced than those of low-intensity exercise.HIIT stimulates the secretion of blood irisin,affecting secretion levels,and may represent a novel mechanism for maintaining metabolic homeostasis.This has important implications for controlling significant weight gain.

Near-Field Beam Training for Holographic MIMO Communications: Typical Methods, Challenges and Future Directions

Holographic multiple-input multiple-output(HMIMO)has become an emerging technology for achieving ultra-high frequency spectral efficiency and spatial resolution in future wireless systems.The increasing antenna aperture leads to a more significant characterization of the spherical wavefront in near-field communications in HMIMO scenarios.Beam training as a key technique for wireless communication is worth exploring in this near-field scenario.Compared with the widely researched far-field beam training,the increased dimensionality of the search space for near-field beam training poses a challenge to the complexity and accuracy of the proposed algorithm.In this paper,we introduce several typical near-field beam training methods:exhaustive beam training,hierarchical beam training,and multi-beam training that includes equal interval multi-beam training and hash multi-beam training.The performances of these methods are compared through simulation analysis,and their effectiveness is verified on the hardware testbed as well.Additionally,we provide application scenarios,research challenges,and potential future research directions for near-field beam training.

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.

Risk of bias and reporting practices in studies comparing VO2max responses to sprint interval vs.continuous training:A systematic review and meta-analysis

Background:It remains unclear whether studies comparing _(max)imal oxygen uptake(VO_(2max))response to sprint interval training(SIT)vs.moderate-intensity continuous training(MICT)are associated with a high risk of bias and poor reporting quality.The purpose of this study was to evaluate the risk of bias and quality of reporting in studies comparing changes in VO_(2max) between SIT and MICT.Methods:We conducted a comprehensive literature search of 4 major databases:AMED,CINAHL,EMBASE,and MEDLINE.Studies were excluded if participants were not healthy adult humans or if training protocols were unsupervised,lasted less than 2 weeks,or utilized mixed exercise modalities.We used the Cochrane Collaboration tool and the CONSORT checklist for non-pharmacological trials to evaluate the risk of bias and reporting quality,respectively.Results:Twenty-eight studies with 30 comparisons(3 studies included 2 SIT groups)were included in our meta-analysis(n=360 SIT participants:body mass index(BMI)=25.9±3.7 kg/m^(2),baseline VO_(2max)=37.9±8.0 mL/kg/min;n=359 MICT participants:BMI=25.5±3.8 kg/m^(2),baseline VO_(2max)=38.3±8.0 mL/kg/min;all mean±SD).All studies had an unclear risk of bias and poor reporting quality.Conclusion:Although we observed a lack of superiority between SIT and MICT for improving VO_(2max)(weighted Hedge’s g=0.004,95%con-fidence interval(95%CI):-0.08 to 0.07),the overall unclear risk of bias calls the validity of this conclusion into question.Future studies using robust study designs are needed to interrogate the possibility that SIT and MICT result in similar changes in VO_(2max).

Suppressive effects of exercise-conditioned serum on cancer cells:A narrative review of the influence of exercise mode,volume,and intensity

Cancer is a major cause of morbidity and mortality worldwide,and the incidence is increasing,highlighting the need for effective strategies to treat this disease.Exercise has emerged as fundamental therapeutic medicine in the management of cancer,associated with a lower risk of recur-rence and increased survival.Several avenues of research demonstrate reduction in growth,proliferation,and increased apoptosis of cancer cells,including breast,prostate,colorectal,and lung cancer,when cultured by serum collected after exercise in vitro(i.e.,the cultivation of cancer cell lines in an experimental setting,which simplifies the biological system and provides mechanistic insight into cell responses).The underlying mechanisms of exercise-induced cancer suppressive effects may be attributed to the alteration in circulating factors,such as skeletal muscle-induced cytokines(i.e.,myokines)and hormones.However,exercise-induced tumor suppressive effects and detailed information about training interventions are not well investigated,constraining more precise application of exercise medicine within clinical oncology.To date,it remains unclear what role different training modes(i.e.,resistance and aerobic training)as well as volume and intensity have on exercise-condi-tioned serum and its effects on cancer cells.Nevertheless,the available evidence is that a single bout of aerobic training at moderate to vigorous intensity has cancer suppressive effects,while for chronic training interventions,exercise volume appears to be an influential candidate driving cancer inhibitory effects regardless of training mode.Insights for future research investigating training modes,volume and intensity are provided to further our understanding of the effects of exercise-conditioned serum on cancer cells.

Exercised blood plasma promotes hippocampal neurogenesis in the Alzheimer's disease rat brain

Background:Exercise training promotes brain plasticity and is associated with protection against cognitive impairment and Alzheimer’s disease(AD).These beneficial effects may be partly mediated by blood-borne factors.Here we used an in vitro model of AD to investigate effects of blood plasma from exercise-trained donors on neuronal viability,and an in vivo rat model of AD to test whether such plasma impacts cognitive function,amyloid pathology,and neurogenesis.Methods:Mouse hippocampal neuronal cells were exposed to AD-like stress using amyloid-βand treated with plasma collected from human male donors 3 h after a single bout of high-intensity exercise.For in vivo studies,blood was collected from exercise-trained young male Wistar rats(high-intensity intervals 5 days/week for 6 weeks).Transgenic AD rats(McGill-R-Thyl-APP)were inj ected 5 times/fortnight for 6 weeks at2 months or 5 months of age with either(a)plasma from the exercise-trained rats,(b)plasma from sedentary rats,or(c)saline.Cognitive function,amyloid plaque pathology,and neurogenesis were assessed.The plasma used for the treatment was analyzed for 23 cytokines.Results:Plasma from exercised donors enhanced cell viability by 44.1%(p=0.032)and reduced atrophy by 50.0%(p<0.001)in amyloid-β-treated cells.In vivo exercised plasma treatment did not alter cognitive function or amyloid plaque pathology but did increase hippocampal neurogenesis by~3 fold,regardless of pathological stage,when compared to saline-treated rats.Concentrations of 7 cytokines were significantly reduced in exercised plasma compared to sedentary plasma.Conclusion:Our proof-of-concept study demonstrates that plasma from exercise-trained donors can protect neuronal cells in culture and promote adult hippocampal neurogenesis in the AD rat brain.This effect may be partly due to reduced pro-inflammatory signaling molecules in exercised plasma.