Run Trial Research Articles

Effects of 10KM run on foot morphology and bilateral symmetry in male recreational runners.

Foot morphology and arch integrity do not remain constant during a running bout. Previous studies have reported inconsistent changes in foot sizes and arch parameters and this discrepancy may be related to the variation in their test duration, e.g., 15-min treadmill run vs. 30KM trial. Hence, this study sought to evaluate the change in foot morphology, arch integrity and bilateral symmetry after a 10KM run among 19 male recreational runners. Before and after the run, a portable foot scanner was used to capture the 3-dimensional foot images and measure foot dimensions in both weight-bearing and non-weight-bearing conditions. Foot arch integrity was quantified by arch height ratio, arch height index, and arch stiffness index (ASI). Bilateral symmetry was evaluated by calculating the symmetry index. Increased foot length (p = 0.007; = 0.18) and decreased ball girth (p = 0.038; = 0.11) were demonstrated following the run with absolute differences of less than 2mm. Navicular height, dorsum height, arch height ratio and arch height index significantly decreased after the run (p < 0.001; ≥0.30) whereas ASI increased (p < 0.001, = 0.33) and navicular height drop reduced (p < 0.001, = 0.37). Significances of symmetry index were only demonstrated for navicular height (p = 0.019, effect size = 0.37) and arch height ratio (p = 0.019, effect size = 0.42). A few changes in foot morphology were detected but a reduction in foot arch height was demonstrated, which may give shoe manufacturers insights into shoe design. Male recreational runners were recommended to choose shoes with arch support for maintaining foot arch function during a 10KM run.

Effects of 12 Wk of Omega-3 Fatty Acid Supplementation in Long-Distance Runners.

This study aimed to investigate the effects of 12 wk of omega-3 fatty acid supplementation during endurance training on omega-3 index (O3I) and indicators of running performance in amateur long-distance runners. Twenty-six amateur male long-distance runners ≥29 yr old supplemented omega-3 fatty acid capsules (OMEGA group, n = 14; 2234 mg of eicosapentaenoic acid and 916 mg of docosahexaenoic acid daily) or medium-chain triglycerides capsules as placebo (medium-chain triglyceride [MCT] group, n = 12; 4000 mg of MCT daily) during 12 wk of endurance training. Before and after intervention, blood samples were collected for O3I assessment, and an incremental test to exhaustion and a 1500-m run trial were performed. O3I was significantly increased in the OMEGA group (from 5.8% to 11.6%, P < 0.0001). A significant increase in V̇O 2peak was observed in the OMEGA group (from 53.6 ± 4.4 to 56.0 ± 3.7 mL·kg -1 ⋅min -1 , P = 0.0219) without such change in MCT group (from 54.7 ± 6.8 to 56.4 ± 5.9 mL·kg -1 ⋅min -1 , P = 0.1308). A positive correlation between the change in O3I and the change in running economy was observed when data of participants from both groups were combined (-0.1808 ± 1.917, P = 0.0020), without such an effect in OMEGA group alone ( P = 0.1741). No effect of omega-3 supplementation on 1500-m run results was observed. Twelve weeks of omega-3 fatty acid supplementation at a dose of 2234 mg of eicosapentaenoic acid and 916 mg of docosahexaenoic acid daily during endurance training resulted in the improvement of O3I and running economy and increased V̇O 2peak without improvement in the 1500-m run trial time in amateur runners.

Prolonged cycling lowers subsequent running mechanical efficiency in collegiate triathletes

BackgroundA significant challenge that non-elite collegiate triathletes encounter during competition is the decline in running performance immediately after cycling. Therefore, the purpose of this study was to determine if performing a 40-km bout of cycling immediately before running would negatively influence running economy and mechanical efficiency of running during simulated race conditions in collegiate triathletes.MethodsEight competitive club-level collegiate triathletes randomly performed two trials: cycling for 40 km (Cycle-Run) or running for 5 km (Run–Run), immediately followed by a four-minute running economy and mechanical efficiency of running test at race pace on an instrumented treadmill. Blood lactate, respiratory exchange ratio, mechanical work, energy expenditure, and muscle glycogen were also measured during the four-minute running test.ResultsMechanical efficiency of running, but not running economy, was significantly lower in Cycle-Run, compared to Run–Run (42.1 ± 2.5% vs. 48.1 ± 2.5%, respectively; p = 0.027). Anaerobic energy expenditure was significantly higher in the Cycle-Run trial, compared to the Run–Run trial (16.3 ± 2.4 vs. 7.6 ± 1.1 kJ; p = 0.004); while net (151.0 ± 12.3 vs. 136.6 ± 9.6 kJ; p = 0.204) and aerobic energy expenditure (134.7 ± 12.3 vs. 129.1 ± 10.5 kJ; p = 0.549) were not statistically different between trials. Analysis of blood lactate, respiratory exchange ratio, mechanical work, and changes in muscle glycogen revealed no statistically significant differences between trials.ConclusionsThese results suggest that mechanical efficiency of running, but not running economy, is decreased and anaerobic energy expenditure is increased when a 40-km bout of cycling is performed immediately before running in collegiate triathletes.

Comparison of energy expenditure and substrate oxidation between walking and running in men and women.

[Purpose]The present study compared energy metabolism between walking and running at equivalent speeds during two incremental exercise tests.[Methods]Thirty four university students (18 males, 16 females) were recruited. Each participant completed two trials, consisting of walking (Walk) and running (Run) trials on different days, with 2-3 days apart. Exercise on a treadmill was started from initial stage of 3 min (3.0 k/m in Walk trial, 5.0 km/h in Run trial), and the speed for walking and running was progressively every minute by 0.5 km/h. The changes in metabolic variables, heart rate (HR), and rating of perceived exertion (RPE) during exercise were compared between the trials.[Results]Energy expenditure (EE) increased with speed in each trial. However, the Walk trial had a significantly higher EE than the Run trial at speeds exceeding 92 ± 2 % of the maximal walking speed (MWS, p < 0.01). Similarly, carbohydrate (CHO) oxidation was significantly higher in the Walk trial than in the Run trial at above 92 ± 2 %MWS in males (p < 0.001) and above 93 ± 1 %MWS in females (p < 0.05).[Conclusion]These findings suggest that EE and CHO oxidation during walking increase non-linearly with speed, and walking at a fast speed causes greater metabolic responses than running at the equivalent speed in young participants.

Long Term Habituation To Carbohydrate-Restricted Diet Preserved Performance And Central Drive After 2 Hours Of Running: A Case Study

PURPOSE: While the brain is usually wholly dependent on glucose for fuel, prolonged carbohydrate deprivation results in adaptations that allow the brain to access fat via ketone bodies. Given the depletion of carbohydrate that takes place during prolonged exercise, a shift toward ketone bodies may maintain central nervous system function, preventing the central fatigue observed during long-duration exercise. In addition, enhancing peripheral muscle’s use of free fatty acids and intra-muscular lipids might prolong contractions. Thus, high fat/low carb diets have been proposed to delay fatigue during endurance exercise. However, studies utilizing periods of 1 to 5 weeks of adaptation to high fat diets have shown equivocal changes in performance at moderate or high intensities. We compare endurance and time trial performance of a keto-adapted male runner (KETO) to 8 subjects (NORM) on whom we have previously reported. METHODS: We measured peripheral and central fatigue in 8 men runners (38±2 yrs; VO2peak 59±3 ml/kg/min) who habitually ate a carbohydrate-liberal diet (NORM) and in a runner (41 yrs, 70 ml/kg/min) who followed a high fat/low carb diet for >2 years. Water was provided at 1% of body mass/hr, during a 2-hr run at ventilatory threshold (~65% VO2peak), followed by a self-paced 2-km time trial (TT). RPE and respiratory measures were determined every 20 minutes. Strength was tested in a semi-reclined position [75° hip flexion, to facilitate femoral nerve stimulation] pre-exercise, after the 2-hr run and post-time trial as follows: voluntary isometric quad strength was measured on the Biodex with the knee flexed 60°, and with superimposed peripheral magnetic stimulation of the femoral nerve to determine central activation (CAR). RESULTS: Respiratory exchange ratio indicated that KETO (0.78) used less carbohydrate than NORM (0.86±0.01) during the 2-hr run. While we measured no fatigue of any kind in KETO, NORM declined in voluntary strength (-16±5%) and experienced loss of central drive to the muscle (CAR decreased from 0.85±0.04 to 0.76±0.05). KETO ran the TT at a mean pace of 16.4 km/hr compared to 14.8±0.7 km/hr in NORM. CONCLUSIONS: Our KETO runner did not display strength loss and may have had better TT performance after exhausting exercise as compared to our NORM runners who exhibited central fatigue.

Acute Caffeine Mouth Rinse Does Not Change the Hydration Status following a 10 km Run in Recreationally Trained Runners.

Background and Aims Caffeine mouth rinsing has emerged as an alternative to oral caffeine consumption for improving performance without provoking lower gastrointestinal distress. However, it remains unclear if hydration status and sweat rate are negatively affected by caffeine mouth rinsing. This study is aimed at evaluating the effects of 10 seconds of caffeine mouth rinsing (1.2% anhydrous caffeine solution) on hydration status and sweat rate following a 10 km run trial. Methods Ten recreationally trained runners (30.1 ± 6.4 y) volunteered to participate in this double-blind, placebo-controlled, and crossover research study. Participants completed two 10 km run trials separated by approximately one week. Immediately prior to running, participants completed a 10-second mouth rinse protocol with either 300 mg of caffeine or microcrystalline cellulose (placebo) diluted in 25 mL of water. The effects of caffeine mouth rinsing on hydration status and sweat rate were assessed following a 10 km run trial. Results Sweat rate (placebo: 15.34 ± 9.71 vs. caffeine: 11.91 ± 6.98 mL · min−1; p = 0.39), dehydration (placebo: 1.20 ± 0.57 vs. caffeine: 1.49 ± 0.29%; p = 0.15), and hydration (placebo: 15.32 ± 9.71 vs. caffeine: 11.89 ± 6.99 mL · min−1; p = 0.37) measures were not significantly different between trials. Conclusion Caffeine mouth rinse does not appear to alter the hydration status or sweat rate following a 10 km run.

Cardiometabolic and Perceptual Responses to Maximal Exercise: Comparing Graded Walking to Ungraded Running

Graded exercise testing for determination of aerobic capacity can be conducted in numerous ways with treadmill testing representing the primary modality. Achieving maximal effort on a treadmill can be accomplished by increasing speed and/or grade. Research to date comparing graded walking maximal tests to ungraded running tests is limited. PURPOSE: Compare the cardiometabolic responses to two treadmill-based maximal tests, namely graded walking and ungraded running. METHODS: 20 healthy participants (11 females, 9 males; mean BMI = 25; mean age = 24) completed two counterbalanced cardiometabolic exercise tests. The WALK trial started with a brisk and comfortable walking speed and increased grade by 2% every minute until exhaustion and the RUN trial started with a comfortable walking speed and increased by 0.5 mph every minute until exhaustion. Expired gases, HR, overall RPE (RPE-O), and legs only RPE (RPE-L) were assessed during the test. RESULTS: Data was analyzed using dependent t-tests. The RUN and WALK trials produced similar maximal values for RPE-O, RPE-L, and VO2 (all p-values > 0.05; all ES values < 0.2), though HR was significantly higher in the RUN trial (p < 0.05; ES = 0.4), and RER was significantly higher in the WALK trial (p < 0.01; ES = 0.8). CONCLUSIONS: Findings indicate that both walk-based and run-based exercise tests produce similar perceptual responses that indicate maximal effort, and similar VO2max values despite very different approaches to creating intense work. The observed difference in HR suggests that a run-based maximal exercise test produces a greater cardiovascular response, while the higher RER value within the walk-based maximal exercise test suggests greater metabolic acidosis. Results support treadmill exercise testing as a flexible multiple assessment modality.

Similar Central and Peripheral Fatigue in Men and Women after Running

PURPOSE: Women may be less fatiguable than men during prolonged endurance exercise. There are a paucity of studies which have compared fatigue in both sexes after moderately long duration running typical of marathon-type training. METHODS: We compared sex differences in peripheral and central fatigue in 8 men and 6 premenopausal women runners. Volunteers [38±2 and 32±2 yrs, p=0.017; VO2peak 59±3 and 54±3, ml/kg/min, p=0.202, men vs women respectively] ate a standardized breakfast [6 Kcal/kg] 90 minutes prior to commencing testing. Water was provided at 1% of body mass/hr, during a 2-hr run at their ventilatory threshold [~65% VO2peak], followed by a self-paced 2-km time trial. RPE and respiratory measures were determined every 20 minutes. Strength was tested in a semi-reclined position [75o hip flexion, to facilitate femoral nerve stimulation] pre-exercise, after the 2-hr run and post-time trial as follows: voluntary isometric quad strength was measured on the Biodex with the knee flexed 60°, and with superimposed peripheral magnetic stimulation [PMS] of the femoral nerve to determine central activation [CAR]. PMS was also applied in a 3-second pulse train on a relaxed muscle to measure peripheral fatigue. Changes in strength and in metabolic measures were analyzed with repeated measures ANOVA. RESULTS: Following running, voluntary strength declined by ~16% in both sexes [effect of time p<0.001; sex X time p=0.206]. CAR also decreased in both men and women [effect of time p=0.020, time X sex p=0.762]. PMS-stimulated forces, our measure of peripheral fatigue, were unchanged after running: there was no effect of time [p=0.10] in men or women [time X sex, p=0.322]. Substrate use and RPEs did not differ between sexes. CONCLUSIONS: We found that both sexes fatigued similarly after a 2-hr run plus a 2-km time trial, and that all of the fatigue was central in nature. While women may be more fatigue-resistant than men, those differences might not be apparent until a greater duration of running is engaged in, e.g. ultramarathon distances.

Assessment of vibration exposure and physiological responses of crew members during Infantry Combat Vehicle (ICV) operation: a pilot study

BackgroundOperation of infantry combat vehicle (ICV) influences the cardiorespiratory responses as well as the risk of vibration exposure on the crew members which adversely affect their performance and health.AimTo assess...

Effects of Cycling on Subsequent Running Performance, Stride Length, and Muscle Oxygen Saturation in Triathletes.

Running performance is a determinant factor for victory in Sprint and Olympic distance triathlon. Previous cycling may impair running performance in triathlons, so brick training becomes an important part of training. Wearable technology that is used by triathletes can offer several metrics for optimising training in real-time. The aim of this study was to analyse the effect of previous cycling on subsequent running performance in a field test, while using kinematics metrics and SmO2 provided by wearable devices that are potentially used by triathletes. Ten trained triathletes participated in a randomised crossover study, performing two trial sessions that were separated by seven days: the isolated run trial (IRT) and the bike-run trial (BRT). Running kinematics, physiological outcomes, and perceptual parameters were assessed before and after each running test. The running distance was significantly lower in the BRT when compared to the IRT, with a decrease in stride length of 0.1 m (p = 0.00) and higher %SmO2 (p = 0.00) in spite of the maximal intensity of exercise. No effects were reported in vertical oscillation, ground contact time, running cadence, and average heart rate. These findings may only be relevant to ‘moderate level’ triathletes, but not to ‘elite’ ones. Triathletes might monitor their %SmO2 and stride length during brick training and then compare it with isolated running to evaluate performance changes. Using wearable technology (near-infrared spectroscopy, accelerometry) for specific brick training may be a good option for triathletes.

The Impact of Morning versus Afternoon Exercise on Iron Absorption in Athletes.

This study examined postexercise inflammatory, hepcidin, and iron absorption responses to endurance exercise performed in the morning versus the afternoon. Sixteen endurance-trained runners (10 male, 6 female) with serum ferritin (sFer) < 50 μg·L completed a 90-min running protocol (65% vV˙O2max) in the morning (AM), or the afternoon (PM), in a crossover design. An iron-fortified fluid labeled with stable iron isotopes (Fe or Fe) was administered with a standardized meal 30 min following the exercise and control conditions during each trial, serving as a breakfast and dinner meal. Venous blood samples were collected before, immediately after, and 3 h after the exercise and control conditions to measure sFer, serum interleukin-6 (IL-6), and serum hepcidin-25. A final venous blood sample was collected 14 d after each trial to determine the erythrocyte iron incorporation, which was used to calculate iron absorption. Linear mixed-modeling was used to analyze the data. Overall, exercise significantly increased the concentrations of IL-6 (4.938 pg·mL; P = 0.006), and hepcidin-25 concentrations significantly increased 3 h after exercise by 0.380 nM (P < 0.001). During the PM trial, hepcidin concentrations exhibited diurnal tendency, increasing 0.55 nM at rest (P = 0.007), before further increasing 0.68 nM (P < 0.001) from prerun to 3 h postrun. Fractional iron absorption was significantly greater at breakfast after the AM run, compared with both the rested condition (0.778%; P = 0.020) and dinner in the AM run trial (0.672%; P = 0.011). Although exercise resulted in increased concentrations of IL-6 and hepcidin, iron was best absorbed in the morning after exercise, indicating there may be a transient mechanism during the acute postexercise window to promote iron absorption opposing the homeostatic regulation by serum hepcidin elevations.

The effect of post-exercise application of either graduated or uniform compression socks on the mitigation of delayed onset muscle soreness

A series of studies were conducted to test the hypothesis that compression socks (uniform or graduated compression) worn after exercise mitigate exercise-induced pain. Fifty-nine (59) participants took part in three separate exercise protocols to induce a degree of muscle soreness from low to severe. Participants wore either ankle height socks with no compression (NoCo), knee height socks with uniform (UNI) or graduated compression (GRAD) for 8 h/day following exercise. Before, immediately after and during recovery, we measured muscle strength, flexibility and the perception of pain. The three exercise protocols were as follows. (1) Hike: compared the effects of GRAD and NoCo socks following a 10-km treadmill hike with a 1000 m ascent and descent. (2) Trail Run: compared the effect of GRAD and UNI following a 14-km trail run with 250 m ascent and descent. (3) Calf Exercise: compared the effect of GRAD and UNI socks with a predominately eccentric calf exercise. GRAD socks significantly mitigated the perception of calf pain compared to NoCo (Hike). The UNI socks were superior to the GRAD socks in mitigating the perception of pain during recovery in the Trail Run. No statistical difference was noted between UNI and GRAD socks after the Calf Exercise. Compression socks mitigated the perception of calf muscle pain (Hike trial), with UNI providing more benefit compared to GRAD socks (Trail Run trial). No differences between the UNI and GRAD socks were observed in the Calf Exercise trial. Compression socks aid in the perception of recovery following low to moderate pain from delayed onset muscle soreness.

The effects of single versus twice daily short term heat acclimation on heat strain and 3000 m running performance in hot, humid conditions

Endurance performances are impaired under conditions of elevated heat stress. Short term heat acclimation (STHA) over 4–6 days can evoke rapid adaptation, which mitigate decrements in performance and alleviate heat strain. This study investigated the efficacy of twice daily heat acclimation (TDHA) compared to single session per day heat acclimation (SDHA) and normothermic training, at inducing heat acclimation phenotype and its impact upon running performance in hot, humid conditions.Twenty one, moderately trained males were matched and assigned to three groups; SDHA (mean±SD) (peak oxygen consumption [V̇O2peak] 45.8±6.1mLkg−1min−1, body mass 81.3±16.0kg, stature 182±3cm), TDHA (46.1±7.0mLkg−1min−1, 80.1±11.9kg, 178±4cm) or control (CON) (47.1±3.5mLkg−1min−1, 78.6±16.7kg, 178±4cm). Interventions consisted of 45min cycling at 50% V̇O2peak, once daily for 4d (SDHA) and twice daily for 2d (TDHA), in 35°C, 60% relative humidity (RH), and once daily for 4 days (CON) in 21°C, 40% RH. Participants completed a pre- and post-intervention 5km treadmill run trial in 30°C, 60% RH, where the first 2km were fixed at 40% V̇O2peak and the final 3km was self-paced.No statistically significant interaction effects occurred within- or between-groups over the 2–4 days intervention. While within-group differences were found in physiological and perceptual measures during the fixed intensity trial post-intervention, they did not statistically differ between-groups. Similarly, TDHA (−36±34s [+3.5%]) and SDHA (−26±28s [+2.8%]) groups improved 3km performances (p=0.35), but did not differ from CON (−6±44s [+0.6%]).This is the first study to investigate the effects of HA twice daily and compare it with traditional single session per day STHA. These STHA protocols may have the ability to induce partial adaptive responses to heat stress and possibly enhance performance in environmentally challenging conditions, however, future development is warranted to optimise the administration to provide a potent stimuli for heat adaptation in athletic and military personnel within a rapid regime.

Limiter Redesign Process Expands To Cover Flat-Time Operations

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 170751, “Maximizing Capital Efficiency by Expanding the Limiter Redesign Process to Flat-Time Operations,” by M.A. Valenta, SPE, M.W. Walker, SPE, P.E. Pastusek, SPE, J.R. Bailey, SPE, W.C. Elks, SPE, S.B. Lewis, SPE, and N.D. Mitchell, ExxonMobil Development Company, prepared for the 2014 SPE Annual Technical Conference and Exhibition, Amsterdam, 27–29 October. The paper has not been peer reviewed. The Fast Drill Process has become a well-known work flow to identify hole-making limiters and mitigate them through redesign to the economic limit of performance. To address operations that do not include drilling of rock, the operator launched a similar effort and work flow that focus on flattime portions of well construction. This process is yielding significant savings globally and has been accomplished through planning, realtime recognition and response, and collaboration while improving safety performance continuously. Evolution of the Fast Drill Process In 2004, the operator started a pilot program to determine if drilling performance could be improved by analyzing and reacting to trends in mechanical specific energy (MSE). MSE is a performance measurement parameter that approximates the bit’s drilling efficiency and is a function of weight on bit (WOB), surface torque, bit rotation per revolution, and rate of penetration (ROP) for a given hole size. Results of a pilot program confirmed that significant ROP performance gains could be obtained simply by monitoring MSE trends and adjusting the drilling parameters (WOB and bit rotation per revolution) at the rigsite to minimize MSE. This process was deployed in 2005 and is known as the Fast Drill Process. The operator refined the work flow to improve drill rate performance. The work flow follows a plan/do/analyze/improve cycle to identify and overcome limiters in the drilling operation. The key elements of the Limiter Redesign Process are Identify the current limiter. Plan to extend the limiter. Identify risks with change. Plan to mitigate risks. Run trial and take data. Adjust trial on the basis of real-time events. Capture learnings. Repeat the cycle to the economic limit. Internally the Limiter Redesign Process was renamed Fast Drill Borehole Management (FDBM). The new expanded objective was to improve borehole quality and address near-misses in the upfront drilling-design process and in real-time drilling operations. The FDBM initiative was the continued evolution of the Fast Drill Process.

Validity and reliability of GPS for measuring distance travelled in field-based team sports

The aim of the present study was to examine the effects of movement intensity and path linearity on global positioning system (GPS) distance validity and reliability. One participant wore eight 1-Hz GPS receivers while walking, jogging, running, and sprinting over linear and non-linear 200-m courses. Five trials were performed at each intensity of movement on each 200-m course. One receiver was excluded from analysis due to errors during data collection. The results from seven GPS receivers showed the mean (±s) and percent bias of the GPS distance values on the 200-m linear course were 205.8 ± 2.4 m (2.8%), 201.8 ± 2.8 m (0.8%), 203.1 ± 2.2 m (1.5%), and 205.2 ± 4 m (2.5%) for the walk, jog, run, and sprint trial respectively. Walk and sprint distances were significantly different from jogging and running distances (P < 0.05). The GPS distance values on the 200-m non-linear course were 198.9 ± 3.5 m (−0.5%), 188.3 ± 2 m (−5.8%), 184.6 ± 2.9 m (−7.7%), and 180.4 ± 5.7 m (−9.8%) for the walk, jog, run, and sprint trial respectively; these were significantly lower than those for the corresponding values on the linear course (P < 0.05). Differences between all non-linear movement intensities were significant (P < 0.05). The overall coefficient of variation within and between receivers was 2.6% and 2.8% respectively. Path linearity and movement intensity appear to affect GPS distance accuracy via inherent positioning errors, update rate, and conditions of use; reliability decreases with movement intensity.

Effects of Exercise on Hepcidin Response and Iron Metabolism during Recovery

Urinary hepcidin, inflammation, and iron metabolism were examined during the 24 hr after exercise. Eight moderately trained athletes (6 men, 2 women) completed a 60-min running trial (15-min warm-up at 75-80% HR(peak) + 45 min at 85-90% HR(peak)) and a 60-min trial of seated rest in a randomized, crossover design. Venous blood and urine samples were collected pretrial, immediately posttrial, and at 3, 6, and 24 hr posttrial. Samples were analyzed for interleukin-6 (IL-6), C-reactive protein (CRP), serum iron, serum ferritin, and urinary hepcidin. The immediate postrun levels of IL-6 and 24-hr postrun levels of CRP were significantly increased from baseline (6.9 and 2.6 times greater, respectively) and when compared with the rest trial (p < or = .05). Hepcidin levels in the run trial after 3, 6, and 24 hr of recovery were significantly greater (1.7-3.1 times) than the pre- and immediate postrun levels (p < or = .05). This outcome was consistent in all participants, despite marked variation in the magnitude of rise. In addition, the 3-hr postrun levels of hepcidin were significantly greater than at 3 hr in the rest trial (3.0 times greater, p < or = .05). Hepcidin levels continued to increase at 6 hr postrun but failed to significantly differ from the rest trial (p = .071), possibly because of diurnal influence. Finally, serum iron levels were significantly increased immediately postrun (1.3 times, p < or = .05). The authors concluded that high-intensity exercise was responsible for a significant increase in hepcidin levels subsequent to a significant increase in IL-6 and serum iron.

Microstructural, compositional and residual stress evaluation of CO 2 laser welded superaustenitic AISI 904L stainless steel

CO 2 laser welding was performed on AISI 904L superaustenitic stainless steel sheets, with optimised processing parameters determined by means of melt run trial evaluations. X-ray diffraction phase identification and light microscopy confirmed that the weld structure is fully austenitic and dendritic. A hardness increase in the weld bead with respect to the parent metal occurred and was related to both the microstructural refinement induced by a rapid cooling of the fusion zone and the presence of nanometric scale precipitates observed by TEM in the weld bead. Residual stresses were determined by means of X-ray diffraction, exhibiting tensile stresses, close to the yield strength, in the longitudinal direction in the weld bead, while the stresses were compressive in the transverse direction and in the base material. Tensile tests showed that welded specimens retained strength and ductility values comparable to those of the base material.

Decrement of the skin conductance response to repeated volitional inspiration

Objective To examine response decrement of the recently reported inspiratory skin conductance response (SCR) [Lim CL, Seto-Poon M, Clouston PD, Morris JG. Sudomotor nerve conduction velocity and central processing time of the skin conductance response. Clin Neurophysiol 2003;114:2172–80]. Methods Twelve healthy adult volunteers performed 3 tasks (A) a control task of maintaining tidal breathing and then two randomized tasks, (B) a deep inspiration to a target oral pressure and (C) tapping with a finger. Each task was performed 30 times on cue every 20 s in 3 runs with 5 min of rest between runs. The SCR, oral pressure, airflow, inspired volume and cue signal were recorded continuously and analysed offline. SCR amplitude was logarithmically transformed and then statistically analysed, using a linear mixed effects model, as a function of run number, trial number and absolute error between target and actual oral pressures. Results Inspiratory efforts elicited exponentially decreasing SCR amplitude with increasing trial number during each run ( P<0.0001). After adjusting for trial number, the mean SCR amplitude of the second and the third run were, respectively, 24.2 (95% CI (0.175, 0.336), P<0.001) and 14.4% (95% CI (0.104, 0.200), P<0.001) of the first run amplitude. Conclusions Volitional deep inspiration reliably activates an SCR that exhibits response decrement with repetition, which may be habituation. Significance The volitional inspiratory SCR may assist in the assessment of sympathetic autonomic status in patients with peripheral afferent neuropathy.

全段樹脂ロール化によるスーパーカレンダーの操業経験

Hachinohe Mill has been operated to optimized the productivity of the coaters, and as the result, productivity of the supercalender has been a bottle-neck of the mill productivity. To clear this bottle-neck, resin roll was introduced to the supercalender as a measure to improve the productivity of the supercalender.Through the discussions with resin roll producers, roll matches to 1, 000 m/minute maximum operation speed, 350 kg/cm maximum linear pressure, 90°C steel roll temperature was prepared and subjected to the trial. Trail showed the improvement of the productivity without any scratch to the roll, but showed some reduction of product qualities such as 3 to 5% loss of gloss. Reconsideration of the resin material and the increase of linear pressure resulted the quality equivalent to our conventional products but the long run trial showed the occasional peel off of the roll surface, surface crack and other operation troubles, and thus roll material is further changed to the material having high heat resistance and high load resistance. Furthermore, regularly scheduled roll cleaning and roll grinding, and temperature control was introduced. All those measures allow the improved productivity of the supercalender without any sacrifice to the product quality.Price for the new resin roll is much expensive that of the conventional roll but can be paid off by the extension of the grinding period and also the life of the roll. As the result, 10% increase of the supercalender productivity was acheved.

Radial maze performance following hippocampal kindling

The relation between hippocampal epileptiform activity and 8-arm radial maze performance was assessed following repetitive afterdischarges (ADs) evoked by stimulation of the hippocampal CA1 region (kindling). Hippocampal kindling, whether to stage V (generalized) convulsions or to a preconvulsive stage, induced deficits in radial maze performance, evaluated by correct arm entries in 8 choices or total maze run (trial) time. The deficits persisted at least until 21 days after the last AD. Hippocampal interictal spikes (ISs) were induced by kindling, but the rate of ISs declined to near zero in a few days. The rate or presence of ISs was not related to maze performance.