High-load Exercise Research Articles

Unilateral high-load resistance training induced a similar cross-education of strength between the dominant and non-dominant arm

ABSTRACT It was previously hypothesized that the cross-education of strength is asymmetrical, where a greater transfer of strength is observed from the dominant to the non-dominant limb. The purpose of this study was to examine if the magnitude of cross-education of strength differed between dominant and non-dominant limbs following unilateral high-load resistance training. One hundred and twenty-two participants were randomized to one of the three groups: 1) training on the dominant arm (D-Only), 2) training on the non-dominant arm (ND-Only) and 3) a time-matched non-exercise control (Control). The training groups completed 6 weeks (18 sessions) of unilateral elbow flexion exercise. Each training session started with one-repetition maximum (1RM) training (≤ five attempts), followed by four sets of high-load exercise (i.e. 8–12RM). Strength changes of the untrained arm were compared between groups. Changes in the strength of the untrained arm were greater in D-Only (1.5 kg) and ND-Only (1.3 kg) compared to Control (−0.2 kg), without differences between D-Only and ND-Only. Unilateral resistance training increased strength in the opposite untrained arm, and the magnitude of this effect was similar regardless of which arm was trained. However, there is still considerable uncertainty on this topic and additional research is warranted to confirm the current findings.

Large inter-individual variability in force-velocity profile changes in response to acute high-load resistance training.

While the acute effects of high-load resistance training on the force generating capacity of muscles have been widely examined, limited data exist on the relationship with the force-velocity profile (FV). Evidence suggests high sensitivity of the vertical FV profile to monitor changes in the muscle's mechanical properties according to the type of the exercise protocol. However, the interpretation of the findings seems not as straightforward. Therefore, the purpose of this study was to examine the effects of a high-load resistance training protocol on the muscle's mechanical properties during loaded jumps and on the vertical force-velocity profile (FV) in relation to maximal strength. 29 resistance-trained male (mean age±SD: 35.4 ± 7.8 years) and 29 female athletes (mean age±SD: 32.5 ± 7.0 years) participated in the study. Five-repetition maximum (5RM) in back squat, unloaded countermovement jump (CMJ) and FV profile were assessed. Loaded jumps were performed against 25, 50, 75, and 100 percent of body mass. Participants performed exercise protocols corresponding to their 5RM. Immediately after, unloaded CMJ and FV profile measurements were repeated. A significant decrease in CMJ height (∼5-6%) and in average power (∼4%) was recorded for both men and women. The FV profile did not change after the exercise protocol; however, there was a significant decrease in theoretical maximal power (from 4 to 5%) and in theoretical maximal velocity (∼3%). Maximal strength was not associated with the changes in FV profile. Findings suggest that an acute high-load exercise decreased vertical jump performance and maximal power output, but without a concomitant change in FV profile. The large interindividual variability in FV measures indicates a less straightforward connection of the applied exercise with the acute response in the FV profile, highlighting the complexity of the FV profile to monitor changes in response to an acute training load.

Acute hypoalgesic, neurophysiological and perceptual responses to low-load blood flow restriction exercise and high-load resistance exercise.

This study compared the acute hypoalgesic and neurophysiological responses to low-load resistance exercise with and without blood flow restriction (BFR), and free-flow, high-load exercise. Participants performed four experimental conditions where they completed baseline measures of pain pressure threshold (PPT), maximum voluntary force (MVF) with peripheral nerve stimulation to determine central and peripheral fatigue. Corticospinal excitability (CSE), corticospinal inhibition and short interval intracortical inhibition (SICI) were estimated with transcranial magnetic stimulation. Participants then performed low-load leg press exercise at 30% of one-repetition maximum (LL); low-load leg press with BFR at 40% (BFR40) or 80% (BFR80) of limb occlusion pressure; or high-load leg press of four sets of 10 repetitions at 70% one-repetition maximum (HL). Measurements were repeated at 5, 45min and 24h post-exercise. There were no differences in CSE or SICI between conditions (all P>0.05); however, corticospinal inhibition was reduced to a greater extent (11%-14%) in all low-load conditions compared to HL (P<0.005). PPTs were 12%-16% greater at 5min post-exercise in BFR40, BFR80 and HL compared to LL (P≤0.016). Neuromuscular fatigue displayed no clear difference in the magnitude or time course between conditions (all P>0.05). In summary, low-load BFR resistance exercise does not induce different acute neurophysiological responses to low-load, free-flow exercise but it does promote a greater degree of hypoalgesia and reduces corticospinal inhibition more than high-load exercise, making it a useful rehabilitation tool. The changes in neurophysiology following exercise were not related to changes in PPT.

Investigating the Effects of Blood Flow Restriction Exercises on Strength and Cross Section Area of Hamstring Muscles and Tendons: A Case Report

Introduction: Hamstring injuries are one of the most common tendon injuries, especially in sports that require running and jumping. A comprehensive training program can help athletes to prevent this injury. Among suggested exercises, the Nordic eccentric training can reduce the injury rate by up to 50%; however, it is a high-load exercise that cannot be prescribed in the first stages of rehabilitation. Here, we describe a football player who used low-load resistance exercise with blood flow restriction as an alternative method to strengthen their hamstring after nine months of anterior cruciate ligament reconstruction surgery&#x0D; Case Description: A 19-year-old non-professional footballer with a body mass index of 22.18 kg/cm2 was invited to participate in this study. The variables examined included strength and cross-sectional area of the hamstring muscles (mean and maximum strength) and the crosssectional area of the hamstring tendons at their origin. The treatment program included a seated hamstring curl with a load of 30% 1 RM with blood flow restriction for four weeks (thrice a week).&#x0D; Results: The hamstring muscle strength improved by 6.54%, and the cross-sectional area of the muscles and tendons changed as follows: Semimembranosus (tendon=0.07%, muscle=2.57%), semitendinosus (tendon=0.00%, muscle=-4.04%), and biceps-femoris (tendon=5.5%, muscle=4.34%).&#x0D; Conclusion: Low load resistance training with blood flow restriction in this athlete improved the strength and cross-sectional area of the hamstring muscles as well as the cross-sectional area of the tendons. The changes observed in tendon, and muscle cross-sectional areas were more prominent for biceps-femoris. This case showed that a training program with blood flow restriction may be a good alternative for people who cannot tolerate high-load exercises in the early stages of their rehabilitation. Doing more extensive studies with more cases and a control group in the future can help our knowledge in giving the best exercise prescription to our patients.

Efficacy of personalized exercise program on physical function in elderly patients with rheumatoid arthritis at high risk for sarcopenia: study protocol for a randomized controlled trial

BackgroundPatients with rheumatoid arthritis (RA) are prone to muscle atrophy due to inflammatory cytokines and corticosteroid use and immobility due to joint pain and deformity. Although resistance training is effective and safe in reversing muscle atrophy in RA, some patients are unable to perform a conventional high-load exercise program due to disease-related limitations. This study aims to examine the efficacy of individualized exercise therapy on physical function in elderly patients with RA who are at a high risk for sarcopenia.MethodsThis study is a single-center, parallel-group, two-arm, healthcare provider- and outcome assessor-blinded, superiority randomized controlled trial with a 1:1 allocation ratio. A total of 160 participants with RA between 60 and 85 years of age with a positive screening test for sarcopenia will be included. The intervention group will receive nutritional guidance and a four-month individualized exercise program in addition to the usual treatment. The control group will receive nutritional guidance in addition to the usual care. The primary endpoint will be physical function assessed using the Short Physical Performance Battery (SPPB) at 4 months. The data on outcome measures will be collected at baseline and at the two- and four-month follow-ups. Linear mixed-effects models for repeated measures will be conducted using the modified intention-to-treat analysis population.DiscussionThis study will provide evidence on whether a personalized exercise program can improve physical function and quality of life in elderly patients with RA. Some limitations include limited generalizability due to the single-center study and lack of blinding of the patients to the intervention assignment because of the nature of the exercise. Physical therapists may use this knowledge in their daily practice to improve RA treatment. Tailored exercise may enhance the health outcomes of the RA population and contribute to a reduction in healthcare costs.Trial registrationThe study protocol was retrospectively registered at the University hospital Medical Information Network-Clinical Trial Repository (UMIN-CTR) (registration number: UMIN000044930, https://www.umin.ac.jp/ctr/index-j.htm) on January 4, 2022.

Low-Load Resistance Exercise with Blood Flow Restriction Increases Hypoxia-Induced Angiogenic Genes Expression.

The aim of the study was to determine whether low-load exercise (LL) with blood flow restriction (LL-BFR) would induce similar changes in expression of genes involved in hypoxia and angiogenesis compared to LL and high-load exercise (HL). Twenty-four males (age: 21.3 ± 1.9 years, body height: 1.74 ± 0.8 m, body mass: 73 ± 1.8 kg) were allocated into three groups: low-load exercise (LL), low-load exercise with blood-flow restriction (LL-BFR), and high-load exercise (HL). For the LL-BFR group a pneumatic cuff was inflated at 80% of the arterial occlusion pressure. All participants performed bilateral knee extension exercise, twice a week, for 8 weeks. LL and LL-BFR groups performed 3-4 sets of 15 reps at 20% 1RM, whilst the HL group performed 3-4 sets of 8-10 reps at 80% 1RM with a 60-s rest interval between sets. The hypoxia-inducible factor-1 alpha (HIF-1α) and beta (HIF-1β), vascular endothelial growth factor (VEGF), neuronal (nNOS), and inducible nitric oxide synthase (iNOS) genes expression were assessed before and after training. HIF-1α and HIF-1β mRNA levels significantly increased in the LL-BFR group and exceeded those elicited by HL and LL groups (p < .0001). VEGF gene expression was increased in both LL-BFR and HL groups, however, LL-BFR elicited a greater increase than LL (p < .0001). nNOS and iNOS genes expression significantly increased in all groups with greatest increases being observed in the LL-BFR group (p < .0001). The findings suggest that LL-BFR induces greater increases in genes expression related to hypoxia and angiogenesis than traditional resistance training.

The Effects Of High Load And Low Load Unilateral Bicep Training On Changes In Post-activation Performance Enhancement

Post-activation performance enhancement (PAPE) represents the short-term improvement in muscle performance following a conditioning stimulus. Previous research has shown that PAPE is enhanced following high-load training. Since PAPE represents a local response, we hypothesize that this effect might provide insight into changes at the muscle level, which might influence strength adaptations. To test this, we compared PAPE following two training protocols known to produce differences in maximal strength. PURPOSE: To determine if PAPE is augmented to a greater extent following high load training compared to low load training. METHODS: 13 participants (3 males) were randomly assigned to a group completing high-load exercise with their dominant arm, and low-load exercise with their non-dominant arm. This is part of a larger ongoing study, which is why conditions were not counter-balanced based on dominancy. The high load training consisted of performing a 1RM test (five attempts maximum), followed by 4 sets of traditional exercise (~8-12 repetitions). The low-load condition completed 4 sets of exercise, aiming for ~30-40 repetitions. 18 sessions of elbow flexion exercise were completed over six weeks. PAPE was measured before and after training using isokinetic dynamometry at 210 deg/sec. PAPE testing began with a warm-up, the pre-conditioning torque attempt, the 6 s isometric conditioning stimulus, followed by the post-conditioning torque attempt 3 minutes later. There were two hypotheses: H0: differences would be equal or H1: greater following training (specifically high load training in comparison across conditions). Hypotheses were tested using Bayes Factors for Informative Hypotheses (BAIN). RESULTS: PAPE was not greater following six weeks of high-load (Pre Δ: 1.6 Nm vs. Post Δ: 0.26 Nm, BF01: 11.2) or low-load (Pre Δ: 0.33 Nm vs. Post Δ: -0.32 Nm, BF01: 5.6) resistance training. The available data suggests that each condition changed similarly across time (difference of -0.7 Nm, BF01: 5.4). CONCLUSIONS: Preliminary data suggests that high load, as well as low load, training for six weeks does not result in an improvement in PAPE, when performing unilateral bicep exercise. As such, high load training does not appear to be superior to low load training for improved PAPE responses.

ANALYSIS OF THE CARDIOPULMONARY ENDURANCE RESPONSE OF WOMEN TO AEROBIC EXERCISE

ABSTRACT Introduction: The main purpose of aerobic exercise is to enhance cardiopulmonary endurance, so it is necessary to build cardiopulmonary endurance response models based on different frequencies of aerobic exercise. Objective: To study the cardiopulmonary endurance response of women to different frequencies of aerobic exercise. Methods: Twenty young female desk workers (female teachers and civil servants) who worked out at a fitness club were randomly divided into two groups. Cardiopulmonary function, both before and after 16 weeks of aerobic exercise at different exercise loads, was studied and analyzed. Results: After 16 weeks of aerobic exercise at different exercise loads, all the young women had significantly improved their vital capacity (VC), and their maximum oxygen uptake ability was improved to a certain extent. Compared with the 45-minute aerobic exercise group, the vital capacity (VC)of 90-minute aerobic exercise group was significantly increased (P&gt;0.05). Conclusions: When performed at a consistent frequency level, aerobic exercise with a relatively high exercise load can better develop the body’s respiratory system function. This may be due to deep stimulation of the respiratory system from high-load aerobic exercise, and ultimately to the intensive exercising of lung function. Level of evidence II; Therapeutic studies - investigation of treatment results.

Effect of one-time high load exercise on skeletal muscle injury in rats of different genders: oxidative stress and mitochondrial responses

To evaluate the impact of one-time high load exercise on skeletal muscle injury and analysis its mechanism in different genders. Twenty-four male and 24 female rats were divided randomly into four groups respectively: control, 0 h, 6 h, and 24 h after exercise. The activities of creatine kinase (CK), lactate dehydrogenase (LDH), and myohemoglobin (MYO) in serum, the expression level of oxidative stress markers, mitochondrial respiratory chain complex enzyme, and the apoptosis related protein in quadriceps were detected. The results showed that the activities of CK, LDH and MYO in serum increased immediately after exercise and restored faster in female rats. More obvious structural disorder and apoptosis in male rats were showed. Malondialdehyde (MDA) and superoxide dismutase (SOD) were increased while catalase (CAT) and glutathione (GSH) were decreased in male rats. SOD, CAT and GSH were increased in female rats. Mitochondrial complex enzyme activity was decreased in males and increased in females. The skeletal muscle injury in both genders of rat could be induced by one-time high load exercise due to the mitochondrial respiratory enzyme dysfunction and oxidative stress, which was relatively mild and recovered quicker in female rats.

EFFECT OF PHYSICAL EXERCISE ON INCREASING THE MAXIMUM OXYGEN UPTAKE OF SKELETAL MUSCLE

ABSTRACT Introduction: Aerobic exercise can improve the physical function of athletes and increase the oxygen content in skeletal muscles. This has a significant reference value for evaluating training effects and judging sports fatigue. Objective: Maximum oxygen uptake is one of the most critical indicators of aerobic work capacity. The thesis analyzes the medical promotion effect of physical exercise on the oxygen content of skeletal muscle. Methods: The thesis performed aerobic exercises on two groups of young rowers. Athletes in group A performed high-load exercise, and athletes in group B performed low-load exercise. At the same time, we placed a detector on the athletes’ skeletal muscle to test the volunteer's muscle oxygen content and other physiological indicators. Results: Comparing high-load exercise and low-load exercise, the maximum oxygen uptake and the utilization rate of the maximum oxygen uptake when reaching the anaerobic net were 10% and 16% higher, respectively. There was no difference in the activity of muscle enzymes between the two groups. Conclusions: After aerobic training, the muscle's oxygen utilization capacity is strengthened. Physical exercise promotes the maximum oxygen uptake of skeletal muscles. Level of evidence II; Therapeutic studies - investigation of treatment results.

A Functional High-Load Exercise Intervention for the Patellar Tendon Reduces Tendon Pain Prevalence During a Competitive Season in Adolescent Handball Players.

Imbalances of muscle strength and tendon stiffness may increase the risk for patellar tendinopathy in growing athletes. The present study investigated if a functional high-load exercise intervention, designed to facilitate tendon adaptation and reduce muscle-tendon imbalances, may prevent patellar tendon pain in adolescent male handball players (12–14 years). Tendon pain prevalence (using VISA-P scores), knee extensor strength, vastus lateralis (VL) architecture and patellar tendon mechanical properties were measured at four measurement time points (M1–M4) over a season. The control group (CON; n = 18; age 13.1 ± 0.7 yrs, height 170 ± 8 cm, mass 58 ± 10 kg) followed the usual strength training plan, including muscular endurance and explosive strength components. In the experimental group (EXP; n = 16; 13.1 ± 0.6 yrs, 169 ± 11 cm, 58 ± 16 kg), two sessions per week with functional high-load exercises for the patellar tendon were integrated in the strength training schedule, aiming to provide repetitive high-intensity loading of at least 3 s loading duration per repetition. While in the control group 30% of the athletes reported a clinically significant aggravation of symptoms, all players in the experimental group remained or became pain-free at M2 until the end of the season. There was a similar increase of strength (normalized to body mass; CON: 3.1%, d = 0.22; EXP: 6.8%, d = 0.47; p = 0.04) and VL thickness (CON: 4.8%, d = 0.28; EXP: 5.7%, d = 0.32; p < 0.001) in both groups, but no significant changes of tendon stiffness or maximum tendon strain. Further, both groups demonstrated similar fluctuations of tendon strain over time. We conclude that functional high-load exercises can reduce the prevalence of patellar tendon pain in adolescent athletes even without a reduction of tendon strain.

Leptin and inflammatory factors play a synergistic role in the regulation of reproduction in male mice through hypothalamic kisspeptin-mediated energy balance

BackgroundEnergy balance is closely related to reproductive function, wherein hypothalamic kisspeptin mediates regulation of the energy balance. However, the central mechanism of kisspeptin in the regulation of male reproductive function under different energy balance states is unclear. Here, high-fat diet (HFD) and exercise were used to change the energy balance to explore the role of leptin and inflammation in the regulation of kisspeptin and the hypothalamic-pituitary-testis (HPT) axis.MethodsFour-week-old male C57BL/6 J mice were randomly assigned to a normal control group (n = 16) or an HFD (n = 49) group. After 10 weeks of HFD feeding, obese mice were randomly divided into obesity control (n = 16), obesity moderate-load exercise (n = 16), or obesity high-load exercise (n = 17) groups. The obesity moderate-load exercise and obesity high-load exercise groups performed exercise (swimming) for 120 min/day and 120 min × 2 times/day (6 h interval), 5 days/week for 8 weeks, respectively.ResultsCompared to the mice in the normal group, in obese mice, the mRNA and protein expression of the leptin receptor, kiss, interleukin-10 (IL-10), and gonadotropin-releasing hormone (GnRH) decreased in the hypothalamus; serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels and sperm quality decreased; and serum leptin, estradiol, and tumor necrosis factor-α (TNF-α) levels and sperm apoptosis increased. Moderate- and high-load exercise effectively reduced body fat and serum leptin levels but had the opposite effects on the hypothalamus and serum IL-10 and TNF-α levels. Moderate-load exercise had anti-inflammatory effects accompanied by increased mRNA and protein expression of kiss and GnRH in the hypothalamus and increased serum FSH, LH, and testosterone levels and improved sperm quality. High-load exercise also promoted inflammation, with no significant effect on the mRNA and protein expression of kiss and GnRH in the hypothalamus, serum sex hormone level, or sperm quality. Moderate-load exercise improved leptin resistance and inflammation and reduced the inhibition of kisspeptin and the HPT axis in obese mice. The inflammatory response induced by high-load exercise may counteract the positive effect of improving leptin resistance on kisspeptin and HPT.ConclusionDuring changes in energy balance, leptin and inflammation jointly regulate kisspeptin expression on the HPT axis.

Sex difference in pulmonary hypertension in the evaluation by exercise echocardiography.

Male patients with pulmonary hypertension have poor survival than their female counterparts. Poor right ventricular function in men may be one of the major determinants of poor prognosis. This study aimed to investigate the difference in hemodynamics during exercise between men and women by exercise echocardiography. Consecutive patients with pulmonary hypertension who underwent right heart catheterization were enrolled, and survival was analyzed. In patients who underwent exercise echocardiography, the change in tricuspid regurgitation pressure gradient during exercise was calculated at multiple stages (low-, moderate-, and high-load exercise), and the mortality was also recorded. In a total of 93 patients, although there were no differences in pulmonary artery pressure and vascular resistance between sexes, male patients showed poor survival. In patients with exercise echocardiography, change in tricuspid regurgitation pressure gradient at low-load (25 W) exercise was significantly lower in men, although that at maximum-load exercise was not different between men and women. In the Kaplan–Meier analysis, in a median follow-up duration of 1760 days, male patients and those with lower change in tricuspid regurgitation pressure gradient at low-load exercise showed poorer survival (P = 0.002 and 0.026, respectively). In the Cox proportional hazards analysis, the change in tricuspid regurgitation pressure gradient at low-load exercise was independently associated with poor survival after adjustment for age and sex. In conclusion, a lower change in tricuspid regurgitation pressure gradient at low-load exercise was observed in male patients and was a prognostic marker, which may be associated, at least in part, with poorer prognosis in male patients with pulmonary hypertension.

Construction and Simulation of Injury Early Warning Model for Retired Athletes Based on Improved Self-organizing Neural Network.

With the progress of sci-tech, the interdisciplinary and comprehensive development, and various advanced sci-tech gradually integrated into the field of sports, it has become possible to study how to reasonably prevent sports injuries, minimize the risk of sports injuries, and maintain the best physical condition of retired athletes. Due to the long-term high-load exercise of retired athletes during their sports career, athletes' physical functions have been damaged to varying degrees, resulting in more injuries. According to the characteristics that many factors need to be considered in the prediction of retired athletes' injuries, this paper puts forward an improved self-organizing neural network (SOM) method to predict retired athletes' injuries. In this paper, an early warning analysis model of retired athletes' susceptibility to injury based on SOM is proposed, which screens the state of retired athletes' physical function variables in each stage, considers athletes' physical function data whose standard deviation is higher than the limit specification of susceptibility to injury as susceptible injury data, quickly judges all vulnerable injury data, and completes the high-speed early warning analysis of retired athletes' susceptibility to injury.

Effects Of Treadmill Exercise On DCX And A Beta1-42 In AD Mice

PURPOSE: To investigate the effects of different load exercise on the hippocampal neurogenesis markers DCX and Aβ1-42 in adult AD mice. METHODS: The 3-month-old APP/PS1 dual-transgenic AD mice were randomly divided into four groups: Control group(ADC), Low-load exercise group(ADL), Medium-load exercise group(ADM) and High-load exercise group(ADH), Wild-type control group(WTC) was also be set, 6 mice in each group. ADC and WTC group mice were fed naturally for 5 months. Intervention with different loads of aerobic exercise for every exercise group. Low load running speed was 12 m/min, medium load running speed was 15 m/min, and high load running speed was 18m/min. 5d/w for 30 min/d for 5 months. Then, the Morris Water Maze (MWM) test was performed to estimate mice’ learning and memory abilities, the immunofluorescence technique was used to determine the expression levels of DCX and Aβ1-42 in the hippocampus. RESULTS: (1)In the process of navigation training, all mice’ escape latencies gradually shortened. On the second day, the average escape latency of the ADC group was significantly higher than that of the WTC group (p<0.05). Compared with the ADC group and the ADL group, the mice in the ADM group were significantly reduced from the third day, and the mice in the ADH group were significantly reduced from the fourth day (p<0.05). In the MWM navigation experiment, for the time of through the area of the original platform, ADC group was significantly reduced than WTC group (p<0.01), ADM group and ADH group was significantly higher than ADC group and ADL group (p<0.01,p<0.05). (2) Compared with WTC group, the expression of DCX in ADC group was lower but Aβ1-42 was higher(P<0.05). Compared with ADC group, the expression of DCX in every exercise group was higher but Aβ1-42 was lower(P<0.05, P<0.01). Compared with ADL group, the expression of DCX in ADM group was higher but Aβ1-42 was lower(P<0.05). CONCLUSIONS: Medium and high load exercise can significantly improve the spatial learning and memory ability of AD mice. Exercise, especially medium load exercise, can enhance the expression of DCX in AD mice and reduce the expression of Aβ1-42 in hippocampal.

Effects of high-load exercise induced skeletal muscle injury on autophagy ultrastructure and Beclin1 and LC3-II / I in rats

To investigate the effects of high-load eccentric exercise on the ultrastructure of autophagy and the autophagy-related proteins Beclin1 and LC3II / I in rats. Forty-eight SD male rats were randomly divided into control group (C, n=8) and high-load eccentric exercise group (E, n=40) after adaptive training. Group E was run downhill for 90 minutes on the running platform, and soleus muscles were collected at 0, 12, 24, 48 and 72 hours after exercise. Transmission electron microscopy was used to observe the ultrastructural changes of skeletal muscle autophagosomes. Western blot was used to detect the expressions of Beclin1 and LC3II / I protein. Immunofluorescence was used to observe the localization and content of LC3. The number of soleus muscle autophagosomes in group E was increased at 0, 12 and 24 hours after exercise, and LC3 autophagic fluorescence was significantly increased (P＜0.01), while autophagic fluorescence at 48 hours after exercise was still increased significantly (P＜0.05). Beclin1 and LC3II / I expression levels were increased after high-load centrifugal intervention (P＜0.05), and were peaked at 12 h～24 h after exercise (P＜0.01), and fully recovered at 72 h after exercise. High-load eccentric exercise can induce ultrastructural changes in skeletal muscle autophagy and increase the expression of autophagy protein. The peak value appears at 12 hours after exercise. The above may be one of the reasons for the decline in skeletal muscle function caused by sports injury.

Adaption of Maximal Glycolysis Rate after Resistance Exercise with Different Volume Load.

The aim of this study was to investigate the effect of six-weeks of resistance training with different volume load on the maximum glycolysis rate. 24 male strength-trained volunteers were assigned in a high volume low load (50% of their 1RM with 5 sets and reps up to muscle failure) and a low volume high load (70% of their 1RM with 5 sets of ten reps) resistance exercise group. The resistance training performed 3 days per week over 6 weeks. The maximum glycolysis rate was determined using isokinetic force testing before and after the intervention. There was a significant increase in glycolysis rate over the training period across all subjects (p=0.032). High volume low load exercise increased significantly from 0.271±0.067 mmol·l −1 ·s −1 to 0.298±0.067 mmol·l −1 ·s −1 (p=0.022) and low volume high load exercise showed no significant changes from 0.249±0.122 mmol·l −1 ·s −1 to 0.291±0.089 mmol·l −1 ·s −1 (p=0.233). No significant effect on glycolysis rate was observed between the training groups (p=0.650). Resistance training increases glycolysis rate regardless of volume load.

Effect of Different Exercise Loads on Testicular Oxidative Stress and Reproductive Function in Obese Male Mice.

This study is aimed at investigating the effect of different exercise loads on the reproductive function of obese male mice and the underlying mechanisms. Male mice with high-fat diet-induced obesity were divided into obesity control (OC), obesity moderate-load exercise (OME), and obesity high-load exercise (OHE) groups. The OME and OHE groups were subjected to swimming exercise 5 days per week over a duration of 8 weeks, with the exercise load progressively increased to 2 h per day in the OME group and 2 h twice per day in the OHE group. In the OC group mice without exercise regimen, we observed a decrease in mRNA expression of antioxidant enzymes, increase in free radical products, upregulation of mRNA and protein expression of nuclear factor-κB and proinflammatory cytokines, inhibition of mRNA and protein expression of testosterone synthases, decrease in the serum testosterone level and sperm quality, and increase in sperm apoptosis. Although both moderate-load exercise and high-load exercise reduced body fat, only moderate-load exercise effectively alleviated obesity-induced oxidative stress, downregulated the expression of nuclear factor-κB and proinflammatory cytokines, and reversed the decrease in mRNA and protein expression of testosterone synthases, serum testosterone level, and sperm quality. These changes were not observed in the OHE group mice. Obesity-induced testicular oxidative stress and inflammatory response decreased testosterone synthesis and sperm quality. Moderate-load exercise alleviated the negative effect of obesity on male reproductive function by decreasing testicular oxidative stress and inflammatory responses. Although high-load exercise effectively reduced body fat, its effects on alleviating oxidative stress and improving male reproductive function were limited.

An Intense, But Ecologically Valid, Resistance Exercise Session Does Not Alter Growth Factors Associated With Cognitive Health.

The purpose of this investigation was to assess the acute changes in growth factors associated with cognitive health following two ecologically valid, intense resistance exercise sessions. Twenty-nine late-middle-aged adults performed one session of either (a)moderate-load resistance exercise or (b)high-load resistance exercise. Venous blood was collected prior to warm-up, immediately following exercise and 30min following exercise. Serum was analyzed for brain-derived neurotrophic factor, insulin-like growth factor 1, and vascular endothelial growth factor. Session intensity was determined by blood lactate concentration and session rating of perceived exertion. Postexercise blood lactate was greater following moderate-load when compared with high-load resistance exercise. Subjective session intensity was rated higher by the session rating of perceived exertion following moderate-load when compared with high-load resistance exercise. No differences were observed in serum growth factor levels between groups. Ecologically valid and intense moderate-load or high-load exercise methods do not alter serum growth factor levels in late-middle-aged adults.

A Case of Buttock Claudication Treated with High Load Exercise Therapy

A Case of Buttock Claudication Treated with High Load Exercise Therapy