Wearable near-infrared spectroscopy: reliability and sensitivity among different endurance cycling exercise intensities

The present study investigated the reliability and sensitivity of a wearable near-infrared spectroscopy (wNIRS) device in moderate and heavy exercise intensity domains. On three separate days, eleven males performed an incremental test to exhaustion, and in the following visits, four submaximal constant-load bouts (i.e., test and retest) were performed in the moderate-intensity domain (100 and 130 W) and heavy-intensity domain (160 and 190 W). The local tissue oxygen saturation index (SmO2) and pulmonary oxygen uptake (V̇O2) were measured continuously. The absolute SmO2 and V̇O2 values and the change (Δ) from the 3rd to 6th min of exercise were calculated. There was good reliability for SmO2 measurements, as indicated by the high intraclass correlation coefficient analysis (ICC ≥0.84 for all) and low coefficient of variation between the two trials (CV ≤4.1% for all). Steady-state responses were observed for SmO2 and V̇O2 from the 3rd to the 6th min in the two moderate-intensity bouts (P>0.05), whereas SmO2 decreased and V̇O2 increased from the 3rd to the 6th min in the two heavy-intensity bouts (P<0.05). Together, these findings suggested that the SmO2 measured with a wNIRS device is reliable and sensitive to track local metabolic changes provoked by slight increments in exercise intensity.

The role of mitochondrial autophagy-related receptor proteins and signaling pathways in the prevention and treatment of sarcopenia through exercise / 中国组织工程研究

BACKGROUND:Sarcopenia is an age-related degenerative syndrome,and the relationship between mitochondrial autophagy and exercise in preventing and treating sarcopenia has been demonstrated.However,there is a lack of comprehensive reviews detailing the specific receptor proteins and signaling pathways involved in the role of exercise in sarcopenia prevention and treatment. OBJECTIVE:To comprehensively introduce the specific receptor proteins and signaling pathways related to mitochondrial autophagy and their role in the prevention and treatment of sarcopenia through exercise. METHODS:A literature search was conducted between February 1,2023,and April 1,2023,covering literature from database inception to April 2023.Databases included the Web of Science,PubMed,China National Knowledge Infrastructure(CNKI),WanFang Data,and VIP.Keywords used for the search included sarcopenia,muscle wasting,aging,elderly,mitochondria,mitochondrial function,proteins,pathways,and others.After strict inclusion and exclusion criteria,76 articles were ultimately included. RESULTS AND CONCLUSION:Sarcopenia is a disease characterized by a decline in muscle mass and function with age,and its pathogenesis involves neuro-muscular functional decline,chronic inflammation,acid-base imbalance,and mitochondrial dysfunction.Mitochondrial autophagy is an important process for clearing damaged mitochondria in cells,in which receptor proteins and signaling pathways are involved in the regulation of mitochondrial autophagy.Exercise can promote the occurrence of mitochondrial autophagy by regulating the activity of these receptor proteins and signaling pathways,thereby playing an important role in the prevention and treatment of sarcopenia.Exercise can induce mitochondrial autophagy in sarcopenia by upregulating AMPK,phosphorylating ULK1,and reducing mitochondrial energy,enhancing the expression of mitochondrial autophagy-related proteins associated with AMBRA1,and regulating the PINK1/Parkin pathway,to improve mitochondrial dysfunction caused by sarcopenia.In addition,exercise can activate the mTOR pathway to promote muscle growth and increase glucose uptake,thereby preventing and treating sarcopenia.Future studies are needed to further investigate the specific mechanisms and regulatory pathways of mitochondrial autophagy-related receptor proteins and signaling pathways in the prevention and treatment of sarcopenia by exercise,and to conduct more clinical trials in humans,thereby to promote further development in this field.

Effects of Intermittent Fasting on Exercise Performance and Its Mechanisms / 华中科技大学学报(医学版)

Intermittent fasting,as a dietary nutrition program of fasting and eating alternately,mainly includes alternate-day fasting,time-restricted fasting,periodic fasting and Ramadan fasting.Positive effects of intermittent fasting on metabolic disea-ses such as obesity,diabetes and cardiovascular disease has been confirmed,but its effect on exercise performance is yet to be re-vealed.This paper summarizes the effects of intermittent fasting on anaerobic exercise,aerobic endurance exercise and strength alternation as well as related mechanism.It can provide theoretical reference for diet optimization,intermittent fasting selection and scientific exercise amony athletes,sports enthusiasts and patients with chronic diseases.

Serum BDNF Changes during Bicycle Ergometer Exercise Combined with Hot Bath in Young Healthy Men / 日本温泉気候物理医学会雑誌

  [Objectives] The aim of this study was to evaluate the changes in serum brain-derived neurotrophic factor (BDNF) concentrations during 15 min of combined hot bath and bicycle ergometer endurance exercise in healthy young men.  [Methods] The experiment was conducted in a parallel design. The subjects were 10 healthy men (aged 23.7±0.8 years). The experimental group performed a combination of head-out water immersion (HOI) at 40°C and bicycle ergometer exercise (40°C HOI-ex), while the control group performed only HOI at 40°C (40°C HOI). After 30 min of rest, 40°C HOI-ex or 40°C HOI was performed for 15 min, followed by a 30 min recovery period. During the experiment, heart rate, blood pressure, and core temperature (esophageal temperature) were continuously measured. Blood samples were collected at four time points: after rest, immediately after intervention, 15 min after recovery, and 30 min after recovery. Serum BDNF, P-selectin, platelet count, hemoglobin, hematocrit, plasma cortisol, and lactic acid were then measured.  [Results] A significant increase in serum BDNF concentrations was observed immediately after intervention and 15 min after recovery in the 40°C HOI-ex group compared with the values taken after resting. No changes in serum BDNF concentrations were observed in the 40°C HOI group. Core temperatures significantly increased immediately after intervention, 15 min after recovery, and 30 min after recovery compared with resting for both 40°C HOI-ex and 40°C HOI groups, with between-group differences. Platelet counts were unchanged in both 40°C HOI and 40°C HOI-ex groups. A significant increase in P-selectin was observed immediately after intervention and 15 min after recovery in the 40°C HOI-ex group compared with when at rest. No changes in P-selectin were observed in 40°C HOI.  [Discussion] The combination of hyperthermia and exercise can increase serum BDNF in a short time of 15 min by an additive effect, and the increase in serum BDNF in this study may be platelet-derived.

Impact of cigarette smoke and aerobic physical training on histological and molecular markers of prostate health in rats

Recent evidence suggests that aerobic physical training may attenuate the deleterious effects of cancer risk factors, including smoking. We investigated the effects of cigarette smoke inhalation and aerobic physical training on the expression of steroid receptors and inflammatory and apoptotic proteins in the prostate. Forty male Wistar rats were distributed in four groups: control (CO), exercise (EXE), cigarette smoke exposure (CS), and cigarette smoke exposure with exercise (CS+EXE). For eight weeks, animals were repeatedly exposed to cigarette smoke for 30 min or performed aerobic physical training either with or without the cigarette smoke inhalation protocol. Following these experiments, we analyzed prostate epithelial morphology and prostatic expression of androgen (AR) and glucocorticoid receptors (GR), insulin-like growth factor (IGF-1), B-cell lymphoma-2 (BCL-2), BCL-2-associated X protein (BAX), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) via immunohistochemistry. Cigarette smoke exposure stimulated the expression of AR, IGF-1, BCL-2, and NF-κB while downregulating BAX, IL-6, and TNF-α labeling in the prostate. In contrast, aerobic physical training attenuated cigarette smoke-induced changes in AR, GR, IGF-1, BCL-2, IL-6, TNF-α, and NF-κB. This suggests that cigarette smoke stimulates inflammation and reduces apoptosis, culminating in increased prostatic epithelial and extracellular matrices, whereas physical training promoted beneficial effects towards maintaining normal prostate morphology and protein levels.

Sudden Cardiac Death in Sports: Not a Fatality!

Sudden cardiac death in sports is still controversial. Despite being a rare event, the death of an apparently healthy young athlete causes a major impact on the media. On the other hand, for being a rare event, it is clearly undervalued. Sports preparticipation cardiological assessment is one of the most effective preventive medical actions for professional and amateur endurance athletes. The regular and supervised practice of physical exercise does not kill. We believe that deaths are triggered by excessive physical training and use of drugs, in individuals with not diagnosed or undervalued heart diseases. It is necessary to make health professionals and athletes aware of the athletes' physiological limits, in addition to preparing the athletes properly when they try to overcome human limits

Benfotiamine supplementation prevents oxidative stress in anterior tibialis muscle and heart / 中西医结合学报

OBJECTIVE@#This study aimed to evaluate the influence of oral supplementation with benfotiamine on oxidative stress in the liver, heart and muscles of endurance-trained mice.@*METHODS@#Twenty-five male BALB/c mice were allocated to the following treatment groups: standard diet and sedentary activity (Sta-Sed), benfotiamine-supplemented diet and sedentary activity (Ben-Sed), standard diet and training activity (Sta-Tr) and benfotiamine-supplemented diet and training activity (Ben-Tr). The training comprised 6 weeks of endurance swimming training. The concentration of thiobarbituric acid reactive substances (TBARS), carbonylated proteins, total thiols and non-protein thiols was analyzed in the liver, heart and tibialis anterior muscle.@*RESULTS@#In the muscle, TBARS concentration in the Sta-Sed group was higher than that in other groups; in the heart, TBARS concentration in the Sta-Sed and Ben-Tr groups was higher than that in the Ben-Sed group. The carbonyl content of the muscle tissues was higher in the Sta-Sed group than in both supplemented groups. In liver, the carbonyl content was lower in the Ben-Sed group than in the Sta-Sed group. The level of total thiols was lower in the Ben-Sed group than in the Sta-Tr group. In the heart, the level of total thiols was higher in the Ben-Sed group than in the Ben-Tr group. The concentration of non-protein thiols in the muscle was higher in the Ben-Sed group than in the Ben-Tr group, whereas in the heart, concentration of non-protein thiols of Sta-Tr group was lower than that of Sta-Sed group.@*CONCLUSION@#The results show that benfotiamine is an efficient antioxidant for the anterior tibialis muscle and heart; however, swimming training did not alter redox status.

The effect of aerobic endurance exercise on renal fibrosis and the expression of TGF-beta 1 and E-cadherin in aged mice / 中华物理医学与康复杂志

Objective@#To explore the effect of aerobic endurance exercise on renal fibrosis in elderly mice and its possible mechanism.@*Methods@#Thirty-six healthy, male C57 mice were sorted into a young control group (2 months old), a senile control group (19 months old) and a senile exercise group (also 19 months old). The senile exercise group underwent aerobic endurance exercise for 7 weeks. Then all of the mice were sacrificed and any changes of in their renal tissues were recorded, especially the expression of fibrosis indicators using HE staining, Sirius red staining, RT-PCRs and immunohistochemical methods.@*Results@#Collagen fibers deposited in the kidney tissue of the senile groups were significantly more numerous than in the young control group, but their number had decreased significantly after the exercise.@*Conclusion@#Aerobic endurance exercise can inhibit collagen deposition and delay the formation of renal fibrosis, at least in rats. This may be related to its inhibition of TGF-β1 and α-SMA expression and up-regulation of E-cadherin expression.

Effects of 10000 Meters Run on the Anticipatory and Compensatory Postural Adjustments of Lumbar Stable Muscles / 中国运动医学杂志

Objective To explore the effect of acute endurance exercise on the balance control,maximum contraction of the back extensor and the anticipatory postural adjustments(APAs) and compensatory postural adjustments (CPAs) of the lumbar vertebra.Methods Seventeen male students from a police college participated in this study voluntarily.Three tests were performed right before and after the 10000 meters run:the single foot standing test with eyes closed,maximum contraction test of the back extensor and arm-rising test.The maximum voluntary contraction (MVC) of the back extensor and the time of standing with eyes closed were collected.The sEMG activities of lumbar erector spinae(LES) and Lumbar multifidus(LMF) as lumbar stable muscles were recorded.The pre-activation time and integrated EMG of APAs and CPAs were calculated.Results Before and after the 10000 meters run,no significant difference was observed in MVC,but the time of single foot standing decreased significantly.On the condition of the internal postural perturbation,the LES was activated significantly earlier and the APAs IEMG of LMF decreased significantly after the run,but no significant difference was observed in the pre-activation time of LMF and APAs IEMG of LES.The CPAs IEMG of LES and LMF both decreased significantly after the run.Conclusions The acute endurance exercise of 10000 meters run does not cause fatigue of lumbar stable muscles,but it has an effect on the performance of body balance control.It has effects on the postural control strategies of the central nerve system in response to the internal sudden postural perturbation,resulting in the earlier pre-activation of LES to compensate the decreased activation magnitude of LMF.

Effects of periodic hypobaric hypoxic environments on physiological responses during endurance exercise and recovery after exercise / 体力科学

<p>We developed a periodic hypobaric hypoxic environment (PHHE) system. Characteristics of this system varied between decreased pressure at an altitude of 1,500 m for 180 seconds and increased pressure at an altitude of 0 m for 180 seconds. The present study aimed to determine the effects of PHHE on physiological responses during endurance exercise and recovery after exercise. This study included 12 healthy men, and they provided written informed consent. All subjects performed a cycling exercise for 30 minutes and recovered after exercise for 10 minutes. The exercise protocol was performed with 20% maximum oxygen uptake for 6 minutes (warm-up), 40 % for 18 minutes (main exercise), and 20 % for 6 minutes (cool down). We established two experimental conditions: exercise with the PHHE and the control (C). The C condition involved exercise using the PHHE at an altitude of 0 m, and the atmospheric pressure was not changed. In the PHHE condition, the atmospheric pressure was changed periodically from 967 to 817 hPa (the external pressure was 1,008 hPa). Subjects’ heart rate (HR), blood pressure (BP), arterial oxygen saturation (SpO₂), rating of perceived exertion, and respiratory responses were measured in both conditions. The SpO₂, HR and systolic BP during exercise were significantly lower in the PHHE condition than in the C condition. The HR post-exercise was significantly lower. After exercise, the ln HF, an index of cardiac parasympathetic nervous system modulation, was significantly higher. In conclusion, during endurance exercise, cardiocirculatory responses in the PHHE condition were decreased.</p>

Physical Therapy Program Improves the Physiological Impact Towards Better Quality of Life and Low Cardiac Risk Factors in Patients Following Coronary Artery Bypass Grafting. Systematic Review.

Introduction: Studies suggest that exercise therapy may enhance heart rate variability in myocardial infarction, chronic heart failure and revascularization patients by increasing vagal tone and decreasing sympathetic activity. This review addressed the impact of cardiac rehabilitation programs (CRPs) in post CABG patients on the quality of life, in terms of physical function and cardiac risk factors. Methods: OVID, Science direct, Embase, AMED and Cochrane controlled Trial Register were searched for studies published from 2005 up to 2015. Two reviewers assessed the eligibility of each study based on predefined inclusion criteria. Results: Of 35 abstracts reviewed, 9 studies met the inclusion criteria. All studies compared CRPs of different interventions to a control (non-intervention) group. From the selected 9 studies, 6 studies included interventions compared with control groups (usual or standard care) while 3 studies compared two different intervention strategies with groups and included a no-intervention control group. Conclusion: This systematic review concludes that all types of CRPs lead to improvements in the quality of life and reduction of cardiac risk factors in post CABG patients. However, these improvements were quite varied between the 9 studies according to variations in the components of CRPs.

Endogenous nitric oxide synthase inhibitor increase skeletal muscle con-tractility and mitochondria biosynthesis in 4-week running rats / 中国病理生理杂志

[ ABSTRACT] AIM:To observe the effect of endogenous nitric oxide synthase ( NOS) inhibitor asymmetric dimeth-ylarginine ( ADMA ) and its signaling pathways on NO levels and skeletal muscle contractility in 4-week running rats. METHODS:The 4 weeks running rat model was established.The twitch tension, tetanic tension and the fatigue test of sole-us muscle induced by electrical stimulation ex vivo were detected.The ATP content, mitochondrial DNA levels and the mR-NA expression of peroxisome proliferator-activated receptor γcoactivator-1α(PGC-1α), nuclear respiratory factor (NRF) were measured to reflect the mitochondrial function and biosynthesis in the skeletal muscle.Serum ADMA concentration was detected by high performance liquid chromatography.The endogenous ADMA enzymes PRMT1 and 2 subtypes of ADMA me-tabolism enzyme DDAH, 3 subtypes of NOS protein expression in the skeletal muscle were determined by Western blot.NOS activity and nitric oxide ( NO) content were analyzed by colorimetric method.RESULTS: Compared with normal control group, the twitch tension, tetanic tension and the anti-fatigue capability of soleus muscle in running group were significantly enhanced, ATP content, mitochondrial DNA content and the mRNA expression of PGC-1αand NRF were significantly in-creased (P ance of soleus muscle.The mechanism may be that increased cNOS expression feedbacks to increase ADMA concentration, thus maintaining the increase in NO synthesis at a relatively low level, and resulting in promoting skeletal muscle mitochon-dria biosynthesis and mitochondrial function.

Preventive effects of endurance exercise on slow-to-fast fiber transition in plantaris muscle of non-obese type 2 diabetic rats / 体力科学

We investigated preventive effects of chronic endurance exercise on the slow-to-fast fiber transition in the plantaris muscles of non-obese type 2 diabetic rats. Eleven-week-old male Spontaneously Diabetic Torii Rats were used as diabetic animals, and assigned to sedentary (DB) and exercise (DB+Ex) groups. Age matched male non-diabetic Sprague-Dawley rats were used as sedentary control (Cnt) group. DB+Ex group was trained on low-intensity treadmill running for 14 weeks. Although glucose level in DB group at 25 weeks of age was higher compared to Cnt group, that in DB+Ex group was significantly lower compared to DB group. DB group exhibited lower percentages of high-oxidative type IIA fibers and higher percentages of low-oxidative type IIB fibers compared to Cnt group in the superficial layer of muscles. While DB+Ex group exhibited higher percentages of type IIA fibers and lower percentages of type IIB fibers compared to DB group in the superficial and deep layers of muscles. Additionally, succinate dehydrogenase intensity in the deep layer of muscles in DB+Ex group was increased by endurance exercise. The present study indicated that endurance exercise could prevent the slow-to-fast fiber transition of the muscle fibers and enhance mitochondrial oxidative enzyme activity in the skeletal muscles of non-obese type 2 diabetic rats.

Effect of low-level laser therapy (808 nm) on skeletal muscle after endurance exercise training in rats

BACKGROUND: Low-level laser therapy (LLLT) has been demonstrated to be effective in optimizing skeletal muscle performance in animal experiments and in clinical trials. However, little is known about the effects of LLLT on muscle recovery after endurance training. OBJECTIVE: This study evaluates the effects of low-level laser therapy (LLLT) applied after an endurance training protocol on biochemical markers and morphology of skeletal muscle in rats. METHOD: Wistar rats were divided into control group (CG), trained group (TG), and trained and laser irradiated group (TLG). The endurance training was performed on a treadmill, 1 h/day, 5 days/wk, for 8 wk at 60% of the maximal speed reached during the maximal effort test (Tmax) and laser irradiation was applied after training. RESULTS: Both trained groups showed significant increase in speed compared to the CG. The TLG demonstrated a significantly reduced lactate level, increased tibialis anterior (TA) fiber cross-section area, and decreased TA fiber density. Myogenin expression was higher in soleus and TA muscles in both trained groups. In addition, LLLT produced myogenin downregulation in the TA muscle of trained animals. CONCLUSION: These results suggest that LLLT could be an effective therapeutic approach for stimulating recovery during an endurance exercise protocol.

Effects and mechanisms of endurance exercise for 8 weeks on contractile function and mitochondrial biogenesis in rat skeletal muscles / 中国药理学通报

Aim This study was aimed to explore the influence and mechanism of the long-term exercise on skeletal muscle contraction and mitochondrial biosyn-thesis in different muscle fibers.Methods Soleus (SOL)and extensor digitorum longus (EDL)were i-solated from SD male rats with platform running train-ing for eight weeks.The changes of contractility under different electrical stimulation were observed, mito-chondrial biosynthesis,including ATP content,mito-chondrial DNA,the gene expression of PGC-1αand NRF were also detected.Results Long-term endur-ance exercise can improve twitch tension and titanic tension of SOL and EDL ,but only enhanced the fa-tigue resistance in SOL.ATP contents were significant-ly increased in the two types of muscles,but mtDNA content,PGC-1αexpression and NRF translation were only obviously enhanced in SOL,in accompanied with an increase in p-AMPK/AMPK protein ratio.Conclu-sion Long-term endurance exercise increased skeletal muscle contractility and improved the anti-fatigue abili-ty in SOL,which may be associated with increase in mitochondrial biosynthesis via activated AMPK-PGC-1αaxis.

Experiment research of cinnamic acid on endurance exercise in mice / 重庆医学

Objective To investigate the effects of cinnamic acid to enhance the exercise endurance in mice .Methods Through the exhaustive swimming to establish mice exhaustive exercise model ,the mice were divided into control group ,exercise control group and exercise cinnamic group(n=10) ,the mice exhaustive swimming time were comparted ,blood lactic acid(LAC) lev‐els were used to explore the endurance of cinnamic acid in mice;the super oxide dismutase (SOD) ,malondialdehyde (MDA) and peroxidase (CAT) content in liver homogenates were used to detect mice endurance enhancement and antioxidant capacity of cin‐namic acid ,and expression of Na+ /K+‐ATP enzyme ,Ca2+ /Mg2+‐ATP enzyme on mice quadriceps by Western blot to further study its effect on improving exercise capacity in mice .Results Cinnamic acid significantly prolonged the swimming time of mice;Exercise cinnamic group compared with control group:although the LAC content in plasma elevated ,the difference was not statistically sig‐nificant(P>0 .05) ,SOD and CAT in liver homogenate was significantly decreased(P0 .05) ,the expression level of Na+ /K+‐ATP enzyme and Ca2+ /Mg2+‐ATP enzyme decreased significantly (P< 0 .01) .Exercise control group compared with control group:the LAC content in plasma increased significantly(P<0 .01) ,SOD and CAT in liver homogenate was significantly decreased(P<0 .01) ,MDA increased significantly(P< 0 .01) ,expression level of Na+ /K+‐ATP enzyme and Ca2+ /enzyme Mg2+‐ATP decreased significantly (P<0 .01);Exercise cinnamic group exercise control group:the LAC content in plasma was significantly reduced(P<0 .01) ,SOD and CAT in liver tissue significantly increased(P< 0 .01) ,MDA decreased significantly(P<0 .01) ,CAT decreased significantly(P<0 .01) ,the expression level of Na+ /K+‐ATP enzyme and Ca2+ /Mg2+‐ATP enzyme decreased significantly(P<0 .05) .Conclusion Cinnamic acid has good oxidation resistances and anti‐fatigue ability .

Effect of ß-alanine supplementation on 20 km cycling time trial performance

The effects of ß-alanine supplementation on high-intensity cycling performance and capacity have been evaluated, although the effects on longer duration cycling performance are unclear. Nineteen UK category 1 male cyclists completed four 20 km cycling time trials, two before and two after supplementation with either 6.4 g•d-1 ß-alanine (n = 10; BA) or a matched placebo (n = 9; P). Performance time for the 20 km time trial and 1 km split times were recorded. There was no significant effect of ß-alanine supplementation on 20 km time trial performance (BA-pre 1943 ± 129 s; BA-post 1950 ± 147 s; P-pre 1989 ± 106 s; P-post 1986 ± 115 s) or on the performance of each 1 km split. The effect of ß-alanine on 20 km time trial performance was deemed unclear as determined by magnitude based inferences. Supplementation with 6.4 g•d-1 of ß-alanine for 4 weeks did not affect 20 km cycling time trial performance in well trained male cyclists

Effects of Endurance Training on the Serum Levels of Tumour Necrosis Factor-alpha and Interferon-gamma in Sedentary Men

Physical activity could be considered one of the factors that affect the immune system status and function. To find the relation between exercise and cytokines, we examined the possible effects of an 8-week endurance training program on the serum levels of cytokines, including tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in sedentary men. A total of 30 healthy young male volunteers were randomly divided into an endurance training group and a control group. The training group followed a specific exercise protocol (running on a treadmill for 15~30 min at 50~70% maximal heart rate) for 8 weeks and the control group did not participate in any exercise program. Venous blood samples were collected from both the groups 24 h before and 24 h and 48 h after the exercise. Repeated ANOVA was used for statistical purposes. The serum levels of TNF-alpha and IFN-gamma were determined by ELISA. Significant (p0.05) decreases were observed in the serum levels of IFN-gamma and TNF-alpha, respectively, after the 8-week endurance training program. Our findings indicated that an 8-week endurance exercise may affect the serum levels of some inflammatory cytokines, suggesting the beneficial role of this training protocol in elderly population and people with certain conditions (inflammation of the vertebrae or other inflammatory diseases).

The Effect of Transcutaneous Carbon Dioxide (CO₂) Application after Endurance Exercise in Rats / The Japanese Journal of Rehabilitation Medicine

Objective : In Europe, carbon dioxide therapy has been used for treating cardiac disease and skin problems for a long time. Previously, we demonstrated that transcutaneous carbon dioxide (CO₂) application facilitated dioxygen (O₂) dissociation from hemoglobin (Hb) in the human body. Additionally, we proved that transcutaneous CO₂ application to the lower limbs of rats increased the expression of peroxisome proliferator-activated receptor (PPAR) gamma coactivator-1α (PGC-1α), vascular endothelial growth factor (VEGF) and silent mating type information regulation 2 homologs 1 (SIRT1). It also increased the number of mitochondria, and changed IIB fiber to IIA fiber in similar manner to the change that occurs after exercise. The transcutaneous CO₂ application caused a similar effect to that of exercise training in skeletal muscle and indicated the possibility of improved endurance strength. However, the effect of transcutaneous CO₂ application on endurance exercise and the recovery of muscle fatigue has not been studied. Methods : In this study, we investigated the performance of endurance exercise in rats with/without transcutaneous CO₂ application and analyzed the muscle fiber changes, capillary density and mitochondrial DNA number of the skeletal muscles after training, using activity wheels. Results： Training with CO₂ application resulted in a higher percentage of TA muscle transformed to IIA and/or IID than training alone, suggesting that transcutaneous CO₂ application may increase the production of ATP, mitochondria number, and capillary density. Therefore, transcutaneous CO₂ application might lead to muscle damage recovery. Conclusion : We suggest that transcutaneous CO₂ application has a therapeutic potential for recovery of damaged muscle after excessive exercise and rehabilitation.

Effect of Endurance Training on the Cardiac Akt/mTOR Signaling Pathway in Aged Mice / 中国运动医学杂志

Objective To study the effect of endurance training on the cardiac Akt/mTOR signaling pathway in aged mice.Methods Male 2-month.old SAMP8 mice were randomly divided into young control group(YC)(n=12),endurance training group(E)(n=12)and aged control group(AC)(n=12).The group YC was executed at three-month old;and the group AC was executed at six-month old.The group E underwent a 3-month endurance training program (three times per week,40min once a day).After completion of the training program,the ratio of hean mass to body mass(heart mass/body mass)was measured,cardiac tissue of each group was observed using the HE stain,and the mRNA expressions of Akt,mTOR,p70S6K and eIF-4E in mouse heart of each group were analyzed using the real-time PCR.Results The heart weight and the heart weight/body weight ratio significantly increased in group E comparing with that in group AC(P<0.05)without any pathological change.The mRNA expressions of Akt,mTOR, p70S6K and eIF-4E in group AC decreased more significantly than that in group YC(P<0.05).The expression of targets in group E increased more significantly than that in group AC(P<0.05),however,there was no significance difference between group E and group YC.Conclusion Endurance training can elevate the cardiac Akt/mTOR signaling pathway expression,produce exercise-induced cardiac hypertrophy for aged mice.