Geir Resaland - Academia.edu (original) (raw)

Papers by Geir Resaland

Research paper thumbnail of Associations Of Physical Activity, Cardiorespiratory Fitness And Motor Skill With Cognition In Children

Medicine & Science in Sports & Exercise, 2016

Research paper thumbnail of Muscle Fitness, Executive Function And Academic Performance In 10-year-old Children

Medicine & Science in Sports & Exercise, 2016

Research paper thumbnail of Level of physical activity, cardiorespiratory fitness and cardiovascular disease risk factors in a rural adult population in Sogn og Fjordane

Norsk Epidemiologi, 2011

Background: Physical activity (PA) and high cardiorespiratory fitness (CRF) are associated with r... more Background: Physical activity (PA) and high cardiorespiratory fitness (CRF) are associated with reduced risk of cardiovascular disease (CVD). Sogn og Fjordane County has the reputation of being the most healthy county in Norway. The level of PA and/or CRF may partly explain this health status. However, only one study with regional objectively measured PA data and one study with regional data on CRF currently exist. Thus, the aim of this study was to describe levels of PA, CRF and CVD risk factors in an adult population in the county of Sogn og Fjordane. Methods: In total, 314 (♀:178 ♂:136) 40-42-year-olds and 308 (♀:175 ♂:133) 53-55-yearolds participated in this cross-sectional study. PA was measured objectively by accelerometry, while CRF was measured directly. Results: There were no sex differences in total PA level. For the 40-42-year-olds, women spent 6.0 min/day [95% CI: -11.7 to -0.3] less participating in moderate PA compared to men. For the 53-55year-olds, women were inactive for 36.0 min/day [95% CI: -55.2 to -16.8] less and they participated in light activity for 26.4 min/day [95% CI: 7.7 to 45.2] more than men. In total, 30.0% [95% CI: 24.8 to 35.2] of the 40-42-year-olds and 30.2% [95% CI: 25.0 to 35.4] of the 53-55-year-olds met the Norwegian recommendations for PA. CRF was 49.0 ml·kg -1 ·min -1 for men and 41.6 ml·kg -1 ·min -1 for women for the 40-42-year-olds. For 53-55-year-olds CRF was 41.2 ml·kg -1 ·min -1 for men and 33.9 ml·kg -1 ·min -1 for women. Conclusions: These results suggest that the level of PA and CRF are higher compared to other available data. This might explain the advantageous health status in Sogn og Fjordane.

Research paper thumbnail of Active Smarter Kids (ASK): Rationale and design of a cluster-randomized controlled trial investigating the effects of daily physical activity on children's academic performance and risk factors for non-communicable diseases

BMC public health, 2015

Evidence is emerging from school-based studies that physical activity might favorably affect chil... more Evidence is emerging from school-based studies that physical activity might favorably affect children's academic performance. However, there is a need for high-quality studies to support this. Therefore, the main objective of the Active Smarter Kids (ASK) study is to investigate the effect of daily physical activity on children's academic performance. Because of the complexity of the relation between physical activity and academic performance it is important to identify mediating and moderating variables such as cognitive function, fitness, adiposity, motor skills and quality of life (QoL). Further, there are global concerns regarding the high prevalence of lifestyle-related non-communicable diseases (NCDs). The best means to address this challenge could be through primary prevention. Physical activity is known to play a key role in preventing a host of NCDs. Therefore, we investigated as a secondary objective the effect of the intervention on risk factors related to NCDs. T...

Research paper thumbnail of Physical activity and cardiovascular risk factors in a 40- to 42-year-old rural Norwegian population from 1975-2010: repeated cross-sectional surveys

BMC public health, 2014

Geographical differences in cardiovascular diseases (CVD) have been observed among Norwegian coun... more Geographical differences in cardiovascular diseases (CVD) have been observed among Norwegian counties. Better long-term health status and higher physical activity (PA) levels have been documented in the county of Sogn & Fjordane compared with other counties. However, recent trends in CVD risk factors have not been documented. The aim of this study was to investigate the secular trends in leisure time physical activity (LTPA) and other CVD risk factors over a 35-year period in a rural population of 40- to 42-year-olds in western Norway and to compare these trends with national trends. Data from eight cross-sectional studies from 1975-2010 (n = 375,682) were obtained from questionnaires and physical examinations and were analyzed using mixed model regression analyses. Decreasing trends were observed for sedentary behavior (for women), moderate PA, smoking, systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL-c) and total cholesterol (TC), wherea...

Research paper thumbnail of Determinants of erythropoietin release in response to short-term hypobaric hypoxia

Journal of applied physiology (Bethesda, Md. : 1985), 2002

We measured blood erythropoietin (EPO) concentration, arterial O(2) saturation (Sa(O(2))), and ur... more We measured blood erythropoietin (EPO) concentration, arterial O(2) saturation (Sa(O(2))), and urine PO(2) in 48 subjects (32 men and 16 women) at sea level and after 6 and 24 h at simulated altitudes of 1,780, 2,085, 2,454, and 2,800 m. Renal blood flow (Doppler) and Hb were determined at sea level and after 6 h at each altitude (n = 24) to calculate renal O(2) delivery. EPO increased significantly after 6 h at all altitudes and continued to increase after 24 h at 2,454 and 2,800 m, although not at 1,780 or 2,085 m. The increase in EPO varied markedly among individuals, ranging from -41 to 400% after 24 h at 2,800 m. Similar to EPO, urine PO(2) decreased after 6 h at all altitudes and returned to baseline by 24 h at the two lowest altitudes but remained decreased at the two highest altitudes. Urine PO(2) was closely related to EPO via a curvilinear relationship (r(2) = 0.99), although also with prominent individual variability. Renal blood flow remained unchanged at all altitudes. ...

Research paper thumbnail of Cardiovascular risk factor clustering and its association with fitness in nine-year-old rural Norwegian children

Scandinavian Journal of Medicine & Science in Sports, 2010

This paper describes cardiovascular disease (CVD) risk factor levels in a population-representati... more 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 AE 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 (VO 2peak ). 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.

Research paper thumbnail of Secular trends in physical fitness in Danish adolescents

Scandinavian Journal of Medicine & Science in Sports, 2010

It is important to monitor changes over time in aerobic fitness and obesity in order to target in... more It is important to monitor changes over time in aerobic fitness and obesity in order to target interventions when health deteriorates. We analyzed data from three population studies of adolescents carried out in 1983, 1997 and 2003. Participants were 1050 adolescents from the whole country of Denmark in 1983Denmark in , 410 in 1997Denmark in and 418 in 2003 the two latter cohorts from the City of Odense. VO 2max was estimated from maximal power output (MPO) in a cycle test with progressively increasing workload. Estimated VO2max for boys and girls was 52 ml·min -1 ·kg -1 and 41 ml·min -1 ·kg -1 , respectively, both in 1983, 1997 and 2003 with no difference between the three cohorts. However, body mass index (BMI) increased 10% in the upper decentile of the distribution since 1983. MPO decreased over time, but validation studies showed that this was not due to decreased VO 2max . The cohort from 1983 was tested twice by school teachers and experienced scientists, and the scientists found higher MPO than school teachers in the same subjects, which emphasize the importance of good validation studies.

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

Scandinavian Journal of Medicine & Science in Sports, 2011

The aim of this study was to investigate the effect of a 2-year school-based physical activity (P... more 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.

Research paper thumbnail of New examination of the performance of the MetaMax I metabolic analyser with the Douglas-bag technique

Scandinavian Journal of Clinical & Laboratory Investigation, 2012

Purpose. To examine the performance of the MetaMax ® I metabolic analyser of Cortex Biophysik, ru... more Purpose. To examine the performance of the MetaMax ® I metabolic analyser of Cortex Biophysik, running a recent version of the software (MetaSoft v. 1.11.05), using the Douglas-bag method as reference. Experiments. First, 182 measurements of the maximal O 2 uptake on school children were analysed both by a former version of the software (MetaMax Analysis) and by a recent version (MetaSoft). In further experiments, seven grown-up subjects of different fi tness levels cycled for 5 min at constant powers between 50 and 350 W while the O 2 uptake was measured simultaneously by the MetaMax I and the Douglas-bag method during the last minute of altogether 39 exercises. Results. The calculated maximal O 2 uptake of the 182 school children was on average 3% lower when the data were reanalysed by MetaSoft than when analysed by the former version of the software. There was in addition a 2% variation. In further experiments on grown-up subjects the O 2 uptake reported by the MetaMax I did not differ from that reported by the Douglas-bag system when data for all subjects were pooled, and the random error was 4%. However, the relationships differed slightly between the subjects ( p ϭ 0.005), and consequently the random error within each subject was 2 -3%. The respiratory exchange ratio (R-value) reported by the MetaMax I differed systematically from that of the control method. However, a reliable R-value could be calculated from the instrument ' s raw data. Conclusions. Our data suggest that the MetaMax I running MetaSoft reports unbiased values of the O 2 uptake and with moderate random error.

Research paper thumbnail of Optimal Altitude for ???Living High-Training Low???

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of External Nasal Strips Do Not Alter Cardio-Respiratory Respons During Submaximal and Maximal Exercise

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of The Population In Sogn og Fjordane, Norway - Fittest There Is?

Medicine & Science in Sports & Exercise, 2011

Research paper thumbnail of Epo Response to 24 HRS of Artificial Hypobaric Hypoxia Predicts Epo Response to Natural Altitude

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of Levels Of Vo2peak, Body Mass Index, Waist Circumference Index And Waist To Hip Ratio In 116 Nine Year Old Children In Rural Norway

Medicine & Science in Sports & Exercise, 2005

Research paper thumbnail of Effects Of A Two-year School-based Daily Physical Activity Intervention On Cvd Risk Factors

Medicine & Science in Sports & Exercise, 2011

The aim of this study was to investigate the effect of a 2-year school-based physical activity (P... more The aim of this study was to investigate the effect of a 2-year school-based physical activity (PA) intervention in 9-yearold children on cardiovascular disease (CVD) risk factors. One intervention school (I-school) (n 5 125) and one control school (C-school) (n 5 131) 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 5 0.003) and diastolic (P 5 0.002) blood pressure, total cholesterol-to-high-density lipoprotein cholesterol ratio (P 5 0.011), triglyceride (P 5 0.030) and peak oxygen uptake (Po0.001) 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.

Research paper thumbnail of Intermittent Isometric Exercise, a New Model to Study VO2 Slow Component

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of Defining the "dose" of altitude training: how high to live for optimal sea level performance enhancement

Journal of Applied Physiology, 2014

Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, ... more Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, but not all, groups of athletes; however, responses of erythropoietin (EPO) and red cell mass to a given altitude show substantial individual variability. We hypothesized that athletes living at higher altitudes would experience greater improvements in sea level performance, secondary to greater hematological acclimatization, compared with athletes living at lower altitudes. After 4 wk of group sea level training and testing, 48 collegiate distance runners (32 men, 16 women) were randomly assigned to one of four living altitudes (1,780, 2,085, 2,454, or 2,800 m). All athletes trained together daily at a common altitude from 1,250-3,000 m following a modified live high-train low model. Subjects completed hematological, metabolic, and performance measures at sea level, before and after altitude training; EPO was assessed at various time points while at altitude. On return from altitude, 3,000-m time trial performance was significantly improved in groups living at the middle two altitudes (2,085 and 2,454 m), but not in groups living at 1,780 and 2,800 m. EPO was significantly higher in all groups at 24 and 48 h, but returned to sea level baseline after 72 h in the 1,780-m group. Erythrocyte volume was significantly higher within all groups after return from altitude and was not different between groups. These data suggest that, when completing a 4-wk altitude camp following the live high-train low model, there is a target altitude between 2,000 and 2,500 m that produces an optimal acclimatization response for sea level performance.

Research paper thumbnail of Urine Acid–Base Compensation at Simulated Moderate Altitude

High Altitude Medicine & Biology, 2006

Acute exposure to high altitude elicits respiratory alkalosis, and this is partially corrected by... more Acute exposure to high altitude elicits respiratory alkalosis, and this is partially corrected by renal compensation. To determine the time course and magnitude of renal compensation during short-term moderate altitude exposure, we measured urine gas tensions and acid-base status in 48 healthy men and women at four levels of simulated altitude exposures. Each subject was exposed in pseudorandom order to simulated altitudes of 1780, 2085, 2455, and 2800 m in a decompression chamber for 24 h, separated by 1 week at sea level. Fresh urine was collected anaerobically at sea level and after 6 and 24 h of each altitude exposure. Urine pH increased significantly (p < 0.01) after 6 h at all altitudes and returned to baseline values by 24 h at the lowest altitudes. In contrast, urine pH remained elevated at the highest altitudes. The mean value of urine HCO at sea level was 1.67 +/- 0.25 mmol/L, increased significantly after 6 h at all altitudes, and then returned to near baseline after 24 h at three lower altitudes (1780, 2085, and 2455 m). However, it remained elevated at 2800 m. PCO2 in urine was significantly increased after 6 h and returned to baseline after 24 h at all altitudes. These results suggest that (1) short-term low to moderate altitude exposure results in a marked HCO diuresis, which may be caused by inhibition of the secretion of renal tubular H+, and (2) renal HCO compensation was completed by 24 h at low to moderate altitude, but still incomplete at higher altitude.

Research paper thumbnail of Physical Activity and Cardiovascular Risk Factors among Elderly Men in Finland, Italy, and The Netherlands

American Journal of Epidemiology, 1996

Physical activity pattern and its relation with cardiovascular risk factors was investigated in 1... more Physical activity pattern and its relation with cardiovascular risk factors was investigated in 1,402 men aged 69-90 years who participated in the 30-year follow-up survey of the Finnish (Eastern and Western Finland), Italian (Montegiorgio and Crevalcore), and Dutch (Zutphen) cohorts of the Seven Countries Study. Physical activity was assessed with a validated self-administered questionnaire designed for retired men. Total physical activity varied largely within cohorts. Median total reported physical activity ranged from 50 minutes/day in Montegiorgio to 89 minutes/day in Crevalcore. Walking, gardening, and bicycling together contributed more than 70% of total physical activity in all cohorts. Depending on the definition of physical inactivity, the estimated prevalence of inactivity varied between 5% and 33% in Zutphen and between 18% and 68% in Montegiorgio. Total physical activity was inversely associated with resting heart rate (r= -0.11, p < 0.001) and was positively associated with high density lipoprotein (HDL) cholesterol (r = 0.08, p < 0.01) in pooled data. These associations remained statistically significant after adjustment for age, cohort, smoking, body mass index, and alcohol intake. Total activity was not associated with total cholesterol, non-HDL cholesterol, blood pressure, or body mass index. The authors conclude that physical activity may have a beneficial effect on HDL cholesterol levels in elderly men. Walking, gardening, and bicycling contribute substantially to their physical activity pattern.

Research paper thumbnail of Associations Of Physical Activity, Cardiorespiratory Fitness And Motor Skill With Cognition In Children

Medicine & Science in Sports & Exercise, 2016

Research paper thumbnail of Muscle Fitness, Executive Function And Academic Performance In 10-year-old Children

Medicine & Science in Sports & Exercise, 2016

Research paper thumbnail of Level of physical activity, cardiorespiratory fitness and cardiovascular disease risk factors in a rural adult population in Sogn og Fjordane

Norsk Epidemiologi, 2011

Background: Physical activity (PA) and high cardiorespiratory fitness (CRF) are associated with r... more Background: Physical activity (PA) and high cardiorespiratory fitness (CRF) are associated with reduced risk of cardiovascular disease (CVD). Sogn og Fjordane County has the reputation of being the most healthy county in Norway. The level of PA and/or CRF may partly explain this health status. However, only one study with regional objectively measured PA data and one study with regional data on CRF currently exist. Thus, the aim of this study was to describe levels of PA, CRF and CVD risk factors in an adult population in the county of Sogn og Fjordane. Methods: In total, 314 (♀:178 ♂:136) 40-42-year-olds and 308 (♀:175 ♂:133) 53-55-yearolds participated in this cross-sectional study. PA was measured objectively by accelerometry, while CRF was measured directly. Results: There were no sex differences in total PA level. For the 40-42-year-olds, women spent 6.0 min/day [95% CI: -11.7 to -0.3] less participating in moderate PA compared to men. For the 53-55year-olds, women were inactive for 36.0 min/day [95% CI: -55.2 to -16.8] less and they participated in light activity for 26.4 min/day [95% CI: 7.7 to 45.2] more than men. In total, 30.0% [95% CI: 24.8 to 35.2] of the 40-42-year-olds and 30.2% [95% CI: 25.0 to 35.4] of the 53-55-year-olds met the Norwegian recommendations for PA. CRF was 49.0 ml·kg -1 ·min -1 for men and 41.6 ml·kg -1 ·min -1 for women for the 40-42-year-olds. For 53-55-year-olds CRF was 41.2 ml·kg -1 ·min -1 for men and 33.9 ml·kg -1 ·min -1 for women. Conclusions: These results suggest that the level of PA and CRF are higher compared to other available data. This might explain the advantageous health status in Sogn og Fjordane.

Research paper thumbnail of Active Smarter Kids (ASK): Rationale and design of a cluster-randomized controlled trial investigating the effects of daily physical activity on children's academic performance and risk factors for non-communicable diseases

BMC public health, 2015

Evidence is emerging from school-based studies that physical activity might favorably affect chil... more Evidence is emerging from school-based studies that physical activity might favorably affect children's academic performance. However, there is a need for high-quality studies to support this. Therefore, the main objective of the Active Smarter Kids (ASK) study is to investigate the effect of daily physical activity on children's academic performance. Because of the complexity of the relation between physical activity and academic performance it is important to identify mediating and moderating variables such as cognitive function, fitness, adiposity, motor skills and quality of life (QoL). Further, there are global concerns regarding the high prevalence of lifestyle-related non-communicable diseases (NCDs). The best means to address this challenge could be through primary prevention. Physical activity is known to play a key role in preventing a host of NCDs. Therefore, we investigated as a secondary objective the effect of the intervention on risk factors related to NCDs. T...

Research paper thumbnail of Physical activity and cardiovascular risk factors in a 40- to 42-year-old rural Norwegian population from 1975-2010: repeated cross-sectional surveys

BMC public health, 2014

Geographical differences in cardiovascular diseases (CVD) have been observed among Norwegian coun... more Geographical differences in cardiovascular diseases (CVD) have been observed among Norwegian counties. Better long-term health status and higher physical activity (PA) levels have been documented in the county of Sogn & Fjordane compared with other counties. However, recent trends in CVD risk factors have not been documented. The aim of this study was to investigate the secular trends in leisure time physical activity (LTPA) and other CVD risk factors over a 35-year period in a rural population of 40- to 42-year-olds in western Norway and to compare these trends with national trends. Data from eight cross-sectional studies from 1975-2010 (n = 375,682) were obtained from questionnaires and physical examinations and were analyzed using mixed model regression analyses. Decreasing trends were observed for sedentary behavior (for women), moderate PA, smoking, systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL-c) and total cholesterol (TC), wherea...

Research paper thumbnail of Determinants of erythropoietin release in response to short-term hypobaric hypoxia

Journal of applied physiology (Bethesda, Md. : 1985), 2002

We measured blood erythropoietin (EPO) concentration, arterial O(2) saturation (Sa(O(2))), and ur... more We measured blood erythropoietin (EPO) concentration, arterial O(2) saturation (Sa(O(2))), and urine PO(2) in 48 subjects (32 men and 16 women) at sea level and after 6 and 24 h at simulated altitudes of 1,780, 2,085, 2,454, and 2,800 m. Renal blood flow (Doppler) and Hb were determined at sea level and after 6 h at each altitude (n = 24) to calculate renal O(2) delivery. EPO increased significantly after 6 h at all altitudes and continued to increase after 24 h at 2,454 and 2,800 m, although not at 1,780 or 2,085 m. The increase in EPO varied markedly among individuals, ranging from -41 to 400% after 24 h at 2,800 m. Similar to EPO, urine PO(2) decreased after 6 h at all altitudes and returned to baseline by 24 h at the two lowest altitudes but remained decreased at the two highest altitudes. Urine PO(2) was closely related to EPO via a curvilinear relationship (r(2) = 0.99), although also with prominent individual variability. Renal blood flow remained unchanged at all altitudes. ...

Research paper thumbnail of Cardiovascular risk factor clustering and its association with fitness in nine-year-old rural Norwegian children

Scandinavian Journal of Medicine & Science in Sports, 2010

This paper describes cardiovascular disease (CVD) risk factor levels in a population-representati... more 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 AE 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 (VO 2peak ). 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.

Research paper thumbnail of Secular trends in physical fitness in Danish adolescents

Scandinavian Journal of Medicine & Science in Sports, 2010

It is important to monitor changes over time in aerobic fitness and obesity in order to target in... more It is important to monitor changes over time in aerobic fitness and obesity in order to target interventions when health deteriorates. We analyzed data from three population studies of adolescents carried out in 1983, 1997 and 2003. Participants were 1050 adolescents from the whole country of Denmark in 1983Denmark in , 410 in 1997Denmark in and 418 in 2003 the two latter cohorts from the City of Odense. VO 2max was estimated from maximal power output (MPO) in a cycle test with progressively increasing workload. Estimated VO2max for boys and girls was 52 ml·min -1 ·kg -1 and 41 ml·min -1 ·kg -1 , respectively, both in 1983, 1997 and 2003 with no difference between the three cohorts. However, body mass index (BMI) increased 10% in the upper decentile of the distribution since 1983. MPO decreased over time, but validation studies showed that this was not due to decreased VO 2max . The cohort from 1983 was tested twice by school teachers and experienced scientists, and the scientists found higher MPO than school teachers in the same subjects, which emphasize the importance of good validation studies.

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

Scandinavian Journal of Medicine & Science in Sports, 2011

The aim of this study was to investigate the effect of a 2-year school-based physical activity (P... more 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.

Research paper thumbnail of New examination of the performance of the MetaMax I metabolic analyser with the Douglas-bag technique

Scandinavian Journal of Clinical & Laboratory Investigation, 2012

Purpose. To examine the performance of the MetaMax ® I metabolic analyser of Cortex Biophysik, ru... more Purpose. To examine the performance of the MetaMax ® I metabolic analyser of Cortex Biophysik, running a recent version of the software (MetaSoft v. 1.11.05), using the Douglas-bag method as reference. Experiments. First, 182 measurements of the maximal O 2 uptake on school children were analysed both by a former version of the software (MetaMax Analysis) and by a recent version (MetaSoft). In further experiments, seven grown-up subjects of different fi tness levels cycled for 5 min at constant powers between 50 and 350 W while the O 2 uptake was measured simultaneously by the MetaMax I and the Douglas-bag method during the last minute of altogether 39 exercises. Results. The calculated maximal O 2 uptake of the 182 school children was on average 3% lower when the data were reanalysed by MetaSoft than when analysed by the former version of the software. There was in addition a 2% variation. In further experiments on grown-up subjects the O 2 uptake reported by the MetaMax I did not differ from that reported by the Douglas-bag system when data for all subjects were pooled, and the random error was 4%. However, the relationships differed slightly between the subjects ( p ϭ 0.005), and consequently the random error within each subject was 2 -3%. The respiratory exchange ratio (R-value) reported by the MetaMax I differed systematically from that of the control method. However, a reliable R-value could be calculated from the instrument ' s raw data. Conclusions. Our data suggest that the MetaMax I running MetaSoft reports unbiased values of the O 2 uptake and with moderate random error.

Research paper thumbnail of Optimal Altitude for ???Living High-Training Low???

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of External Nasal Strips Do Not Alter Cardio-Respiratory Respons During Submaximal and Maximal Exercise

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of The Population In Sogn og Fjordane, Norway - Fittest There Is?

Medicine & Science in Sports & Exercise, 2011

Research paper thumbnail of Epo Response to 24 HRS of Artificial Hypobaric Hypoxia Predicts Epo Response to Natural Altitude

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of Levels Of Vo2peak, Body Mass Index, Waist Circumference Index And Waist To Hip Ratio In 116 Nine Year Old Children In Rural Norway

Medicine & Science in Sports & Exercise, 2005

Research paper thumbnail of Effects Of A Two-year School-based Daily Physical Activity Intervention On Cvd Risk Factors

Medicine & Science in Sports & Exercise, 2011

The aim of this study was to investigate the effect of a 2-year school-based physical activity (P... more The aim of this study was to investigate the effect of a 2-year school-based physical activity (PA) intervention in 9-yearold children on cardiovascular disease (CVD) risk factors. One intervention school (I-school) (n 5 125) and one control school (C-school) (n 5 131) 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 5 0.003) and diastolic (P 5 0.002) blood pressure, total cholesterol-to-high-density lipoprotein cholesterol ratio (P 5 0.011), triglyceride (P 5 0.030) and peak oxygen uptake (Po0.001) 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.

Research paper thumbnail of Intermittent Isometric Exercise, a New Model to Study VO2 Slow Component

Medicine & Science in Sports & Exercise, 2001

Research paper thumbnail of Defining the "dose" of altitude training: how high to live for optimal sea level performance enhancement

Journal of Applied Physiology, 2014

Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, ... more Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, but not all, groups of athletes; however, responses of erythropoietin (EPO) and red cell mass to a given altitude show substantial individual variability. We hypothesized that athletes living at higher altitudes would experience greater improvements in sea level performance, secondary to greater hematological acclimatization, compared with athletes living at lower altitudes. After 4 wk of group sea level training and testing, 48 collegiate distance runners (32 men, 16 women) were randomly assigned to one of four living altitudes (1,780, 2,085, 2,454, or 2,800 m). All athletes trained together daily at a common altitude from 1,250-3,000 m following a modified live high-train low model. Subjects completed hematological, metabolic, and performance measures at sea level, before and after altitude training; EPO was assessed at various time points while at altitude. On return from altitude, 3,000-m time trial performance was significantly improved in groups living at the middle two altitudes (2,085 and 2,454 m), but not in groups living at 1,780 and 2,800 m. EPO was significantly higher in all groups at 24 and 48 h, but returned to sea level baseline after 72 h in the 1,780-m group. Erythrocyte volume was significantly higher within all groups after return from altitude and was not different between groups. These data suggest that, when completing a 4-wk altitude camp following the live high-train low model, there is a target altitude between 2,000 and 2,500 m that produces an optimal acclimatization response for sea level performance.

Research paper thumbnail of Urine Acid–Base Compensation at Simulated Moderate Altitude

High Altitude Medicine & Biology, 2006

Acute exposure to high altitude elicits respiratory alkalosis, and this is partially corrected by... more Acute exposure to high altitude elicits respiratory alkalosis, and this is partially corrected by renal compensation. To determine the time course and magnitude of renal compensation during short-term moderate altitude exposure, we measured urine gas tensions and acid-base status in 48 healthy men and women at four levels of simulated altitude exposures. Each subject was exposed in pseudorandom order to simulated altitudes of 1780, 2085, 2455, and 2800 m in a decompression chamber for 24 h, separated by 1 week at sea level. Fresh urine was collected anaerobically at sea level and after 6 and 24 h of each altitude exposure. Urine pH increased significantly (p < 0.01) after 6 h at all altitudes and returned to baseline values by 24 h at the lowest altitudes. In contrast, urine pH remained elevated at the highest altitudes. The mean value of urine HCO at sea level was 1.67 +/- 0.25 mmol/L, increased significantly after 6 h at all altitudes, and then returned to near baseline after 24 h at three lower altitudes (1780, 2085, and 2455 m). However, it remained elevated at 2800 m. PCO2 in urine was significantly increased after 6 h and returned to baseline after 24 h at all altitudes. These results suggest that (1) short-term low to moderate altitude exposure results in a marked HCO diuresis, which may be caused by inhibition of the secretion of renal tubular H+, and (2) renal HCO compensation was completed by 24 h at low to moderate altitude, but still incomplete at higher altitude.

Research paper thumbnail of Physical Activity and Cardiovascular Risk Factors among Elderly Men in Finland, Italy, and The Netherlands

American Journal of Epidemiology, 1996

Physical activity pattern and its relation with cardiovascular risk factors was investigated in 1... more Physical activity pattern and its relation with cardiovascular risk factors was investigated in 1,402 men aged 69-90 years who participated in the 30-year follow-up survey of the Finnish (Eastern and Western Finland), Italian (Montegiorgio and Crevalcore), and Dutch (Zutphen) cohorts of the Seven Countries Study. Physical activity was assessed with a validated self-administered questionnaire designed for retired men. Total physical activity varied largely within cohorts. Median total reported physical activity ranged from 50 minutes/day in Montegiorgio to 89 minutes/day in Crevalcore. Walking, gardening, and bicycling together contributed more than 70% of total physical activity in all cohorts. Depending on the definition of physical inactivity, the estimated prevalence of inactivity varied between 5% and 33% in Zutphen and between 18% and 68% in Montegiorgio. Total physical activity was inversely associated with resting heart rate (r= -0.11, p < 0.001) and was positively associated with high density lipoprotein (HDL) cholesterol (r = 0.08, p < 0.01) in pooled data. These associations remained statistically significant after adjustment for age, cohort, smoking, body mass index, and alcohol intake. Total activity was not associated with total cholesterol, non-HDL cholesterol, blood pressure, or body mass index. The authors conclude that physical activity may have a beneficial effect on HDL cholesterol levels in elderly men. Walking, gardening, and bicycling contribute substantially to their physical activity pattern.