Biomedical subjects

O Galy

Publications and source records attributed to O Galy.

14 recordsLinked to original sources

PubMed2004

Competitive season of triathlon does not alter bone metabolism and bone mineral status in male triathletes.

This longitudinal study evaluated the effects of a triathlon season on bone metabolism and hormonal status. Seven male competitive triathletes (mean age 19.3 years, range 18 - 20) with 5.0 +/- 0.3 years of competition experience were tested twice during the season: at the beginning of training and 32 weeks later. Total and regional bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry, while bone turnover was evaluated by specific biochemical markers: bone-specific alkaline phosphatase (B-ALP), osteocalcin, and urinary type I collagen C-telopeptide. In addition, sexual, calciotropic and somatotropic hormones were also analyzed. After 32 weeks, a BMD increase was found at the lumbar spine (1.9 %; p = 0.031) and skull (3.1 %; p = 0.048), while no variation was observed for total body or at the proximal femur. The B-ALP level decreased (-23.2 %; p = 0.031), but no variation was found for the other bone markers. 1.25 (OH) (2)D3, IGF-1 and the bioavailability IGF-1 index (IGF-1/IGFBP-3) increased by 18.3 % (p = 0.047), 29 % (p = 0.048), 33 % (p = 0.011), respectively, while PTH, testosterone, IGFBP-3 and cortisol concentrations were unchanged. In conclusion, the triathlon season had a moderately favourable effect on BMD, although a slowing down of bone formation activity was observed. No variation in hormonal levels was observed that could have limited the effects of exercise on bone tissue.

Absorptiometry, Photon↗

PubMed2004

Field and laboratory testing in young elite soccer players.

AIM: To determine if there are correlations between the physical fitness of young soccer players assessed by field and laboratory testing. METHODS: Thirty four male soccer players took part in the study (mean (SD) age 17.5 (1.1) years, height 177.8 (6.7) cm, weight 70.5 (6.4) kg). Maximal oxygen uptake (VO(2)MAX) during treadmill running and vertical jump height on a force platform were measured in the laboratory. Field tests consisted of a soccer specific endurance test (Bangsbo test) and 30 m sprint with 10 m lap times. RESULTS: The Bangsbo test correlated with the lowest velocity associated with VO(2)MAX (vVO(2)MAX; R(2) = 0.55, p<0.001), but not with VO(2)MAX. Sprint times at 30 m and 20 m were related to peak extension velocity and peak extension force measured during vertical jumping, but not to vertical jump height per se. The jumping force and velocity could explain 46% of the 30 m sprint performance (R(2) = 0.46, p<0.001). CONCLUSION: The Bangsbo test and 30 m sprint test correlate with vVO(2)MAX and vertical jump force and velocity respectively. The Bangsbo test does not give a good estimate of VO(2)MAX in young soccer players.

Adolescent↗

PubMed2004

Effects of 8 days acclimation on biological and performance response in a tropical climate.

BACKGROUND: This study was designed to determine the acclimation process elicited by exposure to a tropical climate. METHODS: Nine triathletes performed 3 outdoor indirect continuous running multistage tests in both thermoneutral and tropical conditions. Before travelling to the tropical area (Martinique Island, FWI), the triathletes performed the thermoneutral test (TN) in 14 degrees C and 45% rh conditions. The tropical tests were performed 2 and 8 days after arrival (T2 and T8, performed at a mean environmental temperature of 33.4 degrees C and 75.5% rh). The day before T8, blood samples were drawn for biochemical analysis. During each test, tympanic temperature, sweat rate, weight loss, heart rate (HR), and performance were recorded. RESULTS: The results demonstrated that: 1) the mean tympanic temperature was greater in T2 (p<0.001) and T8 (p<0.01) than in TN; 2) the mean sweat rate was significantly greater (p<0.001) in T2 and T8 than in TN and significantly greater in T8 than in T2 (p<0.03); 3) the weight loss after trials was significantly greater (p<0.001) in T2 and T8 than in TN and in T8 than in T2 (p<0.04); 4) the mean HR and the HR at rest were significantly greater in T2 than in TN (p<0.001) and T8 (p<0.005); 6) significant reductions were observed in T8 vs TN in red cell count (p<0.05) and plasma proteins (p<0.04), the consequence of a 7.5% plasma volume expansion; and 7) the performance was significantly lower in both T2 (p<0.02) and T8 (p<0.03) than in TN. CONCLUSIONS: We concluded that 8 days exposure to hot/wet conditions induced impairments in physiological responses and performance that were still evident on the 8th day. Further and longer outdoor studies are needed to investigate if return to optimal performance levels after adaptation to hot/wet conditions is possible.

Acclimatization↗

PubMed2004

Effects of successive running and cycling on the release of atrial natriuretic factor in highly trained triathletes.

AIM: To evaluate the influence of successive running and cycling on both exercise-induced arterial hypoxemia (EIAH) and atrial natriuretic factor (ANF) release, 5 triathletes performed 2 separate exercise trials. METHODS: One trial consisted of a 20-min+20-min successive cycle-run exercise (C(1)-R(2)) and the other consisted of a 20-min+20-min successive run-cycle exercise (R(1)-C(2)). Arterial oxygenation (PaO(2)) and ANF were determined at pre-exercise, at the end of each 20-min segment of exercise and after 10 min of recovery. RESULTS: EIAH was noted during C(1)-R(2) and R(1)-C(2) trials. A higher EIAH was observed during running compared with cycling performed in the 1(st) position (R(1) vs C(1)) in the succession. In contrast, no difference was observed between successive running and successive cycling (R(2) vs C(2)), (-10.6+/-7.0 vs -15.6+/-4.0 mmHg for C(1)-R(2) and -20.9+/-6.0 vs -16.2+/-2.4 mmHg for R(1)-C(2)). ANF showed no difference between cycling and running performed in first position, whereas a significantly lower ANF was observed during successive cycling compared with successive running (C(2) vs R(2)) (19.9+/-3.72 vs 36.2+/-6.4 pmol.L(-1)). During recovery, neither PaO(2) nor ANF plasma returned to baseline level after either trial. CONCLUSION: This study provides new information on some of the physiological modifications that occur during multi-sports. Specifically, the impact of the modality of the successive exercise on ANF release and body fluid regulation was observed. Cycling as the successive exercise seems to cause lower ANF release than does running.

Adaptation, Physiological↗

PubMed2003

Maximal oxygen uptake and power of lower limbs during a competitive season in triathletes.

BACKGROUND: In order to study the effect of a competitive triathlon season on maximal oxygen uptake (VO2max), aerobic power (AeP) and anaerobic performance (AnP) of the lower limbs, eight triathletes performed exercise tests after: (1) a pre-competition period (Pre-COMP) (2) a competitive period (COMP), and (3) a low (volume and intensity) training period (Post-COMP). The tests were a vertical jump-and-reach test and an incremental exercise test on a cycle ergometer. Ventilatory data were collected every minute during the incremental test with an automated breath-by-breath system and the heart-rate was monitored using a telemetric system. RESULTS: No changes in VO2max were observed, whereas AeP decreased after Post-COMP compared to Pre-COMP and COMP and AnP decreased during COMP compared to Pre-COMP and Post-COMP. In addition, second ventilatory threshold (VT2) and power output at first ventilatory threshold (VT1) and VT2 decreased after Post-COMP. CONCLUSION: This study showed that six weeks of low volume and intensity of training is too long a period to preserve adaptations to training, although a stable maximal oxygen uptake throughout the triathlon season was observed. Moreover, the AnP decrease during COMP was probably in relation with the repetitive nature of the training mode and/or triathlon competitions.

Adult↗

PubMed2003

The effects of prior cycling and a successive run on respiratory muscle performance in triathletes.

The aim of the present study was to compare the effects of prior cycling and a successive run on respiratory muscle performance during a cycle-run succession as performed in the triathlon. We hypothesized that despite the moderate intensity of exercise and the absence of exhaustion, the crouched cycling position would induce a decrease in respiratory muscle performance that would be reversed by the successive vertical run position. Ten male triathletes (22.6 +/- 1.1 yr) performed a four-trial protocol: (1) an incremental cycle test to assess maximal oxygen uptake (VO2max), (2) 20 min of cycling (C), (3) 20 min of running (R), and (4) 20 min of cycling followed by 20 min of running (C-R). Trials 2, 3 and 4 were performed at the same metabolic intensity, i. e., 75 % of VO2max. Respiratory muscle force was assessed by measuring maximal expiratory (P(Emax)) and inspiratory (P(Imax)) pressures from the functional residual capacity (FRC) before and 10 min after C, R, and C-R. Respiratory muscle endurance was assessed one day before and 30 min after C, R, and C-R, by measuring the time limit (T(lim)), which corresponds to the length of time a respiratory load can be sustained before the process of fatigue develops sufficiently to cause task failure. The results showed a similar significant decrease in P(Imax) (132.4 +/- 4.9 versus 125.7 +/- 5.6 cm H2O, p < 0.05) and T(lim) (5.22 +/- 0.28 versus 3.68 +/- 0.32 min, p < 0.05) post-C and post-C-R (133.7 +/- 4.0 versus 126.9 +/- 5.2 cm H2O, and 5.29 +/- 0.18 versus 3.49 +/- 0.41 min, respectively, p < 0.05) compared with the pre-trial values. In contrast, P(Imax) and T(lim) were not significantly decreased post-R (131.8 +/- 6.1 cm H2O versus 129.6 +/- 6.4 cm H2O, and 4.90 +/- 0.69 versus 4.40 +/- 0.56 min, respectively, p > 0.05). We concluded that moderate intensity exercise not performed to exhaustion induced a decrease in respiratory muscle performance. Moreover, the respiratory muscle fatigue induced by prior cycling was maintained, and neither reversed nor worsened, by the successive run.

Adaptation, Physiological↗

PubMed2002

The effect of cycling followed by running on respiratory muscle performance in elite and competition triathletes.

This study investigated the possibility of there being differences in respiratory muscle strength and endurance in elite and competition triathletes who have similar maximal oxygen uptakes (VO(2max)) and ventilatory thresholds (Th(vent)). Five internationally-ranked elite, [mean (SD) age 23.8 (1.4) years] and six nationally- and regionally-ranked competition [age 21.1 (1.1) years] male triathletes performed two successive trials: first an incremental cycle test to assess VO(2max) and Th(vent) and second 20 min of cycling followed by 20 min of running (C-R) at intensities higher than 85% VO(2max). Cardioventilatory data were collected every minute during the two trials, using an automated breath-by-breath system. Maximal expiratory and inspiratory (P(Imax)) strength were assessed before and 10 min after C-R from the functional residual capacity. Respiratory muscle endurance was assessed 1 day before and 30 min after C-R by measuring the time limit (t(lim)). The results showed firstly that during C-R, the competition triathletes had significantly (P < 0.05) higher minute ventilation [mean (SEM) 107.4 (3.1) compared to 99.8 (3.7) l x min(-1)], breathing frequency [44.4 (2.0) compared to 40.2 (3.4) x min(-1)] and heart rate [166 (3) compared to 159 (4) beats x min(-1)] and secondly that after C-R, they had significantly lower P(Imax) [127.1 (4.2) compared to 130.7 (3.0) cmH(2)O] and t(lim) [2:35 (0:29) compared to 4:12 (0:20) min] than the elite triathletes. We conclude that, despite similar VO(2max) and Th(vent), the competition triathletes showed less extensive adaptive mechanisms, including those in the respiratory muscles, than did the elite triathletes. This led to higher ventilation, which appeared to be the cause of the faster development of fatigue in the inspiratory muscles in this group.

Adult↗

PubMed2002

Cardiorespiratory responses and blood lactate during an experimental run-cycle transition in duathletes.

The aim of this study was to determine the effects of a prior run on the cardiorespiratory responses measured during a subsequent cycle segment. Twelve duathletes underwent three successive laboratory trials at an interval of one week: 1) an incremental cycle test, 2) 20 min of running followed by 20 min of cycling (RC), and 3) 20 min of control cycling (C) at the same intensity as the cycling segment of RC. Ventilatory data were collected every minute using a breath-by-breath automated system. Blood samples were collected to measure venous blood lactate concentration, [La], at rest, after the running and cycling segments of RC and after C. The results showed that the C segment of RC had significantly higher VE, VE/VO2, f and HR than C alone and significantly lower VT (p < 0.05) than C alone. Moreover, steady state during C of RC was reached at the 2nd min for VO2, VE, VCO2, VE/VO2, VE/VCO2, and VdT; at the 4th min for R and HR, and at the 5th min for f. The C of RC induced a significant increase in [La] in comparison with C alone. We concluded that the first minute of cycling after running during an RC trial induced specific metabolic and cardiorespiratory responses.

Adult↗

PubMed2002

Carbohydrate dependence during hard-intensity exercise in trained cyclists in the competitive season: importance of training status.

To test the hypothesis that intensive endurance training increases CHO utilisation during hard-intensity exercise, seven competitive road cyclists (Cy) performed three 50-min steady-state exercise tests on a cycle ergometer above their ventilatory threshold (+ 15 %) over the course of a cycling season (January [ET1], May [ET2] and September [ET3]). We compared the data with the baseline values of seven sedentary controls (Sed). CHO oxidation in Cy was higher in ET2 and ET3 than in ET1 (p < 0.05), was lower in ET3 than in ET2 (p < 0.05) and was higher in Cy than in Sed only in ET2 (p < 0.05). Lactate kinematics were lower in Cy than in Sed in all conditions (p < 0.05), but in Cy they were lower in ET2 than in ET1 and higher in ET3 than in ET2 (p < 0.05). Race performance was impaired and the overtraining score was increased at ET3 in comparison with ET2 (p < 0.05). We conclude that competitive cyclists increase CHO oxidation during hard-intensity exercise over the course of a season, but show a decline by the end of the season in association with the appearance of an overtraining state. Thus, well-trained cyclists develop a CHO dependence, which is modified with training status.

Adult↗

PubMed2001

Enhancing cycling performance using an eccentric chainring.

PURPOSE AND METHODS: This study was designed to compare the physiological responses and performance of well trained cyclists riding with two different chainring designs, round or eccentric, during a brief and intense cycling exercise: an "all-out" 1-km laboratory test. The eccentrically designed chainring was made of two crank arms sliding into each other, with the inside arm fixed on the center of the arm of a circular chainring and the outside arm sliding along the inside and revolving around an elliptical cam. This design increases crank arm length at the downstroke and decreases it during the upstroke, thus increasing and decreasing the torque. In terms of the chainring's revolution, the crank arm length at 0 degrees and 180 degrees is similar to the arm length of circular chainrings (175 mm). However, during the downstroke (0-180 degrees ), it increases to its maximum length of 200 mm at 90 degrees and then returns to its original length of 175 mm at 180 degrees. During the upstroke, it decreases to a minimum length of 150 mm at 270 degrees and then increases to 175 mm at 360 degrees. Eleven cyclists performed an all-out 1-km laboratory test using each chainring. The study was conducted over two consecutive weeks with the order of chainring use randomized. During all trials, ventilatory data were collected every minute using an automated breath-by-breath system. Heart rate was measured using a telemetry system. RESULTS: None of the cardiorespiratory variables showed significant differences between chainring trials. Performance, however, was significantly improved using the eccentric design (64.25 +/- 1.05 vs 69.08 +/- 1.38 s, P < 0.004, with the eccentric and the round design, respectively). CONCLUSION: We concluded that the eccentric chainring significantly improved the cycling performance during an all-out 1-km test. Further testing with indoor cycling specialists performing on a velodrome would be helpful to define the maximal possibilities of such a chainring.

Adolescent↗

PubMed2001

The effect of exercise modality on respiratory muscle performance in triathletes.

PURPOSE: The aim of this study was to examine the effects of the cycle-run and run-cycle successions of the triathlon and duathlon, respectively, on respiratory muscle strength and endurance. METHODS: Respiratory muscle strength was assessed by measuring maximal inspiratory (P(Imax)) and expiratory (P(Emax)) pressures. Respiratory muscle endurance was assessed by measuring the time limit (T(lim)). Twelve triathletes participated in a three-trial protocol. The first trial consisted of an incremental cycle test to assess the maximal oxygen uptake (.VO(2max)) of triathletes. Trial 2 consisted of 20 min of cycling followed by 20 min of running (C-R), and trial 3 consisted of 20 min of running followed by 20 min of cycling (R-C). Trials 2 and 3 were performed at the same metabolic intensity (%.VO(2max)). P(Imax) and P(Emax) were measured before and 10 min after C-R and R-C, and 1 min after the post-C-R and post-R-C T(lim) measurements (P(Imax) 1'). T(lim) was measured 1 d before and 30 min after C-R and R-C. RESULTS: The results showed a significant decrease in P(Imax) after C-R (126.7 +/- 4.3 cmH(2)O, P < 0.05) and R-C (123.7 +/- 4.9 cmH(2)O, P < 0.05) compared with the baseline values (130 +/- 3.8 and 129.6 +/- 4.3 cmH(2)O, respectively). P(Imax) 1' showed a significantly greater decrease after R-C versus C-R (111.2 +/- 5.5 cmH(2)O vs 121.2 +/- 3.9 cmH(2O), respectively, P < 0.001). Tlim after C-R (3.3 +/- 0.3 min) and R-C (2.1 +/- 0.3 min) decreased significantly compared with baseline values (4.19 +/- 0.3 min and 4.02 +/- 0.3 min, respectively). However, the Tlim decrease after R-C was significantly greater than after C-R (P < 0.001). CONCLUSION: We concluded that respiratory muscle strength and endurance were less decreased after the cycle-run succession and that cycling induced a greater decrease in respiratory muscle endurance than running.

Adult↗

PubMed2001

Pulmonary responses during the cycle-run succession in elite and competitive triathletes.

OBJECTIVES: The purpose of this study was to determine the effect of performance level on the pulmonary responses in triathletes during the cycle-run succession. METHODS: Eight regionally and nationally ranked (Competitive) and six internationally ranked (Elite) male triathletes underwent 30 min of cycling followed by 20 min of running (C-R) and 30 min of control cycling (C). Before and 10 min after each trial, the triathletes underwent lung function testing. Ventilatory data were collected every minute using an automated breath-by-breath system. RESULTS: The results showed that (a) cycling induced a significant increase in residual volume and functional residual capacity in the Elite group (P <.05); (b) although cycling induced a significant decrease in DLCO in both groups, this decrease persisted at the end of the cycle-run exercise in the Competitive group only (P <.05); and (c) the rise in breathing frequency was significantly greater in the Competitive triathletes during the first 8 min of the subsequent run (P <.04). CONCLUSIONS: We conclude that the internationally ranked--or elite-performance--triathletes may have developed specific responses to the cycle-run succession.

Adult↗

PubMed2001

The effect of multi-cycle-run blocks on pulmonary function in triathletes.

BACKGROUND: This study was designed to determined the pulmonary responses elicited by multi-cycle-run exercise in triathletes and to compare them to those elicited during a simple cycle-run succession. METHODS: Twelve male triathletes underwent three successive laboratory trials: 1) an incremental cycle test, 2) 30 min of cycling followed by 20 min of running (C-R), and 3) five repeated bouts of 6 min of cycling and 4 min of running (X-CR). Before and 10 minutes after the third and fourth trials, the triathletes underwent lung function testing, especially spirometry and diffusing capacity testing for carbon monoxide (DL(CO)). During all trials, ventilatory data were collected every minute using an automated breath-by-breath system. RESULTS: The results showed that: 1) the cardiorespiratory responses observed during running were greater in the X-CR trial for VE/VCO2 and HR, 2) DL(CO) and DL(CO)/VA were significantly reduced after both trials, and 3) there were no significant changes in pulmonary volumes. CONCLUSIONS: We concluded that 1) the multi-block trial elicited greater cardioventilatory responses than simple the cycle-run succession and 2) multi-block seems a good method to stimulate the specific adaptations required for the cycle-run succession, and particularly for the cycle-run transition. In any case, the efficacy of the multi-block model needs to be more thoroughly evaluated over the course of a longer-term training programme.

Adult↗

PubMed2000

Catecholamine, blood lactate and ventilatory responses to multi-cycle-run blocks.

PURPOSE AND METHODS: This study was designed to determine whether the physiological responses elicited during the run part of repeated bouts of cycle-run exercise are similar to those required during the run segment of a cycle-run succession. Thirteen male triathletes underwent four successive laboratory trials: 1) an incremental treadmill test, 2) an incremental cycle test, 3) 30 min of cycling followed by 20 min of running (C-R), and 4) five repeated bouts of 6 min of cycling and 4 min of running (X-CR). During the C-R and X-CR trials, venous blood samples were obtained to measure lactate, epinephrine and norepinephrine concentrations. During all trials, ventilatory data were collected every min using an automated breath-by-breath system. RESULTS: The results showed that 1) the cardiorespiratory responses observed during running were similar in the X-CR and C-R trials, 2) the lactate concentration was similar in both trials, 3) the epinephrine concentration was greater (277.9 +/- 11.9 vs 169.8 +/- 86.7 pg x mL(-1), P < 0.025) in X-CR than in C-R, and 4) the norepinephrine concentration was similar in both trials, except at the first cycle-run succession (T1) of X-CR. CONCLUSION: We concluded that 1) multi-block training is a good method to stimulate the specific adaptations required for the cycle-run succession, and particularly for the cycle-run transition, and 2) multi-block training seems to induce a greater catecholaminergic response, which may be due to a combination of an inherent effect of this type of training and the triathletes' relative lack of experience with it. In any case, the efficacy of the multi-block model needs to be more thoroughly evaluated over the course of a longer-term training program.

Adult↗