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Effect of sprint duration (6 s or 30 s) on plasma glucose regulation in untrained male subjects

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Abstract

We have explored in the following study the glucoregulatory responses (glycemia, insulinemia, catecholamines) at the end of 2 supramaximal tests of different durations. Seven untrained male subjects (21.9+/-0.3 y) performed an isolated exercise of 6 s (T6) and a Wingate-test of 30 s. To determine the levels of lactate (La), plasma concentrations of glucose, insulin, adrenaline (A) and noradrenaline (NA), blood samples have been collected successively at rest, after a warm-up period of 15 min, immediately after T6 and T30, and after 5, 10, 20, and 30 min of recovery. Whether expressed as absolute or relative values, the peak power recorded during the 2 tests is statistically the same in T6 and T30. The maximal value of lactate (L(amax)) measured 5 min after the end of the 2 exercises is significantly greater after T30 (12.3+/-0.9 mmol x L(-1)) than after T6 (5.4+/-0.4 mmol x L(-1)) and T30 (4.2+/-0.2 mmol x L(-1)). No significant difference is observed between the plasma glucose concentrations recorded after the 2 tests until the first 10 min of recovery. However the plasma glucose values recorded after 20 and 30 min of recovery are significantly higher after T6 than after T30. Whatever the duration of the test, the insulinemia level remains unchanged at the end of the exercise and during the 30 min of recovery. On the other hand, the values of adrenaline and noradrenaline after T6 and T30 become considerably higher than those recorded at rest. However, the increase remains significantly higher after T30 (13.5+/-1.8 nmol x L(-1) for NA and 2.7+/-0.7 nmol x L(-1) for A) than after T6 (4.9+/-0.3 nmol x L(-1) for NA and 1.2+/-0.2 nmol x L(-1) for A). These results suggest that the mechanism responsible for increasing blood glucose surpass those which decrease it during supramaximal exercise. However, plasma glucose concentrations is affected by the duration of supramaximal exercise. The lower increase of plasma glucose concentration after T30 than after T6 might be explained by the resting of muscle glycogen stores which are more used during T30 than after T6, but in the absence of muscle glycogen content measurement we cannot conclude.

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... Among the sedentary and athletic, catecholamine concentrations are influenced by emotional factors and physical exercise among others. Indeed, exercise, hypoglycemia, and hypoxia are stressful situations that can TANAFFOS Messan F,et al. 137 Tanaffos 2017; 16 (2): [136][137][138][139][140][141][142][143] cause instability in the major functions of organs (6). To restore homeostasis, the nervous and endocrine systems generate potent mediators involved in physiological regulation and, therefore, homeostasis. ...
... Even at very low-intensity exertion, increased adrenaline and noradrenaline concentrations are observed; however, the noradrenaline increase occurs faster than that of adrenaline (12). Increasing catecholamine concentrations are relatively more sensitive to high intensities that maximal aerobic power (13)(14)(15)(16)(17)(18)(19)(20)(21)(22). For example, in training and in competition, professional cyclists are faced with high levels of intensity and exposure to air pollutants. ...
... Moreover, Caillaud et al. (32) showed that a minimal exercise time was required to induce an increase in catecholamine, even at high intensity. However, this hypothesis has not been not confirmed because the study methods differ from each other (16,22,33). In fact, the results of the present work suggest that adrenaline and noradrenaline concentrations are more sensitive to exercise intensity (34)(35)(36). ...
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Background The concentration of circulating catecholamine increases during exercise in healthy athletes, but the variation has not been studied much in athletes who develop exercise-induced bronchospasm. This study measured changes in circulating catecholamine levels using the induced maximal effort test in the laboratory in professional cyclists sensitive to bronchospasm. Materials and Methods This experimental study included 86 professional cyclists. They underwent two pulmonary function tests (to determine forced expiratory volume in one second [FEV1]) and two blood samples (to measure adrenaline and noradrenaline levels) were drawn before and after the stress test. Two subsets emerged: subjects whose FEV1 decreased by at least 10% from the resting value and non-sensitive subjects whose FEV1 do not meet this criterion. Results A total of 51 cyclists (59%) were classified into the sensitive group. Resting catecholamine levels showed no significant difference (p > 0.05) between the two groups. In contrast, at the end of the exercise test, the adrenaline (581.9 ± 321.0 pg/mL versus 1783.5 ± 1001.0 pg/mL) and noradrenaline (4994.0 ± 2373.0 pg/mL versus 3205.0 ± 7714.4 pg/mL) levels were both lower in the sensitive group than those in the resting group (p < 0.0001). Conclusion The frequency of the occurrence of bronchospasm observed in the studied cyclists was one of the highest among professional sports environments and the circulating catecholamine level was low in cyclists susceptible to bronchospasm. A training protocol adapted to their respiratory physiological profile may be indicated.
... A significant increase was observed after the repeated sprint test. These observations are in accordance with those of Moussa et al. 16 demonstrating a significant climb of the plasma glucose concentrations after an isolated supramaximal exercise of six seconds and a Wingate-Test of 30 seconds, and using an enzymatic fluorometric method. Our results concords also with the findings of Saraslanidis et al. 17 recorded after 300 and 400-m race, and using an enzymic photometric method with the aid of reagent kit from Best (Athens, Greece). ...
... This reflects strong glycolysis participation to ATP molecules turnover required by the strong muscle contractions. Our results were in conformity with those of Moussa et al. 16 who measured the lactate concentration after a Wingate-Test of 30 seconds, and using a micro enzymatic method. Our findings were also in line with those of Saraslanidis et al. 17 recorded after 300 and 400-m race using an enzymic photometric method, and with those of Minetto et al. 18 measured spectrophotometrically after two types of controlled strenuous exercise (spinning activity and maximal isokinetic test). ...
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BACKGROUND: The repeated-sprint ability (RSA) plays a crucial role for determining success in many team sports. Unfortunately, several studies hypothesized that strenuous exercise could cause functional disorders or even some pathologies. These constraints are often associated to different physiological and metabolic disturbances that may reduce the sportive performance or even stop the activity. The purpose of this study was to examine the metabolic, immune and inflammatory responses to a repeated sprint test in trained subjects using a FT-IR spectrometry determination. METHODS: Eleven male football players were required to perform six sprints of six seconds each with 24 seconds of recovery between repetitions. Two blood samples were collected, before and immediately after effort, and 19 parameters related to metabolic, immune and inflammatory responses were assessed by FT-IR spectrometry. RESULTS: This study reported that the total work was positively correlated to the VO2max of subjects (r=0.74; P<0.05) and the lactate concentration (r=0.64; P<0.05). Our results noted also that glucose, lactate, protein, transferrin, Apo-A1, Apo-B, IgG, C-reactive protein, haptoglobin and orosomucoid concentrations increased; however, IgA and IgM concentrations decreased after multiple sprints (P<0.001 for lactate, and P<0.05 for the rest). No significant changes were noted in cholesterol, amino acids and albumin concentrations. CONCLUSIONS: Our data noted that the ability to sprint repeatedly with a short time interval of rest is related to the aerobic system’s ability to resynthesize energy, and eliminate lactate during rest periods. Unfortunately, RSA-Test is often associated with different physiological and metabolic disturbances that may lead to a transit immuno-depressive period, and an inflammatory status.
... Le pic de [La] pl est observé cinq minutes après l'exercice de sprint, en accord avec les études menées chez l'adulte avec des protocoles semblables [22,26]. Par ailleurs, les pics de lactate mesurées chez nos adolescents sont similaires à ceux retrouvés par Moussa et al. [27] chez des adultes non entraînés lors du même type d'effort. D'autres études notent également des valeurs maximales de lactate semblables à la suite de tests de sprint de dix secondes [7] et de quinze secondes [22]. ...
... Un entraînement spécifique de sprint de six mois n'apparaît pas en mesure de modifier cette réponse physiologique. Néanmoins, il apparaît nécessaire, tout comme il l'a été suggéré chez l'adulte [27,39], de corriger les concentrations plasmatiques de tous les substrats mesurés en fonction des VP lors d'exercices supramaximaux de ce type. ...
... Le pic de [La] pl est observé cinq minutes après l'exercice de sprint, en accord avec les études menées chez l'adulte avec des protocoles semblables [22,26]. Par ailleurs, les pics de lactate mesurées chez nos adolescents sont similaires à ceux retrouvés par Moussa et al. [27] chez des adultes non entraînés lors du même type d'effort. D'autres études notent également des valeurs maximales de lactate semblables à la suite de tests de sprint de dix secondes [7] et de quinze secondes [22]. ...
... Un entraînement spécifique de sprint de six mois n'apparaît pas en mesure de modifier cette réponse physiologique. Néanmoins, il apparaît nécessaire, tout comme il l'a été suggéré chez l'adulte [27,39], de corriger les concentrations plasmatiques de tous les substrats mesurés en fonction des VP lors d'exercices supramaximaux de ce type. ...
... Le pic de [La] pl est observé cinq minutes après l'exercice de sprint, en accord avec les études menées chez l'adulte avec des protocoles semblables [22,26]. Par ailleurs, les pics de lactate mesurées chez nos adolescents sont similaires à ceux retrouvés par Moussa et al. [27] chez des adultes non entraînés lors du même type d'effort. D'autres études notent également des valeurs maximales de lactate semblables à la suite de tests de sprint de dix secondes [7] et de quinze secondes [22] . ...
... Un entraînement spécifique de sprint de six mois n'apparaît pas en mesure de modifier cette réponse physiologique . Néanmoins, il apparaît nécessaire, tout comme il l'a été suggéré chez l'adulte [27,39], de corriger les concentrations plasmatiques de tous les substrats mesurés en fonction des VP lors d'exercices supramaximaux de ce type. ...
... Le pic de [La] pl est observé cinq minutes après l'exercice de sprint, en accord avec les études menées chez l'adulte avec des protocoles semblables [22,26]. Par ailleurs, les pics de lactate mesurées chez nos adolescents sont similaires à ceux retrouvés par Moussa et al. [27] chez des adultes non entraînés lors du même type d'effort. D'autres études notent également des valeurs maximales de lactate semblables à la suite de tests de sprint de dix secondes [7] et de quinze secondes [22] . ...
... Un entraînement spécifique de sprint de six mois n'apparaît pas en mesure de modifier cette réponse physiologique . Néanmoins, il apparaît nécessaire, tout comme il l'a été suggéré chez l'adulte [27,39], de corriger les concentrations plasmatiques de tous les substrats mesurés en fonction des VP lors d'exercices supramaximaux de ce type. ...
Article
Aim : The aim of this study was to investigate the effects of a 6-months sprint training program followed by 5 months of detraining on cycling peak performance and plasma volume variations after a 6-s cycle sprint in adolescent boys. Method : Twelve adolescent boys [training group (TG), n=6; control group (CG), n=6] were included in the present study. TG participated in 6 months of a supervised sprint training program (2-3 days/week) and has no training past, whereas CG continued with their normal activity. A 6s-sprint test on cycle ergometer was performed before training (P1) and after training (P2) in both groups. TG only performed a 6s-sprint test after 5 months of detraining (P3). Hematocrit (Ht) and plasma lactate concentration were assessed at rest, immediately after the warm-up and the 6s-sprint and after 5 and 20 minutes of recovery. Results : Cycling peak power expressed in absolute terms was significantly increased in the trained group (P<0.05) but did not change in CG. Plasma volume was significantly decreased after the warm-up and the sprint test in both groups after P1, P2 and only in TG after P3 (P<0.05). No significant differences were observed in VP and plasma lactate before and after training program in teenage boys. Conclusion : The present study showed that the training program did not affect the VP after a 6 s cycle sprint in adolescent boys.
... Sympatho-adrenergic activity is influenced by several factors, as exercise and training. In adult men, it has been shown that plasma A and NA concentrations increase markedly in response to intense exercise (Hartley et al. 1972; Zouhal et al. 1998; Moussa et al. 2003). Similarly, several studies have reported higher plasma A concentrations in response to maximal or supramaximal exercise in endurance or sprint trained subjects compared to untrained ones ( Zouhal et al. 2001; Jacob et al. 2004). ...
... The purpose of the present study was, therefore, to investigate the effect of a 6-month controlled sprint training program (3 times a week) followed by 5 months of detraining, on plasma A, NA and blood La in response to a 6 s-sprint on a cycle ergometer in adolescent girls without any training past. Adolescent girls performed a 6s-sprint test as this kind of exercise is known to induce a significant response of the sympatho-adrenal system (Moussa et al. 2003 ). Moreover, the sprinttraining program is essentially based on the repetition of short distances, running as fast as possible and did not exceed 10 s. ...
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Training is well known to influence catecholamine responses to exercise. In women, this training effect is still not well characterized and has been studied mostly in adults. Hence, we investigated in this longitudinal study, the effects of a 6-month sprint training program followed by 5 months of detraining on plasma catecholamine responses to a sprint exercise in young female subjects. Twelve healthy adolescent girls [ training group (TG), n=6; control group (CG), n=6] took part in our study. TG participated in 6 months of supervised sprint training program ( 3 days/week) and has no training past whereas, CG continued with it's normal activity. A 6s-sprint test was performed on a cycle ergometer before training (P1) and after training (P2) in both the groups. TG only realized a 6s-sprint test after 5 months of detraining (P3). Blood lactate concentrations ( La) as well as plasma adrenaline ( A) and noradrenaline (NA) concentrations were measured at rest, immediately after the warm-up and the 6s-sprint and during recovery. Peak power ((W) over dot peak), expressed both in absolute and relative values, were significantly increased in TG in P2 (P< 0.01) but did not change in CG. After the sprint-training period, the warm-up and the 6s-sprint induced plasma A increase and the maximal A concentrations were significantly higher than in P1 and P3 for TG only ( P< 0.05). Plasma A did not change in CG after 6 months. In P3, (W) over dot peak and maximal lactate concentrations ([La](max)) were significantly greater compared to P1 and P2 in TG ( P< 0.05). In CG, [ La] max were significantly increased in P2 ( P< 0.05). The present study demonstrates that 6 months of sprint training in adolescent girls induce both an increase in performances and in A responses to sprint exercise. This adrenergic adaptation disappears after 5 months of detraining whereas the gain in performance is maintained. These new data may lead to practical considerations.
... The invasive glycaemic monitoring techniques used in these pioneering studies (e.g., venous catheter) often limited the follow-up period [50] to a few hours postexercise. Due to the ease of use and affordability of CGM devices in the last 10 years [51], it has been possible to monitor the glycaemic response up to 24 h or more after exercise and, as identified by this systematic review and meta-analysis, the effects obtained are very different from those that may be expected. ...
Article
Background and Aims: Despite the crucial role of exercise in the prevention of comorbidities and complications in type 1 diabetes mellitus (T1DM), people living with the disease are often insufficiently physically active, mainly due to the fear of hypoglycaemia. Research using continuous glucose monitoring (CGM) devices has shown that exercise affects glycaemic control in T1DM for over 24 hours. The aim of this systematic review and meta-analysis is, therefore, to investigate the delayed effects of different exercise modalities on glycaemic control in adults with T1DM. Methods and Results: The literature search of experimental studies was conducted on PubMed, SPORTDiscus and EMBASE from January 2000 to September 2019. Twelve studies using CGM devices were included. Compared to endurance, intermittent exercise increased the time spent in hypoglycaemia (0.62, 0.07 to 1.18; standardised effect size, 95% CI) and reduced the mean interstitial glucose concentration (-0.88, -1.45 to -0.33). No differences emerged in the time spent in hyperglycaemia (-0.07, -0.58 to 0.45) or in the proportion of exercisers experiencing hypoglycaemic events (0.82, 0.45 to 1.49; proportion ratio, 95% CI) between conditions. The systematic review also found a reduced risk of hypoglycaemia if exercise is performed in the morning rather than in the afternoon, and with a 50% rapid-acting insulin reduction. It was not possible to determine the benefits of resistance exercise. Conclusions: For the first time, we systematically investigated the delayed effect of exercise in adults with T1DM, highlighted undetected effects, shortcomings in the existing literature, and provided suggestions to design future comparable studies. Keywords: Exercise; Type 1 diabetes; Glycaemic control; Hypoglycaemia, Continuous Glucose Monitoring.
... Previous study on assessing of alactic anaerobic power, conducted on top Congolese team players (volleyball, basketball, football), indicated also a link between WA n T and football performance [13]. In addition, the international literature indicates that during the WA n T lactate concentrations increase notably at the immediate end of the effort continues to increase after 2 minutes postexercise recovery [14,15]; these changes, which cannot be modified for glycemia [16], are also noted for pyruvates [9]. However, a difference is observed between lactates and pyruvates, lactates whose dissociation constant is lower diffusing faster than pyruvates [17]. ...
... Previous research suggested that intensive physical stress affects PV and hematological parameters, which may negatively influence players' physical performance [8,9]. Variation in PV and the parameters associated with it is considered an important form of body fluid adaptation in response to different training loads [10] and exercise intensity [11]. For example, Hb values determine the oxygen transport and consumption [12], which is linked to physical performance through aerobic capacity [13]. ...
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Objectives The aims of this study were to investigate the effects of a six-week in-season period of soccer training and games (congested period) on plasma volume variations (PV), hematological parameters, and physical fitness in elite players. In addition, we analyzed relationships between training load, hematological parameters and players’ physical fitness. Methods Eighteen elite players were evaluated before (T1) and after (T2) a six-week in-season period interspersed with 10 soccer matches. At T1 and T2, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). In addition, PV and hematological parameters (erythrocytes [M/mm³], hematocrit [%], hemoglobin [g/dl], mean corpuscular volume [fl], mean corpuscular hemoglobin content [pg], and mean hemoglobin concentration [%]) were assessed. Daily ratings of perceived exertion (RPE) were monitored in order to quantify the internal training load. Results From T1 to T2, significant performance declines were found for the YYIR1 (p<0.001, effect size [ES] = 0.5), RSSA (p<0.01, ES = 0.6) and SJ tests (p< 0.046, ES = 0.7). However, no significant changes were found for the CMJ (p = 0.86, ES = 0.1). Post-exercise, RSSA blood lactate (p<0.012, ES = 0.2) and PV (p<0.01, ES = 0.7) increased significantly from T1 to T2. A significant decrease was found from T1 to T2 for the erythrocyte value (p<0.002, ES = 0.5) and the hemoglobin concentration (p<0.018, ES = 0.8). The hematocrit percentage rate was also significantly lower (p<0.001, ES = 0.6) at T2. The mean corpuscular volume, mean corpuscular hemoglobin content and the mean hemoglobin content values were not statistically different from T1 to T2. No significant relationships were detected between training load parameters and percentage changes of hematological parameters. However, a significant relationship was observed between training load and changes in RSSA performance (r = -0.60; p<0.003). Conclusions An intensive period of “congested match play” over 6 weeks significantly compromised players’ physical fitness. These changes were not related to hematological parameters, even though significant alterations were detected for selected measures.
... PV variations are considered a form of body fluid adaptation in response to several factors such as age (Berthoin et al. 2003), training level (Moussa et al. 2003) and exercise intensity (El-Sayed et al. 2011). Several investigators (Leaf 1984;Phillips et al. 1984) have observed that by aging individuals have difficulty maintaining body fluid balance, contributing to fluctuations in PV. ...
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Plasma volume (PV) is affected by several factors including age, physical train- ing and, acutely, by exercise intensity. The purpose of this study was to inves- tigate the effects of 6 weeks of high-intensity interval training (HIT) on PV and blood pressure (BP) changes among sedentary individuals. Thirty subjects aged between 18 and 71 years [body mass index=30.1(1.2) kg/m2] completed a 6-weeks HIT program. Anthropometric and fitness variables were obtained at pre- and post- HIT. PV variations during warm-up and after supramaximal cycling test (SCT) were calculated using two methods based on Hematocrit (Ht) and Hemoglobin (Hb) measures. After both the warm-up and SCT, PV decreased significantly among participants at pre- and at post-HIT (P < 0.01). However, PV decreases were significantly greater at pre-HIT compared with post-HIT during warm-up and after SCT (P < 0.01, respectively). In addition, at pre-HIT, a positive relationship was found between age and both PV varia- tions at warm-up and after SCT (r2 = 0.55 and r2 = 0.46; P < 0.01 respec- tively). However, no relationship was found during the post-HIT period. After SCT and after both visits, only body weight predicted 22% of PV variations. In the current study, a significant relationship was found between systolic and diastolic BP improvements and PV variations in post-HIT (r2 = 0.54 and r2=0.56, P < 0.05, respectively). Our results suggest that HIT may improve PV values and reduce the effects of age on the decrease in PV. These interventions led to improvements in systolic and diastolic BP values among participants.
... <5%) and a small coefficient of variation (CV; <5%). Similar testing procedures have been used in numerous studies involving normal weight adolescent [46], young adults [47][48][49], and middle-aged men [32,[50][51][52][53]. The standard WAnT procedure has limitations because factors such as i) active muscle mass volume and ii) exercise bioenergetics tend to alter maximal power output (Pmax) (for review see Driss and Vanderwalle [54]. ...
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The aim of this investigation was to compare serum growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) in response to a combined sprint and resistance training (CSRT) program in young and middle-aged men.Thirty-eight healthy, moderately trained men participated in this study. Young and middle-aged men were randomly assigned to, a young training group (YT = 10, 21.4±1.2yrs) ora young control group (YC = 9, 21.6±1.8 yrs), a middle-aged training group (MAT = 10, 40.4±2.1 yrs) or a middle-aged control group (MAC = 9, 40.5±1.8 yrs). Participants performed the Wingate Anaerobic Test (WAnT) before and after a 13-week CSRT program (three sessions per week). Blood samples were collected at rest, after warm-up, immediately post-WAnT, and 10 min post-WAnT. CSRT induced increases in GH at rest and in response to the WAnT in YT and MAT (P<0.05). CSRT-induced increases were observed for IGF-1 and IGFBP-3 at rest in MAT only (P<0.05). Pre-training, GH, IGF-1 and IGFBP-3 were significantly higher at rest and in response to the WAnT in young participants as compared to their middle-aged counterparts (P<0.05). Post-training, YT and MAT had comparable basal GH (P>0.05). In response to the WAnT, amelioration of the age-effect was observed between YT and MAT for IGF-1 and IGF-1/IGFBP-3 ratio following CSRT (P>0.05). These data suggest that CSRT increases the activity of the GH/IGF-1 axis at rest and in response to the WAnT in young and middle-aged men. In addition, CSRT reduces the normal age-related decline of somatotropic hormones in middle-age men.
... It is noteworthy that not all forms of exercise increase the risk of hypoglycaemia in T1DM individuals. In both T1DM and non-T1DM individuals, it has been shown that engaging in intense aerobic exercise (≥ 80% VO 2 max) while under a basal insulinaemic state results in a significant rise in blood glucose levels (Brooks et al., 1990;Harmer et al., 2008;Kindermann et al., 1982;Lavoie et al., 1987;Marliss and Vranic, 2002;Moussa et al., 2003;Schnabel et al., 1984;Wahren and Ekberg, 2007). This glycaemiaincreasing effect of high-intensity exercise results, in part, from the exercise-mediated rise in catecholamine levels causing a disproportionate increase in hepatic glucose production rate relative to the rise in the rate of muscle glucose utilisation (Kreisman et al., 2003;Marliss and Vranic, 2002;Purdon et al., 1993;Sigal et al., 1999). ...
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Background: Performing a 10-sec sprint immediately before or after moderate intensity exercise or performing 4-sec sprints every two min during moderate intensity exercise prevents blood glucose level from falling in response to exercise in individuals with type 1 diabetes mellitus (T1DM). Purpose: Since these findings were obtained in controlled laboratory conditions, the aims of this pilot study were to test the hypothesis that these benefits may also hold true in free-living conditions, and to test the suitability of our study design for a large randomised control trial. Methods: Participants with T1DM (n=7) were required to incorporate for 2 weeks either repeated 4-second sprints at least every 2 min or repeated 10-second sprints every 20 min into their normal preferred modality of sustained exercise. The effectiveness of these protocols at reducing hypoglycaemia risk was compared to participants’ normal activity. Results: Hypoglycaemia risk was not affected by the incorporation of either sprint protocol (p>0.05) compared to the participants’ preferred exercise modality. However, given the small sample size, that a number of factors known to affect blood glucose response to exercise were not matched between conditions (e.g. duration, intensity and timing of exercise, and pre-exercise insulin and blood glucose levels), and some compliance issues with our protocols, our findings must be taken with caution. Conclusion: The effectiveness of including repeated maximal sprints to sustained exercise as a means to prevent hypoglycaemia under free-living conditions could not be conclusively addressed in this study due to limitations with sample size, study design and compliance issues.
... Catecholamine concentrations are influenced by several factors in athletes such as exercise characteristics, duration of exercise, training status and gender [14][15][16][17]. However, published data are conflicting maybe due to the lack of an approach to evaluate complex hormonal responses. ...
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Objective: Our objective was to evaluate complex hormonal response in ball game and cyclic sport elite athletes through an incremental treadmill test, since, so far, variables in experimental procedures have often hampered comparisons of data. Methods: We determined anthropometric data, heart rate, maximal oxygen uptake, workload, plasma levels of lactate, adrenaline, noradrenaline, dopamine, cortisol, angiontensinogen and endothelin in control (n = 6), soccer (n = 8), handball (n = 12), kayaking (n = 9) and triathlon (n = 9) groups based on a Bruce protocol through a maximal exercise type of spiroergometric test. Results: We obtained significant increases for adrenaline, 2.9- and 3.9-fold by comparing the normalized means for soccer players and kayakers and soccer players and triathletes after/before test, respectively. For noradrenaline, we observed an even stronger, three-time significant difference between each type of ball game and cyclic sport activity. Conclusions: Exercise related adrenaline and noradrenaline changes were more pronounced than dopamine plasma level changes and revealed an opportunity to differentiate cyclic and ball game activities and control group upon these parameters. Normalization of concentration ratios of the monitored compounds by the corresponding maximal oxygen uptake reflected better the differences in the response level of adrenaline, noradrenaline, dopamine and cortisol.
... Studies on LA time course following judo match showed bi-phase changes (risedrop), and that dynamics within the period from +1 to +15 minutes is the best fitted by an equation of the parabola [2], but for longer recovery period (0.5h) that way of approximation is not adequate. The LA behavior in blood were recorded after various supra-maximal exertions including classic Wingate (30s) test [3][4][5][6][7][8][9][10][11]. An alternative to parabola approximation non-linear curves was proposed by other authors. ...
... La concentration de lactate dans le sang représente alors un index indirect du degré de sollicitation de la glycogénolyse musculaire (Cheetham et al. 1986 ). Par ailleurs, il est aussi bien admis que les catécholamines , l'adrénaline (A) et la noradrénaline (NA), en favorisant la glycogénolyse musculaire, sont susceptibles de jouer un rôle majeur dans la performance a ` l'exercice bref et intense (Sigal et al. 1994). Une e ´lévation significative des concentrations en catécholamines est ainsi observée en association avec une forte augmentation de la lactatémie chez des hommes en réponse a ` un exercice de sprint de 6 s sur ergocycle (Moussa et al. 2003 ) mais aussi chez des femmes , lors d'une e ´preuve de Wingate (Vincent et al. 2003). De plus, dans beaucoup d'e ´tudes, des relations significatives sont observées entre ces deux derniers paramètres et les performances a ` l'exercice de sprint (Brooks et al. 1988; Collomp et al. 1991). ...
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Lobjectif de cette tude est de vrifier si la phase du cycle menstruel influence les rponses en catcholamines (adrnaline (A) et noradrnaline (NA)) ainsi que les puissances pic (Ppic) et la lactatmie pic (Lapic) lissue dun exercice de sprint de 6 s sur ergocycle chez huit femmes non entranes (19,1 0,9 ans, 167,7 5,4 cm, 59,5 4,7 kg). Lexercice est ralis le matin, lors du mme cycle menstruel, en phase folliculaire (PF) puis en phase lutale (PL). Les concentrations plasmatiques en A et NA sont mesures au repos (A0 et NA0), la fin de lexercice de sprint de 6 s (AEX et NAEX) et aprs 5min de rcupration (A5 et NA5). Ppic ainsi que Lapic ne diffrent pas statistiquement entre PF et PL. Les concentrations en A et en NA mesures au repos, larrt du test de sprint et aprs 5min de rcupration ne diffrent pas significativement entre PF et PL. Des relations significatives sont observes entre AEX et Lapic (r = 0,53; p < 0,01) et entre AEX et Ppic (r = 0,70; p < 0,01) lors des deux phases du cycle. En conclusion, cette tude montre que chez des femmes non entranes, la phase du cycle menstruel ninfluence ni la performance, ni la lactatmie, ni la rponse sympatho-adrnergique lexercice de sprint court.
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Physical activity highly impacts the neuroendocrine system and hormonal secretion. Numerous variables, both those related to the individual, including genetics, age, sex, biological rhythms, nutritional status, level of training, intake of drugs or supplements, and previous or current pathologies, and those related to the physical activity in terms of type, intensity, and duration of exercise, or environmental conditions can shape the hormonal response to physical exercise. The aim of this review is to provide an overview of the effects of physical exercise on hormonal levels in the human body, focusing on changes in concentrations of hormones such as cortisol, testosterone, and insulin in response to different types and intensities of physical activity. Regular monitoring of hormonal responses in athletes could be a potential tool to design individual training programs and prevent overtraining syndrome.
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Background and Aim: Inactivity increases the risk of chronic diseases. The aim of the present study was to investigate the acute changes in Normetanephrine and glucose in boxing with Kinect Xbox with and without blood flow restriction as an alternative to aerobic exercise during quarantine in young non-athletes. Material and Methods: Fourteen healthy non-athlete individuals with a range of 20 to 40 years of age were randomly and purposefully selected. And on two different days with and without restriction of blood flow, they played boxing with Xbox 360 for 20 minutes. Blood samples were taken before and immediately after Results: There was a significant increase in serum Normetanephrine playing compared to before the test in both training groups, but the amount of changes between the two groups with and without blood flow restriction was not significant (P≤0.05). Exergames, in the case of unrestricted blood flow, has a significant effect on glucose, but the restriction of blood flow did not lead to a significant difference in the amount of glucose (P≤0.05). Conclusion: Exergames provide the necessary stimulus for catecholamine secretion and glucose response, and it is recommended for people with limited blood flow. Further studies are needed on the effect of restricting blood flow as a new training method on video game with movement.
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Catecholamines play an important role in a number of bodily functions such as metabolism of carbohydrates and lipids. Any change in the quantity of the hormones has negative effect on the performance of athletes. Fourteen young athletes participated in this study. The participants took Bruce Test with an average of 16.05 minutes and were totally exhausted. Four blood samples were taken. The results of the sample tests were analyzed by using paired sample t-test and repeated measures. The results showed that exhaustive aerobic exercises significantly increase Epinephrine (E) (P = 0.0001) and Norepinephrine (NE) (P = 0.01). The results also showed that the increase for norepinephrine continued two days after physical exercise. It seems that Catecholamines react differently to physical exercises and might be influenced by the psychological state of the athlete before the exercise and the duration and intensity of the exercise.
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Catecholamines play an important role in a number of bodily functions such as metabolism of carbohydrates and lipids. Any change in the quantity of the hormones has negative effect on the performance of athletes. Fourteen young athletes participated in this study. The participants took Bruce Test and ran on the treadmill with an average of 16.05 minutes and were totally exhausted. Four blood samples were taken. The first sample served as a pretest and the second sample was taken after Bruce test. The third and fourth samples were taken one day and two days after the Bruce test, respectively. The results of the sample tests were analyzed by using paired sample t-test and repeated measures. The results showed that extreme exhaustive aerobic exercises significantly increase Epinephrine (E) (P = 0.0001) and Norepinephrine (NE) (P = 0.01). The results also showed that the increase for norepinephrine continued two days after physical exercise. It seems that Catecholamines react differently to physical exercises and might be influenced by the psychological state of the athlete before the exercise and the duration and intensity of the exercise. The amount of increase in the epinephrine and norepinephrine seem to contribute to the better athletic performance because these two hormones perhaps have a positive effect on cardiovascular system and metabolism.
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Introduction: Effects of Phenotypic changes in adipose tissue due to training are a new theory. However, the cellular - molecular mechanisms for these phenotypic changes are not yet clearly understood. The purpose of the study was to determine the effect of high intensity interval training (HIIT) and Pilates on levels of Irisin and Insulin resistance in overweight women.
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IntroductionThe purpose of this study was to evaluate the effect of sprint training on plasma catecholamine concentrations in response to a-6 second-sprint exercise in adolescent boys (GE). Moreover, to judge of the respective effects of training and pubertal maturation, we proposed the same protocol to a control group of adolescents (GT).
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Context: Recently we showed that a 10-sec maximal sprint effort performed before or after moderate intensity exercise can prevent early hypoglycemia during recovery in individuals with type 1 diabetes mellitus (T1DM). However, the mechanisms underlying this protective effect of sprinting are still unknown. Objective: The objective of the study was to test the hypothesis that short duration sprinting increases blood glucose levels via a disproportionate increase in glucose rate of appearance (Ra) relative to glucose rate of disappearance (Rd). SUBJECTS AND EXPERIMENTAL DESIGN: Eight T1DM participants were subjected to a euglycemic-euinsulinemic clamp and, together with nondiabetic participants, were infused with [6,6-(2)H]glucose before sprinting for 10 sec and allowed to recover for 2 h. Results: In response to sprinting, blood glucose levels increased by 1.2 ± 0.2 mmol/liter (P < 0.05) within 30 min of recovery in T1DM participants and remained stable afterward, whereas glycemia rose by only 0.40 ± 0.05 mmol/liter in the nondiabetic group. During recovery, glucose Ra did not change in both groups (P > 0.05), but glucose Rd in the nondiabetic and diabetic participants fell rapidly after exercise before returning within 30 min to preexercise levels. After sprinting, the levels of plasma epinephrine, norepinephrine, and GH rose transiently in both experimental groups (P < 0.05). Conclusion: A sprint as short as 10 sec can increase plasma glucose levels in nondiabetic and T1DM individuals, with this rise resulting from a transient decline in glucose Rd rather than from a disproportionate rise in glucose Ra relative to glucose Rd as reported with intense aerobic exercise.
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Visfatin is a newly characterized protein that is highly expressed in visceral adipose tissue and may play a role in insulin resistance. We investigated the effects of repeated short bouts of high-intensity exercise on plasma visfatin and related metabolic responses. Six young, physically fit men (22.8 +/- 2.3 years; 78.5 +/- 2.3 kg; and body mass index 22.1 +/- 1.2) performed a single session of a running-based anaerobic sprint exercise (7 sets of 6 x 35 m every 10 s, with 1 min rest between sets). Venous blood samples were collected before, immediately after, and 45 and 90 min after exercise to assess plasma visfatin, insulin, glucose, lactate and glutathione responses. After adjustment for postexercise changes in plasma volume, the data indicate a significant increase in plasma visfatin (12.5 +/- 2.0 vs. 26.6 +/- 3.9 ng/ml, p < 0.02), insulin (p < 0.05), and glucose (p < 0.002) concentrations, and homeostasis model assessment of insulin resistance (p < 0.02), immediately after the exercise session. At 45 min of recovery, all metabolic measures, with the exception of lactate, had returned to baseline levels. The elevation in plasma visfatin, together with increased plasma glucose and insulin concentrations immediately after high-intensity exercise, may sensitize tissues for postexercise glucose uptake and glycogen restoration. Our results also support a temporary and early postexercise anorexigenic metabolic state.
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The ergogenic effect of arginine has been demonstrated in research focusing on its intake before exercise. However, in these studies, the effect of arginine in combination with other various metabolites were assessed. The aim of this study was to determine whether a single oral intake of arginine, without any other compounds, 60 minutes prior to exercise, modifies performance and exercise metabolism during a repeated Wingate anaerobic test. Six healthy, active, but not highly trained volunteers participated in the study. Subjects performed three 30s all-out supramaximal Wingate Anaerobic Tests (WAnTs) with 4 minute-interval rest periods between WAnTs. Arginine ingestion before exercise did not influence physical performance. Triple WAnTs resulted in a marked increase in white blood cell (WBC) count, lactate and ammonia concentrations, however there were no differences between arginine and the placebo trials. Our data indicated that 2 g of arginine ingested in a single dose, neither induced nitrite/nitrate (NOx) concentrations changes, nor improved physical performance.
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The purpose of this study was to investigate the effects of a 6-month sprint training program on plasma androgens and catecholamine (CA) concentrations in response to a 6 s sprint in adolescent boys [training group (TG), n=6; control group (CG), n=6]. A 6 s-sprint test was performed on a cycle ergometer before and after training (Pre-T and Post-T, respectively). Plasma total testosterone (TT), bioavailable testosterone (BT), and CA concentrations were measured at rest, after a warm-up, immediately after a 6 s-sprint, and during the recovery (i. e. 5 and 20 min). After training period, plasma TT concentrations increased significantly at the end of the sprint and during the recovery in the TG. No effects for sampling times and period were observed in BT levels. Plasma TT concentrations after 5 min of recovery were positively correlated with the corresponding values of plasma lactate (La) concentrations and with post-6 s-sprint plasma adrenaline (A) concentrations (r=0.52; p<0.01 and r=0.61; p<0.01, respectively). These results suggest that sprint training increases plasma TT concentrations in response to sprint exercise in adolescent boys. Plasma A and plasma La concentrations increases in response to sprint exercise could be involved in this elevation of plasma TT concentrations.
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The influence of gender on the glucose response to exercise remains contradictory. Moreover, to our knowledge, the glucoregulatory responses to anaerobic sprint exercise have only been studied in male subjects. Hence, the aim of the present study was to compare glucoregulatory metabolic (glucose and lactate) and hormonal (insulin, catecholamines and estradiol only in women) responses to a 30-s Wingate test, in physically active students. Eight women [19.8 (0.7) years] and eight men [22.0 (0.6) years] participated in a 30-s Wingate test on a bicycle ergometer. Plasma glucose, insulin, and catecholamine concentrations were determined at rest, at the end of both the warm-up and the exercise period and during the recovery (5, 10, 20, and 30 min). Results showed that the plasma glucose increase in response to a 30-s Wingate test was significantly higher in women than in men [0.99 (0.15) versus 0.33 (0.20) mmol l(-1) respectively, P<0.05]. Plasma insulin concentrations peaked at 10 min post-exercise and the increase between this time of recovery and the end of the warm-up was also significantly higher in women than in men [14.7 (2.9) versus 2.3 (1.9) pmol l(-1) respectively, P<0.05]. However, there was no gender difference concerning the catecholamine response. The study indicates a gender-related difference in post-exercise plasma glucose and insulin responses after a supramaximal exercise.
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The purpose of this study was to clarify the effect of sex on plasma catecholamine responses to sprint exercise in adolescents and adults. Thirty-six untrained participants took part in this study-9 girls and 10 boys (Tanner Stage 4) and 9 women and 8 men. Each participant performed a 6-s sprint test on a cycle ergometer. Plasma adrenaline (A) and noradrenaline (NA) concentrations were determined successively at rest (A0 and NA0), immediately after the 6-s sprint test (AEX and NAEX), and after 5 min of recovery (A5 and NA5). Peak power, expressed in absolute values or relative to body weight and fat-free mass, was significantly higher in boys than in girls and higher in men than in women (p < .001). No sex effect was observed in AEX in the adolescents, but the NA increase was significantly higher in boys in response to the 6-s sprint (p < .05). In adults, no sex difference was found in NAEX, but AEX was significantly higher in men than in women (p < .05). NAEX was significantly higher in women than in girls (p < .05), and AEX was significantly higher in men than in boys (p < .01). The results of this study suggest that male and female adolescents and young adults might exhibit different catecholamine responses to sprint exercise.
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Stress hormones, adrenaline (epinephrine) and noradrenaline (norepinephrine), are responsible for many adaptations both at rest and during exercise. Since their discovery, thousands of studies have focused on these two catecholamines and their importance in many adaptive processes to different stressors such as exercise, hypoglycaemia, hypoxia and heat exposure, and these studies are now well acknowledged. In fact, since adrenaline and noradrenaline are the main hormones whose concentrations increase markedly during exercise, many researchers have worked on the effect of exercise on these amines and reported 1.5 to >20 times basal concentrations depending on exercise characteristics (e.g. duration and intensity). Similarly, several studies have shown that adrenaline and noradrenaline are involved in cardiovascular and respiratory adjustments and in substrate mobilization and utilization. Thus, many studies have focused on physical training and gender effects on catecholamine response to exercise in an effort to verify if significant differences in catecholamine responses to exercise could be partly responsible for the different performances observed between trained and untrained subjects and/or men and women. In fact, previous studies conducted in men have used different types of exercise to compare trained and untrained subjects in response to exercise at the same absolute or relative intensity. Their results were conflicting for a while. As research progressed, parameters such as age, nutritional and emotional state have been found to influence catecholamine concentrations. As a result, most of the recent studies have taken into account all these parameters. Those studies also used very well trained subjects and/or more intense exercise, which is known to have a greater effect on catecholamine response so that differences between trained and untrained subjects are more likely to appear. Most findings then reported a higher adrenaline response to exercise in endurance-trained compared with untrained subjects in response to intense exercise at the same relative intensity as all-out exercise. This phenomenon is referred to as the ‘sports adrenal medulla’. This higher capacity to secrete adrenaline was observed both in response to physical exercise and to other stimuli such as hypoglycaemia and hypoxia. For some authors, this phenomenon can partly explain the higher physical performance observed in trained compared with untrained subjects. More recently, these findings have also been reported in anaerobic-trained subjects in response to supramaximal exercise. In women, studies remain scarce; the results are more conflicting than in men and the physical training type (aerobic or anaerobic) effects on catecholamine response remain to be specified. Conversely, the works undertaken in animals are more unanimous and suggest that physical training can increase the capacity to secrete adrenaline via an increase of the adrenal gland volume and adrenaline content.
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We have studied the effects of the braking force on the results of an anaerobic capacity test derived from the Wingate test (an all out 45 s exercise on a Monark 864 cycle ergometer against a given force at the fastest velocity from the beginning to the end of the test). Seven men and seven women participated in the study and performed a total of 63 all-out tests against different braking forces. The same subjects performed a force-velocity test on the same cycle ergometer. Since the relationship between force and velocity is approximately linear for peak velocities between 100 and 200 rev X min-1 (Pérès et al. 1981a, b; Nadeau et al. 1983; Vandewalle et al. 1983) we characterized each subject by three parameters: P0 (the intercept of the force-velocity regression line with the force axis), V0 (the intercept of the regression line with the velocity axis) and Wmax (maximal power). The relationship between force and mean power was parabolic for the all-out anaerobic capacity test. In the present study the optimal force (the force giving the maximal value of mean power during an all out test) was higher for the men (approximately 1 N X kg BW-1) than the force proposed by others (0.853 N X kg BW-1 for Dotan and Bar-Or 1983). However, because of the parabolic relationship between force and mean power, the mean power which corresponds to the optimal force was approximately the same in both studies.(ABSTRACT TRUNCATED AT 250 WORDS)
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A study was performed to determine reference ranges for whole body plethysmographic gas volumes and single breath gas transfer in healthy prepubertal and pubertal schoolchildren. The study was performed in 772 white London schoolchildren (455 male) who were clinically examined, assessed auxologically and, in 63% of cases, pubertally staged. Regression equations for the calculation of standard deviation scores were derived. Male lung function variables showed a discontinuous pattern of increase with standing height. Linear increases until puberty were followed by a sudden pubertal rise and a further increase with height which was more marked than before puberty. Correction for varying thoracic dimensions eliminated these changes. In females a smoother curvilinear relationship was observed with no correction possible for thoracic size. Male puberty leads to profound changes in pulmonary function mostly related to thoracic size, an effect not observed in females.
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The purpose of the present study was to examine the growth hormone (GH) response to treadmill sprinting in male (M) and female (F) sprint- and endurance-trained athletes. A group of 11 sprint-trained (ST; 6M, 5F) and 12 endurance-trained (ET; 6M, 6F) athletes performed a maximal 30-s sprint on a nonmotorized treadmill. Peak power and mean power expressed in watts or in watts per kilogram body mass were higher in ST than in ET (P < 0.01) and in the men compared to the women (P < 0.01). Serum GH was greater in ST than in ET athletes, but was not statistically significantly different between the men and the women [mean peak GH: ST 72.4 (SEM 12.5) compared to ET 26.3 (SEM 4.9) mU.1(-1), P < 0.01; men 59.8 (SEM 13.3) compared to the women 35.8 (SEM 7.4) mU.1(-1), n.s.]. Plasma ammonia and blood lactate concentrations were higher and blood pH lower during 1 h of recovery after the sprint in ST compared to ET (all P < 0.01). Multiple log linear regression showed that 82% of the variation in the serum peak GH response was explained by the peak power output and peak blood lactate response to the sprint. As serum GH was still approximately ten times the basal value in ST athletes after 1 h of recovery, it is suggested that the exercise-induced increase in GH could have important physiological effects in this group of athletes, including increased protein synthesis and sparing of protein degradation leading to maintained or increased muscle mass.
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We investigated metabolic and hormonal responses during repeated bouts of brief and intense exercise (a force-velocity test; Fv test) and examined the effect of glucose ingestion on these responses and on exercise performance. The test was performed twice by seven subjects [27 (2) years] according to a double-blind randomized crossover protocol. During the experimental trial (GLU), the subjects ingested 500 ml of glucose polymer solution containing 25 g glucose 15 min before starting the exercise. During the control trial (CON), the subjects received an equal volume of sweet placebo (aspartame). Exercise performance was assessed by calculating peak anaerobic power ( W˙ an,peak). Venous plasma lactate concentration increased significantly during the Fv test (P < 0.001), but no difference was found between CON and GLU. Blood glucose first decreased significantly from the beginning of exercise up to the 6-kg load (P < 0.001) and then increased significantly at W˙ an,peak and for up to 10 min during the recovery period (P < 0.001) in both CON and GLU. Insulin concentrations decreased significantly in both groups, but were higher at W˙ an,peak in GLU compared with CON (P < 0.05). Glucagon and epinephrine did not change significantly in either group, but epinephrine was significantly lower in GLU after glucose ingestion (P < 0.05) and at W˙ an,peak (P < 0.05). W˙ an,peak was not significantly different between CON and GLU. In conclusion, blood glucose and insulin concentrations decreased during repeated bouts of brief and intense exercise, while blood lactate concentration increased markedly without any significant change in glucagon and epinephrine concentrations. Glucose ingestion altered metabolic and hormonal responses during the Fv test, but the performance as measured by W˙ an,peak was not changed.
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The Third National Health and Nutrition Examination Survey (NHANES III) reference is currently recommended for interpreting spirometry results, but it is limited by the lack of subjects younger than 8 years and does not continuously model spirometry across all ages. By collating pediatric data from other large-population surveys, we have investigated ways of developing reference ranges that more accurately describe the relationship between spirometric lung function and height and age within the pediatric age range, and allow a seamless transition to adulthood. Data were obtained from four surveys and included 3,598 subjects aged 4-80 years. The original analyses were sex specific and limited to non-Hispanic white subjects. An extension of the LMS (lambda, mu, sigma) method, widely used to construct growth reference charts, was applied. Measurements and Main Results: The extended models have four important advantages over the original NHANES III analysis as follows: (1) they extend the reference data down to 4 years of age, (2) they incorporate the relationship between height and age in a way that is biologically plausible, (3) they provide smoothly changing curves to describe the transition between childhood and adulthood, and (4) they highlight the fact that the range of normal values is highly dependent on age. The modeling technique provides an elegant solution to a complex and longstanding problem. Furthermore, it provides a biologically plausible and statistically robust means of developing continuous reference ranges from early childhood to old age. These dynamic models provide a platform from which future studies can be developed to continue to improve the accuracy of reference data for pulmonary function tests.
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Previous studies of pulmonary diffusing capacity in healthy children primarily focused upon Caucasian (C) subjects. Since lung volumes in African-Americans (AA) are smaller than lung volumes in C subjects of the same height, diffusing capacity values in AA children might be interpreted as low or abnormal using currently available equations without adjusting for race. Healthy AA (N = 151) and C (N = 301) children between 5 and 18 years of age performed acceptable measurements of single breath pulmonary diffusing capacity for carbon monoxide (DLCO ) and alveolar volume (VA ) according to current ATS/ERS guidelines. The natural log of DLCO and VA were associated with height, gender, age, and race; AA children had lower DLCO and VA compared to C children. Adjustment of DLCO for Hemoglobin (Hgb) resulted in no significant difference in DLCO among these healthy subjects with normal Hgb. In summary, we report prediction equations for DLCO and VA that include adjustment for race (C; AA) demonstrating that AA have lower DLCO and VA compared to C children for the same height, gender, and age. Pediatr Pulmonol. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
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Previous studies of pulmonary diffusing capacity in children differed greatly in methodologies; numbers of subjects evaluated, and were performed prior to the latest ATS/ERS guidelines. The purpose of our study was to establish reference ranges for the diffusing capacity to carbon monoxide (DLCO) and alveolar volume (VA) in healthy Caucasian children using current international guidelines and contemporary equipment. Healthy children from the United States (N = 303) and from Australia (N = 176) performed acceptable measurements of single breath pulmonary diffusing capacity and alveolar volume according to current ATS/ERS guidelines. The natural log of DLCO and VA were associated with height, age and an age–sex interaction term, while DLCO/VA was related to height and the age–sex interaction term only. Adjustment of DLCO for hemoglobin (n = 303; USA data only) resulted is a small but significant decrease in DLCO of ∼1% but did not significantly alter the regression equations. In this dataset there was no influence of center for DLCO or DLCO/VA, while Australian children had a statistically smaller VA (mean difference 0.14 L after accounting for height, age and age–sex; P = 0.012). We report that diffusing capacity outcomes can be collated from multiple centers using similar equipment and collection protocols. Using collated data we have derived regression equations for pulmonary diffusing capacity outcomes in healthy Caucasian children aged 5–19 years. Pediatr Pulmonol. 2012; 47:469–475.
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Since populations evolve, measurement protocols and equipment improve and analysis techniques progress, there is an ongoing need to reassess reference data for pulmonary function tests. Furthermore, reference values for total lung capacity and carbon monoxide diffusion capacity are scarcely available in children. We aimed to provide updated reference equations for most commonly used pulmonary function indices in Caucasian children. In the 'Utrecht Pulmonary Function Reference Data Study' we collected data in Caucasian children aged 2-18 years. We analyzed them using the 'Generalized Additive Models for Location Scale and Shape' (GAMLSS) statistical method. Measurements of interrupter resistance (R(int)) (n = 877), spirometry (n = 1042), body plethysmography (n = 723) and carbon monoxide diffusion/helium dilution (n = 543) were obtained in healthy children. Height (or the natural logarithm of height) and age (or the natural logarithm of age) were both significantly related to most outcome measures. Also sex was a significant determinant, except for RV, RV/TLC, FRC(pleth), Raw(0,5), Raw(tot), R(int) and FEF values. The application of previously published reference equations on the study population resulted in misinterpretation of pulmonary function. These new paediatric reference equations provide accurate estimates of the range of normality for most commonly used pulmonary function indices, resulting in less underdiagnosis and overdiagnosis of pulmonary diseases.
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We analyzed six spirometric data sets collected in the Netherlands, Austria, the United Kingdom, Spain, and Italy. The objectives were to establish whether (1) it was possible to describe spirometric indices from childhood to adulthood, taking into account the adolescent growth spurt, and (2) there are systematic differences in ventilatory function between children and adolescents in different parts of Western Europe. The study comprised 2,269 girls and 3,592 boys, aged 6–21 years. The range in standing height was 110–185 in girls, 110–205 in boys. The model applicable to all data sets was In FVC or In FEV1 = a + (b + c · A)· H, where H = standing height and A = age; this model prevents the phase shift between the adolescent growth spurt in length and lung volume from leading to an age-dependent bias in predicted values. There was surprising agreement between most of the data sets; systematic differences are probably due to technical factors arising from ATPS-BTPS corrections and from defining the end of breath with pneumotachometer systems. Taking those into account, prediction equations for FVC, FEV1, and FEV1%FVC were developed with “lower limits of normal” which should be applicable to children and adolescents of European descent. It is proposed that the approach of analyzing available data sets should also be applied to other ventilatory indices, data collected in adults and elderly subjects, or in other ethnic groups, and that an international data base be set up to that end. © 1995 Wiley-Liss, Inc.
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Plethysmographic measurement is the most reliable method for evaluating lung volumes in children. Current published normative data are based on studies in primarily Caucasian children. To establish Chilean normal values with new reference equations and to compare these results with previously published data. Lung function was measured [slow vital capacity (SVC), inspiratory capacity (IC), expiratory reserve volume (ERV), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), and RV/TLC] in 245 healthy Chilean school children and adolescents, using spirometry and plethysmography; 123 girls and 122 boys were studied, aged 7-18 years. Almost all variables of pulmonary volume differed between boys and girls (P < 0.05). Z scores were significantly higher than zero in all age groups when compared with predicted values. We present predictive exponential equations for each variable of static lung volume; all of these variables had a strong correlation with height, but not weight. Normal values of lung volumes of Chilean school children and adolescents are significantly higher than the current predictive values. These differences may be related to differences in anthropometric characteristics. We recommend using these data in our population and postulate that Latin-American populations like ours may have similar lung volumes.
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Ten prepubertal boys performed 60-min cycle exercise at about 60% of their maximal oxygen uptake as previously measured. To measure packed cell volume, plasma glucose, free fatty acids (FFA), glycerol and catecholamines, blood samples were drawn at rest using a heparinized catheter and at the 15th, 30th and 60th min of the exercise and after 30 min of recovery. At rest, the blood glucose concentrations were at the lowest values for normal. Exercise induced a small decrease of blood glucose which was combined with an abrupt increase of the noradrenaline concentration during the first 15 min. The FFA and glycerol concentrations increased throughout the exercise linearly with that of adrenaline. Compared to adults, the FFA uptake expressed per minute and per litre of oxygen uptake was greater in children. These results suggested that it is difficult for children to maintain a constant blood glucose concentration and that prolonged exercise provided a real stimulus to hypoglycaemia. An immediate and large increase in noradrenaline concentration during exercise and a greater utilization of FFA was probably used by children to prevent hypoglycaemia.
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Plasma glucose is an important energy source in exercising humans, supplying between 20 and 50% of the total oxidative energy production and between 25 and 100% of the total carbohydrate oxidised during submaximal exercise. Plasma glucose utilisation increases with the intensity of exercise, due to an increase in glucose utilisation by each active muscle fibre, an increase in the number of active muscle fibres, or both. Plasma glucose utilisation also increases with the duration of exercise, thereby partially compensating for the progressive decrease in muscle glycogen concentration. When compared at the same absolute exercise intensity (i.e. the same V̇O2), reliance on plasma glucose is also greater during exercise performed with a small muscle mass, i.e. with the arms or just 1 leg. This may be due to differences in the relative exercise intensity (i.e. the %V̇O2peak), or due to differences between the arms and legs in their fitness for aerobic activity. The rate of plasma glucose utilisation is decreased when plasma free fatty acid or muscle glycogen concentrations are very high, effects which are probably mediated by increases in muscle glucose-6-phosphate concentration. However, glucose utilisation is also reduced during exercise following a low carbohydrate diet, despite the fact that muscle glycogen is also often lower. When exercise is performed at the same absolute intensity before and after endurance training, plasma glucose utilisation is lower in the trained state. During exercise performed at the same relative intensity, however, glucose utilisation may be lower, the same, or actually higher in trained than in untrained subjects, because of the greater absolute V̇O2 and demand for substrate in trained subjects during exercise at a given relative exercise intensity. Although both hyperglycaemia and hypoglycaemia may occur during exercise, plasma glucose concentration usually remains relatively constant. Factors which increase or decrease the reliance of peripheral tissues on plasma glucose during exercise are therefore generally accompanied by quantitatively similar increases or decreases in glucose production. These changes in total glucose production are mediated by changes in both hepatic glycogenolysis and hepatic gluconeogenesis. Glycogenolysis dominates under most conditions, and is greatest early in exercise, during high intensity exercise, or when dietary carbohydrate intake is high. The rate of gluconeogenesis is increased when exercise is prolonged, preceded by a restricted carbohydrate intake, or performed with the arms. Both glycogenolysis and gluconeogenesis appear to be decreased by endurance exercise training. These effects are due to changes in both the hormonal milieu and in the availability of hepatic glycogen and gluconeogenic precursors. Hepatic glucose production during exercise is stimulated by glucagon and the catecholamines and suppressed by insulin or an increase in plasma glucose concentration. In contrast to earlier suggestions, it appears that a decrease in insulin and an increase in glucagon are both required for hepatic glucose production to increase normally during moderate intensity, moderate duration (40 to 60 minutes) exercise. Changes in the catecholamines. however, may still prove to be important, especially during more intense or more prolonged exercise.
Article
Muscle ATP, creatine phosphate and lactate, and blood pH and lactate were measured in 7 male sprinters before and after running 40, 60, 80 and 100 m at maximal speed. The sprinters were divided into two groups, group 1 being sprinters who achieved a higher maximal speed (10.07±0.13 m ·s−1) than group 2 (9.75±0.10 m ·s−1), and who also maintained the speed for a longer time. The breakdown of high-energy phosphate stores was significantly greater for group 1 than for group 2 for all distances other than 100 m; the breakdown of creatine phosphate for group 1 was almost the same for 40 m as for 100 m. Muscle and blood lactate began to accumulate during the 40 m exercise. The accumulation of blood lactate was linear (0.55±0.02 mmol · s−1 ·1−1) for all distances, and there were no differences between the groups. With 100 m sprints the end-levels of blood and muscle lactate were not high enough and the change in blood pH was not great enough for one to accept that lactate accumulation is responsible for the decrease in running speed over this distance. We concluded that 1) in short-term maximal exercise, performance depends on the capacity for using high-energy phosphates at the beginning of the exercise, and 2) the decrease in running speed begins when the high-energy phosphate stores are depleted and most of the energy must then be produced by glycolysis.
Article
Cotes, J. E., Dabbs, J. M., Hall, A. M., Axford, A. T., and Laurence, K. M. (1973) . Thorax, 28 , 709-715. Lung volumes, ventilatory capacity, and transfer factor in healthy British boy and girl twins . Normal values are reported for the lung volumes, ventilatory capacity, and transfer factor of 212 healthy British twin children aged 8 to 16 years. The boys and the girls share a common relationship to height for the residual volume, peak expiratory flow rate, and Kco (transfer factor per litre of lung volume). For the inspiratory capacity and the transfer factor, also its membrane component (Dm), the values for the boys exceed those for the girls by, on average, 10%. This difference may be due, at least in part, to the boys taking more exercise.
Article
1. Skinfold thickness and body density were measured on 105 young adult men and women and 86 adolescent boys and girls. 2. The correlation coefficients between the skinfold thicknesses, either single or multiple, and density were in the region of −0.80. 3. Regression equations were calculated to predict body fat from skinfolds with an error of about ±3.5%. 4. A table gives the percentage of the body-weight as fat from the measurement of skin-fold thickness.
Article
The metabolic and hormonal responses to exhaustive short-term supramaximal exercise were studied in 10 male physical education students. The exercise task was a single bout of running on the treadmill at 22 km·h−1 and 7.5% slope. It was performed with single oral doses of 100 mg Bupranolol (non-selective Β-blockade), 100 mg Metoprolol (Β-1-selective blockade), and placebo. Arterialized capillary and venous blood were sampled until 30 min post exercise. Time to exhaustion was 52.0±2.6, 47.6±2.0, and 46.0±1.9 s in the control, Metroprolol, and Bupranolol experiments. At cessation of exercise, adrenaline and noradrenaline were grossly elevated in all three conditions. Lactate and glucose increased markedly, this being accompanied by increasing insulin in the control and Metoprolol, but not the Bupranolol trials. Glycerol increased moderately, while FFA were depressed. Growth hormone showed a delayed increase at 15 and 30 min post exercise. Cortisol was unaffected by exercise. Β-blockade reduced the increases of lactate, glucose, glycerol, insulin, and growth hormone, exaggerated the depression of FFA and had no effect on cortisol. The results demonstrate that the strong sympatho-adrenal response to exercise of this nature is a major determinant of the increase of glucose at cessation of exercise. The hyperglycemia in concert with Β-2-adrenergic stimulation leads to elevation of insulin. Furthermore, lipolysis is controlled by Β-adrenergic stimulation. The delayed increase of growth hormone seems to be triggered by the declining glucose level during recovery.
Article
Seventeen male physical education students performed three types of treadmill exercise: (1) progressive exercise to exhaustion, (2) prolonged exercise of 50 min duration at the anaerobic threshold of 4 mmol . l-1 blood lactate (AE), (3) a single bout of short-term high-intensity exercise at 156% of maximal exercise capacity in the progressive test, leading to exhaustion within 1.5 min (ANE). Immediately before and after ANE and before, during, and after AE adrenaline, noradrenaline, growth hormone, cortisol, insulin, testosterone, and oestradiol were determined in venous blood, and glucose and lactate were determined in arterialized blood from the earlobe. Adrenaline and noradrenaline increased 15 fold during ANE and 3--4 fold and 6--9 fold respectively during AE. The adrenaline/noradrenaline ratio was 1 : 3 during ANE and 1 : 10 during AE. Cortisol increased by 35% in ANE (12% of which appeared in the postexercise period) and 54% in AE. Insulin increased during ANE but decreased during AE. Testosterone and oestradiol increased by 14% and 16% during ANE and by 22% and 28% during AE. The results point to a markedly higher emotional stress and higher sympatho-adrenal activity in anaerobic exercise. Growth hormone and cortisol appear to be the more affected by intense prolonged exercise. Taking plasma volume changes and changes of metabolic clearance rates into consideration, neither of the exercise tests appeared to affect secretion of testosterone and oestradiol.
Article
A total of six male and six female sprinters at the same national competition level and aged 18-20 years performed a force/velocity test and a 30-s supramaximal exercise test (Wingate test) on 2 different days, separated by a maximal interval of 15 days. The maximal anaerobic power (Wmax) was determined from the force/velocity test, and the mean anaerobic power (W) from the Wingate test. Immediately after the Wingate test, a 5-ml venous blood sample was drawn via a heparinized catheter in an antebrachial vein for subsequent catecholamine (adrenaline and noradrenaline) analysis. After 5 min recovery a few microliters of capillary blood were also taken for an immediate lactate determination. Even expressed per kilogram lean body mass, Wmax and W were significantly lower in women. The lactate and adrenaline responses induced by the Wingate test were also less pronounced in this group whereas the noradrenaline levels were not significantly different in men and women. Above all, very different relationships appeared between lactate, adrenaline, noradrenaline and W according to sex. Thus, as reported by other authors, the adrenergic response to a supramaximal exercise seemed to be lower in women than in men. Nevertheless a different training status between the two groups, even at same national competition level, could not be excluded and might contribute, at least in part, to the gender differences observed in the present study.
Article
The study investigated the concentrations of plasma catecholamine, adrenaline (A) and noradrenaline (NA), and the adrenal medulla responsiveness to the sympathetic nervous activity in sprinters (S), endurance runners (E) and untrained subjects (U) during a supramaximal exercise (the Wingate-test). A group of 19 men took part in the tests: 6 S (20.5+/-0.7 years), 6 E (21.0+/-1.0 years) and 7 U (20.9+/-0.4 years). The maximal power (Wmax) and the mean power (W) were determined from the Wingate-test on a cycle ergometer. The plasma lactate, A and NA were analysed at rest (La0, A0 and NA0), immediately at the end of the exercise (Amax and NA(max)) and after 5 min recovery (La(max), A5 and NA5). The disappearance of A and NA was judged by the difference between the maximal values and those determined after 5 min recovery (Amax-A5 and NA(max)-NA5) and the ratio A/NA was considered as an index of the adrenal medulla responsiveness to the sympathetic nervous activity. During the Wingate-test S exhibited higher performances and higher La(max) than the two other groups. At the end of the Wingate-test the NA(max) values were similar in the three groups whereas the Amax values were significantly higher in S than in E and U (8.00+/-0.5 nmol x l(-1) in S vs 3.47+/-0.30 nmol x l(-1) and 3.29+/-1.14 nmol x l(-1) respectively in E and U). This leads to a higher Amax/NA(max) ratio for S compared to the other two groups (0.77+/-0.10 in S vs 0.23+/-0.03 and 0.28+/-0.05, respectively in E and U). As the disappearance of A (Amax-A5) was significantly higher in S (6.80+/-0.47 nmol x l(-1) in S vs 2.64+/-0.19 nmol x l(-1) and 1.64+/-1.37 nmol x l(-1), respectively in E and U), the higher values of Amax in S could be explained by an increase of the adrenal medullary secretory capacity in this group. It was concluded that essentially short term and intense exercises as sprint ones or interval-training may alter the adrenal medulla responsiveness to supramaximal exercise but not long duration exercises.
Article
Ever since the publication of the first textbook on human growth by Johann Augustin Stoeller in 1729, temporal changes (or secular trends) in growth and pubertal maturation have been observed throughout the world. Data covering the longest time span are often reported from European populations. For example, in Norway and Denmark the age at menarche has fallen rapidly since the 19th century, by up to 12 months per decade. These changes have broadly paralleled increases in adult height in most European countries over the last century, with rates of around 10-30mm per decade. These secular trends are influenced by background ethnic, geographical and socio-economic factors, and clearly nutritional changes have an important role as reflected by positive correlations between age at puberty onset or age at menarche and childhood body size. Changes in height, pubertal maturation, and childhood body size have all also been related to rate of weight gain in infancy, and there is growing evidence to suggest that this early postnatal period may represent an early window of susceptibility to long-term 'programming' of various outcomes in humans. There is debate as to whether the secular trends in pubertal maturation are continuing or have reached their limit. Even where temporal changes are overall clearly significant, they are most marked in the more nutritionally deprived sub-groups. Whether over-nutrition and increasing childhood obesity will continue to lead earlier puberty is uncertain. The confirmation of an estimated advance in the age at menarche of 6-12 months per 100 years will require a long-term perspective on behalf of current investigators, and new consideration of methodological approaches in an age of increasing recognition of children's rights for privacy.
Statement Snowbird workshop on standardisation of spirometry
American Thoracic Society Statement Snowbird workshop on standardisation of spirometry. Am Rev Respir Dis 1979; 119: 831-838.