NEW EQUATIONS TO DETERMINE EXERCISE INTENSITY USING DIFFERENT EXERCISE MODES

The purpose of this study was to determine new equations from the relationship of %·VO2max versus %HRmax, based on direct measures of oxygen uptake, in four exercise modes (leg cycling, rowing, stepping and running), in young adult females and males with low risk for cardiovascular disease. Ten adult males and ten females volunteered for the study. The participants performed an incremental test for each exercise mode until exhaustion. Regression analyses were carried out for each participant at a target % of VO2max and %HRmax was computed. At 40-90%·VO2max, the regression equations predicted similar values of %HRmax for males and females in the four exercise modes. In contrast, estimated %HRmax for cycling was higher at 40-70%·VO2max, when compared with stepping and running. The results support the notion that a single equation to predict target heart rate values for both males and females can be applied. Furthermore, at light and moderate intensities, leg cycling produces different %·VO2max-%HRmax regression equations than stepping and running

Developmental fitness curves: Assessing sprint acceleration relative to age and maturity status in elite junior tennis players

Background The influence of maturity-status on athletic performance is reasonably well-documented. Methodological and practical issues of assessment and lack of longitudinal data have impacted the success of various models. Aim To develop age- and sex-specific developmental curves for sprint acceleration in elite youth tennis players and to address variation in performance relative to chronological and biological age. Subjects and methods Measures of acceleration were available for 3120 elite youth tennis players aged 8–15 years attending National and Regional Talent Identification days. Variation in acceleration by chronological and estimated biological ages was evaluated in corresponding data for an independent sample of elite youth players 8.9 to 15.1 years of age. Results Acceleration varied as a function of chronological and biological age relative to developmental curves. Early maturing males and females had significantly poorer performances when acceleration was considered relative to biological age. Significant discrepancy in percentiles relative to biological versus chronological ages was also evident between early and late maturing players of each sex. Conclusion Evaluating performance relative to developmental curves and maturity status may be a practical means of monitoring long-term athlete development in tennis

Assessment of reliability in isokinetic testing among adolescent basketball players

Background. The reproducibility of day-to-day testing of isokinetic concentric and eccentric muscular actions among adolescent basketball players aged 14 to 16 years and relationships of mean within-subject variation in two isokinetic testing sessions with chronological age, biological maturation (estimated age at peak height velocity), training experience, body size, lower-body morphology, and initial strength performance were evaluated. Material and Methods. The sample included 27 basketball players who completed replicate test sessions of 5 repetitions of reciprocal concentric and eccentric knee extensions and flexions at 60 degrees s(-1). A randomly selected subsample of 8 players completed a third testing session to confirm reliability estimates. Results. Coefficients of variation (CV) between sessions 1 and 2 ranged from 8.1% to 17.4%, and intraclass coefficients (ICCs) ranged from 0.72 to 0.89. For sessions 1 and 3, CVs ranged from 3.9% to 6.0%, and ICCs ranged from 0.95 to 0.99. The initial level of strength of eccentric knee flexion (r=-0.43) and eccentric knee extension (r=-0.42) were correlated (P<0.05) with eccentric knee extension within-variation between two sessions. Training experience (r=-0.37, P<0.05) and initial values of concentric knee flexion (r=-0.62, P<0.01) were correlated with concentric knee flexion within-subject differences. Within-subject variation of eccentric knee extension was correlated (P<0.05) with chronologic age (r=0.41), estimated age at peak height velocity (r=-0.38), body size (r=0.41 to 0.47), and leg volume (r=0.39). Conclusions. Familiarization sessions may improve the reliability of concentric and eccentric knee isokinetic strength testing at 60 s(-1) in adolescent basketball players. Age, maturity status, and training experience of young athletes should be considered when testing knee isokinetic strength at 60 degrees s(-1)

A Kinematic Analysis of the Basketball Shot Performed with Different Ball Sizes

In youth basketball, the ball’s size is adapted to fit the participants’ physical capacities and improve the development of manipulative skills. The current study compared the kinematic param eters of the basketball shot (BS) performed with two different ball sizes. Twenty-seven adolescent females aged 12.1 ± 0.9 years (height: 153.3 ± 8.0 cm; body mass: 48.8 ± 12.8 kg) completed 10 BS trials from a frontal position at 5.75 m from the basket with two ball sizes: a smaller and lighter ball (size five, 480 g) and the standard ball size for their age (size six, 566 g). No statistically significant differences were observed for ball release variables or efficacy levels. Significantly greater shoulder flexion was detected at release while shooting with a size six ball (F = 2.982, p ≤ 0.01). The shoulder’s angular velocity at release was significantly lower while performing with a size six ball (F = 3.089, p ≤ 0.01). No significant differences were found for the elbow or knee angles or angular velocities. Stature and upper-body strength were significantly correlated with selected kinematic parameters. A change in ball size may be a helpful strategy for coaches seeking to promote optimal shoot ing patterns, enhancing effectiveness and enjoyment, particularly among young people and more inexperienced players.info:eu-repo/semantics/publishedVersio

Effects of aerobic and strength-based training on metabolic health indicators in older adults

Background: The weakening of the cardiovascular system associated with aging could be countered by increasing levels of physical activity and functional fitness. However, inconsistent findings have been found, and the variety of characteristics of exercise used in previous studies may partly explain that inconsistent results. Objective: To investigate the training effect of sixteen weeks of moderate intensity, progressive aerobic and strengthbased training on metabolic health of older women and men. Methods: Sixty three sedentary individuals (mean (SD) age 76 (8) years) were randomly assigned to control (n = 31) or exercising (n = 32) groups. The training group was separated to aerobic (n = 18) or strength-based (n = 14). Training took place three times a week. Subjects agreed not to change their diet or lifestyle over the experimental period. Results: Exercising group attained after treatment significant differences on body weight, waist circumference, body mass index, diastolic blood pressure, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol, total cholesterol/ HDL-cholesterol relationship, high sensitivity C-reactive protein, and 6-minute walk distance. The control group only had significant differences on waist circumference. Conclusion: The training programs produced significant benefits on metabolic health indicators of sedentary older women and men

Endothelial Wall Thickness, Cardiorespiratory Fitness And Inflammatory Markers In Obese And Non-obese Adolescents.

Increased carotid intima-media thickness (c-IMT) is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated. To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents. Thirty-five obese subjects (19 boys) and 18 non-obese subjects (9 boys), aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max), and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, C-reactive protein (CRP), and adiponectin were assessed. c-IMT was measured by ultrasound. The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c), adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max. Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents.1847-5

Glycated hemoglobin and associated risk factors in older adults

BACKGROUND: The aim of this study is to investigate the relationships between HbA1c and other risk factors like obesity, functional fitness, lipid profile, and inflammatory status in older adults. Epidemiological evidence suggests that HbA1c is associated with cardiovascular and ischemic heart disease risk. Excess of body weight and obesity are considered to play a central role in the development of these conditions. Age is associated with several risk factors as increased body fat and abdominal fat, deterioration of the lipid profile, diabetes, raising in inflammatory activity, or decreased functional fitness. METHODS: Data were available from 118 participants aged 65-95 years, including 72 women and 46 men. Anthropometric variables were taken, as was functional fitness, blood pressure and heart rate. Blood samples were collected after 12 h fasting, and HbA1c, hs-CRP, TG, TC, HDL-C, LDL-C, and glycaemia were calculated. Bivariate and partial correlations were performed to explore associations amongst the variables of interest. Differences between groups were explored by performing factorial analysis of variance. RESULTS: HbA1c levels ranged from 4.6%-9.4% with 93% of the cases below 6.5%. Women had higher HbA1c, glycaemia, TC, BMI, and lower and upper flexibility than men. Men had higher BW, WC, 6-min walking distance, and VO2peak than women. Age, SBP, DBP, HRrest, HRpeak, HDL-C, LDL-C, TG, TG/HDL-C ratio, Log10 hs-CRP, upper and lower strength, and agility and dynamic balance were similar in men and women. HbA1c had positive associations with glycaemia, HDL-C, TG/HDL-C, BW, WC, BMI, but not with functional fitness, TC, LDL-C, Log10 hs-CRP, PAD, or PAS. Obese participants had higher HbA1c than non-obese only when IDF and not USDHHS criteria were applied. CONCLUSIONS: Older women had higher HbA1c than men, even after controlling for BMI. HbA1c associates equally with BW, BMI or WC. Population-based criteria are recommended to classify obesity and to identify higher levels of HbA1c in obese older adults. HbA1c associates with atherogenic dyslipidemia particularly with TG and TG/HDL-C ratio, but not with TC, HDL-C, or LDL-C. HbA1c is not associated with hs-CRP, and with functional fitness and aerobic endurance

Age and menarcheal status do not influence metabolic response to aerobic training in overweight girls

BACKGROUND: Multidisciplinary intervention is an alternative for the treatment of children and adolescent obese. However, the influence of age and menarcheal status in the pattern of metabolic response of obese girls has not been investigated. The following study examined the effects of a 12-week multidisciplinary intervention on metabolic health in overweight girls and the contribution of age and menarcheal status on the resulting changes. METHODS: Eighty-eight overweight girls (10 - 16 years) were considered initially for this study and randomly assigned (intervention group: n = 58; control group: n = 30). Forty-six girls completed the intervention program and 16 girls completed the follow-up for the control group. The 12-week intervention included aerobic exercises (three times per week) and nutritional intervention. Anthropometrical measures (body mass, body mass index and waist circumference), menarcheal status and metabolic profiles including glucose, insulin, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were assessed in the beginning and after of intervention. Additionally, were calculated homeostatic model assessment-insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI). RESULTS: After 12-week, girls decreased significantly the body mass (76.6 ± 14.7 to 75.7 ± 14.6 kg) body mass index (30.1 ± 4.0 to 29.4 ± 4.0 kg/m(2)) and waist circumference (98.9 ± 10.9 to 96.5 ± 11.4 cm). There were differences in HDL-C (43.1 ± 8.2 to 50.3 ± 9.4 mg/dl), TG (120.9 ± 64.3 to 93.3 ± 47.9 mg/dl) and insulin (16.9 ± 7.6 to 15.6 ± 9.8 mg/dl). Relative contribution of age was significant only for within-subject variability in waist circumference. CONCLUSIONS: The multidisciplinary based on aerobic training intervention used in this study produced substantial benefits on metabolic health indicators in overweight girls. The changes observed were not related to inter-individual variability in age and maturity status

Physical activity and movement proficiency:the need for a biocultural approach

“Gaps in Our Knowledge” are discussed in the context of the need to integrate biological and behavioral factors in a biocultural approach to physical activity and movement proficiency. Specific issues considered include outdoor play, organized and informal activity, biological maturation, tracking of activity, development of movement proficiency, and individual differences. Studies considered are largely based on youth in economically better-off, developed countries in the western culture context. There is a need to extend studies of physical activity and movement proficiency to different cultural contexts.</jats:p