Pulmonary function was measured in 48 air divers (age range: 8–38 yr) and 56 control participants (age range: 8–34 yr). Static lung volumes, dynamic lung volumes and flows, and the pulmonary diffusing capacity for carbon monoxide were measured twice, 29 months apart. At both times the adult divers (>18 yr) had higher forced vital capacity, forced expiratory volume in 1 s and maximal expiratory flow rate at 50%, as well as lower pulmonary diffusing capacity for carbon monoxide, than did the adult controls. Whatever the age, mean annual changes in these parameters did not differ between groups. Our results indicate that there were no significant changes in pulmonary function in the young (8–12 yr), adolescent, or adult divers compared with healthy controls over the 29-month period. The mean annual changes in forced expiratory flow and volume, however, were negatively correlated with number of years of diving experience in adult divers and with maximal diving depth in adolescent (13–18 yr) divers (p < .05 and p < .001, respectively). Deep diving during the teenage years coupled with years of recreational diving might increase the risk of airway obstruction.
Frédéric Lemaître, Mario Bedu and Jean Coudert
Han C.G. Kemper, Mariëlle Spekreijse, Jaap Slooten, G. Bertheke Post, Desiree C. Welten and Jean Coudert
The main purpose of this study was to measure physical activity of 10- to 12-year-old prepubescent boys and girls living in Bolivia at low altitude (400 m above sea level) and at high altitude (4,000 m) with either a low socioeconomic status (LSES) or a high socioeconomic status (HSES). Habitual physical activity was measured by 24-hour heart rate (HR) monitoring during a normal school day. The mean HR is expressed as a percentage of heart rate reserve (HRR%) and the time spent at 50–85% HRR. Analysis by ANOVA showed no significant effects (p > .05) in HRR%. However, the boys spent significantly (p < .05) more time at 50–85% HRR (M = 51 min) than did girls (M = 34 min), and LSES children significantly (p < .01) more (M = 51 min) than HSES children (M = 32 min). There was also a significant interaction between SES and gender, indicating that the difference between boys and girls was significantly (p < .05) greater in LSES than in HSES, and the difference between LSES and HSES children was significantly (p < .05) greater in boys than in girls.
Emmanuel Van Praagh, Nicole Fellmann, Mario Bedu, Guy Falgairette and Jean Coudert
This study was done to determine the extent to which body composition accounts for differences in anaerobic characteristics between 12-year-old girls and boys. Peak leg power (PP), mean leg power (MP), percent body fat, fat free mass (FFM), and lean thigh volume (LTV) were determined by various tests. Pubertal stages and salivary testosterone concentration (in boys) were used to assess sexual maturation. Laboratory anaerobic indices were compared with performances in two running tests. Blood samples were taken for lactate determination. Absolute PP and MP outputs were similar in both sexes and were better correlated with LTV in girls, whereas in boys both PP and MP were highly correlated with FFM. Although nonsignificant gender difference in lean tissue was observed, PP and MP when corrected for LTV were significantly greater in boys than in girls. Factors other than the amount of lean muscle mass should be considered in explaining the gender differences in PP and MP in early pubertal children.