Erfolge mittels Rudererergometer und anaerobe leistungsmöglichkeit bei den Ruderern-studenten

The aim of the study presented was to assess the relationships between the 6-minute "all-out" rowing ergometer test with physical performance indices in college rowers. Ten male rowers (21.60+4.20 yrs; 186,90+5.64 cm; 84.10+6.59 kg; %body fat: 9.62+2.81%) performed a 6-minute "all-out" rowing ergometer test on a rowing ergometer (Concept II, USA) at the first measurement session. In addition, a graded exercise test at the intensities of 150, 200 and 250 W (6-minutes each) and a maximal 5x1 minute interval test were performed at separate measurement sessions. The heart rate (HR) was recorded at the end of each load during a graded exercise test. The individual physical working capacity (PWC) of the rowers was calculated at the maximum of HR recorded during a 6-minute "all-out" test. Blood samples for lactate (LA) determination were obtained from the fingertip before and immediately after each bout of exercise. The anaerobic threshold (AT) indices were determined by interpolation from the relationships between the LA concentration and the respective variable at a LA concentration of 4.0 mmol/l. The LA concentration in the blood was also determined before, immediately after and after 3 minutes and 5 minutes of recovery of the maximal 5 x 1 minute interval test. Significant correlations (p<0.05) were observed between the AT (W) and power (r=0.56) and the covered distance (r=0.55) of a 6-minute "all-out" test. In addition, the power and distance covered of the 6-minute "all-out" test were significantly related to the covered distance and power of all five trials of the maximum interval test (r=0.64-0.77). The stepwise multiple interval test indicated that the power of a 6-minute "all-out" test was explained by the mean power of a maximal 5 x 1 minute interval test at 82.75% (R2). In conclusion, the results of our study suggest that our proposed interval test has a high diagnostic value in the assessment of the anaerobic work capacity of rowers.Das Ziel dieser Untersuchung war, die Zusammenhange zwischen 6-Minuten Leistungstest mittels eines Rudererergometers und Indexen der körperlichen Leistungsmöglichkeit von Ruderern-Studenten zu erstellen. Zehn männliche Ruderer (21.60+/-4.20 Jahre; 186,90+/-5,64cm; 84,10+/-6,59kg; 9,62+/-2,81% Fettgewebe) wurden dem 6-Minuten Leistungstest am Rudererergometer (Concept II, USA) in der ersten Messung unterzogen. Zusätzlich wurden der progressive Belastungstest mit den Werten 150, 200 und 250 W (je 6 Minuten) und der Intervall-Leistungstest in der Zeitspanne von 5x1 Minute in abgesonderten Messungen durchgeführt. Die Herzfrequenz (Heart Rate - HR) wurde in der Endphase jeder Belastung des Stufentestes gemessen. Persönliche körperliche Arbeitsleistung (PWC - engl. physical working capacity) der Ruderer wurde nach maximal gemessener Herzfrequenz in der Zeitspanne des 6-Minuten Leistungtestes errechnet. Aus der Fingerkuppe wurden vor und nach jeder Leistung die Blutproben zur Feststellung des Milchsäurespiegels (LA) entnommen. Die Indexe der anaeroben Schwelle (anaerobic threshold - AT) wurden nach der vorgenommenen Interpolation der Wechselbeziehung zwischen dem LA-Spiegel und der entsprechenden Variable mit der Konzentration von 4,0 mmol/ festgestellt. Der LA-Spiegel wurde im Blut vorher, anschließend, 3 wie auch 5 Minuten nach dem Intervall-Leistungstest 5x1 gemessen. Es wurde eine bedeutende Wechselbeziehung (p<0,05) zwischen der anaeroben Schwelle (W) und dem Kraftaufwand (r=0,56) einerseits und der zurückgelegten Entfernung (r=0,55) in den Zeitspannen des Leistungtestes festgestellt. Der Kraftaufwand und die zurückgelegten Entfernung im Laufe des Leistungtestes hingen auch bedeutend von der zurückgelegten Entfernung und dem Kraftaufwandin allen fünf Zeitspannen des Intervall- Leistungtestes (r=0,64-0,77) ab, Der wicderholende Intervall-Test mit progressiver Belastung ‘beweist, dass sich der 82,75% (R2) Kraftaufwand, gemessen in 6-Minuten Leistungtest, über arithmetisches Mittel vom Kraftaufwand, gemessen im Leistungtest mit Intervallen von 5x1 Minute erklären lasst. Wir schlussfolgern, dass die Ergebnisse unserer Untersuchung darauf hinweisen, wie hoch der diagnostische Wert des vorgeschlagenen Intervall-Leistungtests bei der Einschätzung von Arbeitsleistung der Ruderer ist

Adiponectin and osteocalcin responses to rowing exercise, and the relationship to substrate oxidation in female rowers

This study investigated the effects of acute exercise and menstrual phase on adiponectin and osteocalcin concentrations, and the possible role of these biomarkers in exercise-induced substrate oxidation in rowers. Thirteen female rowers (19.3 ± 2.3 years; height: 172.7 ± 3.9 cm; body mass: 66.5 ± 7.9 kg) performed 1-h rowing ergometer exercise at 70% of maximal oxygen consumption (VO2max) during follicular phase and luteal phase of the menstrual cycle. Oxygen consumption (VO2), total energy expenditure (EE), carbohydrate EE, and lipid EE were assessed during the exercise. Venous blood samples were collected before and after ergometer exercise. No differences (p > 0.05) were observed in substrate oxidation values during exercise across menstrual cycle. Exercise resulted in an acute rise in osteocalcin and no changes in adiponectin at both menstrual cycle phases. Adiponectin and osteocalcin were not related across phase or time (r  0.05). Post-exercise adiponectin was related (p 2 (r = 0.459) and total EE rate (r = 0.598), while post-exercise osteocalcin was correlated (p < 0.05) with mean total (r = 0.411) and lipid (r = 0.557) EE rates. In conclusion, menstrual cycle phase had no effect on substrate oxidation, and adiponectin and osteocalcin responses to acute exercise. It appears that adiponectin and osteocalcin may serve as signals for metabolic reaction to the energy cost of the acute exercise in female rowers

Frequency and duration of vigorous physical activity bouts are associated with adolescent boys’ bone mineral status: A cross-sectional study

Purpose: Vigorous physical activity (VPA) has been proven to promote osteogenesis in adolescents; however the specifics of the optimal pattern of frequency and duration of VPA are unknown. The main goal of the present study was to analyze the associations of different length of VPA bouts with bone health. Methods: 180 healthy male adolescents (11–13 years) had their bone mineral content and density assessed by dual-energy X-ray absorptiometry scans at the whole body, femoral neck (FN) and lumbar spine and their physical activity measured by an accelerometer during one week. Results: VPA was the intensity with the strongest associations with bone mineral parameters especially at the FN. Subjects whose longest VPA bout was 5 min or above had higher FN bone mineral density (BMD) than those who did not complete any 5-min bout and these differences were greater with participants who reached 15 consecutive minutes of VPA (>15': 0.977 ± 0.020 g/cm2; 5'-15': 0.907 ± 0.009 g/cm2; <5': 0.876 ± 0.009 g/cm2; all p < 0.05). When comparing the relevance of VPA bouts and volume of physical activity, the group with low volume and having a VPA bout had better FN BMD compared to the group with high volume but no VPA bout. Additionally, the group with both high volume and VPA bout showed better FN BMD than the rest of the groups. Conclusions: VPA may be the most effective activity intensity to improve bone mineral density and content of adolescent boys, with greater benefits if VPA periods either long or frequent

Vigorous physical activity patterns affect bone growth during early puberty in boys

Summary: This study aims to analyze the impact of participation in vigorous physical activity as it can promote a healthy bone development. Adolescents who increased their participation in vigorous physical activity showed higher improvements in bone parameters compared to those who did not, which highlights the relevance of vigorous physical activity engagement. Introduction: The main purpose of the study was to analyze the effects of different patterns of vigorous physical activity (VPA) on bone development. Methods: One-week accelerometry registers and dual-energy X-ray absorptiometry scans at the whole body, hip, and lumbar spine of 140 healthy male adolescents (11–13 years, at baseline) were performed twice with a 1-year interval between measurements. Four patterns of VPA evolution (“low–low, ” “low–high, ” “high–low, ” and “high–high”) and three patterns of bone growth (“optimal, ” “mean, ” and “reduced”) were defined according to the median participation in VPA and a cluster analysis of the longitudinal changes in BMC and BMD in all sites measured, respectively. Bone mineral parameters were adjusted for skeletal age and body weight prior to statistical comparison among groups. Results: Participants in the “low–high” group had greater adjusted BMD increases at both the femoral neck and lumbar spine when compared to the “low–low” group (estimated mean (95% CI) 0.066 (0.047–0.085) vs. 0.034 (0.021–0.047) g/cm2 and 0.074 (0.054–0.093) vs. 0.049 (0.035–0.062) g/cm2 respectively, both p &lt; 0.05). Femoral neck BMD adjusted increase was also different between the “high–high” and the “high–low” groups (0.053 (0.041–0.066) vs. 0.030 (0.011–0.049) g/cm2, p &lt; 0.05). Additionally, a higher percentage of “optimal” growth was found in the “low–high” group than in the “low–low” and “high–low” categories (36.3, 12.5 and 13.6% respectively, p &lt; 0.05). Conclusions: Engaging in VPA as well as maintaining high levels of VPA during puberty is associated with greater gains in bone mass, which can have an impact in future bone health

Inflammatory markers and bone mass in children with overweight/obesity: the role of muscular fitness

Objectives To examine which inflammatory markers are associated with bone mass and whether this association varies according to muscular fitness in children with overweight/obesity. Methods Plasma interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), epidermal growth factor, vascular endothelial growth factor A (VEGF), and C-reactive protein were analyzed in 55 children aged 8–11 years. A muscular fitness score was computed. Bone mineral content (BMC) of the total body-less head (TBLH) and lumbar spine (LS) were assessed using dual-energy x-ray absorptiometry. Results IL-6 (β = −0.136) and VEGF (β = −0.099) were associated with TBLH BMC, while TNF-α (β = −0.345) and IL-1β (β = 0.212) were associated with LS BMC (P < 0.05). The interaction effect of muscular fitness showed a trend in the association of VEGF with TBLH BMC (P = 0.122) and TNF-α with LS BMC (P = 0.057). Stratified analyses by muscular fitness levels showed an inverse association of VEGF with TBLH BMC (β = −0.152) and TNF-α with LS BMC (β = −0.491) in the low-fitness group, while no association was found in the high-fitness group. Conclusion IL-6, VEGF, TNF-α, and IL-1β are significantly associated with bone mass. Higher muscular fitness may attenuate the adverse effect of high VEGF and TNF-α on bone mass

Absence of Bilateral Differences in Child Baseball Players with Throwing-related Pain

© Georg Thieme Verlag KGStuttgart · New York.The aim of this study was to assess whether side-to-side differences in morphology and function of the upper limbs in 11-12 year-old male baseball players with throwing-related pain (n=14) were more pronounced than that of age-matched healthy untrained subjects (n=16). Baseball players 1) had played baseball≥4.5 h·wk−1 for ≥ 4 years and (2) suffered from moderate-intensity (3-6 points on 10-point questionnaire scale) throwing-related pain in the shoulder or elbow in at least 2 training sessions within the past month. The range of motion (ROM), function and structure of the elbows and shoulders were assessed using goniometry, isokinetic dynamometry and ultrasonography. While the ROM and eccentric external peak torque of internal shoulder rotation were lower, the thickness of the supraspinatus tendon, the ulnar collateral ligament and articular cartilage of the humeral head were larger in baseball players than controls. There were, however, no significant side-to-side differences in any parameter in either group. In conclusion, it is unlikely that side-to-side differences in shoulder and upper limb structure and function contributed to the throwing-related pain in young baseball players, but low shoulder eccentric external peak torque and range of internal rotation may predispose to throwing-related pain

Early anterior knee pain in male adolescent basketball players is related to body height and abnormal knee morphology.

To compare knee torque, range of motion, quality of movement, and morphology in dominant and nondominant legs of male adolescent basketball players with and without anterior knee pain and untrained peers.Cross-sectional.Sports performance laboratory.Male basketball players aged 14-15 years with and without anterior knee pain and healthy untrained subjects (n = 88).Basketball players were allocated to a symptomatic or asymptomatic group based on self-reported anterior knee pain. Associations between pain and body mass, height, passive range of motion, muscle peak torque, coactivation, neuromuscular control, proprioception, and ultrasound observations were investigated.The prevalence of pain did not differ significantly between sides. Of 176 knees inspected, 44 were painful, and 26 of these exhibited abnormalities in ultrasonography. Symptomatic players were 5.0 and 6.9 cm taller than asymptomatic players and controls, respectively (P < 0.05). In athletes with knee pain, the odds ratios of morphological abnormalities and greater height were increased by 8.6 and 5.0 times (P < 0.001).Knee pain prevalence in adolescent basketball players was not related to differences between sides but was higher in tall players. Knee pain was accompanied by morphological abnormalities detected with ultrasound

Report Card grades on the physical activity of children and youth comparing 30 very high Human Development Index countries

Background: To better understand the childhood physical inactivity crisis, Report Cards on physical activity of children and youth were prepared concurrently in 30 very high Human Development Index countries. The aim of this article was to present, describe, and compare the findings from these Report Cards. Methods: The Report Cards were developed using a harmonized process for data gathering, assessing, and assigning grades to 10 common physical activity indicators. Descriptive statistics were calculated after converting letter grades to interval variables, and correlational analyses between the 10 common indicators were performed using Spearman's rank correlation coefficients. Results: A matrix of 300 grades was obtained with substantial variations within and between countries. Low grades were observed for behavioral indicators, and higher grades were observed for sources of influence indicators, indicating a disconnect between supports and desired behaviors. Conclusion: This analysis summarizes the level and context of the physical activity of children and youth among very high Human Development Index countries, and provides additional evidence that the situation regarding physical activity in children and youth is very concerning. Unless a major shift to a more active lifestyle happens soon, a high rate of noncommunicable diseases can be anticipated when this generation of children reaches adulthood.</p

Vitamin C and E treatment blunts sprint interval training–induced changes in inflammatory mediator-, calcium-, and mitochondria-related signaling in recreationally active elderly humans

Sprint interval training (SIT) has emerged as a time-efficient training regimen for young individuals. Here, we studied whether SIT is effective also in elderly individuals and whether the training response was affected by treatment with the antioxidants vitamin C and E. Recreationally active elderly (mean age 65) men received either vitamin C (1 g/day) and vitamin E (235 mg/day) or placebo. Training consisted of nine SIT sessions (three sessions/week for three weeks of 4–6 repetitions of 30-s all-out cycling sprints) interposed by 4 min rest. Vastus lateralis muscle biopsies were taken before, 1 h after, and 24 h after the first and last SIT sessions. At the end of the three weeks of training, SIT-induced changes in relative mRNA expression of reactive oxygen/nitrogen species (ROS)and mitochondria-related proteins, inflammatory mediators, and the sarcoplasmic reticulum Ca2+ channel, the ryanodine receptor 1 (RyR1), were blunted in the vitamin treated group. Western blots frequently showed a major (>50%) decrease in the full-length expression of RyR1 24 h after SIT sessions; in the trained state, vitamin treatment seemed to provide protection against this severe RyR1 modification. Power at exhaustion during an incremental cycling test was increased by ~5% at the end of the training period, whereas maximal oxygen uptake remained unchanged; vitamin treatment did not affect these measures. In conclusion, treatment with the antioxidants vitamin C and E blunts SIT-induced cellular signaling in skeletal muscle of elderly individuals, while the present training regimen was too short or too intense for the changes in signaling to be translated into a clear-cut change in physical performance