Training reduces catabolic and inflammatory response to a single practice in female volleyball players.

We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Thirteen female, national team level, Israeli volleyball players (age 16.0 ± 1.4 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60 minutes of volleyball practice, before and after 7 weeks of training during the initial phase of the season. Training involved tactic and technical drills (20% of time), power and speed drills (25% of time), interval sessions (25% of time), endurance-type training (15% of time), and resistance training (15% of time). To achieve greater training responses, the study was performed during the early phase (first 7 weeks) of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor-I (IGF-I) and IGF-binding protein-3, the catabolic hormone cortisol, the proinflammatory marker interleukin-6 (IL-6), and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of vertical jump, anaerobic properties (peak and mean power by the Wingate Anaerobic Test), and predicted VO2max (by the 20-m shuttle run). Volleyball practice, both before and after the training intervention, was associated with a significant increase of serum lactate, GH, and IL-6. Training resulted in a significantly reduced cortisol response ([INCREMENT]cortisol: 4.2 ± 13.7 vs. -4.4 ± 12.3 ng · ml, before and after training, respectively; p < 0.02), and IL-6 response ([INCREMENT]IL-6: 1.3 ± 1.0 vs. 0.3 ± 0.4 pg · ml, before and after training, respectively; p < 0.01) to the same relative intensity volleyball practice. The results suggest that along with the improvement of power and anaerobic and aerobic characteristics, training reduces the catabolic and inflammatory response to exercise.

Training increases anabolic response and reduces inflammatory response to a single practice in elite male adolescent volleyball players.

We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Fourteen male, elite, national team-level, Israeli volleyball players (age, 16.3±1.1 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60-min volleyball practice, before and after 7 weeks of training during the initial phases of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, and testosterone; the catabolic hormone cortisol; the pro-inflammatory markers interleukin (IL) 6, and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of both anaerobic and aerobic properties. Before the training intervention, the typical volleyball practice was associated with a significant increase of GH and testosterone and also with a significant increase of IL-6. Training resulted in a significantly greater GH response (ΔGH, 2.5±2.4 vs. 4.7±3.0 ng/mL, before and after training, respectively; p<0.02) and reduced IL-6 response (ΔIL-6, 2.0±1.6 vs. 0.6±0.7 pg/mL, before and after training, respectively; p<0.01) to the same relative intensity volleyball practice. The results suggest that, along with the improvement of anaerobic and aerobic characteristics, training leads to a greater anabolic and reduced inflammatory response to exercise.

The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled study.

The use of ergogenic nutritional supplements is becoming inseparable from competitive sports. ß-Hydroxy-ß-Methylbutyric acid (HMB) has recently been suggested to promote fat-free mass (FFM) and strength gains during resistance training in adults. In this prospective randomized, double-blind, placebo-controlled study, we studied the effect of HMB (3 g/day) supplementation on body composition, muscle strength, anaerobic and aerobic capacity, anabolic/catabolic hormones and inflammatory mediators in elite, national team level adolescent volleyball players (13.5-18 years, 14 males, 14 females, Tanner stage 4-5) during the first 7 weeks of the training season. HMB led to a significant greater increase in FFM by skinfold thickness (56.4 ± 10.2 to 56.3 ± 8.6 vs. 59.3 ± 11.3 to 61.6 ± 11.3 kg in the control and HMB group, respectively, p < 0.001). HMB led to a significant greater increase in both dominant and non-dominant knee flexion isokinetic force/FFM, measured at fast (180°/sec) and slow (60°/sec) angle speeds, but had no significant effect on knee extension and elbow flexion and extension. HMB led to a significant greater increase in peak and mean anaerobic power determined by the Wingate anaerobic test (peak power: 15.5 ± 1.6 to 16.2 ± 1.2 vs. 15.4 ± 1.6 to 17.2 ± 1.2 watts/FFM, mean power: 10.6 ± 0.9 to 10.8 ± 1.1 vs. 10.7 ± 0.8 to 11.8 ± 1.0 watts/FFM in control and HMB group, respectively, p < 0.01), with no effect on fatigue index. HMB had no significant effect on aerobic fitness or on anabolic (growth hormone, IGF-I, testosterone), catabolic (cortisol) and inflammatory mediators (IL-6 and IL-1 receptor antagonist). HMB supplementation was associated with greater increases in muscle mass, muscle strength and anaerobic properties with no effect on aerobic capacity suggesting some advantage for its use in elite adolescent volleyball players during the initial phases of the training season. These effects were not accompanied by hormonal and inflammatory mediator changes.

Effect of HMB supplementation on body composition, fitness, hormonal profile and muscle damage indices.

There is a huge market for ergogenic supplements for athletes. However, only a few products have been proven to have ergogenic effects and to be effective at improving muscle strength and body composition. One such supplement is beta-hydroxy beta-methylbutyrate (HMB). Derived from the amino acid leucine and its keto acid alpha-ketoisocaproate (KIC), HMB has been well documented as an oral ergogenic supplement commonly used by athletes. Several studies have shown that combining exercise training with HMB supplementation leads to increased muscle mass and strength, and there is some anecdotal evidence of aerobic improvement. However, HMB supplementation has been found to be effective mainly for untrained individuals. While previous reviews have emphasized three main pathways for HMB's mode of action: 1) enhancement of sarcolemmal integrity via cytosolic cholesterol, 2) inhibition of protein degradation via proteasomes, and 3) increased protein synthesis via the mTOR pathway, more recent studies have suggested additional possible mechanisms for its physiological effects. These include decreased cell apoptosis and enhanced cell survival, increased proliferation, differentiation and fusion via the MAPK/ERK and PI3K/Akt pathways, and enhanced IGF-I transcription. These are described here, and hormonal interactions are discussed, along with HMB dosage and safety issues.

Body fat measurements in elite adolescent volleyball players: correlation between skinfold thickness, bioelectrical impedance analysis, air-displacement plethysmography, and body mass index percentiles.

BACKGROUND: Determination of body composition is an essential parameter in training athletes because low fat-muscle ratio might improve physical performance in many types of sports. Since training is often conducted in the field, it is important to determine whether simple field measurements of body composition assessment correlate with laboratory measurements. OBJECTIVE: Examine the correlation of body fat content as measured using skinfold thicknesses (SF), air-displacement plethysmography (BOD POD), bioelectrical impedance analysis (BIA) and body mass index (BMI) age and gender adjusted percentiles. METHOD: Body mass as measured by SF, BOD POD, BIA, and BMI percentiles were examined in 29 elite, national team level, male and female volleyball players (age range 13 to 18) at the beginning of the training season. RESULTS: Body fat percent measured by SF, BIA and BOD POD were highly positively correlated (r > 0.83). Measurements of body fat by SF, BIA and BOD POD were weakly correlated with BMI percentiles (r < 0.45). CONCLUSIONS: Results suggest that BMI percentile is not a good measure for body fat in adolescent elite male and female volleyball players. SF and measurements of body composition by BIA and BOD POD are essentially interchangeable.

The effect of a volleyball practice on anabolic hormones and inflammatory markers in elite male and female adolescent players.

The effect of a single exercise as well as exercise training on the growth hormone (GH)-insulin-like growth factor (IGF-I) axis and inflammatory cytokines was studied mainly in adults participating in individualized endurance-type sports. The gender-specific effect of exercise on these systems in adolescents is unknown. Therefore, the purpose of this study was to evaluate the effect of a typical volleyball practice on anabolic (GH, IGF-I, and testosterone) and catabolic hormones (cortisol) and inflammatory mediators (interleukin-6 [IL-6]) in elite, national team level, male (n = 14) and female (n = 13) adolescent volleyball players (13-18 years, Tanner stage 4-5). Exercise consisted of a typical 1-hour volleyball practice. Blood samples were collected before and immediately after the practice. Exercise led to significant increases in GH (0.2 +/- 0.1 to 2.7 +/- 0.7 and 1.7 +/- 0.5 to 6.4 +/- 1.4 ng x mL, in men and women, respectively, p < 0.05 for both), testosterone (6.1 +/- 0.9 to 7.3 +/- 1.0 and 2.4 +/- 0.6 to 3.3 +/- 0.7 ng x mL, in men and women, respectively, p < 0.05 for both), and IL-6 (1.1 +/- 0.6 to 3.1 +/- 1.5 and 1.2 +/- 0.5 to 2.5 +/- 1.1 pg x mL, in men and women, respectively, p < 0.002 for both). Exercise had no significant effect on IGF-I, insulin-like growth factor binding protein-3, and cortisol levels. There were no gender differences in the hormonal response to training. Changes in GH and testosterone after the volleyball practice suggest exercise-related anabolic adaptations. The increase in IL-6 may indicate its important role in muscle tissue repair. These changes may serve as an objective quantitative tool to monitor training intensity in unique occasions in team sports.

[Iron deficiency and anemia in female athletes--causes and risks].

Iron deficiency is probably the most common nutrient deficiency in the western world. Low levels of iron in the body are caused by several mechanisms, and become symptomatic with the onset of iron deficiency anemia. Athletes are a special group with additional reasons for iron or blood loss, such as plasma expansion, increase perspiration, 'foot strike hemolysis, and occasionally--malnutrition. Female athletes have yet another source of blood loss--menstruation. However, the most common cause for low hemoglobin levels in an athlete is dilutional pseudoanemia, which is caused by exercise-induced fluid retention. Athletes are more sensitive to the effects of anemia and iron deficiency, as exercise performance depends on maximal oxygen carrying capacity to the active muscle, and efficient oxygen utilization. Iron deficiency without anemia can also reduce athletic performance. Diagnosis is ultimately made by a blood count and red blood cell parameters, with ferritin serving as an index of body iron stores. Treatment requires iron supplements, as it is nearly impossible to refill the iron stores through diet alone.