scholarly journals VO2 Attained During Treadmill Running: The Influence of a Specialist (400-m or 800-m) Event

2007 ◽  
Vol 2 (2) ◽  
pp. 128-136 ◽  
Author(s):  
David V.B. James ◽  
Leigh E. Sandals ◽  
Stephen B. Draper ◽  
Sara Maldonado-Martín ◽  
Dan M. Wood
Keyword(s):  
Treadmill Running ◽  
Lower Percentage ◽  
Distance Running ◽  
Pacing Strategy

Purpose:Previously it has been observed that, in well-trained 800-m athletes, VO2max is not attained during middle-distance running events on a treadmill, even when a race-type pacing strategy is adopted. Therefore, the authors investigated whether specialization in a particular running distance (400-m or 800-m) influences the VO2 attained during running on a treadmill.Methods:Six 400-m and six 800-m running specialists participated in the study. A 400-m trial and a progressive test to determine VO2max were completed in a counterbalanced order. Oxygen uptakes attained during the 400-m trial were compared to examine the influence of specialist event.Results:A VO2 plateau was observed in all participants for the progressive test, demonstrating the attainment of VO2max. The VO2max values were 56.2 ± 4.7 and 69.3 ± 4.5 mL · kg−1 · min−1 for the 400-m- and 800-m-event specialists, respectively (P = .0003). Durations for the 400-m trial were 55.1 ± 4.2 s and 55.8 ± 2.3 s for the 400-m- and 800-m-event specialists, respectively. The VO2 responses achieved were 93.1% ± 2.0% and 85.7% ± 3.0% VO2max for the 400-m- and 800-m-event specialists, respectively (P = .001).Conclusions:These results demonstrate that specialist running events do appear to influence the percentage of VO2max achieved in the 400-m trial, with the 800-m specialists attaining a lower percentage of VO2max than the 400-m specialists. The 400-m specialists appear to compensate for a lower VO2max by attaining a higher percentage VO2max during a 400-m trial.

scholarly journals Pacing Profiles of Middle-Distance Running World Records in Men and Women

2021 ◽  
Vol 18 (23) ◽  
pp. 12589
Author(s):  
Arturo Casado ◽  
Fernando González-Mohíno ◽  
José María González-Ravé ◽  
Daniel Boullosa
Keyword(s):  
Distance Running ◽  
Men And Women ◽  
The Third ◽  
Pacing Strategy ◽  
World Records

The aims of the current study were to compare the pacing patterns of all-time 800 m, 1500 m and mile running world records (WRs) and to determine whether differences exist between sexes, and if 800 m and 1500 m WRs were broken during championship or meet races. Overall and lap times for men and women’s 800 m, 1500 m, and mile WRs from World Athletics were collected when available and subsequently compared. A fast initial 200 m segment and a decrease in speed throughout was found during 800 m WRs. Accordingly, the first 200 m and 400 m were faster than the last 200 m and 400 m, respectively (p < 0.001, 0.77 ≤ ES ≤ 1.86). The first 400 m and 409 m for 1500 m and mile WRs, respectively, were faster than the second lap (p < 0.001, 0.74 ≤ ES ≤ 1.46). The third 400 m lap was slower than the last 300 m lap and 400 m lap for 1500 m and mile WRs, respectively (p < 0.001, 0.48 ≤ ES ≤ 1.09). No relevant sex-based differences in pacing strategy were found in any event. However, the first 409 m lap was faster than the last 400 m lap for men but not for women during mile WRs. Women achieved a greater % of WRs than men during championships (80% vs. 45.83% in the 800 m, and 63.63% vs. 31.58% in the 1500 m, respectively). In conclusion, positive, reverse J-shaped and U-shaped pacing profiles were used to break 800 m, men’s mile and 1500 m, and women’s mile WRs, respectively. WRs are more prone to be broken during championships by women than men.

A Novel Method to Characterize the Pacing Profile of Elite Male 1500-m Freestyle Swimmers

2020 ◽  
pp. 1-7
Author(s):  
Katie E. McGibbon ◽  
David B. Pyne ◽  
Laine E. Heidenreich ◽  
Robin Pla
Keyword(s):  
Great Britain ◽  
Confidence Interval ◽  
Age Groups ◽  
Lower Percentage ◽  
Long Distance ◽  
Race Time ◽  
Pacing Strategy ◽  
Fast Start ◽  
Novel Method ◽  
Long Course

Purpose: Pacing, or the distribution of energy expenditure, is particularly important in swimming; however, there is limited research examining pacing profiles in long-distance freestyle events. This study aimed to characterize the pacing profiles of elite male 1500-m freestyle swimmers using a novel method to provide a detailed analysis of different race segments. Methods: The race data for 327 male 1500-m freestyle long-course races between 2010 and 2019 were analyzed retrospectively. The raw 50-m split times for each lap were converted to a percentage of overall race time. The races were classified as a fast-, average-, or slow-start strategy (laps 1–2); as an even, negative, or positive pacing strategy (laps 3–28); and as a fast-, average-, or slow-finish strategy (laps 29–30) to give an overall pacing profile. Results: Slow- and average-start strategies were associated with faster overall 1500-m times than a fast-start strategy (mean = −21.2 s; 90% confidence interval, −11.4 to −32.3 s, P = .00). An even pacing strategy in laps 3 to 28 yielded faster overall 1500-m times than a positive pacing strategy (−8.4 s, −3.9 to −13.0 s, P = .00). The overall 1500-m times did not differ substantially across the finish strategies (P = .99). The start strategy differed across age groups and nationalities, where younger swimmers and swimmers from Australia and Great Britain typically spent a lower percentage of race time in laps 1 to 2 (faster start strategy; −0.10%, −0.01% to −0.23%, P ≤ .02). Conclusion: Adopting a relatively slower start strategy helps conserve energy for the latter stages of a 1500-m freestyle race.

scholarly journals Loss of Hypoxia Signaling Limits Physiologic and Muscle Adaptations to Aerobic Exercise in Aging

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 684-685
Author(s):  
Yori Endo ◽  
Mehran Karvar ◽  
Yuteng Zhang ◽  
Shayan Olumi ◽  
Indranil Sinha
Keyword(s):  
Muscle Mass ◽  
Treadmill Running ◽  
Distance Running ◽  
Lean Muscle Mass ◽  
Aryl Hydrocarbon ◽  
Maximal Distance ◽  
Muscle Adaptations ◽  
Maximal Speed ◽  
Response To Exercise ◽  
Hypoxia Signaling

Abstract To assess the differential effects of exercise with age, Young (Y, 10-12 weeks) and Old (O, 23-25 months) mice were subjected to regimented treadmill running or no regimented exercise. Y, trained mice experienced a significant increase in maximal distance running, maximal speed of running, and lean muscle mass in comparison to age-matched, untrained controls. O mice did not improve significantly in any of these measures following training. Transcriptome analysis of gastrocnemius from Y mice demonstrated differential regulation of 120 genes with exercise. None of these genes were similarly regulated in the O group. Genes most upregulated following exercise in Y mice were direct targets of the hypoxia signaling pathway. Immunoblotting demonstrated that aryl hydrocarbon receptor nuclear translocator (ARNT), a critical regulator of hypoxia signaling, increased 3-fold with exercise in Y mice, but this increase was absent in O mice following exercise. To assess whether this loss of ARNT in O muscle impaired the exercise response, we generated a mouse with inducible, skeletal muscle-specific knockout of ARNT (ARNT muscle (m) KO). Following regimented exercise, ARNT mKO mice did not improve maximal distance running, maximal running speed, or lean muscle mass in comparison to untrained ARNT mKO mice. Littermate, age-matched ARNT wild type mice increased significantly in all of these measures following training. Administration of ML228, an ARNT agonist, increased maximal running distance and speed in response to exercise training in O mice. These results suggest that restoration of ARNT and hypoxia signaling may restore the physiologic response to exercise in aging.

Pacing Strategy During 24-Hour Ultramarathon-Distance Running

2017 ◽  
Vol 12 (5) ◽  
pp. 590-596 ◽  
Author(s):  
Arthur H. Bossi ◽  
Guilherme G. Matta ◽  
Guillaume Y. Millet ◽  
Pedro Lima ◽  
Leonardo C. Pertence ◽  
...  
Keyword(s):  
Herd Behavior ◽  
Age Group ◽  
Distance Running ◽  
Running Speed ◽  
Running Time ◽  
Pacing Strategy ◽  
Performance Group ◽  
General Behavior ◽  
Overall Performance ◽  
Shaped Pattern

Purpose:To describe pacing strategy in a 24-h running race and its interaction with sex, age group, athletes’ performance group, and race edition.Methods:Data from 398 male and 103 female participants of 5 editions were obtained based on a minimum 19.2-h effective-running cutoff. Mean running speed from each hour was normalized to the 24-h mean speed for analyses.Results:Mean overall performance was 135.6 ± 33.0 km with a mean effective-running time of 22.4 ± 1.3 h. Overall data showed a reverse J-shaped pacing strategy, with a significant reduction in speed from the second-to-last to the last hour. Two-way mixed ANOVAs showed significant interactions between racing time and both athlete performance group (F = 7.01, P < .001, ηp2 = .04) and race edition (F = 3.01, P < .001, ηp2 = .02) but not between racing time and either sex (F = 1.57, P = .058, ηp 2 < .01) or age group (F = 1.25, P = .053, ηp2 = .01). Pearson product–moment correlations showed an inverse moderate association between performance and normalized mean running speed in the first 2 h (r = –.58, P < .001) but not in the last 2 h (r = .03, P = .480).Conclusions:While the general behavior represents a rough reverse J-shaped pattern, the fastest runners start at lower relative intensities and display a more even pacing strategy than slower runners. The “herd behavior” seems to interfere with pacing strategy across editions, but not sex or age group of runners.

scholarly journals Interaction of exercise bioenergetics with pacing behavior predicts track distance running performance

2021 ◽  
Author(s):  
Brett S. Kirby ◽  
Brad J. Winn ◽  
Brad W. Wilkins ◽  
Andrew M. Jones
Keyword(s):  
Critical Speed ◽  
Balance Model ◽  
Distance Running ◽  
Running Performance ◽  
Finite Amount ◽  
Pacing Strategy ◽  
Start Line ◽  
Split Time ◽  
Distance Running Performance

The best possible finishing time for a runner competing in distance track events can be estimated from their critical speed (CS) and the finite amount of energy that can be expended above CS (D'). During tactical races with variable pacing, the runner with the 'best' combination of CS and D' and, therefore, the fastest estimated finishing time prior to the race, does not always win. We hypothesized that final race finishing positions depend on the relationships between the pacing strategy employed, the athletes' initial CS, and their instantaneous D' (i.e., D' balance) as the race unfolds. Using publicly available data from the 2017 IAAF World Championships men's 5,000 m and 10,000 m races, race speed, CS, and D' balance were calculated. The correlation between D' balance and actual finishing positions was non-significant utilizing start-line values but improved to R2 > 0.90 as both races progressed. The D' balance with 400 m remaining was strongly associated with both final 400 m split time and proximity to the winner. Athletes who exhausted their D' were unable to hold pace with the leaders, whereas a high D´ remaining enabled a fast final 400 m and a high finishing position. The D' balance model was able to accurately predict finishing positions in both a 'slow' 5,000 m and a 'fast' 10,000 m race. These results indicate that while CS and D' can characterize an athlete's performance capabilities prior to the start, the pacing strategy that optimizes D' utilization significantly impacts final race outcome.

Effects of treadmill running and fatigue on impact acceleration in distance running

2014 ◽  
Vol 13 (3) ◽  
pp. 259-266 ◽  
Author(s):  
José Antonio García-Pérez ◽  
Pedro Pérez-Soriano ◽  
Salvador Llana Belloch ◽  
Ángel Gabriel Lucas-Cuevas ◽  
Daniel Sánchez-Zuriaga
Keyword(s):  
Treadmill Running ◽  
Distance Running ◽  
Impact Acceleration

scholarly journals Influence of Pacing Strategy on Oxygen Uptake During Treadmill Middle-Distance Running

2006 ◽  
Vol 27 (1) ◽  
pp. 37-42 ◽  
Author(s):  
L. E. Sandals ◽  
D. M. Wood ◽  
S. B. Draper ◽  
D. V. B. James
Keyword(s):  
Oxygen Uptake ◽  
Distance Running ◽  
Pacing Strategy

Modification of the Electron Microscope for Investigation of Fully Hydrated Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 418-419 ◽  
Author(s):  
R. C. Moretz ◽  
D. F. Parsons
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Structural Damage ◽  
Lower Percentage ◽  
Vacuum Drying ◽  
Total Removal ◽  
Total Absence ◽  
Biological Studies ◽  
Electron Microscopes ◽  
Beam Damage

Short lifetime or total absence of electron diffraction of ordered biological specimens is an indication that the specimen undergoes extensive molecular structural damage in the electron microscope. The specimen damage is due to the interaction of the electron beam (40-100 kV) with the specimen and the total removal of water from the structure by vacuum drying. The lower percentage of inelastic scattering at 1 MeV makes it possible to minimize the beam damage to the specimen. The elimination of vacuum drying by modification of the electron microscope is expected to allow more meaningful investigations of biological specimens at 100 kV until 1 MeV electron microscopes become more readily available. One modification, two-film microchambers, has been explored for both biological and non-biological studies.

Burnout of the Mind – Burnout of the Body?

2018 ◽  
Vol 32 (1) ◽  
pp. 30-42 ◽  
Author(s):  
Claudia Traunmüller ◽  
Kerstin Gaisbachgrabner ◽  
Helmut Karl Lackner ◽  
Andreas R. Schwerdtfeger
Keyword(s):  
Blood Pressure ◽  
Allostatic Load ◽  
Maslach Burnout Inventory ◽  
The Body ◽  
Lower Percentage ◽  
Control Group ◽  
Urinary Catecholamines ◽  
Morning Cortisol ◽  
The Mind ◽  
Cortisol Increase

Abstract. In the present paper we investigate whether patients with a clinical diagnosis of burnout show physiological signs of burden across multiple physiological systems referred to as allostatic load (AL). Measures of the sympathetic-adrenergic-medullary (SAM) axis and the hypothalamic-pituitary-adrenal (HPA) axis were assessed. We examined patients who had been diagnosed with burnout by their physicians (n = 32) and were also identified as burnout patients based on their score in the Maslach Burnout Inventory-General Survey (MBI-GS) and compared them with a nonclinical control group (n = 19) with regard to indicators of allostatic load (i.e., ambulatory ECG, nocturnal urinary catecholamines, salivary morning cortisol secretion, blood pressure, and waist-to-hip ratio [WHR]). Contrary to expectations, a higher AL index suggesting elevated load in several of the parameters of the HPA and SAM axes was found in the control group but not in the burnout group. The control group showed higher norepinephrine values, higher blood pressure, higher WHR, higher sympathovagal balance, and lower percentage of cortisol increase within the first hour after awakening as compared to the patient group. Burnout was not associated with AL. Results seem to indicate a discrepancy between self-reported burnout symptoms and psychobiological load.

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