Multifactorial monitoring of training load in elite rugby sevens players: cortisol/cortisone ratio as a valid tool of training load monitoring.

The effectiveness of selected physiological and perceptual measures for monitoring training load and fatigue was studied in 16 male elite rugby sevens players during a 6-week intense training block (IT) and 2-week tapering (TAP). Daily training load (TL) and strain (TS) as well as weekly total score of fatigue (TSF) were quantified respectively by the session-rating of perceived exertion (RPE) method and an 8-item questionnaire. Also, testing was performed and 24 h urinary cortisol (C), cortisone (Cn), adrenaline (A) and noradrenalin (NA) excretion was measured before (T0) and after the IT (T1) and after the TAP (T2). The TL, TS and TSF increased during the IT and decreased during the TAP, in conjunction with a significant drop and improvement, respectively, of performance standards during the two periods. At T1, C and Cn levels increased while A and NA levels decreased, resulting in a higher C/Cn ratio and lower A/NA ratio, respectively. At T2, both C/Cn and A/NA returned to baseline values. The changes in C/Cn ratio, after the 6-week IT, were more closely related to mean TL, TS and TSF (r=0.75-0.76 vs. r=0.48-0.58, p<0.01) and to changes in the majority of performance measures than to A/NA ratio. Only the changes in C/Cn ratio after the 2-week TAP were related to mean TL, TS and TSF (r=0.61-0.68, p<0.01). The changes in hormone levels, training strain and performance standards reflected the physical and mental stressors of training, with complete recovery, as indicated by physiological homeostasis, achieved after an appropriate tapering period.

Six-minute walking test predicts maximal fat oxidation in obese children.

BACKGROUND: Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients. OBJECTIVE: The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders. DESIGN: This study is a cross-sectional study using mixed linear and multiple regression models. RESEARCH METHODS AND PROCEDURES: Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately. RESULTS: Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001). CONCLUSION: In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.

Effect of an individualized physical training program on resting cortisol and growth hormone levels and fat oxidation during exercise in obese children.

OBJECTIVES: The aim of this study was to characterize the resting levels of cortisol and growth hormone (GH), and the substrate profile during exercise of obese children before and after an individualized training program. PATIENTS AND METHODS: Twenty-two obese children (13.1 ± 0.8 yrs) were included in the study. Twelve individuals (six boys and six girls; 31.1 ± 1.1 kg/m², VO2(peak)=1.92 ± 0.16l/min) participated in a two-month endurance training program and 10 individuals (five boys and five girls; 30.9 ± 1.7 kg/m², VO2(peak)=1.98 ± 0.12l/min) served as controls. Training was individualized and targeting at the point were fat oxidation was maximal (Lipox(max)). Substrate oxidation was evaluated by indirect calorimetry. To determine plasma cortisol and GH concentrations, blood was collected at rest before and after the two-month period. RESULTS: Before the program, no significant differences were detected between the training group and the control group for any of the measured anthropometric, metabolic or hormonal variables. At the end of the two-month program, training group showed an increase in VO2(peak) and fat oxidation during exercise. After the program, resting levels of GH and cortisol were significantly increased in the training group (+0.9 ± 0.3 ng/mL and +55.4 ± 10.3 ng/mL respectively, p < 0.01). Following the two-month period, there was no change in any variables measured in control group. CONCLUSION: The present data show that an individualized endurance training program targeting Lipox(max) improves fat oxidation during exercise and increases resting levels of GH and cortisol.

Exercise improves the ApoB/ApoA-I ratio, a marker of the metabolic syndrome in obese children.

AIM: This study was designed to examine the effect of training on components of the metabolic syndrome and ApoB/ApoA-I ratio in obese children. METHODS: We studied thirty-two obese children (13.3 ± 0.4 years) with 16 subjects who participated to 8-week training and 16 subjects serving as a control group. Training was individualized at the point where fat oxidation was maximal (Fat max). In each subject, pre- and postintervention anthropometric measures and biochemical tests on fasting blood were performed. RESULTS: After the programme, the training group showed an increase in VO(2peak) and fat oxidation during exercise. Body mass index (BMI), blood glucose and triglycerides were reduced, and high-density lipoprotein (HDL) was increased. ApoB/ApoA-I ratio decreased significantly (-0.43%, p < 0.01). Systolic and diastolic blood pressure also decreased (-8.4% and -10.9%, respectively). Among the training group, 10 subjects were classified as having the metabolic syndrome before the intervention and none after. No significant changes in any other variables were measured in the control group. CONCLUSIONS: Training targeted at Fat max reduces the prevalence of metabolic syndrome and its associated factors in obese children. In particular, this intervention decreases the ApoB/ApoA-I ratio, which may be considered as a marker for following this syndrome.

Additive effect of diets and training on total insulin-like growth factor-1 (IGF-1) in rats.

OBJECTIVES: Although it is known that circulating levels of insulin-like growth factor-1 (IGF-1) are influenced by both physical exercise and dietary intake separately, there is little information regarding the additive effect of diets and training on IGF-1 regulation. To test this, we examined the combined effect of 30 days of two different diets (high-protein and high-carbohydrate) and exercise training on total IGF-1. MATERIALS AND METHODS: The study was carried out with four groups of rats; the sedentary group with standard diet (SS) (control group), standard diet with exercise (SE), high-protein diet with exercise (PE) and high-carbohydrate diet with exercise (CE). Serum IGF-1, insulin, corticosterone were analyzed. RESULTS: IGF-1 concentrations were decreased by exercise training (p<0.001) and only with protein diet (p<0.05). Physical training, with and without diet, decreased body weight and food intake (p<0.01) and increased corticosterone levels (p<0.05). Carbohydrate diet did not cause major hormonal and metabolic alterations. CONCLUSION: The main result of this study was the decreased levels of IGF-1 in spite of high-protein diet, which is known to enhance IGF-1 secretion, and the little changes with carbohydrate diet. This may be related to the negative energy balance as a result of the catabolic state induced by exercise training and decreased calorie intake in protein diet. Thus, it can be concluded that the caloric restriction, regardless of dietary composition, decreased IGF-1 secretion.

Effect of individualized weight-loss programmes on adiponectin, leptin and resistin levels in obese adolescent boys.

AIM: We investigate the effects of a 2-month weight-loss programme on plasma levels of adiponectin, leptin and resistin in obese adolescent boys. METHODS: Twenty-one obese adolescent boys (BMI = 30.8 +/- 3.2 kg/m(2)) completed the weight-loss programme including: 1/ either energy restriction (R), 2/ or individualized exercise training at the point of maximum lipid oxidation (Lipox(max)) (E), 3/ or energy restriction and training (RE). Body composition, lipid oxidation and plasma levels of adiponectin, leptin and resistin were measured before and after intervention. RESULTS: Following the weight-loss programme, adolescents of the RE group showed an improvement of their body composition (p < 0.01), an increase in plasma adiponectin (+73.7%, p < 0.01) and a decrease in plasma leptin (-38.8%, p < 0.01) leading to an increase in adiponectine/leptin ratio (ALR, +144.4%, p < 0.01) higher than the R or E groups. E and RE groups only showed a similar significant increase in plasma resistin (p < 0.05) and a significant improvement of lipid oxidation rate at Lipox(max) (p < 0.01 and p < 0.001). In addition, in RE group, ALR is correlated with waist/hip and waist/height ratios, resistin level, homoeostasis mode assessment (HOMA-IR) index and Lipox(max). CONCLUSION: In obese adolescents boys, moderate exercise training completed at Lipox(max) and combined with energy restriction improves their ability to oxidize lipids, which is associated with a normalization of their adiponectin, leptin and resistin levels resulting in an improved insulin sensitivity, as attested by a higher ALR and a lower HOMA-IR.

Two-month effects of individualized exercise training with or without caloric restriction on plasma adipocytokine levels in obese female adolescents.

OBJECTIVES: To examine if, in young obese patients, an individualized training programme in association with a caloric restriction programme which had an effect on whole-body lipid oxidation, was able to induce changes on plasma adipocytokine concentrations. MATERIALS AND METHODS: Twenty-seven obese female adolescents participated in the study. Whole-body lipid oxidation during exercise was assessed by indirect calorimetry during a graded cycle ergometer test. Body mass (BM), body mass index (BMI), percentage of body fat (%BF), insulin homeostasis model assessment (HOMA-IR) and fasting levels of circulating adipocytokines were assessed prior and after a two-month diet programme, individualized training programme targeted at Lipox(max) corresponded to the power at which the highest rate of lipids was oxidized and combined diet/training programme. RESULTS: The diet/training programme induced both a shift to a higher-power intensity of Lipox(max) (+27.8 + or - 5.1 W; p<0.01) and an increase of lipid oxidation at Lipox(max) (+96.8 + or - 16.2mg/min; p<0.01). The enhancement in lipid oxidation was significantly (p<0.01) correlated with the diet/training-induced improvement in %BF (r = -0.47), HOMA-IR (r = -0.66), leptin (r = -0.41), TNF-alpha (r = -0.48), IL-6 (r = -0.38), adiponectin (r = 0.43) and resistin (r = 0.51). CONCLUSION: This study showed that in obese female adolescents a moderate training protocol targeted at Lipox(max) and combined with a diet programme improved their ability to oxidize lipids during exercise, and that this improvement was associated with changes in plasma adipocytokine concentrations.

Effects of two-month physical-endurance and diet-restriction programmes on lipid profiles and insulin resistance in obese adolescent boys.

AIM: The aim of this study was to assess the impact of a two-month programme of physical endurance and dietary restriction, alone and combined, on plasma lipids and insulin resistance in obese adolescents. METHODS: A total of 24 obese adolescent boys participated in programmes of either dietary restriction (R), physical endurance at the point of maximum lipid oxidation (LIPOX(max)) (E) or diet combined with training (R+E). Anthropometric characteristics, metabolic measures and biochemical analyses were performed in all subjects before and after the interventions. An estimated insulin resistance was calculated using the homoeostasis model assessment (HOMA-IR) index. RESULTS: At the end of the two-month programmes, adolescents in the R+E group showed greater reductions in body mass index (-3.9+/-0.7 kg/m(2)) and waist circumference (-12.3+/-4.8 cm) (P<0.001) than either the R or E group. A significant decrease (P<0.01) in HOMA-IR index (-2.13+/-0.11), plasma triglycerides, LDL and total cholesterol was also seen in the R+E group. Moreover, at the end of the programme, the ratio of HDL cholesterol to triglycerides was significantly increased from baseline in the R+E group (0.93+/-0.09 vs. 0.68+/-0.11; P<0.01). CONCLUSION: Compared with either moderate physical endurance or dietary restriction, a combination of both resulted in a significant decrease in cardiovascular risk factors and HOMA-IR index in obese adolescent boys.

Visceral fat and total body fat mass correlate differently with hormones in rat.

Forty-eight 67-day-old male Wistar rats (330+/-5g) were fed ad libitum either with a lipid enriched diet or a standard laboratory chow. Half of each sub-group was submitted to training. Training and difference in diet composition induced nonsignificant changes in body adiposity. Visceral fat (perirenal adipose tissue mass) was correlated with leptin (r=0.35, p=0.02) and insulin (r=0.38, p=0.01). Total body fat mass (measured by DEXA) was correlated with leptin only (r=0.58, p=0.003). Other correlations between perirenal adipose tissue or fat mass and adiponectin or insulin like growth factor 1 were nonsignificant. These results suggest that, in rat like in human, visceral fat development is linked with insulin insensitivity.

Effect of a lipid-enriched diet on body composition and some regulatory hormones of food intake in growing rats.

OBJECTIVE: The aim of the present study was to investigate the effects of a lipid-enriched diet on body composition and on main regulatory hormones of food intake (insulin, adiponectin, leptin, ghrelin). METHOD: Two groups of 16 rats, 35 days old, weighing 80+/-6 g, were constituted. One group (S) was given a standard diet during 10 weeks and served as control. The second group (L) was given a lipidic-enriched diet (containing: G: 41.5, L: 38.5, P: 20% calorie). Food and water were given "ad libitum". RESULTS: Total food intake, body weight, skeletal area and lean body mass of rats eating lipid-enriched diet were lowered (6694+/-178 vs. 8160+/-184 kcal, P=0.01; 431+/-38 vs. 468+/-25 g, P=0.003; 72.19+/-0.96 vs. 76.07+/-1.31 cm2, P=0.03; 369+/-18 vs. 409+/-23 g, P=0.0006), fat mass difference was not statistically significant (82.5+/-17 vs. 80+/-17 g, P=0.7). Blood ghrelin, adiponectin levels were lowered (1517+/-224 vs. 1915+/-579 pg/ml, P=0.03; 10+/-3 vs. 19+/-3 microg/ml, P=0.003) whereas insulin and leptin were unchanged (1.8+/-1.5 vs. 2.6+/-1.4 ng/ml, P=0.1; 16+/-11 vs. 13+/-10 ng/ml, P=0.4). CONCLUSION: A period of high fat diet in growing rats leads to a hypophagia, resulting in a lower lean body mass development. Some regulatory hormones of food intake did not change, while others significantly decreased, notably ghrelin being possible causal factor of the observed hypophagia linked to high fat diet.

Bone mineral content and density of Tunisian male rugby players: differences between forwards and backs.

The purpose of this study was to examine the effects of long-term rugby participation on bone mineral content (BMC) and density (BMD) of male rugby players and to determine if the diverse stimuli elicited by the actions of forwards and backs affect their skeleton differently. Dual energy X-ray absorptiometry (DXA) scans were obtained from 20 male rugby players (10 Forwards and 10 Backs) who actively participated in rugby for the past 13 yr, and from 29 age matched non active subjects of the same ethnic origin. Both groups (rugby players and controls) had comparable age (23.6 +/- 3.7 yr vs. 25.6 +/- 3.4 yr), height (178.1 +/- 4.0 cm vs. 178.3 +/- 6.0 cm), and body fat percentage (14.2 +/- 4.4 vs. 16.5 +/- 5.1). Rugby players showed greater total body mass, and greater total lean and fat body masses than control subjects (p < 0.01). Whole spine BMC and BMD were 52 % and 15 % higher, respectively, in the rugby players than in the control subjects (p < 0.001). Furthermore, rugby players displayed higher skeletal BMC (40 %, 37 % and 58 % for legs, arms and pelvis, respectively) and BMD (16 %, 21 % and 17 %, respectively) than controls. Within the rugby group, forwards were taller, heavier and had greater body fat percentage, and greater total lean and fat body masses than backs (p < 0.05 to p < 0.001). Likewise, BMC, BMD and bone area for the whole body and at specific sites such as arms, spine and legs were also greater in the forwards (p < 0.05 to p < 0.001). Long-term rugby participation, starting at pubertal age, is associated with markedly increased BMC, BMD and bone size at all skeletal sites, except at the head. The musculo-skeletal adaptations, greater in forwards than in backs, could mimic training responses and therefore explain the bone features, localized in specific stressed regions.

[Do circannual rhythm of cortisol and testosterone interfere with variations induced by other events?]. / Les rythmes circannuels du cortisol et de la testostérone interfèrent-t-ils avec les variations de ces hormones liées à d'autres évènements?

OBJECTIVE: Cortisol and testosterone are two hormones whose levels may vary in response to sports or occupational events. We wondered if the circannual rhythm of these hormones could have an influence on such responses or whether changes can always be ascribed to a single cause. METHOD: For cortisol, we conducted a cross-sectional study among 102 adult men (mean age 42 years) using saliva samples taken one half hour after awakening. The values were combined over three-month periods corresponding to the four seasons. For testosterone, conclusions were drawn from data reported in the literature. RESULTS: The mean annual cortisol level was 14.36+/-0.44 nmol/l. There was no significant difference between average and peak values nor between maximal and minimal values. For testosterone, there have been a limited number of studies and it is unclear whether there is a seasonal change. In any case, the amplitude of variations is weak (9.7% between peak and annual average), which is partly ascribable to individual and interindividual variability. CONCLUSION: We conclude that there is no seasonal (or circannual) rhythm in cortisol levels to a degree which could interfere with effects resulting from other events. For testosterone, the circannual rhythm may account for 10% of the variation.

Antioxidant status and oxidative stress in professional rugby players: evolution throughout a season.

Physical training is known to increase the antioxidant defence system and reduce exercise-induced oxidative stress. However, intense physical aerobic and anaerobic training and competition such as those imposed on professional rugby players, can induce an increase of oxidative stress which can be implicated with the arrival of overtraining. The aim of this study was to test the effect of training and competition load on oxidative stress, antioxidant status, haematological, and cell damage markers in high-level rugby players during a competitive season. Blood samples were collected four times in one year. Oxidative stress (Rmax), antioxidant (vitamin E, uric acid, TAC, and lag phase), haematological (neutrophils and monocytes) and biochemical (CK and myoglobin) parameters, as well as training and competition load, and competition results were measured. Intense periods of training and competition (T1 and T4) induced a significant higher maximum rate of conjugated dienes oxidation (+67.2% in T1 and +40.6% in T4) compared to those observed at the reference time (T3). Those periods also induced an increase in uric acid (+6.9% and 3.2%), and inflammatory markers such as monocytes (+13.3% and 10.7%). On the other hand, vitamin E (-8.7% in T1) and lag phase (-23.0% and -14.7%) were lower during these periods showing a possible training-induced antioxidant down-regulation. The less intense period of training (T2) was accompanied by lower neutrophils (-8.5%), CK (-53.7%), and myoglobin (-16.2%) values. The results suggest that oxidative stress and antioxidant measurement are significant in the biological follow-up of athletes.

Food restriction, performance, biochemical, psychological, and endocrine changes in judo athletes.

In order to test the hypothesis that dietary restriction may have a negative influence on physiological and psychological adaptation to a judo competition, we examined the effects of weight loss induced by restricting energy and fluid intake on the physiology, psychology, and physical performance of judo athletes. Twenty male judoka were randomly assigned to one of two groups (Group A: called diet, n = 10; height 174.8 +/- 1.9 cm, body weight 75.9 +/- 3.1 kg; they were asked to lose approximately 5 % of their body weight through self-determined means during the week before the competition; Group B: called control, n = 10; height 176.4 +/- 1.1 cm, body weight 73.3 +/- 6.3 kg maintained their body weight during the week before the competition). A battery of tests was performed during a baseline period (T1), on the morning of a simulated competition (T2) and 10 min after the end of the competition (T3). The test battery included assessment for body composition, performance tests, evaluation of mood, determination of metabolic and hormonal responses. Dietary data were collected using a 7-day diet record. The nutrient analysis indicated that all the athletes followed a low carbohydrate diet whatever the period of the investigation. For the Group A, the food restriction (- 4 MJ per day) resulted in significant decreases of the body weight and altered the mood by increasing Fatigue, Tension and decreasing Vigour. Dietary restriction had also a significant influence on metabolic and endocrine parameters and was associated with poor performance. After the competition, significant decreases of the levels in testosterone, T/C ratio, alkali reserve, and free fatty acid were observed in both groups, whereas the plasma concentrations in insulin, ammonia, urea, and uric acid were increased. In conclusion, our results suggest that the combination of energy restriction and intense exercise training, which causes weight reduction before a competition, adversely affects the physiology and psychology of judo athletes and impairs physical performance before the competition. Our data are the first to demonstrate that a competition including five 5-min bouts induced the same changes of physiological and psychological variables and performance whatever the dietary intake (dietary restriction or not) during the seven days before the competition.

IGFBP-3, a sensitive marker of physical training and overtraining.

OBJECTIVE: To investigate the response of the somatotrope axis (insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3)) to intense exercise in relation to tiredness. METHODS: The study involved 11 rugby players who completed a questionnaire intended to evaluate fitness or, conversely, overtraining and who agreed to plasma samples being taken before and after an international rugby match. RESULTS: The main finding of our study is that we observed strong negative correlations between IGF-1 (r = 0.652) and IGFBP-3 (r = 0.824) levels and the overtraining state estimated using the French Society of Sport Medicine questionnaire. In particular, there was a fall (of up to 25%) in IGFBP-3 levels after the match in the more fatigued subjects compared to an increase (of up to 40%) in fit subjects. CONCLUSIONS: A fall in IGFBP-3 in response to an intense bout of exercise may represent an index of tiredness in highly trained sportsmen, as indicated by the scores obtained from the overtraining questionnaire.

Biological and psychological responses to two rapid shiftwork schedules.

This study presents the biological responses to shiftwork in two groups of workers with different shiftwork rotas. Biological responses were studied by recording the heart rate and the changes in the circadian profile of salivary cortisol over 24 h (RIA assays). Various items were recorded through questionnaires aimed at determining self appreciation of sleep quantity, stress, health, satisfaction at work and in private lives. Thirty two male subjects aged from 23 to 56, working for the same company, having given their informed consent, took part in the study. The study was carried out under realistic conditions (at the work place) under the control of an occupational physician. Sixteen day-workers (8 am-6 pm) served as a reference group. Eight shiftworkers included in alternate schedules (morning M 4 am-12 am, evening E 12 am-8 pm, night N 8 pm-4 am) according to a system M, S, N 3/2, (3 work, 2 rest) and eight according to a system 7/5 (3M/2S/2N/5R, 2/3/2/5, 2/2/3/5) constituted the groups of shiftworkers respectively named 3/2 and 7/5. All subjects had comparable ages and BMIs. Shiftworkers expressed a higher stress level and frequency of health problems and a lower satisfaction at work than the control. Among the three groups, the 7/5 group had the best health and fitness score and was in need of less sleep. Heart rate was not affected by shift work. Conversely, consistent changes appeared in cortisol circadian profiles, the greatest changes appearing for the night shift and among the two groups of shiftworkers, more particularly for the 7/5 group. These changes correlated with self-perceived constraints of work and showed the difficulties of adaptation to shiftwork.

Salivary testosterone and cortisol in rugby players: correlation with psychological overtraining items.

BACKGROUND: A psychocomportemental questionnaire has been devised by the consensus group of the Société Française de Médecine du Sport to characterise and quantify, using a list of functional and psychocomportemental signs, a state of "staleness", for which no biological indicator is unanimously recognised. OBJECTIVES: To determine the relation between this diagnostic method and two hormones (cortisol and testosterone) often used as indicators of a state of fitness or staleness. METHODS: The subjects were young rugby players. They were asked to complete the overtraining questionnaire and gave three saliva samples (at 8 am, 11 am, and 5 pm) during a rest day. Concentrations of cortisol and testosterone in the saliva were determined by radioimmunoassay. RESULTS: A preferential relation was found between the questionnaire score and testosterone concentration but not between the questionnaire score and cortisol concentration. CONCLUSIONS: The questionnaire may be a useful tool for screening subjects at risk of overtraining. Testosterone concentration is influenced by tiredness, and is therefore a valid marker of tiredness.

Biological markers for the follow-up of athletes throughout the training season.

During the training season, a state of fatigue known as overtraining may occur, resulting from an excessive load of training, both in volume and intensity. Even now, difficult to predict the risk of overtraining, although this syndrome has been the subject of numerous studies. A lot of biological markers have been propounded. Taken alone, none of them have an absolute significance. This paper aims to review these markers, considering their biological interest, the ease with which they can be measured and the cost, from the simplest (body weight daily recording) to the most up to date markers (e.g. anti-oxidant status). They are grouped into three categories: non-invasive behavioural and biological markers, biochemical markers, and hormonal and immunological markers.

Effects of 16 weeks of training prior to a major competition on hormonal and biochemical parameters in young elite gymnasts.

The aim of this study was to investigate the response to 16 weeks of training on selected hormonal and biological parameters in seven international competition level female artistic gymnasts (14.5 +/- 1.2 years). Data were collected at the beginning of the first training week (W1) and in the 16th week (W16). Assessments also included anthropometric measurements, dietary intake for 7 days and Tanner staging. No gymnast had reached menarche and the puberty stages corresponded to Tanner's pubertal stage 2. The gymnasts were smaller than average for their age group, with a height:weight ratio above the 50th percentile. Energy intake was about 31% lower than recommendations. Significant decreases in IGF-I, IGFBP3, IGF-I:C ratio and triglyceride values and increases in uric acid and creatinine levels were noted. Cortisol values were high regardless of the period. This training provided evidence for alterations in resting somatotropic and adrenocorticotropic parameters.

Behaviour of saliva cortisol [C], testosterone [T] and the T/C ratio during a rugby match and during the post-competition recovery days.

Competition is a more demanding situation than other strenuous exercise of equivalent duration; it results in stronger physiological changes. The object of this study was to get information on the duration of the recovery period by measuring changes of saliva cortisol [C], testosterone [T] and their ratio T/C in a group of international rugby players ( n=20) during the week following a rugby match (6 days). Using non-invasive saliva assays, we were able to take samples during the day of competition and the post-competitive days. Hormone levels were assayed with a routine in-house radioimmunoassay (RIA) method. Throughout the competition, C levels increased sharply (about 2.5-fold compared resting values) and returned to basal values within 4 h. Conversely, the T level decreased slightly. During the recovery period, C levels were lower and T levels were higher than basal values, resulting in a very high T/C ratio until the 5th day. This high post-competitive T/C ratio phase is probably required to restore the break-down of homeostasis induced by the very hard mental and physical strain associated with a rugby match. Thus, a period of 1 week recovery appears to be the minimal duration between two competitions.