«BOOK OF ABSTRACTS Edited by: Loland, S., Bø, K., Fasting, K., Hallén, J., Ommundsen, Y., Roberts, G., Tsolakidis, E. Hosted by: The Norwegian ...»
The discontinuous incremental test (FS_EXT, Roels et al., 2005) comprised 5 x 200 m swims with 30 s rest intervals. Speed was increased by 5-10% for each stage, the last of which was performed at maximal speed (vVO2max). Maximal oxygen uptake (VO2max) was taken as the highest 30 s VO2 average; the ventilatory threshold (VT) was established by the V-slope method, and the OBLA was determined from fingertip blood lactate concentration ([La], obtained between each 200m stage using a Lactate Pro analyser), in FS_EXT).
The two 7-min constant velocity exercise bouts (FS_CTA and FS_CTB) were each performed at Δ70% [= VT + 0.70 x (VO2max - VT)].
Performance was taken as official 400m completion time (T400) within a freestyle swimming competition that took place within one month of FS_EXT, FS_CTA and FS_CTB.
The breath-by-breath data of FS_CTA and FS_CTB were 1-s interpolated, time-aligned and averaged. The parameters of the VO2 kinetics (td1, τ1, A1, td2, τ2, A2; i.e. time delay, time constant and amplitude of the primary phase and slow component, respectively) were modelled with two exponential functions.
Results: τ1 (15.8 ± 4.7 s) was significantly correlated with T400 (251.4 (Mean) ± 12.4 s (SD); r = 0.61; p = 0.02), absolute VO2max (4.2 ± 0.76 L.min-1; r = -0.66; p = 0.01) and vVO2max (1.46 ± 0.07 m s-1; r = -0.61; p = 0.02). None of the other measured VO2 kinetics parameters (td1: 12.2 ± 2.7 s; A1: 40.6 ±4.7 ml.kg-1.min-1; td2: 167 ± 67 s; τ2: 115 ± 172.4 s; A2: 3.6 ± 2.5 ml.kg-1.min-1).were significantly correlated with T400. T400 was significantly correlated with absolute VO2max (r = -0.70, p = 0.01); and speed at both OBLA (1.34 ±
0.01 m.s-1; r = -0.88; p = 0.00) and VT (1.26 ± 0.08 m.s-1; r = -0.80; p = 0.00).
14 ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCETH Wednesday, June 24th, 2009 Conclusion: The shorter time constant for the primary phase of the VO2 response in swimming (but not the amplitude of the slow component) appears to be associated with higher aerobic fitness and performance.
Reference: Roels et al. (2005). Specificity of VO2 max and the ventilatory threshold in free swimming and cycle ergometry: comparison between triathletes and swimmers. Br J Sports Med 39:965-968
THE USE OF NUTRITIONAL SUPPLEMENTS BY ELITE PORTUGUESE SWIMMERSTEIXEIRA, V.H., SOUSA, M., MOREIRA, P.
UNIVERSITY OF PORTOIntroduction: A well-planned diet provides the athlete with adequate levels of nutrients; however, there are many sportsmen/sportswomen taking nutritional supplements (NSs) in spite of their possible contamination with prohibited compounds and the unproved efficacy of the majority of them. In Portugal, no official data regarding the consumption of NSs is available. This study aimed to determine the prevalence and determinants of the use of NSs by elite Portuguese swimmers.
Methods: Thirty six swimmers (14 women; 17.3 years), belonging to the Portuguese national team, volunteered to participate in this study.
Between January and March, subjects were asked to complete a questionnaire that included questions to characterise the use of NSs, and a semiquantitative food-frequency questionnaire.
Results: The prevalence of the use of NSs was 91.7%, with a mean consumption of 3.7 NSs per swimmer (between 1 and 10). Regarding the type of supplements and fluids ingested, the most used were sport drinks (75.8%), magnesium (60.6%), multivitamins/minerals (57.6%), proteins (27.3%) and vitamin C (21.2%), with no significant gender and age category (18 years vs. ≥18 years) differences.
The most frequent reasons for the intake of NSs were: ’to improve sports performance’ (57.6%), ’to have more energy/to reduce fatigue’ (57.6%), ’to accelerate recovery’ (42.4%), “to have more focus” (15.2%, with an age-based difference: 18 years=23.6%; ≥18 years=64.3%; p=0.034) and “to prevent/to treat diseases or injuries” (15.2%). Physicians (57.6%), coaches (30.3%), family (24.2%) and the swimmer him/herself (21.1%) were the main source of information and advice, with no statistical differences between gender and age groups. The estimated intakes for most nutrients (16 studied) were above the recommendations. For girls between 19 and 30 years (n=4), the estimate mean ingestion of potassium (4305 mg/day), calcium (938 mg/day), folate (385 mcg/day), vitamin D (3.6 mcg/day) and vitamin E (10.8 mg/day) was under the recommendations. For boys with 14-18 years (n=11), the estimate mean intake of potassium (4392 mg/day), vitamin D (4.8 mcg/day) and vitamin E (13.2 mg/day) was under the recommendations. For males with ages between 19 and 30 years (n=11), only the estimated mean intake of vitamin E (12.9 mg/day) was under the recommendations.
Conclusions: The prevalence of the consumption of NSs was high and not justified due to an adequate nutrient intake by swimmers. In general, the type of NSs used and their determinants were not associated with gender or age group. Therefore, dietary education could be beneficial to maximize elite swimmers’ performance and health benefits that result from optimal nutrition.
PHYSIOLOGICAL AND PSYCHOLOGICAL ASPECTS OF SWIMMERS IN DIFFERENT TRAINING PERIODSSIMOLA, R., SAMULSKI, D.M., PRADO, L.S.
FEDERAL UNIVERSITY OF MINAS GERAIS, BRAZILIntroduction: Even though many investigations have studied the psychological and physiological responses of athletes to periods of intensified training, only sparse information is provided regarding the interactions of these responses during the recovery period (Steinacker et al. 2000). Therefore, we aimed to investigate the effects of different training loads on stress and recovery perception (SRP) and on plasma activity of creatine kinase (CK).
Methods: Subjects were highly trained, male swimmers (17.7 + 1.3 y.o.). SRP and CK were evaluated after two distinct training phases. On the first, subjects swam approximately 50.000 meters in the week during 5 weeks. On the second, swimmers covered an average of
25.000 meters in the week, for 2 weeks. 05 ml blood were obtained from the antecubital vein for determination of CK. SRP was evaluated using the questionnaire RESTQ-Sport for the Portuguese language (Costa & Samulski, 2005). The Student’s t-test and Pearson’s product moment correlation were used for statistical analysis. Significance level was p0.05.
Results: After the second training phase, a significant reduction of CK was observed when compared to the first measurement (261.66 +
120.04 U/L; 167.92 + 57.14 U/L), along to a reduction of scale scores in RESTQ-Sport Conflicts/Pressure (2.42 + 0.79; 1.98 + 0.9), Fatigue (2.28 + 1.07; 1.12 + 0.71), Lack of Energy (2.02 + 0.83; 1.5 + 0.61), Perturbations on Intervals (2.00 + 0.69; 1.23 + 0.75) e Lesions (2.5 + 0.91;
1,57 + 1,04). Furthermore, significant increases were seen on scales Physical Recovery (3.07 + 1.23; 3.75 + 1.08) and Being in Shape (3.23 + 1.23; 4.00 + 1.12). However, no significant correlations between scores and CK were observed in any of the sampling phases. Conclusion: Sharp training volume decreases after a period of high training loads may cause improvements on psychological and physiological profiles of the athletes investigated. However, these aspects may not necessarily be correlated.
STEINACKER, J. M.; LORMES, W.; KELLMANN, M.; LIU, Y.; REIBNECKER, S.; OPTIZGRESS, A.; BALLER, B.; GUNTHER, K.; PETERSEN, K.G.; KALLUS, K.W.; LEHMANN, M.; ALTENBURG, D. Training of junior rowers before World Championships: effects on performance, mood state and selected hormonal and metabolic responses. Journal of Sports Medicine and Physical Fitness, 40, p. 327-35, 2000.
COSTA, L. O. C.; SAMUSLKI, D. M. Processo de validação do questionário de estresse e recuperação para atletas (RESTQ-Sport) na língua portuguesa. Revista Brasileira de Ciência e Movimento, 13, p. 79-86, 2005.
14:00 - 15:30 Oral presentations OP-HF04 Health and Fitness 4
AGE-RELATED CHANGE IN KNEE EXTENSORS AND FLEXORS RATE OF FORCE DEVELOPMENT AND ITS RELATION TO
POSTURAL STABILITYBEZERRA, P., ZHOU, S., CROWLEY, Z., BAGLIN, R.
SOUTHERN CROSS UNIVERSITY, NSW, AUSTRALIAIntroduction: The ability to develop force rapidly, assessed as the rate of force development (RFD), in the knee extensors declines significantly with increasing age with negative impact in controlling posture 1. Little research has examined the age-related change in knee flexors RFD and its association with postural control. The aim of this study was to examine whether knee extensors and flexors RFD changes differently across lifespan and the relationship between knee flexors RFD and postural control, in both men and women.
Methods: Traditional centre of pressure (COP) and stabilogram parameters were examined on hard and soft surfaces with eyes open and closed. The RFD of knee extensors and flexors was assessed in static knee extension and flexion. Three groups of healthy volunteers, aged 18-30 (YG), 40-50 (MG) and 60-77 (OG) years, with 10 males and 10 females in each were recruited from local populations. General linear model multivariate analysis with group and gender as fixed factors were performed to compare the between group RFD differences, and bivariate correlations were used to examine the relationship between RFD and COP. Testing procedures were approved by the Human Research Ethics Committee of the University and written informed consent was obtained from the subjects.
Results: Significant lower RFD was found in OG compared with YG and MG in knee extensors (p 0.001 and p 0.05) and flexors (p
0.01 and p 0.001) RFD. The ability to develop force rapidly was higher in males than females in all age-groups (p 0.001). Both MG and YG were significantly better from OG in COP mean distance in anterior-posterior (AP) direction (p 0.05) and COP mean velocity in AP and medial-lateral (ML) directions (p 0.001). Moderate negative correlations were found between COP mean velocity in ML and knee extensors (r = -0.30 to -0.37, p = 0.05) and flexors (r = -0.32 to -0.40, p = 0.05 to 0.01) in all posture testing conditions.
Discussion/conclusion: Results showed significant age-related decreases in RFD of knee extensors and flexors. However, the ability to develop force is maintained until the fifth decade. The increased amount of postural sway in ML appears to be the best marker for risk of falling 2. Both knee extensors and flexors RFD showed significant negative correlations with COP mean velocity in ML. It appeared that the higher RFD the better the postural control performance. It is suggested that RFD be further examined for its validity as a good indicator in postural control, particularly in the knee flexors.
1. Izquierdo, M., et al., Maximal and explosive force production capacity and balance performance in men of different ages. European Journal of Applied Physiology & Occupational Physiology, 1999. 79(3): p. 260-7.
2. Maki, B.E., P.J. Holliday, and A.K. Topper, A prospective study of postural balance and risk of falling in an ambulatory and independent elderly population. Journal of Gerontology, 1994. 49(2): p. M72-84.
DO ADHD CHILDREN WITH HIGHER PHYSICAL ACTIVITY HAVE WEIGHT PROBLEMS?LIN, C.Y., YANG, A.L., LIN, C.L., SU, C.T.
NATIONAL CHENG KUNG UNIVERSITYIntroduction: Children with Attention deficit hyperactivity disorder (ADHD) are characterized by higher level of physical activity (PA), which often disturbs the life of these children and their families. Many studies have addressed the negative influences caused by their too much PA. However, few articles explored the possible positive effects produced by the higher level of PA. Appropriate amount of PA was known as an important factor of healthy physical status, such as proper body weight. Since the children with ADHD tended to have higher level of PA, we would like to explore its influences on the body weight. We hypothesized that the percentage of obesity or overweight of the children with ADHD, who have higher level of PA, would be less than the typically developing children.
Methods: 17 boys with ADHD (ADHD group), diagnosed by DSM IV, and 17 typically developing boys (control group) participated in the study. The informed consent was obtained from each participant and their parents. The height, weight, body mass index (BMI), and age in the ADHD group were 134.66+-19.53 cm, 34.94+-15.10 kg, 18.31+-3.20, and 103.29+-33.45 months, respectively. The height, weight, BMI, and age in the control group were 132.96+-11.33 cm, 35.66+-12.20 kg, 19.59+-3.85, and 109.24+-23.22 months, respectively. BMI was calculated by square height (m2) divided by weight (kg), and the weight status was determined by BMI and age. In order to confirm that our ADHD group had higher level of PA, each child was asked to wear a uni-axial accelerometer (ActiGraph GT1M) during the waking time of one week to measure the objective PA in daily life.
Results: PA in ADHD group (1.62+-.11) was confirmed to be higher than the control group (1.46+-.10) as indicated by the metabolic equilibrium (MET) per minute during one week (p.01).The prevalence of normal weight, overweight, and obesity in the ADHD group were 58.82%, 29.41%, and 11.76%, respectively. The prevalence of normal weight, overweight, and obesity in the control group were 64.71%, 17.65%, and 17.65%, respectively. No significantly statistic difference between the two groups in the weight status (chi square =.748, p =.79).
Discussion: The study indicated that the children with ADHD did not have benefit on the weight status by their higher level of PA. We found that the ADHD group has the similar percentage of overweight and obesity with the control group. Our study suggested that the issue of obesity should be also of concerns for children with ADHD, although they demonstrated higher level of PA than their control peers.
References ActiGraph. (2004). GT1M and ActiLife Desktop Software User’s Manual. Florida: ActiGraph, LLC.
American Psychological Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
Cole, T. J., et al. (2000). Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ, 320(7244), 1240-1243.