Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
The aim of this study was to examine the influence of exercise intensity and session duration on rating of perceived exertion (RPE) in adolescent Taekwondo (TKD) athletes. Twelve male youth competitive TKD athletes, aged between 13 and 18 years took part in this study. Training data (368 individual sessions) were collected during the 12 weeks of the precompetitive TKD season. Daily training load was calculated using the heart rate and the session-RPE. Exercise intensity was also classified in five zones [i.e. 5060%, 6170%, 7180%, 8190% and 91100% of maximal heart rate (HRmax)] and the time spent in each zone was expressed as percentage of total session time. The analysis of variance showed a significantmain effect for zone (pB0.001) with most of the time (69%) spent at intensities between 61 and 90% of HRmax, and only 10% spent above 91% (mean differences compared to the other zones ranging from 6.6% versus zone 1 to 14.8% versus zone 3; pB0.0001). The individual correlation between session-RPE and HR-based methods were moderate to large. The stepwise multiple regression showed that RPE was influenced mainly by the time spent in the high intensity zone that explained 22.1% of the variance in RPE. Session duration accounted for only an additional 3.2%. The results suggest the time spent at high-intensity (i.e. between 91 and 100% HRmax) and only marginally the session duration influences theRPE referred to the whole training session. This seems to confirm that the determination of the TL multiplying the RPE andsession duration is acceptable.
ISSN: 1746-1391

hal-01163939
https://hal.univ-antilles.fr/hal-01163939
DOI : 10.1080/17461391.2012.691115

Éditeur(s) : HAL CCSD Ferrata Storti Foundation
Résumé : International audience
BackgroundRecent evidence suggests that autonomic nervous system activity could be involved in thepathophysiology of sickle cell disease, but it is unclear whether differences in autonomic nervoussystem activity are detectable during steady state in patients with mild and severe disease.The aim of the present study was to compare the autonomic nervous system activity, bloodrheology, and inflammation in patients with sickle cell anemia according to the frequency ofacute pain crisis.Design and MethodsTwenty-four healthy volunteers, 20 patients with sickle cell anemia with milder disease, and15 patients with sickle cell anemia with more severe disease were recruited. Milder disease wasdefined as having no pain crisis within the previous year. More severe disease was defined ashaving had within the previous year three or more pain crises which were documented by aphysician and required treatment with narcotics. The autonomic nervous system activity wasdetermined by spectral analysis of nocturnal heart rate variability. Blood viscosity determinationand measurements of several inflammatory markers (interleukin-6, soluble vascular celladhesion molecule-1, soluble CD40 ligand and sL-selectin) were made on blood samples collectedin steady-state conditions.ResultsResults showed that: 1) patients who had suffered more frequent pain crises had lowerparasympathetic activity and greater sympatho-vagal imbalance than both controls andpatients with milder disease. However, when adjusted for age, no significant difference wasdetected between the two sickle cell anemia patient groups; 2) patients who had suffered morefrequent pain crises had higher blood viscosity than patients with milder disease, and this wasnot dependent on age.ConclusionsResults from the present study indicate that both the autonomic nervous system activity andblood viscosity are impaired in patients with sickle cell anemia exhibiting high frequency ofpain crisis in comparison with those who did not experience a crisis within the previous year.
ISSN: 0390-6078

hal-01163973
https://hal.univ-antilles.fr/hal-01163973
DOI : 10.3324/haematol.2011.047365

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
A decreased global autonomic nervous system (ANS) activity and increased sympathetic activation in patients with sickle cell anemia (SCA) seem to worsen the clinical severity and could play a role in the pathophysiology of the disease, notably by triggering vaso-occlusive crises. Because exercise challenges the ANS activity in the general population, we sought to determine whether a short (,15 min) and progressive moderate exercise session conducted until the first ventilatory threshold had an effect on the ANS activity of a group of SCA patients and a group of healthy individuals (CONT group). Temporal and spectral analyses of the nocturnal heart rate variability were performed before and on the 3 nights following the exercise session. Standard deviation of all normal RR intervals (SDNN), total power, low frequencies (LF) and high frequencies powers (HF) were lower but LF/HF was higher in SCA patients than in the CONT group. Moderate exercise did not modify ANS activity in both groups. In addition, no adverse clinical events occurred during the entire protocol. These results imply that this kind of short and moderate exercise is not detrimental for SCA patients.
ISSN: 1932-6203

hal-01136725
https://hal.univ-antilles.fr/hal-01136725
https://hal.univ-antilles.fr/hal-01136725/document
https://hal.univ-antilles.fr/hal-01136725/file/Hedreville%20et%20al.%20-%202014%20-%20Acute%20moderate%20exercise%20does%20not%20further%20alter%20the%20autonomic%20nervous%20system%20activity%20in%20patients%20with%20sick%282%29.pdf
DOI : 10.1371/journal.pone.0095563

Éditeur(s) : HAL CCSD
Résumé : International audience
The aim of the present study was to determine the effects of 40 km of cycling on the biomechanical and cardiorespiratory responses measured during the running segment of a classic triathlon, with particular emphasis on the time course of these responses. Seven male triathletes underwent four successive laboratory trials: (1) 40 km of cycling followed by a 10-km triathlon run (TR), (2) a 10-km control run (CR) at the same speed as TR, (3) an incremental treadmill test, and (4) an incremental cycle test. The following ventilatory data were collected every minute using an automated breath-by-breath system: pulmonary ventilation VE, l x min[-1]), oxygen uptake (VO2, ml x min(-1) x kg[-1]), carbon dioxide output (ml x min[-1]), respiratory equivalents for oxygen (VE/VO2) and carbon dioxide (VE/VCO2), respiratory exchange ratio (R) respiratory frequency (f, breaths x min[-1]), and tidal volume (ml). Heart rate (HR, beats x min[-1]) was monitored using a telemetric system. Biomechanical variables included stride length (SL) and stride frequency (SF) recorded on a video tape. The results showed that the following variables were significantly higher (analysis of variance, P < 0.05) for TR than for CR: VO2 [51.7 (3.4) vs 48.3 (3.9) ml x kg(-1) x min(-1), respectively], VE [100.4 (1.4) l x min(-1) vs 84.4 (7.0) l x min(-1)], VE/VO2 [24.2 (2.6) vs 21.5 (2.7)] VE/VCO2 [25.2 (2.6) vs 22.4 (2.6)], f[55.8 (11.6) vs 49.0 (12.4) breaths x min(-1)] and HR [175 (7) vs 168 (9) beats x min(-1)]. Moreover, the time needed to reach steady-state was shorter for HR and VO2 (1 min and 2 min, respectively) and longer for VE (7 min). In contrast, the biomechanical parameters, i.e. SL and SF, remained unchanged throughout TR versus CR. We conclude that the first minutes of the run segment after cycling in an experimental triathlon were specific in terms of VO2 and cardiorespiratory variables, and nonspecific in terms of biomechanical variables.
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY

hal-00720703
https://hal.univ-antilles.fr/hal-00720703
https://hal.univ-antilles.fr/hal-00720703/document
https://hal.univ-antilles.fr/hal-00720703/file/EJAP.pdf

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
ISSN: 0007-1048

hal-01668324
https://hal.univ-antilles.fr/hal-01668324
DOI : 10.1111/bjh.14064

Éditeur(s) : HAL CCSD Thieme Publishing
Résumé : International audience
We evaluated the eff ects of the fl uid replacement strategy on core temperature, heart rate and urine osmolality during a 27-km trail run in tropical climate. 20 well-trained runners completed a 27-km trail race in tropical conditions. They were acclimatized to these conditions. Heart rate was monitored every 5 s, while core temperature and perceived thermal and comfort sensations were recorded before, at the 11 th km, and just after the end of the race. Water intake, urine osmolality and body mass were measured before and after the race. Core temperature and the scores of perceived thermal and comfort sensations were signifi cantly higher at the 11 th km and at the end of the race compared to before the race, but not at the 11 th km compared to before the race. No participant exhibited dehydration as assessed by urine osmolality. The less the trail runners weighed, the greater the heat retention was. The less hot they felt at the end of the race, the more they lost water, and the better the performance was. The fastest runners were able to tolerate a greater variation in core temperature between the beginning and the end of the trail race with lower water intake.
ISSN: 0172-4622

hal-01152345
https://hal.univ-antilles.fr/hal-01152345
DOI : 10.1055/s-0033-1349108