Inter-individual variability in right ventricle

Inter-individual variability in right ventricle adaptation after an endurance race

Authors

Maria Sanz de la Garza, Gonzalo Grazioli, Bart H Bijnens, Carolina Pajuelo, Daniel Brotons, Enric Subirats,
Ramon Brugada, Emma Roca and Marta Sitges

Abstract

Background: Right ventricle (RV) dysfunction has been described in athletes after endurance races. We aimed to understand and characterize the RV response to endurance exercise, the impact of individual variability and the effects of the amount of exercise.
Methods and results: Echocardiography was performed in 55 healthy adults at baseline and after a three-stage trail race: short (14 km; n 1⁄4 17); medium (35 km; n 1⁄4 21); and long (56 km; n 1⁄4 17). Standard and speckle tracking echocar- diographic assessment of the RV was performed with global and separate analysis of the RV basal (inflow) and apical regions. Although no change was observed in the short distance runners, the RV systolic deformation decreased significantly (p < 0.05) after both the medium length and long races ( % RV global strain 7.6 20.1 and 8.7 21.8, respectively) with significant RV dilatation ( % RV volume þ10.6 9.9 and þ15.3 12.8, respectively). The RV basal segment made a major contribution to stroke volume during exercise, showing larger increases in size and strain compared with the apex. Various patterns of RV adaptation to exercise, ranging from increases in both RV segmental strains and sizes to an insufficient increase in size and a decrease in strain, were identified; this individual variability was not correlated with prior training.
Conclusion: An acute RV impairment was demonstrated after a trail-running race and was related to the amount of exercise. A high inter-individual variability was observed. Differences in RV adaptation patterns were independent of prior training, suggesting the influence was due to other individual factors.

http://DOI: 10.1177/2047487315622298

 

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Sarcomere Disruptions of Slow Fiber

Sarcomere Disruptions of Slow Fiber Resulting From Mountain Ultramarathon

Authors

Gerard Carmona, Emma Roca, Mario Guerrero, Roser Cussó, Alfredo Irurtia, Lexa Nescolarde, Daniel Brotons, Josep L. Bedini, and Joan A. Cadefau

Abstract

To investigate changes after a mountain ultramarathon (MUM) in the serum concentration of fast (FM) and slow (SM) myosin isoforms, which are fiber-type-specific sarcomere proteins. The changes were compared against creatine kinase (CK), a widely used fiber-sarcolemma-damage biomarker, and cardiac troponin I (cTnI), a widely used cardiac biomarker. Methods: Observational comparison of response in a single group of 8 endurance-trained amateur athletes. Time-related changes in serum levels of CK, cTnI, SM, and FM from competitors were analyzed before, 1 h after the MUM, and 24 and 48 h after the start of the MUM by 1-way ANOVA for repeated measures or Friedman and Wilcoxon tests. Pearson correlation coefficient was employed to examine associations between variables. Results: While SM was significantly (P = .009) increased in serum 24 h after the beginning of the MUM, FM and cTnI did not change significantly. Serum CK activity peak was observed 1 h after the MUM (P = .002). Moreover, serum peaks of CK and SM were highly correlated (r = .884, P = .004). Conclusions: Since there is evidence of muscle damage after prolonged mountain running, the increase in SM serum concentration after a MUM could be indirect evidence of slow- (type I) fiber-specific sarcomere disruptions.

http://dx.doi.org/10.1123/ijspp.2014-0267

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Heart Rate Variability in Ultra-Trail Runners

Heart Rate Variability in Ultra-Trail Runners

Authors
Umberto Melia, Montserrat Vallverdú, Emma Roca, Daniel Brotons, Alfredo Irurtia,
Joan A Cadefau, Pere Caminal, Alexandre Perera

Abstract

It is not trivial to understand the interactions between heart rate variability (HRV), activity of the autonomic nervous system (ANS) and exercise training. In this way,
heart rate (HR) signals were analyzed. HR was recorded during a race of 82 km from two groups of runners performing different training regimes, Active and Elite.
Several indexes from time-domain and frequency-domain analysis, time-frequency representation (TFR) and automutual-information function (AMIF) were calculated on
RR series in order to describe their dynamicity. TFR and AMIF indexes presented statistical significant differences when comparing the 1st and the 6th hour of the race
(p<0.002). LF/HF showed an increasing tendency in Active runners, and a decreasing tendency in Elite runners. Extremely low values of RR standard deviation
were found in Elite runners.

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Réponses physiologiques à l’exercice en altitude modérée

Réponses physiologiques à l’exercice en altitude modérée

Authors

A.F. Gaston, E. Roca, G. Doucende, I. Hapkova, E. Subirats, F. Durand

Summary
Aim. — To predict the effect of moderate altitude exposure on performance and cardiorespira- tory adaptations in order to provide recommendations to endurance trained athletes who want to perform exercise at moderate altitude.

Method. — Fifteen endurance trained athletes have performed an incremental maximal exercise at sea level and at 2150 m. Haemoglobin oxygen saturation (SpO2), gas exchanges and heart rate (HR) were recorded continuously during the tests.
Results.—HR at ventilatory threshold (VT) was lower at moderate altitude compared to sea level: −13 ± 3.4 bpm at VT1 and −7 ± 1.5 bpm at VT2 (P < 0.01). Power output was also decrea- sed by around 40watts at both VT1and VT2 (P<0.01). Seven athletes showed a significantly drop in SpO2 at the end of exercise at sea level (exercise induced hypoxemia [EIH]). Maximal oxygen uptake (VO2max ) at altitude was decreased by 22 ± 2.9 % in EIH athletes and by 15 ± 1.9 % in non-EIH athletes (P < 0.01). EIH athletes showed a significantly decrease in HRmax at altitude (−8±3.3bpm, P<0.05). A correlation was found between the decrease in VO2max and two others variables, the decrease in HRmax at altitude and the training load.
Conclusion. — This study points out the importance of SpO2 measurement during exhaustive ramp test at sea level for athletes who want to perform at altitude. Indeed, athletes with a significantly drop in SpO2 at sea level present a greater decrease in VO2max and HRmax at mode- rate altitude. However, HR and power output at VT must be adjusted during acute exposure to moderate altitude for all athletes.

http://dx.doi.org/10.1016/j.scispo.2015.06.006

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