Effects of a 2-year school-based daily physical activity intervention on cardiovascular disease risk factors: the Sogndal school-intervention study.

The aim of this study was to investigate the effect of a 2-year school-based physical activity (PA) intervention in 9-year-old children on cardiovascular disease (CVD) risk factors. One intervention school (I-school) (n=125) and one control school (C-school) (n=131) were included. The children at the I-school carried out 60 min of PA daily. The PA lessons were planned, organized and led by expert physical education (PE) teachers. In the C-school, children were offered the normal 45 min of PE twice weekly. The intervention resulted in a greater beneficial development in systolic (P=0.003) and diastolic (P=0.002) blood pressure, total cholesterol-to-high-density lipoprotein cholesterol ratio (P=0.011), triglyceride (P=0.030) and peak oxygen uptake (P<0.001) in I-school children than in C-school children. No significant differences were observed in waist circumference, body mass index and the homeostasis model assessment for insulin resistance between the two groups. Furthermore, the intervention, primarily carried out at moderate intensity, had the strongest impact in children with the least favorable starting point. In conclusion, a daily school-based PA intervention can beneficially modify children's CVD risk profile if the intervention has sufficient duration and includes a substantial amount of daily PA, and if the PA is implemented by expert PE teachers.

Effects of a 2-year school-based daily physical activity intervention on cardiorespiratory fitness: the Sogndal school-intervention study.

The aim of this study was to describe changes in children's cardiorespiratory fitness (CRF) following a school-based physical activity (PA) intervention. In total, 259 children (age 9.3 ± 0.3 years) were invited to participate, of whom 256 participated. The children from the intervention school (63 boys, 62 girls) carried out 60-min PA over 2 school years. The children from the control school (62 boys, 69 girls) had the regular curriculum-defined amount of physical education in school, i.e. 45 min twice weekly. One hundred and eighty-eight children (73.4%) successfully completed both the baseline and the post-intervention peak oxygen uptake (VO2 peak) test. VO2 peak was measured directly during a continuous progressive treadmill protocol where the children ran until exhaustion. The children from the intervention school increased their mean VO2 peak (95% confidence interval) 3.6 (2.5-4.6) mL/kg/min more than the children from the control school. This VO2 peak value was adjusted for both sex and baseline VO2 peak. Boys and girls demonstrated similar VO2 peak responses. The intervention, primarily carried out at a moderate intensity, had the biggest impact in children with low initial CRF levels. In conclusion, a 2-year school-based 60-min daily PA intervention significantly improved CRF in children.

Contrasting effects in anthropometric measures of total fatness and abdominal fat mass following endurance and concurrent endurance and resistance training.

An increased total fatness, and especially abdominal fat deposition, is associated with a greater risk for a variety of health problems and metabolic disturbances. It is commonly accepted that endurance training induces the greatest alterations in total adiposity despite resistance training possibly having other advantages on body fat distribution. Thirty-seven males were assigned to 16 weeks of endurance training (ET) (N=12), concurrent endurance and resistance training (CT) (N=13) or no exercise (N=12) to compare the effects of these modes of training on anthropometric measures of fat distribution in previously sedentary males on an Ad Libitum diet. The ET significantly (P

Cardiovascular risk factor clustering and its association with fitness in nine-year-old rural Norwegian children.

This paper describes cardiovascular disease (CVD) risk factor levels in a population-representative sample of healthy, rural Norwegian children and examines the association between fitness and clustering of CVD risk factors. Final analyses included 111 boys and 116 girls (mean age 9.3+/-0.3). To determine the degree of clustering, six CVD risk factors were selected: homeostasis model assessment score, waist circumference, triglycerides, systolic blood pressure, total cholesterol to high-density lipoprotein ratio and fitness (VO2peak). Clustering was observed in 9.9% of the boys and 13.8% of the girls. In a different analysis, fitness was omitted as a CVD risk factor and analyzed against the five remaining CVD risk factors. Low fitness was a strong predictor for clustering of CVD risk factors, and children in the least-fit quartile had significantly poorer CVD risk factor values than all of those in the other quartiles. Finally, subjects were cross-tabulated into different fat-fit groups. For both sexes, the unfit and overweight/obese group had a significantly higher CVD risk factor score than the fit and normal weight group. Clustering of CVD risk factors was present in this group of rural children. Low fitness, and low fitness and high fatness combined, were highly associated with a clustered CVD risk.

The aerobic fitness of substance abusers voluntary participating in a rehabilitation project.

AIM: The aim of the study was to assess the physical fitness in a group of substance abusers using direct, maximal testing and testing of blood lactate threshold. METHODS: Forty-seven patients, 34 males and 13 females, with substance dependence, taking part in a rehabilitation project, served as subjects. Mean age and SD were 30.5+/-9.2 years for the males and 29.7+/-10.2 for the females. They performed a lactate threshold test and a maximal oxygen uptake test (V.O(2max)). The threshold test was performed on either a cycle ergometer or a treadmill, the V.O(2max) test was the Bruce protocol. RESULTS: The range in aerobic fitness was large, and the mean result of aerobic power (V.O(2max)) was somewhat higher than previously estimated in groups of similar age: 39+/-10 and 31+/-8 mL.kg(-1).min(-1) for males and females, respectively. The mean heart rate at blood lactate threshold did not differ between the sexes and was 74+/-7% of maximal heart rate (HRmax). There was no statistical difference between the users of different intoxicants on either V.O(2max) or lactate threshold. CONCLUSIONS: This group of substance abusers did show a large range in physical fitness. The maximal oxygen uptake was better than previously assessed in groups of substance dependent people using indirect methods. The primary intoxicant had no significant influence on the fitness.

Cardiorespiratory fitness and body mass index values in 9-year-old rural Norwegian children.

AIM: To describe cardiorespiratory fitness and body mass index (BMI) values in a representative population of 9-year-old Norwegian children in two rural communities and compare present values with previous findings. METHODS: Two hundred and fifty-nine 9-year-old children were invited, and 256 participated in this study. Maximal oxygen uptake was directly measured during a continuous progressive treadmill protocol. Body mass and height were also measured. RESULTS: The mean +/- SD relative maximal oxygen uptake was 52.8 +/- 6.5 for boys and 46.9 +/- 7.2 mL/kg/min for girls. Eight percent of the boys and 16.8% of the girls were classified as overweight, and 1.6% of the boys and 6.9% of the girls as obese. Mean age, body mass, height and Ponderal index were not significantly different between sexes. Girls had a higher BMI than boys (p = 0.05). CONCLUSION: Compared to earlier Norwegian studies, children's BMI values seem to have increased substantially. This increase is most pronounced in girls. When assessing these differences using the PI, this increase is less marked. Comparing maximal oxygen uptake data with that in earlier Nordic studies, there is no evidence that fitness has declined among 9-year olds. However, the limitations of the few earlier studies make reliable comparisons difficult.

Examination of the Metamax I and II oxygen analysers during exercise studies in the laboratory.

The performance of the Metamax I and the Metamax II portable analysers for measuring the O2 uptake has been examined during exercise. Healthy subjects ran on the treadmill or bicycled on ergometers while the O2 uptake was measured by the Metamaxes and also by the Douglas bag technique or the Vmax 29 instrument. In the first series of experiments, O2 uptake was measured by each instrument in turn. In later experiments two or more breathing valves were connected in a series, thus enabling measurement of the O2 uptake simultaneously by more than one instrument. The O2 uptake measured by the Metamax analysers rose linearly by the value given by the control methods. However, there were variations of approximately 5% because the relationships differed between subjects. When the data from each subject were examined separately, the error of regression was 0.5-1 micromol s(-1) kg(-1) (2-3%), and the error of regression when relating the O2 uptake to the exercise intensity was similar to that found when using the Douglas bag technique alone. In most cases the lung ventilation reported by the Metamaxes was a few percent less than that given by the control methods, while the fractional extraction of O2 was higher for the Metamaxes. The respiratory exchange ratios (R-value) reported by the Metamaxes were in good agreement with those of the control methods in the range 0.9-1.0 only; for this parameter, the Metamaxes do not seem to be reliable for exercise testing. The O2 uptake and the R-value were also calculated from the raw data reported by the Metamaxes. The calculated values differed somewhat from those reported by the instruments, and the calculated values were more in agreement with those obtained by the Douglas bag technique than those reported by the instrument. This study suggests that the O2 uptake reported by the Metamaxes is precisely measured within subjects but that there are some systematic errors as well as variations between subjects.

Examination of four different instruments for measuring blood lactate concentration.

Information on the performance of different instruments used to measure blood lactate concentration is incomplete. We therefore examined instruments from Yellow Springs Instruments (YSI 23L and YSI 1500) and three cheaper and simpler instruments: Dr. Lange's LP8+, Lactate Pro from Arkray in the KDK corporation and Accusport from Boehringer Mannheim. First, a number of blood samples were analysed by standard enzymatic photofluorometry (our reference method) and, in addition, by one or more of the instruments mentioned above. Second, measurements using two or more identical instruments were compared. Third, since Lactate Pro and Accusport are small (approximately 100 g, pocket-size), battery-driven, instruments that could be used for outdoor testing, the performance of these instruments was examined at simulated altitudes (O2 pressure of <10 kPa) and at temperatures below -20 degrees C, while screening the instruments as much as possible from the cold. Most of the different instruments showed systematically too high or too low values (10-25% deviation). The observed differences between instruments may affect the "blood lactate threshold" by 2-5%. We found different readings between "equal" YSI 1500 instruments, while we could see no difference when comparing the other instruments of the same type. Lactate Pro gave reliable results at both -21+/-1 degrees C and at simulated altitude. Accusport gave reliable results in the cold, but 1.85+/-0.08 mmol L(-1) (mean+/-SD) too high readings at the simulated altitude. Of the three simpler instruments examined, the Lactate Pro was at least as good as the YSI instruments and superior to the other two.

LSD-like panic from risperidone in post-LSD visual disorder.

Risperidone, a novel antipsychotic agent, is an antagonist of postsynaptic serotonin-2 and dopamine D2 receptors. In certain individuals, the hallucinogenic drug lysergic acid diethylamide (LSD) is associated with apparently lifelong continuous visual disturbances, characterized in DSM-IV as hallucinogen-persisting perception disorder (HPPD). Because the hallucinogenic mechanism of LSD is known to act in part at postsynaptic serotonin-2 receptors, it is noteworthy that three HPPD patients treated with risperidone reported an exacerbation of LSD-like panic and visual symptoms. We conclude that HPPD may be a relative contraindication for the use of risperidone.