Neuromuscular and inflammatory responses to handball small-sided games: the effects of physical contact.

The aim of this study was to investigate the influence of physical contact on neuromuscular impairments and inflammatory response during handball small-sided games. Using a counterbalanced design, 12 elite male junior handball players were divided into two groups: contact (C-SSG) and no-contact (NC-SSG), performing both contact and no-contact small-sided games, in reverse order on two training sessions separated by 5 days. The methodology and rules were identical for the two SSG regimens, with the only difference being the inclusion or prohibition of upper body use for physical contacts. Upper and lower body neuromuscular performances and blood concentrations of inflammatory cytokine IL-6 were assessed before and immediately after the games. During small-sided games, video analysis was used to establish the physical contact counts. Significant differences were found in most upper and lower limbs muscles kinetic variables and in the physical contact events (all P < 0.001) following the two training regimens. There was an increase in IL-6 after C-SSG and no changes following NC-SSG (P < 0.05 and P = 0.12, respectively). Moreover, a strong correlation was found between the number of physical contacts and IL-6 responses (r = 0.971, P < 0.001) in C-SSG. This study indicates that an inflammatory response and large upper and lower body neuromuscular impairments result from physical contact in elite handball players. These outcomes outline the specific physiological profile of C-SSG that, in turn, might be used by practitioners and coaches as a practical approach to strategically select exercises in athlete's overall training program.

Differences in MCT1 A1470T polymorphism prevalence between runners and swimmers.

Skeletal muscle is the major producer and user of lactate in the body. Therefore, transport of lactate across cells' membrane is of considerable importance. Lactate transport is mediated by proton-linked monocarboxylate transporter (MCT1). The A1470T polymorphism (rs1049434) in MCT1 gene influences lactate transport, with T allele associated with reduction of lactate transport rate and elevation in blood lactate levels. The aim of the current study was to compare allelic and genotype frequencies of MCT1 A1470T polymorphism among Israeli track-and-field athletes, swimmers, and non-athletes. Genomic DNA was extracted from 173 track-and-field athletes (age 17-50), 80 swimmers (age 16-49), and 128 non-athletes (age 19-29). Track-and-field athletes were assigned to three subgroups: long-distance runners, middle-distance runners, and power event athletes. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. Genotyping was performed using polymerase chain reaction. T-allele frequency was significantly higher among long-distance swimmers (45%) compared with long- and middle-distance runners (27% and 30%, respectively; P < 0.01). In addition, T-allele frequency was significantly higher among short-distance swimmers (40%) compared with power event athletes (25%, P < 0.01). Overall, T-allele frequency was significantly higher among swimmers (42%) compared with runners (27%, P < 0.001). More research is needed to clarify whether this polymorphism displays advantage for swimming performance.

Genetic score of power-speed and endurance track and field athletes.

Athletic excelling capability in a specific sport results from the combined influence of hundreds of genetic polymorphisms. The aim of the current study was to characterize athletes' polygenetic scores. We developed two polygenetic scores: (a) Power Genetic Distance Score based on two polymorphisms (PGDS2; ACE(I/D), ACTN3(C/T)) or five polymorphisms (PGDS5; ACTN3(C/T), ACE(I/D), IL6(-174G/C), NOS3(T/C), AGT(MET235THR)); and (b) Endurance Genetic Distance Score based on two polymorphisms (EGDS2; ACEI / D , ACTN3C / T ) or five polymorphisms (EGDS5; PPARGC1(AGly482Ser), PPAR(Aintron7G/C), PPARD(T294C), NRF2(A/C), HIF(C/T)). Eighty-two power-speed athletes, 87 endurance athletes, and 119 nonathletic controls participated in the study. Genomic DNA was extracted from peripheral blood. Power-speed athletes' mean PGDS2 (46.1) and PGDS5 (29.4) were significantly higher compared with their mean EGDS2 (36.4) and EGDS5 (23.1; P < 0.05, P < 0.01, respectively); and compared with controls' mean PGDS2 (36.6) and PGDS5 (24.2; P < 0.05, P < 0.05, respectively). Endurance athletes' mean EGDS2 (60.3) and EGDS5 (35.3) were significantly higher compared with their mean PGDS2 (26.9) and PGDS5 (21.8; P < 0.001, P < 0.001, respectively); and compared with controls' mean EGDS2 (51.2) and EGDS5 (26.1; P < 0.05, P < 0.001, respectively). We conclude that polygenetic scores can differentiate power-speed from endurance athletes. Whether these scores may be used to identify elite power-speed or endurance athletes' needs to be addressed in future studies.

Effects of a very short-term preseason training procedure on the fitness of soccer players.

AIM: The aim of the study was to examine the effect of a very short-term training program on the immediate and late changes in the fitness level of young soccer players during the pre-season period. METHODS: Twenty-four young (17-18 years) soccer players were randomly assigned to either an interval (9 to 5 X 1000 m) or continuous (9000 to 5000 m) training group, matched for total running distance. While the number of intervals or total distance was reduced every day, speed was increased in each session throughout the five days of both training programs. Each group performed 20 m shuttle run, 10 m sprint, 5 X 10 m run, 250 m run and vertical jump test, before (pre), immediately after (post) and 10 days after (late) completion of five successive training days during the preseason period for the upcoming soccer season. RESULTS: There was a significant increase in aerobic capacity both immediately post-training and in the late test, in both training groups. We found a significantly greater reduced performance in the 250 m run immediately following training in the interval compared to the continuous training group. In addition, there was a decrease in vertical jump that was significantly greater in the interval compared to the continuous training group, both immediately post-training and in the late test. CONCLUSION: Very short interval or continuous preseason training programs induce significant improvement in aerobic fitness but lead to stagnation or deterioration in anaerobic performance. Considering the opposing effects of both training modes (positive on the aerobic power but negative on the anaerobic performance), coaches should make their choices based on the relevant conditions at hand.

Genetic aspects of exercise and rhabdomyolysis.

Rhabdomyolysis is a syndrome characterized by muscle necrosis and the release of intracellular muscle constituents into the circulation. Consequently, the circulatory levels of intracellular molecular components, such as creatine kinase, are commonly used to evaluate the severity of muscle damage. Nevertheless, there is a wide inter-individual variability in the phenotypic expression of muscle damage, which cannot be predicted by the age, race, body composition, and fitness level of each subject. This suggests that apart from environmental factors, genetic factors might also contribute to the development and progression of exercise-induced muscle damage. Recently, several gene-specific single nucleotide polymorphisms (SNPs) were found to be associated with severe exercise-induced muscle damage. The present manuscript reviews the pathophysiology of exertional muscle damage, emphasizing the influence of gene polymorphisms on its inter-individual severity. This knowledge may be useful for pediatricians for identifying individuals more susceptible to severe exertional muscle damage and related life-threatening comorbidities.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease.

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.

Increased prevalence of MnSOD genetic polymorphism in endurance and power athletes.

The purpose of the current study was to determine the frequency distribution of manganese superoxide dismutase (MnSOD) Val-9Ala polymorphism (rs1799725) among 195 trained endurance and power athletes and 240 healthy controls. Genomic DNA was extracted using a standard protocol. Genotyping of the MnSOD Val-9Ala polymorphism was performed using polymerase chain reaction (PCR). Results showed a higher proportion of the Val/Ala and Ala/Ala genotype, and a lower proportion of Val/Val genotype, in the athletes group compared with that of the controls. The Ala allele frequency was significantly higher (p < 0.001) in the athletes group (46%) compared with that in the control (29%). Interestingly, there was no difference between the endurance and power athletes. In addition, the frequency of Ala/Ala genotype was significantly higher (p < 0.05) among top (international and Olympic-level) athletes (29%) compared with that among national-level endurance and power athletes (17%). We conclude that 1) the Ala allele is more frequent in athletes than in controls; and 2) the higher frequency of the Ala allele was noted in both endurance and power athletes compared with that in controls, suggesting that the positive association between the Ala allele and athletic performance may be related to ROS-related angiogenesis, mitochondrial biosynthesis, and muscle hypertrophy, and not to MnSOD aerobic properties.

Is there an interaction between BDKRB2 -9/+9 and GNB3 C825T polymorphisms and elite athletic performance?

The -9 deletion allele in the BDKRB2 -9/+9 polymorphism was associated previously with improved endurance performance. We compared the frequency distribution of the BDKRB2 -9/+9 (rs5810761) polymorphism between athletes (n=155) of sports with different demands (endurance runners; n=74 vs sprinters; n=81) as well as between athletes of different competitive levels (elite level; n=46 vs national level; n=109). These results were compared with those of 240 non-athletic healthy individuals. We also tested the influence of the interaction between the BDKRB2 -9/+9 and the GNB3 C825T (rs5443) genotypes in relation to endurance performance. Genotype distribution and allele frequencies were found to be similar in the endurance athlete, sprinter, and control groups (P=0.83 for genotype distribution and P=0.9 for allele frequencies). Similarly, no statistical differences were found between the subgroups of elite-level endurance athletes and national-level endurance athletes, or between elite-level and national-level sprinters (P>0.09 for all comparisons). There was no interaction between BDKRB2 -9/+9 and GNB3 C825T polymorphisms in relation to endurance performance (P=0.16 for interaction effect). In conclusion, the BDKRB2 +9/-9 polymorphism is not associated with endurance performance, at least among Israeli athletes, and the GNB3TT+BDKRB2 -9/-9 "optimal genotype" is not associated with endurance performance.

Hormonal response to Taekwondo fighting simulation in elite adolescent athletes.

Exercise training efficiency depends on the training load, as well as on the athlete's ability to tolerate it. The aim of the present study was to evaluate the effect of fighting simulation (3 fights, 6 min each, 30 min rest between fights) on anabolic (IGF-I, LH, FSH, estradiol, and testosterone) and catabolic hormones (cortisol) in elite, male (n = 10) and female (n = 10) adolescent (12-17 years) Taekwondo fighters. Blood samples were collected before the first and immediately after the third fight. The fighting simulation practice led to significant (p < 0.05) decreases in IGF-I (males -27.1 ± 25.6, females -22.4 ± 36.3 ng/ml), LH (males -0.7 ± 1.2, females -2.3 ± 3.3 U/L), and FSH (males -0.9 ± 0.5, females -1.5 ± 1.1 U/L), and to a significant increase (p < 0.05) in cortisol (males 141.9 ± 30.1, females 64.1 ± 30.6 mcg/dL) in both genders. Fighting simulation decreases in testosterone (males -1.9 ± 1.6, females -0.02 ± 0.06 ng/mL), and free androgen index (males -20.1 ± 21.5, females -0.3 ± 0.5) were significant (p < 0.05) only in male fighters. Exercise had no significant effect on estradiol, sex-hormone-binding globulins or thyroid function tests. Our data demonstrate that the physiologic and psychologic strain of a Taekwondo fighting simulation day led to a catabolic-type circulating hormonal response.

Short stature, celiac disease and growth hormone deficiency.

Celiac disease (CD) is a prevalent, genetically determined, autoimmune, chronic inflammatory state caused by intolerance to gluten that results mainly in gastrointestinal manifestations. One of the most common extra-intestinal manifestations of CD is short stature, and in some patients, short stature may be the presenting and only symptom of the disease, making the diagnosis of CD challenging. Impaired growth in children with CD results mainly from nutritional deficits, and withdrawal of gluten from the diet is frequently associated with a marked improvement of linear growth. In some patients, CD may be characterized by growth hormone (GH) resistance, as suggested by normal or elevated GH levels and low insulin-like growth factor-I (IGF-I) levels. Rarely, it has been shown that poor catch-up growth and/or IGF-I response to gluten-free diet may be due to the coexistence of celiac disease and GH deficiency. We present two children with coexisting CD and GH deficiency. One patient had MRI findings suggesting congenital isolated GH deficiency, and a possibility of developing multiple pituitary hormone deficiencies later in life.

Physical activity and nutrition knowledge and preferences in kindergarten children.

The aim of the present study was to determine physical activity and nutritional knowledge and preferences in kindergarten children. Following height and weight measurement, and age and gender adjusted BMI percentile calculation, 202 kindergarten children (4 - 6.5 yr) completed twice in a random order, a photo-pair food and exercise questionnaire. Knowledge was determined by asking the child to choose food/activity that would make a selected doll healthier, while preferences where determined by the child's own choise. Nutritional knowledge score was higher than the physical activity knowledge score (73.4 +/- 1.5 vs. 67.5 +/- 1.9 %, p < 0.006), while the nutrition preference score was lower than the physical activity preference score (42.2 +/- 1. 8 vs. 66.5 +/- 1.6 %, p < 0.0001). There was a difference between nutrition knowledge and preferences (73.4 +/- 1.5 vs. 42.2 +/- 1.8 %, p < 0.0001). No differences were found between physical activity knowledge and preferences. No differences were found between overweight and normal weight kindergartners. Female kindergartners had higher nutrition knowledge and preference scores, but lower physical activity preference scores compared to male kindergartners. Our data suggest that in developing health promotion programs for kindergarten children, an effort should be made to increase physical activity knowledge and to improve nutritional preferences.

The effect of music during warm-up on consecutive anaerobic performance in elite adolescent volleyball players.

Music is believed to improve athletic performance. The aim of the present study was to determine the effect of arousing music during warm-up on anaerobic performance in elite national level adolescent volleyball players. Twenty-four players (12 males and 12 females) performed the Wingate Anaerobic Test following a 10-minute warm-up with and without music (two separate occasions, random order). During warm-up with music, mean heart rate was significantly higher. Following the warm-up with music, peak anaerobic power was significantly higher in all volleyball players (10.7 +/- 0.3 vs. 11.1 +/- 0.3 Watts/kg, p < 0.05, without and with music, respectively). Gender did not influence the effect of music on peak anaerobic power. Music had no significant effect on mean anaerobic output or fatigue index in both genders. Music affects warm-up and may have a transient beneficial effect on anaerobic performance.

A cumulative effect of physical training on bone strength in males.

Weight-bearing, high-impact exercise, as opposed to nonimpact exercise, has been demonstrated to increase bone mineral density. This was traditionally demonstrated with dual energy X-ray absorptiometry. Our objective was to assess the differences in bone properties, using quantitative ultrasound (QUS, Sunlight Omnisense, Sunlight Medical, Ltd., Tel Aviv, Israel), in male athletes involved in a weight-bearing, impact sport (soccer, SC) or a nonimpact sport (swimming and water polo, AQ), compared with nonathletic control (C) males. A total of 266 boys and men, aged 8 - 23 years, were divided into children (11.1 +/- 1.0 years; 34 SC, 34 AQ, 25 C), adolescents (14.7 +/- 1.2 years; 32 SC, 31 AQ, 31 C), and young adults (19.8 +/- 1.1 years; 31 SC, 24 AQ, 24 C) . Training experience varied between 1.5 years in the children to 15 years in the adults. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. Body fat was significantly lower in athletes compared with C. AQ were generally heavier and had a higher fat-free mass compared with SC and C, with no significant differences in height between groups. Radial SOS increased with age, but no differences were observed between activity groups or between the dominant (D) and nondominant (ND) arm. Tibial SOS also increased with age. In the children and adolescents, no differences were observed between activity groups. However, among adults, both SC and AQ had higher tibial SOS compared with C. These differences were mainly explained by differences in fat-free mass. Among young adults but not among children and adolescent males, both soccer and aquatic sports appear to be associated with higher bone SOS in the lower, but not the upper, extremities. Further studies are needed to assess possible sport-specific mechanisms which affect bone properties and to determine the minimal cumulative effect which is needed to influence bone properties.

Assisted exercise and bone strength in preterm infants.

Studies have previously demonstrated that brief (4 weeks) passive range-of-motion exercise is beneficial for bone development in very low birth weight (VLBW) preterm infants. However, the optimal duration of exercise for bone development in preterm infants is yet unknown. The aim of the present study was to examine the effect of 8 weeks of assisted exercise on bone strength and metabolism in VLBW premature infants. Sixteen infants (mean +/- standard error of the mean birth weight 1,009 +/- 55 g and gestational age 27.3 +/- 0.3 weeks) were randomly assigned into exercise (n = 8) and control (n = 8) groups. The intervention started at the first week of life and involved 8 weeks of daily passive extension and flexion range-of-motion exercise of the upper and lower extremities. Biochemical markers of bone turnover were measured at enrollment and after 8 weeks. Bone strength was measured weekly by quantitative ultrasound measurement of tibial bone speed of sound (SOS). Bone SOS decreased significantly in the control group (-108.1 +/- 33.7 m/second, P < 0.0001) during the study period, while remaining stable in the exercise group (11.3 +/- 22.8 m/second). The main beneficial effect of exercise occurred in the first 4 weeks of the intervention. There were no significant differences in the bone turnover marker changes between the groups. There is a significant postnatal decrease in bone SOS in VLBW preterm infants. Eight weeks of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia in premature infants.

A combined dietary-physical activity intervention affects bone strength in obese children and adolescents.

Obesity has become the most common pediatric chronic disease in the modern era. Recent data suggests that unlike obese adults, obese children and adolescents may have decreased bone strength. It was the objective to prospectively examine the short term effects of a 3 month combined dietary-physical activity intervention on anthropometric measures, body composition, fitness and bone strength in obese children. Twelve obese subjects completed the 3 m intervention and were compared to 12 obese age and gender matched controls. Bone strength was measured using quantitative ultrasound measurements of bone speed of sound (SOS). There were significant differences in changes of body weight (0.01 +/- 0.7 vs. 2.3 +/- 0.6 kg, p = 0.033), BMI percentiles (- 2.8 +/- 1.1 vs. - 0.2 +/- 0.2 %, p = 0.037), body fat percent (by skinfolds, - 1.5 +/- 0.8 vs. 0.7 +/- 0.5 %, p = 0.035), and endurance time (170 +/- 42 vs. 50 +/- 27 s, p = 0.045) in the intervention vs. control subjects, respectively. In addition, we found a significant difference in the change of bone SOS between the intervention and control group subjects (21.5 +/- 21.6 vs. - 87.0 +/- 37 m/s, p = 0.023). During the critical period of bone development of childhood and adolescence, a combined dietary-physical activity intervention leads to increased bone strength in obese children. These results highlight the importance of multi-disciplinary programs for the treatment of childhood obesity and its complications.

Bone properties and muscle strength of young haemophilia patients.

PURPOSE: To evaluate bone properties, muscle strength and the relationship between the two, in young (7.0-17.7 years) haemophilia patients (h) and healthy boys (c). SUBJECTS: Twenty-seven boys with severe haemophilia and 33 healthy boys, of similar age, body mass, height, (mean +/- sd for h and c, respectively: 11.2 +/- 3.2 vs. 11.4 +/- 2.9 years, 42.6 +/- 16.6 vs. 41.6 +/- 17.3 kg, 145 +/- 18 vs. 146 +/- 17 cm) and pubertal stage according to secondary sex characteristics, volunteered for the study. all subjects were physically inactive (as determined by questionnaire). METHODS: Subjects performed isokinetic elbow and knee extension and flexion tests at two angular velocities (biodex system ii dynamometer). Bone properties were evaluated by qualitative ultrasound (sunlight omnisense), at the distal radius and tibial mid-shaft. H subjects received prophylactic factor viii treatment within the 24 h preceding testing. No test was performed in the presence of haemorrhage. RESULTS: Muscle strength was consistently higher in c compared with h, especially in the lower limbs (e.g. knee extension: 1.80 +/- 0.44 vs 1.48 +/- 0.53 N x m x kg(-1) body mass, respectively, p = 0.01). No differences were observed in tibial or radial speed of sound between groups. Correlations between muscle strength and bone properties were observed only in the lower limbs and only in c (r = 0.37-0.48). CONCLUSION: Muscle strength, especially lower limbs' strength, was lower in haemophilia patients compared with a matched, similarly inactive population of healthy boys. Nevertheless, at this age range, this relative weakness is not associated with inferior bone properties.

Three novel mutations in POU1F1 in Israeli patients with combined pituitary hormone deficiency.

BACKGROUND: POU1F1, a pituitary-specific transcription factor of the class 1 POU family, is crucial for the development and differentiation of the anterior pituitary gland. Mutations in the POU1F1 gene have been shown to be responsible for a syndrome of combined pituitary hormone deficiency (CPHD), including prolactin, growth hormone and thyroid-stimulating hormone deficiencies. METHODS: Five patients with CPHD from three families were evaluated. The clinical and biochemical data were taken from the medical records. DNA was analyzed by polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and sequencing. RESULTS: Molecular analysis yielded three novel mutations in POU1F1: W193X, Q242R (-2 bp), and F262L. CONCLUSIONS: Three novel POU1F1 mutations were detected in Israeli patients with CPHD. Two of them, a W193X missense mutation and a deletion of two adenine bases at position 242Q, may lead to the production of a truncated protein that lacks the entire POU homeodomain or part of it, respectively. The third mutation, F262L, resides in the POU homeodomain and hence might change the activity of the protein.

Higher tibial quantitative ultrasound in young female swimmers.

BACKGROUND: It has been found that swimming, a non-impact sport, generally has no effect on bone mineral density. OBJECTIVES: To examine bone properties, as measured by quantitative ultrasound, among female swimmers in comparison with control girls and women. METHODS: Subjects included 61 swimmers and 71 controls aged 8.5 to 26.5 years. None of the swimmers was at the elite level and none had included resistance training in her schedule. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. RESULTS: No differences were observed between swimmers and controls in body mass (mean (SD): 49.7 (12.3) v 50.7 (12.4) kg, respectively), although swimmers were taller (159 (12) v 155 (12) cm) and had lower body fat (18.3 (4.2)% v 22.3 (5.4)%). No difference was found in time since menarche (5.2 (4.0) and 4.5 (2.9) years in swimmers and controls, respectively; 21 swimmers and 25 control were premenarcheal). Radial speed of sound (SOS) increased with age but did not differ between swimmers and controls (non-dominant: 3904 (172) and 3889 (165) m/s for swimmers and controls, respectively). Tibial SOS also increased with age and was significantly higher in swimmers than in controls (non-dominant: 3774 (155) v 3712 (171) m/s). No differences were found between dominant and non-dominant sides. CONCLUSIONS: Swimming appears to be associated with higher bone SOS in the lower but not in the upper extremities. Further studies are needed to assess whether this difference reflects higher habitual activity among the swimmers or swimming specific mechanisms.

Changes in circulating IGF-I and their correlation with self-assessment and fitness among elite athletes.

The evaluation of training load and effectiveness in elite athletes is difficult. We determined the effect of a four-week training camp on changes in self-assessment physical conditioning scores, fitness and circulating IGF-I in elite Israeli handball players during their preparation for the 1999 World Junior Handball Championship. Training consisted of two weeks of intense training followed by two weeks of relative tapering. Fitness was assessed by field test measurements of 1000-m run, 4 x 10-m shuttle run and vertical jump. Serum IGF-I levels were measured by immunoradiometric assay. Measurements were performed before, after two weeks, and at the end of training. Training resulted in a significant (p < 0.05) improvement in the results of the 4 x 10-m run, 1000-m run and vertical jump. Changes in the self-assessment physical conditioning score showed a bi-directional pattern. After two weeks of training the players reported decreased physical conditioning scores, with return to basal levels after four weeks. Similarly, circulating IGF-I decreased significantly after two weeks, and returned to basal levels after four weeks of training. We found a significant correlation between changes in circulating IGF-I, and self-assessments of physical conditioning scores (r = 0.71, p < 0.001). Intensive training resulted in a decrease, while tapering was associated with an increase in IGF-I levels. These changes were accompanied by parallel changes in subjective physical conditioning self-assessments.