Trained Distance Research Articles

Faster intervals, faster recoveries - intensified short VO2max running intervals are inferior to traditional long intervals in terms of time spent above 90% VO2max.

High intensity interval training for improving maximal oxygen consumption (VO2max) is a fundamental component of specific preparation phases for middle- and long-distance runners. In this context, short intervals are very popular in practice. The aim of the present study was to determine whether increasing the intensity of short intervals around maximal aerobic speed (vVO2max), compared to traditional long interval runs, leads to a greater time spent above 90% VO2max. 12 highly trained middle distance runners (7 males, 5 females) completed two VO2max sessions (4 × 3 min at 95% vVO2max, recovery: 3 min at 50% vVO2max vs. 24 × 30 s at 100% vVO2max, recovery: 30 s at 55% vVO2max) on the treadmill in randomized order. Spiroergometric data, lactate accumulation, heart rate (HR) and perceived exertion was determined. This allowed the recording of time above 90% VO2max and time above 90% HRmax. To analyze differences between the interval sessions, the paired t-test respectively the Wilcoxon test, if data were not normally distributed, were applied. The time spent above 90% VO2max was significantly lower in the 30-s intervals, despite the higher intensity, compared to the 3-min session (201.3 ± 268.4 s vs. 327.9 ± 146.8 s, p = 0.05, r = 0.57). In contrast, the time spent above 90% HRmax was significantly higher for the 30-s intervals than for the 3-min intervals (820 ± 249 s vs. 545 ± 131 s, p < 0.001, d = 1.73). The blood lactate concentrations showed higher values in the 3-min session (9.69 ± 1.82 mmol/L) compared to the 30-s session (7.59 ± 2.01 mmol/L, p < 0.001, d = 2.34). There was no statistical difference in the rating of perceived exertion between the two sessions (30-s session: 6.5 ± 1.0 vs. 3-min session: 6.8 ± 1.2; p = 0.26). The present study showed that intensified 30-s intervals were inferior to traditional 3-min intervals regarding the time spent above 90% VO2max. Given the observation of an opposing trend in the time spent above 90% HRmax, this parameter should be interpreted with caution in traditional training settings.

Effects of Interval and Power Training on the Physical, Physiological, and Training Characteristics of Trained Distance Runners

Background: Previous research has individually investigated how different types of training affect the physical, physiological, and training characteristics of distance runners. However, there is a lack of studies that collectively examine the effects of interval and power training programs on these factors in trained distance runners. Objectives: This study aims to provide a more comprehensive and up-to-date understanding of how combined training approaches may impact the physical, physiological, and training characteristics of competitive distance runners. Methods: A census sampling approach was used, with all 108 athletes (100%) participating in the study. Participants were divided into three parallel training groups: The interval training group (ITG), the power training group (PTG), and the control training group (CTG). Each group contained 36 participants, and a randomized block design was implemented within each group, with 12 athletes in each block. The intervention lasted for 32 weeks, with three training sessions per week, on non-consecutive days, lasting 45 - 60 minutes per session. The intensity of the training sessions was maintained between 50 - 70% of the participants' exercise capacity. The measured physical characteristics included demographic and anthropometric variables such as age, sex, height, weight, Body Mass Index (BMI), fat and fat-free mass, and various circumferences. The physiological characteristics assessed included resting heart rate, exercise heart rate, maximum oxygen consumption, measures of leg strength (LS) and power, endurance performance metrics such as time trials (TTs), and aerobic thresholds. The training characteristics assessed included living and training altitude, training habits, training experience, training volume, training sessions, recovery practices, and nutritional intake. Statistical significance was determined with a P-value of &lt; 0.05, and effect size was calculated (η² &gt; 0.14). Results: Interval and power training led to improvements in several physical characteristics, including chronological age (P = 0.02), Body Mass Index (P = 0.03), fat-free mass (P = 0.000), and maximum thigh circumference (P = 0.000). However, no significant changes were observed in certain physical characteristics such as sex, field, and weight (P = 1.000). Interval and power training also resulted in significant improvements in various physiological characteristics, including 400 m sprint performance (P = 0.000), 1.5 km Kosmin test (P = 0.000), 3 km maximum speed TT (P = 0.000), LS (P = 0.000), Sprint Bounding Index (SBI) (P = 0.000), and maximum exercise heart rate (P = 0.000). In contrast, the post-test (POT) results for the ITG and PTG groups, when compared to the CTG, showed no significant differences in certain areas of physiological characteristics, including Balke V̇O2Max (P = 0.000), leg press (P = 0.000), and squat (p = 0.000). Regarding the third subgroup analysis of training characteristics, all POT results showed a decrease, except for the habit of sleeping (P = 0.04). In general, the POT results of the CTG demonstrated less change in all subgroup analyses of performance indices compared to the ITG and PTG. Conclusions: Our key findings emphasize the importance of combined interval and power training in improving V̇O2Max, overall strength endurance, speed endurance, running economy (RE), and muscle adaptation compared to the control group. These factors are vital for enhancing physical and physiological characteristics. Future research should explore additional factors, such as nutrition and psychological needs, which may influence athletic performance.

The effects of stretching on running economy – A systematic review with meta-analysis

Introduction While all running athletes aim to cover the prescribed distance as fast as possible, the physiological and anatomical profiles of athletes are completely different between the disciplines. While sprint athletes have to exert maximal force in the smallest possible time window, the long-distance runner strives for the most economical movement pattern possible (Barnes &amp; Kilding, 2015). Therefore, defined as oxygen uptake at a velocity at a prescribed percentage of the vVO2max, running economy (RE) has been identified as a decisive performance parameter (Saunders et al., 2004). One identified parameter which moderates RE was Achilles tendon stiffness. While stretching frequently used in warm-ups, it also decreases tissue stiffness. Objective: While some authors recommended the avoidance of stretching prior to running (Wilson et al., 2010), others found no affected economy in response to stretching. To address this research gap, this study was conducted to pool available stretching effects on RE. Methods A systematic search was conducted using MEDLINE/PubMed, Web of Science and Scopus (inception to April, 2024), which was supplemented by a manual search in Google Scholar and reference lists of identified studies. To account for multiple dependent study outcomes, robust variance estimation meta-analysis model was chosen to quantify pooled effect sizes. Controlled acute and chronic studies were included if they were performed in young, healthy participants on RE-parameter (energy/O2-consumption at a prescribed velocities determined at a percentage of VO2max (vVO2). Studies without a control group, patients or without the metabolic parameters were excluded. The PEDro scale and GRADE criteria were applied to evaluate the risk of bias and certainty of evidence, respectively. Results A total of 16 studies were investigated, with 14 studies (6 static stretching, 6 dynamic stretching and 2 static/dynamic stretching) addressing acute effects with 169 participants and 33 effect sizes (ES) matched the inclusion criteria. With a PEDro score of 4.88, study quality was rated fair. Overall, there was a low certainty of evidence without confirming any effect of stretching on RE, with overall group effect of ES = 0.007, −0.15 to 0.17 [95% CI], p = 0.93, τ2 = 0, W2 = 0, static group effect of ES = –0,22, –0,40 to 0,70 [95% CI], p = 0.3, τ2 = 0.18, W2 = 0 and dynamic group effect of ES = –0,07, −0.22 to 0.09 [95% CI], p = 0.35, τ2 = 0, W2 = 0, determined at vVO2 65% - 90%. Discussion Currently, there is no evidence supporting previous recommendations to avoid stretching before running due to reduced RE. However, several methodological limitations, such as high heterogeneity in the velocity used in RE determination, small study sample sizes and comparatively short stretching durations without intensity quantification and a lack of pre-post comparisons bias the certainty of evidence. Accordingly, there is a demand for high quality research that controls underlying mechanisms. References Barnes, K. R., &amp; Kilding, A. E. (2015). Running economy: Measurement, norms, and determining factors. Sports Medicine – Open, 1, Article 8. https://doi.org/10.1186/s40798-015-0007-y Saunders, P., Pyne, D., Telford, R., &amp; Hawley, J. (2004). Factors affecting running economy in trained distance runners. Sports Medicine, 34, 465–485. https://doi.org/10.2165/00007256-200434070-00005 Wilson, J. M., Hornbuckle, L. M., Kim, J.-S., Ugrinowitsch, C., Lee, S.-R., Zourdos, M. C., Sommer, B., &amp; Panton, L. B. (2010). Effects of atatic atretching on wnergy cost and running endurance performance. The Journal of Strength &amp; Conditioning Research, 24(9), 2274-2279. https://doi.org/10.1519/JSC.0b013e3181b22ad6

The Cumulative Impacts of Fatigue during Overload Training Can Be Tracked Using Field-Based Monitoring of Running Stride Interval Correlations.

Integrating running gait coordination assessment into athlete monitoring systems could provide unique insight into training tolerance and fatigue-related gait alterations. This study investigated the impact of an overload training intervention and recovery on running gait coordination assessed by field-based self-testing. Fifteen trained distance runners were recruited to perform 1-week of light training (baseline), 2 weeks of heavy training (high intensity, duration, and frequency) designed to overload participants, and a 10-day light taper to allow recovery and adaptation. Field-based running assessments using ankle accelerometry and online short recovery and stress scale (SRSS) surveys were completed daily. Running performance was assessed after each training phase using a maximal effort multi-stage running test-to-exhaustion (RTE). Gait coordination was assessed using detrended fluctuation analysis (DFA) of a stride interval time series. Two participants withdrew during baseline training due to changed personal circumstances. Four participants withdrew during heavy training due to injury. The remaining nine participants completed heavy training and were included in the final analysis. Heavy training reduced DFA values (standardised mean difference (SMD) = -1.44 ± 0.90; p = 0.004), recovery (SMD = -1.83 ± 0.82; p less than 0.001), performance (SMD = -0.36 ± 0.32; p = 0.03), and increased stress (SMD = 1.78 ± 0.94; p = 0.001) compared to baseline. DFA values (p = 0.73), recovery (p = 0.77), and stress (p = 0.73) returned to baseline levels after tapering while performance trended towards improvement from baseline (SMD = 0.28 ± 0.37; p = 0.13). Reduced DFA values were associated with reduced performance (r2 = 0.55) and recovery (r2 = 0.55) and increased stress (r2 = 0.62). Field-based testing of running gait coordination is a promising method of monitoring training tolerance in running athletes during overload training.

Effect of 6-Week Sprint Training on Long-Distance Running Performance in Highly Trained Runners.

Long-distance running performance has been reported to be associated with sprint performance in highly trained distance runners. Therefore, we hypothesized that sprint training could enhance distance running and sprint performance in long-distance runners. This study examined the effect of 6-week sprint training on long-distance running and sprint performance in highly trained distance runners. Nineteen college runners were divided into control (n = 8) and training (n = 11) groups. Participants in the training group performed 12 sprint training sessions in 6weeks, while those in the control group performed 12 distance training sessions. Before and after the interventions, maximal oxygen uptake (V˙O2max), O2 cost during submaximal running (290m·min-1 and 310m·min-1 of running velocity), and time to exhaustion (starting at 290m·min-1 and increased 10m·min-1 every minute) were assessed on a treadmill. Additionally, the 100-m and 400-m sprinting times and 3000-m running time were determined on an all-weather track. In the control group, no measurements significantly changed after the intervention. In the training group, the time to exhaustion, 100-m and 400-m sprinting times, and 3000-m running time improved significantly, while V˙O2max and O2 cost did not change. These results showed that 6-week sprint training improved both sprint and long-distance running performance in highly trained distance runners without a change in aerobic capacity. Improvement in the time to exhaustion without a change in V˙O2max suggests that the enhancement of long-distance running performance could be attributable to improved anaerobic capacity.

Longer Ground Contact Time Is Related to a Superior Running Economy in Highly Trained Distance Runners.

Tanji, F, Ohnuma, H, Ando, R, Yamanaka, R, Ikeda, T, and Suzuki, Y. Longer ground contact time is related to a superior running economy in highly trained distance runners. J Strength Cond Res 38(5): 985-990, 2024-Running economy is a key component of distance running performance and is associated with gait parameters. However, there is no consensus of the link between the running economy (RE), ground contact time, and footstrike patterns. Thus, this study aimed to clarify the relationship between RE, ground contact time, and thigh muscle cross-sectional area (CSA) in highly trained distance runners and to compare these parameters between 2 habitual footstrike patterns (midfoot vs. rearfoot). Seventeen male distance runners ran on a treadmill to measure RE and gait parameters. We collected the CSAs of the right thigh muscle using a magnetic resonance imaging scanner. The RE had a significant negative relationship with distance running performance ( r = -0.50) and ground contact time ( r = -0.51). The ground contact time had a significant negative relationship with the normalized CSAs of the vastus lateralis muscle ( r = -0.60) and hamstrings ( r = -0.54). No significant differences were found in RE, ground contact time, or normalized CSAs of muscles between midfoot ( n = 10) and rearfoot ( n = 7) strikers. These results suggest that large CSAs of knee extensor muscles results in short ground contact time and worse RE. The effects of the footstrike pattern on the RE appear insignificant, and the preferred footstrike pattern can be recommended for running in highly trained runners.

A Biomechanical And Physiological Comparison Of The Nike Vaporfly And Nike Zoom Rival Spikes

Nike has claimed that Vaporfly (VF) shoes will decrease an individual’s racing marathon time by 4%. Several investigators have examined the performance effects of wearing the Nike VF shoes on running economy and marathon running pace. Researchers have shown that the VF shoes out-perform other popular racing shoes, resulting in improved running economy, lower oxygen needs, and improved running mechanics at the slower performance velocities. However, the theoretical biomechanical and physiological costs associated with wearing the VF shoes versus a traditional racing spike at 1500 m pace has not been examined. PURPOSE: To compare the biomechanical and physiological response of highly trained collegiate distance runners wearing the Nike VF and Nike Zoom Rival D 10 (RD) spikes during a 1500 m time trial (TT). METHODS: Sixteen (9F, 7 M) highly trained collegiate distance runners (20 ± 2 yrs) completed a randomized crossover testing protocol utilized during three laboratory sessions. Session one included collection of baseline metabolic measures and establishing VO2peak. The second and third sessions assessed the participants’ biomechanical and physiological responses at 14 and 16 kph and 1500 m-time trial performance in each footwear in a randomized counterbalanced manner. Seven days separated each of the three testing sessions. For baseline measures, participants completed a continuous treadmill test consisting of 3-min stages beginning at 11 kph for females and 12 kph for males set at a 1.0% gradient and increasing at 1 kph increments until volitional exhaustion. Running economy (RE) at 14 and 16 kph and 1500 m-TT performance in VF and RD were assessed on the second and third visits following a force plate assessment. Footwear comparisons were made via paired T-Tests utilizing both effect size and p values. RESULTS: RE (VO2 for 1 km in ml*min-1) at 14 and 16 kph were less in the VF than RD (189 ± 9 vs 195 ± 8 ml*min-1 (ES .778) and 190 ± 10 vs 195 ± 11 ml*min-1 (ES .501), respectively, p < 0.05). Stride length during the TT was greater in the VF than RD by 12 cm (3.19 ± 0.36 vs 3.07 ± .37, ES .930, p < .05). 1500 m TT was faster with VF than RD (299.2 ± 42.4 vs 305.2 ± 41.0 s, ES .530, p < 0.05). CONCLUSION: The use of the VF resulted in improved (2%) 1500 m TT performance compared to RD primarily due to improved RE values and longer stride length for VF trials.

Physiological Responses To Running On The Boost Anti-gravity Treadmill

Lower body positive pressure treadmills have become popular as a training supplement to full weight bearing running. However, the effects of reduced body mass (BM) on an individual’s physiological response to running at high velocity on the Boost Treadmill (BT) has not been investigated. PURPOSE: To determine the physiological responses of running at a range of running velocities and BM support using the BT. METHODS: Twenty trained collegiate distance runners (11 M, 9F, 20 ± 1 yrs) completed maximal running GXTs at three different percentages (100%, 90%, 80%) of BM in a counterbalance manner separated by 7-days. Cardiorespiratory responses were measured at each incremental stage until participants were no longer able to sustain steady-state VO2. Thereafter, the treadmill was increased by 1% grade per minute until volitional exhaustion. An independent t-test was used to compare differences in the dependent variables between genders at 9 and 10 mph and maximal velocity. ANOVA with repeated measures were used to assess differences in these variables at 100, 90 and 80% BM with significance set at p < 0.05. RESULTS: VO2max was different between genders at all three BM percentages (64 ± 4 to 52 ± 3, 66 ± 4 to 55 ± 3, and 71 ± 5 to 60 ± 4 ml*kg-1*min-1 for M vs F at 100%, 90% 80%, respectively, p < 0.05). Gender combined VO2 values were lower at 80% BM at 9 and 10mph than at 90% and 100% BM (44 ± 5 vs 45 ± 5 and 45 ± 4 and 49 ± 6 vs 50 ± 6 and 50 ± 4 ml*kg-1*min-1,p < 0.05) and greater at maximal velocity (66 ± 7 vs 61 ± 7 and 58 ± 8 ml*kg-1*min-1, p,0.05) but not different between 90% and 100% BM. Fractional utilization of O2 measurements were lower at 80% BM at 9 and 10mph than at 90% and 100% BW (67 ± 8 vs 74 ± 9 and 77 ± 10 and 74 ± 9 vs 82 ± 8 and 83 ± 6%, respectively, p < 0.05) but not different between 90% and 100% BM. HR responses were lower at 80% BM at 10mph than at 90% and 100% BM (155 ± 14 vs 169 ± 13 and 172 ± 10 bpm, respectively, p < 0.05). CONCLUSION: The results are predicated on the fact that the participants in this study were actually tested at 94%, 90%, and 80% of their BM. The 100% setting produces positive lifting pressure on the participant resulting in a mean 6% reduction in BM. The metabolic demands of running at 80% BM is significant less than running at 90% and 100% BM and minuscule differences in the metabolic demands while running at the same velocity at the 90% and 100% BM settings on the BT

Open-case series of a remote administration and group setting comprehensive behavioral intervention for tics (RG-CBIT): A pilot trial.

PurposeThe comprehensive behavioral intervention for tics (CBIT) is the first-line psychotherapeutic treatment for individuals with tic disorders. However, most patients with tic disorders do not have access to CBIT due to different factors including lack of trained therapists, treatment cost, and travel distance. Such barriers are more prominent in non-English speaking countries. Therefore, the current study assessed the preliminary efficacy, feasibility, and acceptability of remotely administered group CBIT (RG-CBIT) in Japan.MethodsThis was an open-case series that adopted the AB design. Three Japanese children aged between 6 and 13 years who were diagnosed with TS were recruited. RG-CBIT was developed based on the published CBIT manual. Videoconference application, slide presentation software, and cloud learning platform were used as appropriate.ResultsThe Yale Global Tic Severity Scale scores of all participants decreased from baseline to post-treatment. That is, the score reduced by an average of 7.0. Regarding feasibility and acceptability, the attendance rate of participants was 100%, and the process measurement items had favorable scores.ConclusionsRG-CBIT had satisfactory efficacy, feasibility, and acceptability. Hence, it could mitigate the barriers for treatment access.

Distance running performance and physiological variables in highly trained female distance runners

article: Distance running performance and physiological variables in highly trained female distance runners - Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2022 January-February;181(1-2):1-7 - Minerva Medica - Journals

Effect of beetroot supplementation on 10 km time trial performance of distance runners

Objective: To find out the effect of 15 days of beetroot juice (BRJ) supplementation on 10 km time trial performance in trained distance runners of University level.Methods: Thirty trained athletes,15 males age = 26.3 y ± 1.52, height 170.5 ± 0.2 cm, and 15 females, age = 25.2 y ± 1.30, height 157.8 ± 0.3 cm were selected for the present study. Two experimental and two control groups were made consisting of males and females separately. The first group of male and female (Experimental Group) consumed the BRJdaily 250 ml/dayand the second group (Control Group) did not consume beetroot juice. Both groups underwent a regular athletics training programme. All the subjects were tested on Ten Km Time Trial (TT)performance before supplementation of BRJ and after 15 days of supplementation of BRJ. Results: The significant effect of BRJ supplementationwas observed (p &lt; 0.05) between pre and post measures of 10 km TT in experimental group. BRJ supplementation significantly improved performance in 10 km TT in both groups (respectively male; P&lt; 0.006; F=11.09, ES = .480, female; P &lt; 0.000, F=40.45, ES = .771.Conclusion: Consumption of BRJ250 ml/day in improved 10 km time trial performance in traineddistance runners.

Relationship between respiratory muscle endurance and dyspnea during high-intensity exercise in trained distance runners

We hypothesized that the trained distance runners, who have a relatively high respiratory muscle endurance, but not high respiratory muscle strength, have lower dyspneic sensations during submaximal running. Twenty-one male collegiate distance runners participated. Incremental respiratory endurance tests (IRET) and maximal inspiratory mouth pressure (PImax) measurements were performed under resting conditions. A submaximal exercise test was also performed on a treadmill at two different speeds (16 and 18 km/h) for 4 min each, and the subjects reported the rate of dyspnea (range: 0–10). The time to endpoint during the IRET, an index of respiratory muscle endurance, ranged from 9.4 to 18.8 min, and PImax, as an index of inspiratory muscle strength, ranged from 74.1 to 137.0 cmH2O. The dyspnea rating during running at 16 and 18 km/h ranged from 1 to 6 and from 4 to 8, respectively. The relative exercise intensity was approximately 80 % of peak oxygen uptake (VO2peak) at 16 km/h and 90 %VO2peak at 18 km/h. The time to endpoint during the IRET was significantly negatively correlated with dyspnea during running at 18 km/h (r = -0.459, P = 0.040), but not at 16 km/h (r = -0.161, P = 0.470). There was no significant correlation between PImax and dyspnea during running at 16 km/h (r = -0.003, P = 0.989) or 18 km/h (r = 0.070, P = 0.755). These results suggest that dyspneic sensations during high-intensity running are related to respiratory muscle endurance, but not inspiratory muscle strength, in trained distance runners.

Time-Restricted Feeding and Aerobic Performance in Elite Runners: Ramadan Fasting as a Model.

A distance runner's performance is generally limited by energy availability when competing or training. Modifying meal frequency and timing by abstaining from eating or drinking, from dawn to dusk, during Ramadan fasting is hypothesized to induce hypohydration and reduced caloric and nutrient intake. The purpose of this study was to investigate the impact of Ramadan fasting on runners' performances. Fifteen trained male distance runners who observed Ramadan participated in this study (Age = 23.9 ± 3.1 years; Peak VO2 = 71.1 ± 3.4 ml/kg/min). Each participant reported to the human performance lab on two testing occasions (pre-Ramadan and the last week of Ramadan). In each visit, participants performed a graded exercise test on the treadmill (Conconi protocol) and their VO2, Heart Rate, time to exhaustion, RPE, and running speed were recorded. Detailed anthropometrics, food records, and exercise logs were kept for the entire period of the study. Repeated measure ANOVA, paired t-test, and Cohen's effect size analysis were carried out. Results indicated no significant influence for Ramadan fasting on body mass (p = 0.201), body fat (p = 0.488), lean body mass (p = 0.525), VO2max (p = 0.960), energy availability (p = 0.137), and protein intake (p = 0.124). However, carbohydrate (p = 0.026), lipid (p = 0.009), water (p < 0.001), and caloric intakes (p = 0.002) were significantly reduced during Ramadan Fasting. Daily training duration (p < 0.001) and exercise energy expenditure (p = 0.001) were also reduced after Ramadan. Time to exhaustion (p = 0.049), and maximal running speed (p = 0.048) were improved. Overall, time to exhaustion and maximal running speed of the distance runners was improved during Ramadan fasting, independent of changes in nutrients intake observed during the current study. With proper modulation of training, distance runners performance can be maintained or even slightly improved following the month of Ramadan fasting.

Visual classification of running economy by distance running coaches

Objectives: This study assessed the ability of coaches to rank-order distance runners on running economy (RE) through visual assessment. Methods: Running economy was measured in five trained recreational distance runners at a speed of 3.57 m·s−1, with a minimum VO2 difference of 2-mL.kg−1.min−1 between adjacent runners. Following measurement of RE, participants were filmed from the front, side, and rear while running on a treadmill. Endurance coaches from high school to international level (N = 121) viewed each video and ranked the runners on a scale from 1 (most economical) to 5 (least economical). Coaches also completed a demographic questionnaire and listed running style biomechanical observations they used in determining each ranking. A cumulative odds ordinal logistic regression with proportional odds was run to determine the effect of coaching level, years of coaching experience, years of training experience, competition level, certification status, and education level, on the ability of distance running coaching to accurately rank RE among a group of runners. Results: No coaching characteristic was a significant predictor of ranking accuracy, χ 2 = 3.566, p = .735. Conclusions: Visual assessment of effort, based on RE, is a difficult task, even for the trained eye and could be related to difficulty in understanding the interaction effect of various RE factors or the translation of scientific-based knowledge to the field of play. Practically, coaches should be cautious when recommending biomechanical adjustments without considering the interconnected factors related to such changes.

Rapid Gut Microbiome Changes In A World-Class Ultramarathon Runner: A Case Study

The human gut microbiome is a dynamic ecosystem with prolific health connotations. Physical activity is emerging as a potent regulator of human microbiome composition. PURPOSE: This study examined changes in the gut microbiome of a world-class ultramarathon runner before and after competing in the Western States Endurance Run (WSER), a 163 km mountain footrace. METHODS: Anthropometrics and body composition were assessed and the ultramarathoner’s submaximal and maximal performance profiles were evaluated. Gut microbiome analyses were performed at four time-points: 21 wk and 2 wk before and 2 h and 10 d after WSER. RESULTS: Aerobic power (VO2max) was 4.24 L/min (66.7 ml/kg/min), and running economy (51.1 ml/kg/min at 268 m/min) and lactate threshold (~83% VO2max) values were comparable to that of highly trained distance runners. Two hours post-race, considerable changes in the ultrarunners gut microbiome were observed. Alpha diversity (Shannon Diversity Index) increased from 2.73 to 2.80 and phylum-level bacterial composition (Firmicutes/Bacteroidetes ratio) rose from 4.4 to 14.2. Underlying these macro-level microbial alterations were demonstrable increases in select bacterial genera such as Veillonella (+14,229%) and Streptococcus (+438%) concomitant with reductions in Alloprevotella (-79%) and Subdolingranulum (-50%). CONCLUSIONS: To our knowledge, this case study shows the most rapid and pronounced shifts in human gut microbiome composition after acute exercise in the human literature. These findings provide yet another example of how exercise can be a powerful modulator of human health.

Rapid gut microbiome changes in a world-class ultramarathon runner.

The human gut microbiome is a dynamic ecosystem with prolific health connotations. Physical activity is emerging as a potent regulator of human microbiome composition. This study examined changes in the gut microbiome of a world‐class ultramarathon runner before and after competing in the Western States Endurance Run (WSER), a 163 km mountain footrace. Anthropometrics and body composition were assessed and the ultramarathoner's submaximal and maximal performance profiles were evaluated. Gut microbiome analyses were performed at four time‐points: 21 weeks and 2 weeks before and 2 hours and 10 days after WSER. Aerobic power (VO2max) was 4.24 L/min (66.7 ml kg−1 min−1), and running economy (51.1 ml kg−1 min−1 at 268 m/min) and lactate threshold (~83% VO2max) values were comparable to that of highly trained distance runners. Two hours post‐race, considerable changes in the ultrarunners’ gut microbiome were observed. Alpha diversity (Shannon Diversity Index) increased from 2.73 to 2.80 and phylum‐level bacterial composition (Firmicutes/Bacteroidetes ratio) rose from 4.4 to 14.2. Underlying these macro‐level microbial alterations were demonstrable increases in select bacterial genera such as Veillonella (+14,229%) and Streptococcus (+438%) concomitant with reductions in Alloprevotella (−79%) and Subdolingranulum (−50%). To our knowledge, this case study shows the most rapid and pronounced shifts in human gut microbiome composition after acute exercise in the human literature. These findings provide yet another example of how exercise can be a powerful modulator of human health.

Foam rolling is an effective recovery tool in trained distance runners.

Many endurance athletes use foam rolling (FR) to decrease muscle soreness, but it is unclear whether FR effectively treats soreness in this population. Moreover, the effects of FR in highly trained runners are unknown. The aim of this study was to use downhill running (DHR) to induce muscle soreness in runners and to determine the influence of FR on soreness and running performance when compared to sham compression tights. Participants performed a running economy (RE) test at 75% of 5-km race speed and a 3-km time trial (TT). In a crossover design, subjects then completed DHR followed by either a FR protocol or wearing sham compression tights. Two days post-DHR, subjects repeated the RE and TT tests. Crossover visits occurred 2-4 weeks later. During RE tests, VO2 and rating of perceived exertion (RPE) were recorded. Passive and active soreness were measured on a scale of 0 (no soreness) to 10 (extreme soreness). Eight runners (aged 31 ± 7 years; four females; VO2peak 57 ± 7 ml kg-1 min-1) completed the study. Both treatment conditions experienced passive (p = 0.026) and active soreness (p = 0.012) induced by DHR. Active soreness 2 days postDHR was significantly lower after FR than after sham compression tights (p = 0.025). With tights, there was a trend for an increased RPE compared to pre-DHR (p = 0.056). Foam rolling decreases leg soreness in well-trained runners and attenuates soreness-related increases in perceived exertion during sub-maximal running.

Mammogram Image Retrieval using Ipso Optimized Anfis Classifier

Content-based image retrieval (CBIR) is an research area over the past years that has attracted research. In various medical applications like mammogram analysis CBIR techniques helps the medical team to get similar set of images from a large medical records to help in diagnosis of a disease. This paper proposes an efficient Content-Based Mammogram Image Retrieval method by using an Optimized Classifier. Initially, the input dataset is preprocessed, in which noise removal and contrast enhancement are done. Next, pectoral muscles of the mammogram images are removed using Single Sided Edge Marking (SSEM). Now, feature extraction is done, in which GLCM features, Gabor features and the Local Pattern with Binary features are being removed. The features that are being removed are classified into three classes namely benign, malignant and normal. An optimized classifier named as Adaptive Neuro Fuzzy Inference System (ANFIS), which is optimized by using the Improved Particle Swarm Optimization (IPSO) technique, is used for classification purpose. Finally, similarity is assessed between the trained feature distance vectors and the feature distance vectors of the input query image. Similarity assessment is done using Euclidean Distance metric and the image that has the lowest distance compared with the query is retrieved. The experimental results are obtained for the proposed system and they are compared with the existing techniques.

Lower limb tri-joint synchrony during running gait: A longitudinal age-based study

Biomechanical research exploring the age-based mechanics of running gait can provide valuable insight into the reported decline in master endurance running performance. However, few studies have shown consistent biomechanical differences in the gait of trained distance runners compared to their younger counterparts. It might be that differences occur in the interaction between joints. The aim was to explore the differences in tri-joint synchrony of the lower limb, quantified through cluster phase analysis, of runners at 50 years of age compared to seven years later. Cluster phase analysis was used to examine changes in synchrony between 3 joints of the lower limb during the stance phase of running. Ten male, endurance-trained athletes M50 (age = 53.54 ± 2.56 years, mass = 71.05 ± 7.92 kg) participated in the study and returned after seven years M57 (age = 60.49 ± 2.56 years, mass = 69.08 ± 8.23 kg). Lower limb kinematics (Vicon, 120 Hz) and ground reaction forces (Kistler, 1080 Hz) were collected as participants performed multiple trials at a horizontal running velocity = 3.83 ± 0.40 m·s−1 over the force plate. Significant increase (31%) in rate of force development in the absorption phase, and significantly reduced sagittal plane knee joint range of motion (30.50 v 23.68°) were found following the seven years of ageing. No further discrete single joint measures were significantly different between M50 and M57. Joint synchrony between the hip, knee and ankle was significantly higher at M57 compared to M50 during the absorption phase of stance. The force attenuation strategy is compromised after seven years of ageing, which is associated with more synchronous movements in the lower limb joints. Increased joint synchrony as a function of age could be a mechanism associated with this key injury provoking phase of running gait.

Gender differences of running kinematics and economy in trained distance runners

Gender differences of running kinematics and economy in trained distance runners