Weeks Of Running Training Research Articles

Increased Levels of Spinal Cord KIF1B Protein In Healthy and Diabetic Neuropathic Wistar Rats With in Adaptation to Aerobic Training (KIF1B Changes in Sensory Neurons After Exercise)

Background and Objectives Diabetic neuropathy is one of the most common complications of diabetes and no suitable drug treatment has been found for this complication. The aim of this study was to determine the effect of six weeks of aerobic exercise on KIF1B protein in the sensory part of the spinal cord in rats with diabetic neuropathy. Subjects and Methods In the present experimental study, 12 male Wistar rats were divided into 4 groups: healthy exercise, control exercise, healthy diabetes and control diabetes. The training program included 6 weeks of running training on the treadmill in 5 sessions per week. The dorsal part of the spinal cord was analyzed as sensory neurons. Results The results showed that aerobic exercise significantly reduced blood glucose in the diabetic group compared to the control diabetes group (P=0.002), but no significant difference was observed in the weight of rats. The results also showed that a significant increase (P=0.044) in KIF1B in healthy exercise group compared to healthy control group and a significant increase (P=0.027) in KIF1B in diabetic exercise group compared to control diabetes. Conclusion The results showed that aerobic exercise increases the amount of KIF1B protein in healthy and diabetic rats, and this increase in KIF1B motor protein can improve axonal transmission and thus improve nerve function.

Effects of Endurance Running Training Associated With Photobiomodulation on 5-Km Performance and Muscle Soreness: A Randomized Placebo-Controlled Trial.

This study aimed to investigate the influence of endurance running training associated with PBM on endurance performance variables and muscle soreness in untrained men. Thirty untrained men were distributed randomly into a placebo (PLA) group and photobiomodulation group (PBMG) and they performed 8 weeks of running training. The PBMG had the PBM performed before all training sessions. The PBM was applied using LED equipment with 56 diodes of red light (660 nm) and 48 diodes of infrared light (850 nm). The application was performed in 5 points per leg, with a dose of 60 J at each point and a total energy delivered per leg of 300 J. Peak running velocity, time limit tests and 5-km performance were assessed pre and post-training; muscle soreness was evaluated before all training sessions. The Vpeak increased and 5-km running time (t5–km) decreased (P < 0.001) in both groups. In addition, the magnitude based-inference analysis showed a possibly positive effect on Vpeak and t5–km and for PBMG compared to PLA group. Furthermore, there was a moderate ES of 0.82 on attenuation in muscle soreness in the third week of endurance running training. Therefore, although the magnitude-based inference analysis demonstrated a possibly positive effect on Vpeak and t5–km and for PBMG compared to PLA group and a moderate ES on attenuation in muscle soreness in the last weeks of endurance running training, no significant difference were found between PBMG and PLA interventions.

Effects of different frequencies of physical training on electron transport chain and oxidative damage in healthy mice

Abstract Aims: The present study investigated the effect of different frequencies (three and five times a week) on electron transport chain and oxidative stress after 8 weeks of run training. Methods: Eighteen male mice (CF1, 30-35g) were distributed into the following groups (n=6): untrained (UT); trained three-time per week (T3) and trained five- time per week (T5). All training sessions were at the same intensity and duration (45min/day) in a treadmill for small animals. Forty-eight hours after the last training session, the animals were killed by decapitation and quadriceps (red portion) was removed and stored at -70oC. Succinate dehydrogenase (SDH), complexes I, II, II-III, IV and hydroperoxides were measured. Results: Training sessions for five times per week were more effective in increasing the mitochondrial respiratory chain enzyme activities (SDH, complexes I, II, II-III, IV) as well as in decreasing the formation hydroperoxides than sessions performed for three times training per week (p<0.05). Conclusion: Our findings clearly showed that a higher the frequency of training session promotes a greater activity of the electron transport chain and consequently reduces the oxidative stress in healthy animals.

Adaptations of lumbar biomechanics after four weeks of running training with minimalist footwear and technique guidance: Implications for running-related lower back pain

To investigate the changes in lumbar kinematic and paraspinal muscle activation before, during, and after a 4-week minimalist running training. Prospective cohort study. University research laboratory. Seventeen habitually shod recreational runners who run 10-50km per week. During stance phases of running, sagittal lumbar kinematics was recorded using an electrogoniometer, and activities of the lumbar paraspinal muscles were assessed by electromyography. Runners were asked to run at a prescribed speed (3.1m/s) and a self-selected speed. For the 3.1m/s running speed, significant differences were found in the calculated mean lumbar posture (p=0.001) during the stance phase, including a more extended lumbar posture after minimalist running training. A significant reduction in the contralateral lumbar paraspinal muscle activation was also observed (p=0.039). For the preferred running speed, similar findings of a more extended lumbar posture (p=0.002) and a reduction in contralateral lumbar paraspinal muscle activation (p=0.047) were observed. A 4-week minimalist running training program produced significant changes in lumbar biomechanics during running. Specifically, runners adopted a more extended lumbar posture and reduced lumbar paraspinal muscle activation. These findings may have clinical implications for treating individuals with running-related lower back pain.

Skeletal muscle plasticity with marathon training in novice runners

The purpose of this study was to investigate leg muscle adaptation in runners preparing for their first marathon. Soleus and vastus lateralis (VL) biopsies were obtained from six recreational runners (23 ± 1 years, 61 ± 3 kg) before (T1), after 13 weeks of run training (T2), and after 3 weeks of taper and marathon (T3). Single muscle fiber size, contractile function (strength, speed, and power) and oxidative enzyme activity [citrate synthase (CS)] were measured at all three time points, and fiber type distribution was determined before and after the 16-week intervention. Training increased VO(2max) ∼9% (P<0.05). All soleus parameters were unchanged. VL MHC I fiber diameter increased (+8%; P<0.05) from T1 to T2. VL MHC I V(o) (-12%), MHC I power (-22%) and MHC IIa power (-29%) were reduced from T1 to T2 (P<0.05). No changes in VL single fiber contractile properties were observed from T2 to T3. No change was observed in soleus CS activity, whereas VL CS activity increased 66% (P<0.05). Our observations indicate that modest marathon training elicits very specific skeletal muscle adaptations that likely support the ability to perform 42.2 km of continuous running - further strengthening the existing body of evidence for skeletal muscle specificity.

Sensitivity of neuromuscular junctions to unloading and pre‐habilitation

It has been well documented that muscle unloading elicits significant decrements in muscle strength and size. In contrast, the effects of muscle unloading on the neuromuscular junction (NMJ) are less elucidated and the potential of pre‐habilitative conditioning remains unknown. The aim of this study was to examine the impact of unloading on the NMJs of aged rats, as well as the capacity of pre‐habilitation to affect those synapses. Thirty aged (25 mo) male Fischer 344 rats were assigned to 3 groups; 1) control, 2) unloaded (UL), 3) pre‐habilitation before unloading (PH‐UL). UL rats were subjected to hindlimb suspension for 2 weeks, and PH‐UL rats completed a 2 week (5days/wk) treadmill running program before 2 weeks of hindlimb suspension. Following all interventions, all rats were euthanized and soleus muscles were removed and frozen at resting length. Cytofluorescent techniques were used to visualize pre‐synaptic nerve terminal branching, and post‐synaptic acetylcholine receptors. Confocal microscopy was used to collect images of pre‐ and post‐synaptic morphology. Our results indicated that neither pre‐ nor post‐synaptic morphological parameters were altered in UL or PH‐UL rats. Thus, a 2 week unloading period is insufficient to modify synaptic structure among aged rats. Moreover, the combination of 2 weeks of run training and 2 weeks of unloading also failed to provoke changes in NMJ morphology.Supported by the National Institute on Aging, and The Foundation for Aging Studies and Exercise Science Research.

Reactivity of mesenteric and aortic rings from trained rats fed with high caloric diet

A strong association between the benefits of physical exercise on the cardiovascular disease with an improvement of the endothelium-derived relaxing factor production has been consistently shown. The purpose of this study was to evaluate the effect of exercise training associated with high caloric diet in the reactivity of rat mesenteric and aortic rings. Experimental protocol consisted of 4 weeks of high caloric diet consumption previous to 4 weeks of run training (1.2 km/h, 0% grade, in sessions of 60 min, 5 days/week). Concentrations of triglycerides, glucose, insulin and nitrite/nitrate levels were measured and atherogenic index was calculated. Concentration-response curves to acetylcholine (10 nM-100 microM), sodium nitroprusside (100 pM-100 nM) and phenylephrine (1 nM-3 microM) were obtained. Exercise training reduced body mass (6%) and triglyceride levels (about 54%), without changes in glucose and insulin concentrations. An improvement of endothelium-dependent relaxation responses to acetylcholine in mesenteric and aortic rings was observed in trained group. No changes were seen for sodium nitroprusside and phenylephrine. In conclusion, our study is the first to show clearly that run training promotes an improvement of the endothelium-dependent relaxing response in aorta and mesenteric rings from rats fed with high caloric diet and that is associated with increase of NO production.

Effects Of Constant Versus Stochastic Training Patterns On Development Of Endurance Performance In Running

PURPOSE We tested the hypotheses that 1. endurance performance (VO2max) remains unaffected after 13 weeks of individualized run training with a mean daily volume of 5 % of VO2max' and 2. the effects of the mode of training pattern (stochastic (STO) vs. constant (CON) load over time) on VO2max are similar. METHODS 14 endurance trained runners (33.7 ± 5 yrs., 76.9 ± 3.7 kg, 182.8 ± 4.5 cm) were randomly divided into two run training groups. In group CON, the training load, duration and number of sessions per week was kept constant. Group STO absolved a training program with stochastic changes of duration and number of sessions per week, resulting in a higher variability of number of sessions and volume of each session. Averaging 4 weeks, the total training load was equal for CON and STO. Run velocity was set to 70 % of anaerobic threshold (AT) in both groups, total duration of training was 13 weeks. Mean weekly volume was individually fixed at an energy consumption of 5 % of VO2max according to the protein synthesis model of Mader (1989). Before and after the training period, subjects underwent an incremental treadmill test for the determination of AT, and a further test to determine VO2max. Run economy was determined as mean O2 consumption per 1 m/s. RESULTS Neither mean training duration nor total number of training sessions was different between groups (5102 ± 544 (CON) vs. 4989 ± 561 (STO) min/13 weeks; 60.0 ± 2.3 (CON) vs. 58.4 vs. 6.7 (STO) sessions/13weeks). Furthermore, mean velocity during training was the same for both groups (2.65 ± 0.27 (CON) vs. 2.73 ± 0.32 (STO) m/s). VO2max of both groups remained constant after 13 weeks of run training (CON: 58.1 ± 6.0 vs. 58.7 ± 3.0 ml/min/kg; STO: 60.4 ± 3.8 vs. 59.0 ± 5.0 ml/min/kg). Run velocity at AT also did not change after training (CON: 3.9 ± 0.4 m/s vs. 3.9 ± 0.4 m/s; STO: 3.8 ± 0.4 m/s vs. 3.9 ± 0.2 m/s). Run economy was less well developed in STO as compared to CON prior to the training program (O2 consumption: 11.9 ± 0.8 vs. 10.8 ± 0.6 ml/min/kg per m/s, p<0.05, in STO vs. CON), and declined in STO significantly (p<0.05) to the same low value as compared to CON after the program (10.9 ± 0.5 vs. 10.7 ± 0.6 ml/min/kg per m/s, in STO vs. CON). CONCLUSIONS The unchanged VO2max values and velocities at AT in both groups after the training program are consistent with the protein synthesis model of Mader (1989), which predicts no changes at a mean daily load of 5 % of VO2max. A mean daily training load of more than 5 % of VO2max is necessary to increase endurance performance in trained runners. Our data further indicate that training pattern does not have any different effect on VO2max, if mean velocity during training and mean total load are remained the same.

Improvement in relaxation response in corpus cavernosum from trained rats

To evaluate the contractile and relaxing responses in rat corpus cavernosum (RCC) from rats after 8 weeks of run training, because erectile function is highly dependent on nitric oxide (NO) from nitrergic fibers or endothelium. Physical activity enhances NO production and improves endothelial function, with beneficial effects on cardiovascular disease. The training program consisted of 8 weeks of run training, 5 days/wk, and each session lasted 60 minutes. The RCC was isolated, and concentration-response curves to NO, acetylcholine, sodium nitroprusside, phenylephrine, and endothelin were obtained. The excitatory and inhibitory effects of electrical field stimulation (2 to 32 Hz) were also evaluated. NO (0.1 to 100 microM) and sodium nitroprusside (0.01 to 1000 microM) produced a relaxing effect in RCC in a dose-dependent manner, with the maximal responses to NO (control 62% +/- 4%, trained 88% +/- 3%) and sodium nitroprusside (control 83% +/- 3%, trained 95% +/- 2%) significantly enhanced after 8 weeks of run training. However, acetylcholine-induced relaxations were not affected by exercise. Similarly, electrical field stimulation-induced relaxations were significantly increased in RCC from trained rats at 2 Hz (control 2.4% +/- 0.3%, trained 4.2% +/- 0.5%) and 4 Hz (control 5.3% +/- 1.2%, trained 12.5% +/- 1.7%). The contractile sensitivity of RCC to phenylephrine (0.01 to 100 microM) and endothelin (0.01 to 100 nM) was not modified by training exercise. Our findings suggest that run training enhances functional responses in rat RCC that involves increases in the NO-cyclic guanosine monophosphate signaling pathway by endothelium-independent mechanisms that is not accompanied by changes in contractile sensitivity.

Bovine colostrum supplementation during endurance running training improves recovery, but not performance

This study examined the effect of supplementation with concentrated bovine colostrum protein powder (intact) on plasma insulin-like growth factor I (IGF-I) concentrations, endurance running performance and recovery. Thirty physically active males completed 8 weeks of running training whilst consuming 60 g x day(-1) of intact powder (n=17) or a concentrated whey protein powder placebo (n=13) in a randomised, double-blind, parallel design. Plasma IGF-I concentrations were measured prior to subjects performing two (approximately 30 min) incremental treadmill running tests to exhaustion (RUN1 and RUN2) separated by 20 min of passive recovery at Weeks 0. 4 and 8. Plasma IGF-I concentrations showed little change in either group (p=0.83). Effective peak running speed (PRSE; i.e. equivalent of peak power) during RUN1 was not different between groups at Week 0 (p>0.99), and had increased by a similar amount in both groups by Week 4 (mean+/-SD, intact 2.2+/-4.0%, placebo 3.2+/-3.3%; 95% confidence interval [95% CI 15.7 to -13.7%; p=0.89) and Week 8 (intact 3.6+/-5.6%, placebo 3.4+/-4.4 %; 95% CI -100.0 to 100.0%; p>0.99). PRSE was less in both groups during RUN2 (p<0.05), but was not significantly different between groups at Week 0 (p>0.99). PRSE during RUN2 tended to have increased more in the placebo group by Week 4 (intact 1.8+/-4.8%, placebo 4.2+/-3.9%; 95% CI 0.2 to -5 0%; p=0.07), but the intact group had increased PRSE significantly more by Week 8 (intact 4.6+/-6.1%, placebo 2.0+/-4.5%; 95% Cl 0.0 to 5.2%; p=0.05). resulting in a significantly faster PRSE (p=0.003). We conclude that supplementation with intact powder did not increase plasma IGF-I concentrations or improve performance during an initial bout of incremental running to exhaustion in our sample. However, performance during a second bout of exercise may be improved by as much as 5.2% in the average subject after 8 weeks of supplementation, possibly due to an enhancement of recovery.

Prior running reduces hypertrophic growth of skeletal muscle grafts

Run training can increase the mass of soleus muscle grafts, yet values remain lower than nongrafted muscle even with continued training. Thus we tested the hypothesis that nerve-implant soleus grafts of rats previously run trained would be refractory to the hypertrophic stimulus of ablation of synergistic muscle. We also compared the magnitude of growth of the nerve-implant soleus graft after ablation with that reported by others for the nerve-intact soleus graft. We studied eight groups that differed relative to the combination and order of treatments (running and ablation of synergistic muscle) and the graft age at the time of the ablation operation and study. Graft mass, protein concentration, and histochemical fiber composition were measured. Compared with grafts from cage-sedentary rats, the mass and protein content of the nerve-implant soleus grafts were higher (16-63%) at all times after ablation. When the ablation operation was performed at 56 days postgrafting, there was a 33% increase in protein content of the soleus graft by 84 days for cage-sedentary animals. This increase was twofold greater (P less than or equal to 0.02) than the 15% increase that followed ablation for the grafts from the animals that had been run trained before the ablation operation. Four weeks of run training before the ablation operation impaired the adaptive response of muscle grafts to the ablation of synergistic muscles, which may reflect alterations in motor unit recruitment and/or satellite cell activity. Ablation of synergistic muscles resulted in an absolute growth of the nerve-implant soleus grafts that was comparable with that reported for nerve-intact soleus grafts.

Time dependent response of cardiac myofibrillar ATPase activity to exercise

1. The purpose of the present study was to investigate the time course of run training effects on the Ca2+ kinetics of the cardiac myofibrillar ATPase activity in female Sprague-Dawley rats. 2. The cardiac myofibrillar ATPase activity was measured at varying Ca2+ levels, and the Hill-n and pCa50 were measured in the hearts of rats after 3, 6 and 9 weeks of running training with a training program that began with an initially high intensity (HINT) and a training program with a more progressive increase in intensity (PROG). 3. After 3 and 6 weeks of training cardiac myofibrillar ATPase activity in the hearts of the trained rats in both training programs was elevated by 28-40% over the control group (P less than 0.05) at a pCa5 but was not different from the control groups after 9 weeks of training (P greater than or equal to 0.05). 4. Also the Ca2+ co-operativity as measured by the Hill-n was elevated in the hearts of the trained rats after 6 and 9 weeks of training when compared to control groups suggesting changes in the regulatory proteins of the myofibrils of hearts from trained rats. 5. The elevations in cardiac myofibrillar ATPase activity suggest that the myocardium responded to the training stimulus in a phasic manner. 6. The regression of cardiac myofibrillar ATPase in the late weeks of training might be related to a reduction or a loss of a specific training stimulus for the myocardium.