scholarly journals ACTN3 R577X Genotype and Exercise Phenotypes in Recreational Marathon Runners

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 413 ◽  
Author(s):  
Juan Del Coso ◽  
Victor Moreno ◽  
Jorge Gutiérrez-Hellín ◽  
Gabriel Baltazar-Martins ◽  
Carlos Ruíz-Moreno ◽  
...  
Keyword(s):  
Energy Cost ◽  
Isometric Force ◽  
Weight Bearing ◽  
Fat Percentage ◽  
Body Fatness ◽  
Marathon Runners ◽  
Recreational Athletes ◽  
Energy Cost Of Running ◽  
Isometric Muscle ◽  
Isometric Muscle Force

Background: Homozygosity for the X-allele in the ACTN3 R577X (rs1815739) polymorphism results in the complete absence of α-actinin-3 in sarcomeres of fast-type muscle fibers. In elite athletes, the ACTN3 XX genotype has been related to inferior performance in speed and power-oriented sports; however, its influence on exercise phenotypes in recreational athletes has received less attention. We sought to determine the influence of ACTN3 genotypes on common exercise phenotypes in recreational marathon runners. Methods: A total of 136 marathoners (116 men and 20 women) were subjected to laboratory testing that included measurements of body composition, isometric muscle force, muscle flexibility, ankle dorsiflexion, and the energy cost of running. ACTN3 genotyping was performed using TaqMan probes. Results: 37 runners (27.2%) had the RR genotype, 67 (49.3%) were RX and 32 (23.5%) were XX. There was a difference in body fat percentage between RR and XX genotype groups (15.7 ± 5.8 vs. 18.8 ± 5.5%; effect size, ES, = 0.5 ± 0.4, p = 0.024), whereas the distance obtained in the sit-and-reach-test was likely lower in the RX than in the XX group (15.3 ± 7.8 vs. 18.4 ± 9.9 cm; ES = 0.4 ± 0.4, p = 0.046). Maximal dorsiflexion during the weight-bearing lunge test was different in the RR and XX groups (54.8 ± 5.8 vs. 57.7 ± 5.1 degree; ES = 0.5 ± 0.5, p = 0.044). Maximal isometric force was higher in the RR than in the XX group (16.7 ± 4.7 vs. 14.7 ± 4.0 N/kg; ES = −0.5 ± 0.3, p = 0.038). There was no difference in the energy cost of running between genotypes (~4.8 J/kg/min for all three groups, ES ~0.2 ± 0.4). Conclusions: The ACTN3 genotype might influence several exercise phenotypes in recreational marathoners. Deficiency in α-actinin-3 might be accompanied by higher body fatness, lower muscle strength and higher muscle flexibility and range of motion. Although there is not yet a scientific rationale for the use of commercial genetic tests to predict sports performance, recreational marathon runners who have performed such types of testing and have the ACTN3 XX genotype might perhaps benefit from personalized strength training to improve their performance more than their counterparts with other ACTN3 genotypes.

Contractile force of canine airway smooth muscle during cyclical length changes

1983 ◽  
Vol 55 (3) ◽  
pp. 759-769 ◽  
Author(s):  
S. J. Gunst
Keyword(s):  
Muscle Force ◽  
Isometric Force ◽  
Smooth Muscles ◽  
Rate Of Change ◽  
Dynamic Force ◽  
Airway Caliber ◽  
Length Changes ◽  
Isometric Muscle ◽  
Isometric Muscle Force

Strips of tonically contracted canine tracheal and bronchial airway smooth muscles (AWSM) were studied in vitro to compare dynamic muscle force during stretch-retraction cycles with static isometric muscle force at various length points within the cycling range. At any particular rate, a characteristic force-length loop was obtained by cycling over a given range of lengths. Dynamic muscle force dropped well below static isometric muscle force at lengths short of the peak length at all rates of cycling. When stretch or retraction of the muscle was stopped at any point along either path of the cycle, muscle force rose to approach the isometric force at that length. Dynamic force at the peak length of the cycle remained close to, or slightly greater than, the static isometric force. The results suggest that the velocity of shortening of tonically contracted AWSM is very slow relative to the rates of cycling employed. A slow rate of shortening of AWSM relative to the rate of change in airway caliber during breathing could account for well-known effects of volume history on airway tone.

scholarly journals Relationship between cytokines and running economy in marathon runners

2016 ◽  
Vol 11 (1) ◽  
pp. 308-312 ◽  
Author(s):  
Luiz Antonio Luna Junior ◽  
Juliana de Melo Batista dos Santo ◽  
André Luis Lacerda Bachi ◽  
Roberta Foster ◽  
Alexandre Slowetzky Amaro ◽  
...  
Keyword(s):  
Energy Cost ◽  
Running Economy ◽  
Energetic Cost ◽  
Marathon Runners ◽  
Energy Cost Of Running ◽  
Inflammatory State ◽  
Using Data ◽  
The Relationship

AbstractBackgroundRunning economy (RE), expresses the relationship between the energy cost of running (Cr) and the work performed by a runner and is an predictor of performance. Given the intense effort of marathon runners during training and competition and the dearth of studies that address performance and cytokines in this population, the objective of the current study was to investigate the relationship between RE and cytokines in marathon runners.MethodsA total of 22 recreational marathon runners were examined. Using data obtained from VO2max assessments and sub-maximal tests, the following formula was applied to determine RE: Cr (mLO2·kg-1·km-1) = VO2 (mL·kg-1·h-1) × 60 ÷ speed (km·h-1).ResultsCr values shows no correlation with levels of the serum IL-1β, IL-4, IL-8, IL-10 and TNF-a 24h before, immediately after or 72h after the completion of an official marathon. However, the IL-6 level shows a significant correlation with Cr.Discussion and conclusionThe relationship between higher values of IL-6 and lower RE leads to the hypothesis of a physical under-recovery state by some athletes. Considering the stress caused by training, associated with the higher energetic cost in less economic athletes, it’s possible that the period of resting may not totally compensate for the inflammatory state.

Energy cost of running, cycling and swimming in young triathletes of both sexes

1999 ◽  
Vol 24 (1) ◽  
pp. 301-305
Author(s):  
V. Bunc ◽  
J. Horcic ◽  
J. Heller ◽  
J. Formánek
Keyword(s):  
Energy Cost ◽  
Energy Cost Of Running

scholarly journals Validity of Recreational Marathon Runners’ Self-Reported Anthropometric Data

2020 ◽  
Vol 127 (6) ◽  
pp. 1068-1078
Author(s):  
Pantelis T. Nikolaidis ◽  
Beat Knechtle
Keyword(s):  
Body Mass ◽  
Assessment Method ◽  
Fat Percentage ◽  
Anthropometric Data ◽  
Anthropometric Measures ◽  
Marathon Runners ◽  
Present Sample ◽  
Large Samples ◽  
Anthropometric Characteristics ◽  
Recreational Runners

While studies on large samples of recreational runners have often relied on participants’ self-reported height and body mass, the validity of these data have not been investigated for this population. Hence, this study sought to examine the validity of self-reported anthropometric measures among recreational marathon runners. Female ( n = 32) and male ( n = 135) recreational marathon runners were requested to estimate their body mass and height (and we calculated their self-reported body mass index [BMI]), after which we took actual measures of their body mass and height and calculated their actual BMI. Participants’ self-reported values underestimated their actual body mass by 0.65 kg ( p < .001, η2 = 0.222) and their actual BMI by 0.35 kg ⋅ m−2 ( p < .001, η2 = 0.245). There was a significant Assessment Method × Sex Interaction for both body mass ( p = .019, η2 = 0.033) and BMI ( p = .017, η2 = 0.034), as women underestimated body mass values more than men. Participants overestimated their height by 0.44 cm ( p < .001, η2 = 0.075), but the interaction of sex and assessment method for height was not statistically significant. Underestimates of body mass correlated with marathon racing speed ( r = .24, p = .006) and body fat percentage ( r = −.29, p = .001) in men, but not in women ( p > .05). The disagreement between self-reported and measured anthropometric data in the present sample was lower than has been previously reported for the general population, suggesting that marathon runners may more accurately self-perceive and/or report their anthropometric characteristics. These findings are of practical value for health professionals and researchers (e.g., nutritionists and exercise physiologists) questionnaires to recreational marathon runners.

Effect of dorsiflexion shoes on the energy cost of running

2010 ◽  
Vol 25 (2) ◽  
pp. 81-87 ◽  
Author(s):  
M. Buchheit ◽  
P.B. Laursen ◽  
F. Leblond ◽  
S. Ahmaidi
Keyword(s):  
Energy Cost ◽  
Energy Cost Of Running

Metabolic heat production during fatigue from voluntary repetitive isometric contractions in humans

1996 ◽  
Vol 81 (3) ◽  
pp. 1323-1330 ◽  
Author(s):  
E. Saugen ◽  
N. K. Vollestad
Keyword(s):  
Energy Cost ◽  
Isometric Force ◽  
Recovery Period ◽  
Isometric Exercise ◽  
Muscle Mechanics ◽  
Force Production ◽  
Cellular Level ◽  
Voluntary Contraction ◽  
O2 Uptake ◽  
Postexercise Recovery

The effect of repetitive isometric knee extensions on the energy cost of contraction was examined. The rate of temperature rise (dT/dt) was determined in test contractions at 30 and 50% of maximal voluntary contraction (MVC) force before and during 30% MVC repetitive isometric exercise (RIE) to exhaustion and regularly in a 30-min postexercise recovery period (n = 9). Pulmonary O2 uptake and muscle temperature (Tmus) were determined at regular intervals. During the 30% MVC test contractions, dT/dt was 5.6 +/- 0.6 mK/s in unfatigued muscle, increasing linearly by 68% during exercise. In the 50% MVC test contractions, dT/dt rose by 84% from 9.8 +/- 1.1 mK/s. dT/dt determined during test contractions at both force levels did not decrease significantly throughout the 30-min postexercise recovery period. The rise in dT/dt was paralleled by 76% increased in O2 uptake. In contrast, Tmus rose initially and then leveled off. The present data indicate that RIE induced a gradual rise in the rate of energy turnover associated with isometric force production. Neither increased Tmus nor recruitment of less economic type II fibers can fully explain the increased energy cost. We suggest that energetic changes may occur at the cellular level and argue that this may be associated with the changes in muscle mechanics occurring during fatigue from submaximal voluntary RIE.

scholarly journals Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3694 ◽  
Author(s):  
Hugo A. Kerhervé ◽  
Scott McLean ◽  
Karen Birkenhead ◽  
David Parr ◽  
Colin Solomon
Keyword(s):  
Energy Cost ◽  
Perceived Exertion ◽  
Tissue Oxygenation ◽  
Minute Ventilation ◽  
Exercise Duration ◽  
Moderate Intensity ◽  
Heavy Exercise ◽  
Cerebral Tissue ◽  
Ventilatory Efficiency ◽  
Energy Cost Of Running

PurposeThe physiological mechanisms for alterations in oxygen utilization ($\dot {\mathrm{V }}{\mathrm{O}}_{2}$) and the energy cost of running (Cr) during prolonged running are not completely understood, and could be linked with alterations in muscle and cerebral tissue oxygenation.MethodsEight trained ultramarathon runners (three women; mean ± SD; age 37 ± 7 yr; maximum $\dot {\mathrm{V }}{\mathrm{O}}_{2}$ 60 ± 15 mL min−1 kg−1) completed a 6 hr treadmill run (6TR), which consisted of four modules, including periods of moderate (3 min at 10 km h−1, 10-CR) and heavy exercise intensities (6 min at 70% of maximum $\dot {\mathrm{V }}{\mathrm{O}}_{2}$, HILL), separated by three, 100 min periods of self-paced running (SP). We measured $\dot {\mathrm{V }}{\mathrm{O}}_{2}$, minute ventilation (${\dot {\mathrm{V }}}_{\mathrm{E}}$), ventilatory efficiency (${\dot {\mathrm{V }}}_{\mathrm{E}}:\dot {\mathrm{V }}{\mathrm{O}}_{2}$), respiratory exchange ratio (RER),Cr, muscle and cerebral tissue saturation index (TSI) during the modules, and heart rate (HR) and perceived exertion (RPE) during the modules and SP.ResultsParticipants ran 58.3 ± 10.5 km during 6TR. Speed decreased and HR and RPE increased during SP. Across the modules, HR and $\dot {\mathrm{V }}{\mathrm{O}}_{2}$ increased (10-CR), and RER decreased (10-CR and HILL). There were no significant changes in ${\dot {\mathrm{V }}}_{\mathrm{E}}$, ${\dot {\mathrm{V }}}_{\mathrm{E}}:\dot {\mathrm{V }}{\mathrm{O}}_{2}$,Cr, TSI and RPE across the modules.ConclusionsIn the context of positive pacing (decreasing speed), increased cardiac drift and perceived exertion over the 6TR, we observed increased RER and increased HR at moderate and heavy exercise intensity, increased $\dot {\mathrm{V }}{\mathrm{O}}_{2}$ at moderate intensity, and no effect of exercise duration on ventilatory efficiency, energy cost of running and tissue oxygenation.

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