We examined the prevalence of 14 modifiable CHD risk factors in a sample of 210 provincial Greek children as they progressed from age 12 to 14. It was found that 46.2% of boys and 49.5% of girls (p > 0.05) exhibited three or more risk factors at their 12th year, with values of 42% for boys and 51.1% (p > 0.05) for girls for their 13th year, and 29.4% for boys and 55% (p < 0.001) for girls in their 14th year. Risk factors with the highest prevalence in both sexes included low vigorous physical activity, low aerobic fitness, and elevated body fatness. The fact that boys exhibited progressively fewer risk factors with age was mainly attributed to increased time spent on vigorous physical activity (P < 0.001) and higher predicted oxygen intake (P < 0.001) with a concomitant decrease in body fat (P < 0.001). The opposite pattern demonstrated by girls was primarily due to elevated predicted % body fat (P < 0.05), % saturated fat intake (P < 0.05), total cholesterol (TC; P < 0.001), low-density lipoprotein cholesterol (LDL-C; P < 0.001), and decreased high-density lipoprotein cholesterol (HDL-C)/TC; P < 0.001). In conclusion, a high percentage of young adolescent Greek boys and girls exhibit three or more modifiable CHD risk factors. However, as the children progress from age 12 to 14, gender differences emerge regarding the development of their CHD risk profiles. The present data support the notion that preventive strategies for combating CHD should begin early in life.
Constantin Bouziotas and Yiannis Koutedakis
Alan Nevill, Georgia Tsiotra, Panagiotis Tsimeas and Yiannis Koutedakis
We adopted allometric models to identify the most appropriate body size/shape characteristics associated with physical performance activities of Greek school children. Children underwent assessments for aerobic and anaerobic fitness, flexibility and hand-grip strength. Results suggest that the inverse Ponderal index and not BMI is the most appropriate body-shape indicator associated with running and jumping activities. Height was negatively associated with flexibility, but both height and weight were positively associated with hand-grip strength. In conclusion, allometric models provide a valuable insight into the most appropriate body size and shape characteristics associated with children’s physical performances and at the same time ensure valid inference when investigating group/population differences (e.g., between gender and maturation status).
Constantin Bouziotas, Yiannis Koutedakis, Ruth Shiner, Yiannis Pananakakis, Vasiliki Fotopoulou and Styliani Gara
The prevalence of 14 selected modifiable coronary heart disease (CHD) risk factors was determined in randomly selected adolescent boys (n = 117) and girls (n = 93) from provincial Greece. Based on published criteria thresholds for CHD, 45% of boys and 50% of girls exhibited three or more risk factors with time spent on “vigorous” activities, low cardiorespiratory fitness and fatness being among the most frequent in both sexes. Stronger associations were found between cardiorespiratory fitness and time spent on “vigorous” rather than “moderate-to-vigorous” activities in both boys and girls. Regression analysis indicated that energy expenditure (P < .01) in boys and energy expenditure (P < .05) and energy intake (P < .01) in girls could alone explain about 60% of the body-fat related findings in either group. Broadly based primary prevention strategies aimed at children should concentrate on reducing the overall energy intake and increasing the time spent on “vigorous” activities if future Greek adult CHD mortality is to be reduced.
Athanasios Z. Jamurtas, Antonios Stavropoulos-Kalinoglou, Stilianos Koutsias, Yiannis Koutedakis and Ioannis Fatouros
Childhood obesity is increasing alarmingly, and a strong association with chronic diseases has been established. Specific adipokines are released from the adipose tissue and relate with chronic diseases even in the pediatric population. Adiponectin levels are lower in obesity and increase with decreasing body weight. A few pediatric studies examining a possible relationship between resistin and obesity do not provide a clear picture. Most studies agree that visfatin levels appear elevated in childhood obesity. Exercise seems to increase adiponectin levels whereas resistin levels are reduced. The lack of data on the effects of acute and chronic exercise on visfatin levels precludes us from making safe conclusions as to what the effects of exercise (acute or chronic) would be on visfatin levels in children. Clearly, exercise has an impact on the adipose tissue and the release of adiponectin, resistin, and visfatin. However, other factors affect the secretion rate of these adipokines from the adipose tissue; these factors should also be taken into consideration when examining the effects of exercise on adipokines. Gender, age, body composition, physical activity levels, mode and intensity of exercise are some of the factors that should be looked into in future studies.
Georgia D. Tsiotra, Alan M. Nevill, Andrew M. Lane and Yiannis Koutedakis
We investigated whether children with suspected Developmental Coordination Disorder (DCD+) demonstrate different physical fitness levels compared with their normal peers (DCD−). Randomly recruited Greek children (n = 177) were assessed for body mass index (BMI), flexibility (SR), vertical jump (VJ), hand strength (HS), 40m dash, aerobic power, and motor proficiency. ANCOVA revealed a motor proficiency (i.e., DCD group) effect for BMI (p < .01), VJ (p < .01), and 40m speed (p < .01), with DCD+ children demonstrating lower values than DCD−. Differences between DCD+ and DCD− were also obtained in log-transformed HS (p < .01). These findings suggest that intervention strategies for managing DCD should also aim at physical fitness increases.
Chariklia K. Deli, Ioannis G. Fatouros, Vassilis Paschalis, Kalliopi Georgakouli, Athanasios Zalavras, Alexandra Avloniti, Yiannis Koutedakis and Athanasios Z. Jamurtas
Research regarding exercise-induced muscle-damage mainly focuses on adults. The present study examined exercise-induced muscle-damage responses in adults compared with children.
Eleven healthy boys (10–12 y) and 15 healthy men (18–45 y) performed 5 sets of 15 maximal eccentric contractions of the knee extensors. Range of motion (ROM), delayed onset muscle soreness (DOMS) during squat and walking, and peak isometric, concentric and eccentric torque were assessed before, post, 24, 48, 72, and 96 hr postexercise. Creatine kinase (CK) activity was assessed before and 72 hr postexercise.
Eccentric exercise resulted in DOMS during squat that persisted for up to 96h in men, and 48 hr in boys (p < .05), and DOMS during walking that persisted for up to 72 hr in men, and 48 hr in boys (p < .01). The ROM was lower in both age groups 48 hr postexercise (p < .001). Isometric (p < .001), concentric (p < .01) and eccentric (p < .01) force decreased post, and up to 48 hr postexercise in men. Except for a reduction in isometric force immediately after exercise, no other changes occurred in boys’ isokinetic force. CK activity increased in men at 72 hr postexercise compared with pre exercise levels (p = .05).
Our data provide further confirmation that children are less susceptible to exercise-induced muscle damage compared with adults.
Sofia Aggeloussi, Anastasios A. Theodorou, Vassilis Paschalis, Michalis G. Nikolaidis, Ioannis G. Fatouros, Emmanuel O. Owolabi, Dimitris Kouretas, Yiannis Koutedakis and Athanasios Z. Jamurtas
To investigate the effects of obesity and exercise training on plasma adipocytokines a sample of 42 children (lean = 24, %BF = 17.8 ± 7.5%; obese = 18; %BF = 29.1 ± 9.3%; mean age = 12.4 ± 1.9 yrs), were divided into 4 age-matched for activity groups: lean inactive (n = 11), obese inactive (n = 9), lean active (n = 13) and obese active (n = 9). Active children participated in swimming training (≥1 year, ≥3 times/week, ≥1 h per session, covering a distance of 10,000−12,000 m per week). Obese individuals demonstrated greater visfatin levels (3.3 ± 1.3 ng/ml) than their lean counterparts (2.6 ± 1.1 ng/ml; p = .06) whereas adiponectin was significantly lower in obese children (3.8 ± 1.9) than their lean counterparts (5.9 ± 2.7; p £ .05). Insulin and HOMA values were significantly greater in obese compared with lean children (p £ .05). Within obese individuals, active individuals had significantly lower visfatin levels (2.8 ± 1.2 ng/ml) compared with their inactive counterparts (3.8 ± 1.2 ng/ml; p £ .05). Resistin levels were comparable between groups (p > .05). Childhood obesity elevates visfatin and lowers adiponectin levels whereas exercise training could reduce visfatin levels in obese children.