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We investigated the effect of physical activity and sports participation on LDL oxidation in vivo and on lipid risk factors in 183 teenage girls (9-15 years): 64 gymnasts, 61 runners, and 58 controls. Oxidized LDL was measured as baseline levels of conjugated dienes in LDL lipids (ox-LDL). The gymnasts had a 15% lower ratio of LDL conjugated dienes to LDL cholesterol (ox-LDL:LDL ratio, P = 0.0052) compared to controls, and the difference persisted when the body mass index was included as a covariate (ANCOVA, P = 0.013). Also, the gymnasts had a 12% higher ratio of HDL cholesterol to total cholesterol than the controls (ANCOVA, P = 0.046). There were no differences in the other common lipid risk factors between the groups. The ox-LDL:LDL ratio correlated negatively with HDL cholesterol (r = -0.23, P=0.0021) and with physical activity METs (multiples of resting metabolic rate) (r = -0.21, P=0.0040). Our study strengthens the evidence that the atherogenic risk is influenced favourably by physical exercise and sporting activities as early as in adolescents. This risk reduction is associated with lower mildly oxidized LDL in adolescent girls.

The association of the amount and type of physical activity with bone mineral acquisition was studied in 191 peripubertal Caucasian girls aged 9-16 years (66 gymnasts, 65 runners, and 60 nonathletic controls). Weight, height, stage of puberty, the amount of leisure-time physical activity, and years of training were recorded, and dietary calcium and vitamin D were assessed by a semi-quantitative questionnaire. The bone area, the bone mineral density (BMD), and the bone mineral content (BMC) of the femoral neck, lumbar spine and antebrachium were measured by dual-energy x-ray absorptiometry. The unadjusted mean values of BMD at the femoral neck were 15.2% higher in the pubertal gymnasts than in the controls (P

We compared echocardiographic findings in female (n=30) and male (n=30) endurance athletes to age-matched female (n=15) and male (n=15) sedentary controls. The differences between athletes and controls were similar in both sexes; only left ventricular (LV) mass and septum thickness differed slightly more in men than in women (67% vs 55%, P=0.004, and 36% vs 30%, P=0.03, respectively). LV wall thicknesses were in the normal range in all women, while four (13%) male athletes exceeded 13 mm. In conclusion, the effects of endurance training on echocardiographic findings appear to be quite similar in women and men. However, in female athletes with an abnormally thick left ventricular wall a thorough cardiac evaluation is indicated. This contrasts with male athletes, in whom LV wall thicknesses of over 13 mm are a not uncommon finding.

Background Eye fundus destruction and type II muscle fiber atrophy in gyrate atrophy of the choroid and retina with hyperornithinaemia (GA) may be mediated by elevated ornithine concentrations which strongly inhibit creatine biosynthesis. This results in deficiency of creatine phosphate (PCr), a key intracellular energy source, as we have demonstrated in skeletal muscle of the patients by 31P magnetic resonance spectroscopy (31P MRS). Materials and methods Possible correction of the relative PCr deficiency by long-term daily exogenous supplementation of creatine or its precursors was investigated in four GA patients receiving creatine and in five patients treated with guanidinoacetic acid-methionine combination. The relative PCr concentration, expressed as PCr/Pi (Pi; inorganic phosphate) or as PCr/ATP ratios, was compared with the values of untreated GA patients, and matched healthy volunteers. Results Muscle PCr/Pi ratios (mean ± SD) of the untreated and creatine supplemented GA patients and controls were 4.9 ± 1.4, 7.9 ± 0.4 and 8.4 ± 1.3. Guanidinoacetate-methionine combination was similarly effective (respective PCr/Pi ratios: 4.9 ± 0.7, 6.3 ± 1.1 and 10.7 ± 2.8). Conclusion Supplementation with creatine or creatine precursors almost normalised low muscle PCr/Pi ratios of patients with GA.

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), a genetically determined deficiency of ornithine delta-aminotransferase activity leads to high ornithine concentrations in body fluids. GA is characterized by centripetally progressing retinal and choroidal destruction and selective atrophy with tubular aggregates in type II skeletal muscle fibres. These findings have been suggested to be mediated by hyperornithinaemia-induced deficiency of high-energy creatine phosphate. As abnormal brain magnetic resonance images and electroencephalograms are found in another disorder of creatine metabolism, guanidinoacetate methyltransferase deficiency, we investigated the central nervous system involvement in GA, which seems to be associated with a milder degree of phosphocreatine deficiency. We compared 23 untreated GA patients with age-matched healthy controls, and with 9 patients who had received creatine or creatine precursor supplementation daily for several years. The mean age of the patients (32 +/- 18 years) was similar to that of the controls (36 +/- 22 years). The MRI or EEG findings of the patients on creatine supplementation did not differ from those of the untreated group. Brain MRI revealed degenerative lesions in the white matter in 50% of the GA patients, and 70% of the patients had premature atrophic changes, with a striking increase in the number of Virchow's spaces. Of the patients whose EEG was recorded, 58% had abnormal slow background activity, focal lesions or high-amplitude beta rhythm (50 microV). The EEG findings were not associated with the MRI changes or with the age or the sex of the patients. Early degenerative and atrophic brain changes and abnormal EEG are thus features of GA, in addition to the well-characterized eye and muscle manifestations.

Background In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), inherited deficiency of ornithine-δ-aminotransferase leads to progressive fundus destruction and atrophy of type II skeletal muscle fibres. Because high ornithine concentrations inhibit creatine biosynthesis, the ensuing deficiency of high-energy creatine phosphate may mediate the pathogenesis. Materials and methods Relative concentrations of inorganic phosphate (Pi), creatine phosphate (PCr) and ATP in resting calf muscle were recorded in 23 GA patients and 33 control subjects using 31P-magnetic resonance spectroscopy (MRS). Eight patients with autosomal recessive retinitis pigmentosa with matched control subjects constituted an additional reference group. Results The PCr/Pi and PCr/ATP ratios (means ± SD) were lower for the GA patients than for healthy control subjects [4.66 ± 0.37 vs. 9.75 ± 2.17 (P

Unfavorable diet and lack of physical activity are frequently underlying childhood and juvenile obesity. Recommendations for physical activity advise children under school age to move at least two hours per day and children of school age at least 1 to 2 hours per day. The fact that these recommendations are, however, not met among Finnish children, is reflected in physical activity also in adulthood. Immobility and obesity often develop into a mutually reinforcing vicious circle that predisposes to an increasingly early appearance of cardiometabolic risk factors.

OBJECTIVES: Vascular intima-media thickness (IMT) and elasticity are surrogate markers of atherosclerosis. Data on the effect of cardiorespiratory fitness on these measures of vascular health in adolescence are scarce. The aim was to examine the association of fitness with aortic and carotid artery IMT and elasticity in adolescents. METHODS: Aortic (n = 449) and carotid (n = 467) IMT and elasticity were measured ultrasonographically in 17-year-old adolescents participating in a prospective, longitudinal atherosclerosis prevention study (Special Turku Coronary Risk Factor Intervention Project). Distensibility and Young's elastic modulus (YEM) were used as measures of arterial elasticity. Cardiorespiratory fitness (maximum oxygen uptake, mL/kg/min) was measured with a maximal cycle ergometer test. Data on fitness were available for 341 of adolescents with aortic and 355 with carotid ultrasound measures. RESULTS: Fitness was inversely associated with aortic IMT (β[SE] = –0.0029[0.0013]; P = .031) and YEM (β[SE] = –0.012[0.0053]; P = .025) after adjusting for gender, physical activity, high-density lipoprotein/total cholesterol, triglycerides, high-sensitivity C-reactive protein, homeostasis model of assessment–insulin resistance, BMI, systolic blood pressure, and smoking. Risk of having low aortic distensibility (≤10th percentile) decreased with increasing fitness (odds ratio = 0.89, 95% confidence interval 0.82–0.98); P = .014). The increase in aortic IMT and YEM between ages 11 and 17 years was smaller in adolescents who were fit at age 17 compared with adolescents who had the lowest fitness level (P for IMT = .015, P for YEM = .0072). Fitness was not associated with carotid IMT or elasticity. Lifestyle counseling given in the Special Turku Coronary Risk Factor Intervention Project was not associated with fitness. CONCLUSIONS: Fitness was favorably associated with aortic IMT and elasticity in adolescents. No association of fitness with the respective carotid indices was found. These data suggest that fitness in part enhances vascular health in healthy adolescents.

Objective Sedentary behaviour may contribute to the development of obesity. We investigated the relations between different types of sedentary behaviour and adiposity markers in a well-characterised adult population after controlling for a wide range of potential confounders. Design Cross-sectional study. Setting The Cardiovascular Risk in Young Finns Multicenter Study. Participants Sedentary time (TV viewing, computer time, reading, music/radio listening and other relaxation) was assessed with a questionnaire for 1084 women and 909 men aged 30–45 years. Other study variables included occupational and leisure-time physical activity, sleep duration, socioeconomic status, smoking, alcohol consumption, energy intake, adherence to the recommended diet, multiple individual food items, age and genetic variants associated with body mass index (BMI). Primary outcome measures BMI in kg/m2 and waist circumference (WC in cm). Results Of the different sedentary behaviour types, TV viewing was most consistently related to higher BMI and WC, both in men and women. One additional daily TV hour was associated with a 1.81±0.44 cm larger WC in women and 2 cm±0.44 cm in men (both p

Background— In the Special Turku Coronary Risk Factor Intervention Project for Children (STRIP) study, repeated dietary counseling introduced in infancy and maintained until 20 years of age has led to lower intakes of saturated fat and serum low-density lipoprotein cholesterol. In this study, we examined prospectively the intervention effects on the ideal cardiovascular health concept recently described by the American Heart Association. Additionally, we investigated the association between the concept and vascular intima-media thickness and elasticity in adolescence. Methods and Results— In adolescents participating in the longitudinal, randomized, atherosclerosis-prevention STRIP study, complete data on ideal cardiovascular health metrics were available at 15 (n=394), 17 (n=376), and 19 (n=298) years of age. Aortic intima-media thickness and elasticity were measured with ultrasonography at the same ages. None of the adolescents had all 7 ideal cardiovascular health metrics. At least 5 ideal metrics was found in 60.2%, 45.5%, and 34.2% of the adolescents at 15, 17, and 19 years of age, respectively. Adolescents in the control group had an increased risk of low ideal cardiovascular health (≤3 metrics) compared with the intervention adolescents (risk ratio=1.35; 95% confidence interval=1.04–1.77). The number of ideal cardiovascular health metrics was inversely associated with aortic intima-media thickness ( P P =0.045). The risk of having high intima-media thickness (>85th percentile) was nearly 2-fold in adolescents with a low number of metrics (≤3) compared with those with a higher score (risk ratio=1.78; 95% confidence interval=1.31–2.43). Conclusions— Ideal cardiovascular health as determined by the AHA can be promoted in adolescents. The ideal cardiovascular health concept is beneficially associated with vascular health already in adolescence, supporting the relevance of targeting these metrics as part of primordial prevention. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00223600

Our aim was to determine whether 12 weeks' aerobic Nordic walking (NW) or resistance exercise training (RT) without diet-induced weight loss could decrease oxidative stress and atherogenic index of plasma (AIP), prevalence of metabolic syndrome (MetS) and MetS score in middle-aged men with impaired glucose regulation (IGR) (n=144. 54.5 ± 6.5 years). In addition, we compared effects of intervention between overweight and obese subgroups. Prevalence of MetS and AIP index decreased only in NW group and MetS score in both NW and RT groups but not in control group. The changes in AIP index correlated inversely with changes in plasma antioxidant capacity. The change in AIP index remained a significant independent predictor of the changes in MetS score after the model was adjusted for age, BMI and volume of exercise (MET h/week) in NW group. There were no changes in the other measured markers of oxidative stress and related cytokines (e.g. osteopontin and osteoprotegerin) in any of the groups. Nordic walking decreased prevalence of MetS and MetS score. Improved lipid profile remained a predictor of decreased MetS score only in NW group and it seems that Nordic walking has more beneficial effects on cardiovascular disease risks than RT training.

Carnitine plays a central role in fatty acid (FA) metabolism. It transports long-chain fatty acids into mitochondria for beta-oxidation. Carnitine also modulates the metabolism of coenzyme-A (CoA). It is not surprising that the use of supplementary carnitine to improve physical performance has become widespread in recent years, although there is no unequivocal support to this practice. However, critical reflections and current scientific-based knowledge are important because the implications of reduced or increased carnitine concentrations in vivo are not thoroughly understood. Several rationales have been forwarded in support of the potential ergogenic effects of oral carnitine supplementation. However, the following arguments derived from established scientific observations may be forwarded: (i) carnitine supplementation neither enhances FA oxidation in vivo or spares glycogen or postpones fatigue during exercise. Carnitine supplementation does not unequivocally improve performance of athletes; (ii) carnitine supplementation does not reduce body fat or help to lose weight; (iii) in vivo pyruvate dehydrogenase complex (PDC) is fully active already after a few seconds of intense exercise. Carnitine supplementation induces no further activation of PDC in vivo; (iv) despite an increased acetyl-CoA/free CoA ratio, PDC is not depressed during exercise in vivo and therefore supplementary carnitine has no effect on lactate accumulation; (v) carnitine supplementation per se does not affect the maximal oxygen uptake (VO2max); (vi) during exercise there is a redistribution of free carnitine and acylcarnitines in the muscle but there is no loss of total carnitine. Athletes are not at risk for carnitine deficiency and do not have an increased need for carnitine. Although there are some theoretical points favouring potential ergogenic effects of carnitine supplementation, there is currently no scientific basis for healthy individuals or athletes to use carnitine supplementation to improve exercise performance.

Background Obesity, sedentary lifestyle and poor cardiorespiratory fitness in childhood may increase the risk of health problems later in life. Purpose The authors studied the association of early childhood weight status with cardiorespiratory fitness and leisure-time physical activity (LTPA) in adolescence. The stability and associations of LTPA and fitness from childhood through adolescence were also studied. Methods Body mass index (BMI) was assessed annually since birth in a prospective, longitudinal study. The mean BMI between ages 2 and 7 years indicated weight status at preschool age. Fitness was studied with a shuttle run test at age 9 and with a maximal cycle ergometer test at age 17. The same questionnaire was used to assess LTPA at age 9, 13 and 17. Complete data on preschool BMI, LTPA at ages 13 and 17 and fitness at age 17 years was provided by 351 children, while fitness and LTPA data were available for 74 children at ages 9 and 17. Results Preschool BMI was inversely associated with fitness in adolescence independently of adolescent LTPA (p=0.0001). Children who had a high preschool BMI but whose weight status was reduced in adolescence had similar fitness in adolescence as the children with a persistently low BMI. Regardless of the fitness level in childhood, the children whose LTPA increased between age 9 and 17 had a similar adolescent fitness level as persistently active subjects. Conclusions It is important to maintain a healthy body weight and a physically active lifestyle from very childhood through adolescence to improve fitness during adolescence.

Recurrent glenohumeral instability is challenging to treat when large bony defects are present in the anterior glenoid and there is a large Hill–Sachs lesion. We present a case with extensive glenoid and humeral bone loss treated with open Latarjet procedure combined with posterior arthroscopic Remplissage. 3.5 years after surgery, there have been no dislocations or any subjective signs of instability. After half a year, the patient was able to return to work as an airline pilot. Constant score has improved from 33 to 74 and the Oxford instability score from 8 to 46. We find that in young patients with difficult instability combining the Latarjet and Remplissage is a good and replicable method.

Long-term survivors of childhood acute lymphoblastic leukemia (ALL) have increased risk of cardiovascular disease (CVD). The prevalence of insulin resistance and other cardiometabolic risk factors is increased in ALL survivors, and insufficient physical activity (PA) and low cardiopulmonary fitness are common. The purpose of this study was to evaluate the effects of a simple, inexpensive home-based exercise program on cardiometabolic risk factors and fitness in long-term ALL survivors.Seventeen 16- to 30-year-old survivors of childhood ALL (age at diagnosis ≤16 years) were recruited to a 16-week home-based exercise program. Peak oxygen uptake (VO(2 peak)), muscle strength, and metabolic risk factors were studied before and after the exercise program.Fasting plasma insulin (P = 0.01), HOMA-IR (homeostasis model assessment, insulin resistance) (P = 0.002), waist circumference (P = 0.003), waist-to-hip ratio (P = 0.002), fat percent (P = 0.04), and supine diastolic blood pressure (P = 0.03) decreased during the program, while weight and body mass index remained unchanged. VO(2 peak) and maximal work load (W/kg) improved by 5% (P = 0.01 and P = 0.02, respectively) during the exercise program. The results of the Sit-Up test, Back extensor test, and Full Squatting test improved as well (P = 0.01, P = 0.002, and P = 0.0004, respectively).A simple home-based exercise program was effective in improving cardiometabolic risk factor status and fitness in young adult survivors of childhood ALL. Simple exercise programs should be recommended to this population with increased risk of CVD to improve metabolic risk factor status and fitness.

Physical inactivity is one of the leading risks for mortality worldwide. One of future main drivers for physical activity could be information and communication technology (ICT) gadgets and services that support active way of living. This study is the first attempt to model ICT adaption and awareness matrix to motivate and use ICT to support daily physical activity. This is important for individuals and also for information society and healthcare organizations to cope with physical inactivity challenge. They urgently require new approaches and to reshape their customers’ inactive lifestyle. End-user experience data for this research was collected with semi-structured questionnaire from subjects who used pedometers for a three-month- period. In the questionnaire there were questions related to motivation, awareness and also use of information technology connected to physical activity. Based on the results, usage habits and patterns of pedometers, this paper classifies the end-users into four distinctive groups. This classification is called TAMPA-model (Technology Adaption Matrix for Physical Activity -model).

SPECIFIC AIMSTo study the functional role of the recently found leucine 7 to proline 7 (Leu7Pro) polymorphism in the signal peptide of preproneuropeptide Y, sympathetic responses, including neurope...

Objectives The authors studied the association of leisure-time physical activity (LTPA) with clustered and individual metabolic risk factors in adolescents taking into account diet and pubertal status. The authors also studied whether screen time was associated with clustered risk. Methods Self-reported LTPA and screen time, lipids, lipoproteins, apolipoproteins, high-sensitivity C reactive protein, blood pressure, body mass index (BMI), pubertal status and diet were assessed in 13-year-old adolescents (n=542) participating in an atherosclerosis prevention study (Special Turku Coronary Risk Factor Intervention Project for Children). Activity groups were formed according to sex-specific LTPA index tertile cut-off points. BMI, high-density lipoprotein cholesterol (HDL-C), triglycerides and blood pressure comprised the cluster. Results An increase in LTPA was associated with a decreased risk for clustered metabolic risk in girls. When sedentary and highly active adolescents were compared, an increase in LTPA decreased clustering of risk factors in boys as well. Little extra benefit on clustered risk was obtained by increasing LTPA from 30 MET h/week (eg, 4–5 h/week bicycling or playing soccer) to 50 MET h/week (eg, 7–8 h/week bicycling or playing soccer). LTPA was beneficially associated with BMI, HDL-C, systolic blood pressure and HDL-C/total cholesterol in girls and HDL-C in boys. Diet and pubertal status were similar in all activity groups. In girls, screen time >2 h/day was associated with an increased risk for clustered risk, independent of LTPA. Conclusion Sedentary adolescents had an increased risk for clustered metabolic risk compared with physically more active peers. Only minor extra benefit was obtained when LTPA increased over 30 MET h/week. Focus in the prevention of clustered risk should especially be on avoiding sedentary lifestyle.

The risks of metabolic syndrome and sleep-disordered breathing increase around the time of the menopause. We have previously shown that features of the nocturnal transcutaneous carbon dioxide (TcCO2) profile are associated with metabolic variables such as cholesterol, glycosylated haemoglobin A1C (GHbA1C) and blood pressure in patients with sleep apnoea. In the present study, we investigated whether these metabolic variables can be predicted using noninvasive TcCO2 measurements during sleep in generally healthy post-menopausal females. 22 post-menopausal females underwent an overnight polygraphic sleep study that involved the continuous monitoring of arterial oxygen saturation (S(a,O2)) and TcCO2. Body composition, GHbA1C, plasma cholesterol and blood pressure were measured prior to the sleep study. Nocturnal TcCO2 features were the most important predictors of lipoprotein cholesterols, triglycerides and blood pressure levels. A longer sleep period and higher TcCO2 levels were linked with lower GHbA1C, and fragmented sleep with lower high-density lipoprotein cholesterol. Neither nocturnal S(a,O2) indices nor the apnoea/hypopnoea index had a predictive power. The results suggest that nocturnal TcCO2 events revealed metabolic risk factors already present in healthy post-menopausal females.

The effect of feeding different amounts of a standard laboratory pellet diet on tissue carnitine concentration was studied in four groups of rats. Group I was fed ad libitum, whereas food intake was restricted to 25, 20, and 15g protein/kg body weight/day in group II, III, and IV, respectively. The intake of food, protein, energy and carnitine was constant and adjusted to actual body weight in groups 2-4. Six weeks food restriction had no effect on muscle carnitine. Restricted diet caused lowered concentrations of carnitine in serum (group I, fed ad libitum, total 95.0 +/- 13.8, free 80.2 +/- 2.7; group II total 78.4 +/- 8.4, free 56.9 +/- 4.7; group III total 81.7 +/- 8.8, free 66.0 +/- 8.8; and group IV total 73.8 +/- 8.7, free 59.5 +/- 7.6 micromol/l) and urinary carnitine excretion (group I, total 7.1 +/- 3.3, free 6.3 +/- 3.1; group II, total 2.5 +/- 0.7, free 2.2 +/- 0.7; group III, total 1.9 +/- 0.8, free 1.6 +/- 0.8; and group IV, total 1.3 +/- 0.4 free 1.1 +/- 0.3 micromol/day). In contrast, the liver carnitine tended to increase when dietary intake was reduced (group I total 1.1 +/- 0.1, free 1.0 +/- 0.1; group II total 1.5 +/- 0.2, free 1.4 +/- 0.2; group III total 1.3 +/- 0.1, free 1.1 +/- 0.1; and group IV total 1.5 +/- 0.2, free 1.4 +/- 0.2 micromol/g dry wt). The highest liver carnitine concentrations were observed during the lowest dietary intake when also the serum and urine carnitine were lowest. We conclude that the amount of food intake has a direct impact on carnitine concentrations in the liver, serum, and urine while muscle carnitine concentration remains relatively stable despite wide variations in food intake.

We studied whether the prevalence of overweight since age 2 years differed in sedentary and active adolescents (N=346). Further, we analyzed the energy intake of sedentary and active adolescents across 12 years. BMI was assessed annually since birth, energy intake since age 13 months and parents' BMI from the time their child was 7 months old in a longitudinal atherosclerosis prevention study. Data on physical activity were collected at age 13 years (N=560). Sedentary and Active groups were formed by upper and lower physical activity tertile cut-points. Girls Sedentary at 13 years were more often overweight than Active peers already since age 2 years (P=0.048). Activity habits were not associated with energy intake. Conversely, among boys, activity habits in adolescence were not associated with childhood overweight, while the energy intake of Active boys was higher than that of Sedentary boys (P=0.008). Parental overweight was not associated with the physical activity of children; however, Sedentary girls more often had an overweight mother than Active girls (P=0.021). In conclusion, overweight during early years of life is more common among girls who are Sedentary as adolescents than in Active peers. Overweight mothers more often have Sedentary daughters than normal-weight mothers. A healthy lifestyle right from early childhood requires active support.

Background— Exercise training improves endothelial function in high-risk adolescents, but the influence of habitual leisure-time physical activity on endothelial function in healthy adolescents is unknown. Methods and Results— Brachial artery flow-mediated endothelial function and physical activity habits were assessed in 483 adolescents (13 years of age) participating in an atherosclerosis prevention study (Special Turku Coronary Risk Factor Intervention Project for Children [STRIP]). Endothelial function was examined with ultrasound; physical activity was assessed with self-administered questionnaires. A leisure-time physical activity index was calculated by multiplying mean weekly leisure-time exercise intensity, duration, and frequency [boys, 31.2±23.0 MET h/wk (mean±SD); girls, 24.0±20.9 MET h/wk; P for gender difference=0.0003]. Maximum flow-mediated dilatation (FMD) and total FMD response (the area under the dilatation curve 40 to 180 seconds after hyperemia) were calculated. In boys, maximum FMD and area under the dilatation curve 40 to 180 seconds after hyperemia were directly associated with leisure-time physical activity index in regression analyses adjusted for brachial artery diameter (maximum FMD, P =0.020; area under the dilatation curve 40 to 180 seconds after hyperemia, P =0.0055). These associations remained significant after further adjustments for body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, and systolic blood pressure. A difference of ≈50 MET h/wk corresponding to ≈10 hours of moderate intensity activity weekly between sedentary and active boys was associated with an ≈1% unit difference in maximum FMD. Conclusions— Leisure-time physical activity is directly associated with brachial artery FMD responses in 13-year-old boys, providing evidence that physical activity beneficially influences endothelial function in healthy male adolescents. Lack of association in girls may reflect their overall lower physical activity level.

Vitamin D insufficiency is common particularly during wintertime. After the recommendation by the Ministry of Social Affairs and Health, Finnish fluid milks and margarines have been fortified with vitamin D since February 2003. The aims of the present study were to examine the impact of vitamin D fortification of food supplies on serum 25-hydroxyvitamin D (S-25(OH)D) concentrations and on daily dietary vitamin D intake among adolescent females. One hundred and forty-two girls of Caucasian ethnicity aged 12–18 years completed semi-quantitative FFQ from which the dietary vitamin D and Ca intakes were calculated. S-25(OH)D was measured by radioimmunoassay. The study was performed from February–March 2000 to February–March 2004, one year after the initiation of fortification. The mean dietary intake of vitamin D was v. 48·1 nmol/l, NS). The proportion of participants who had S-25(OH)D concentration

The purpose of this study was to investigate the health related quality of life (HRQL) in a total cohort of general school children.The study population consisted of the children starting 4th grade (age 9-10) in Finnish primary schools in autumn 2004 (n = 1,346) and their parents in a city of 175,000 inhabitants. Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) was used for assessment of HRQL. The response rate was 81% for the children (n = 1,091). Most children had parents who participated (n = 999).The children reported highest HRQL mean values in physical (85.00, SD 10.95) and social (84.71, SD 14.28), and lowest in school (78.89, SD 14.53) and emotional (75.43, SD 15.67), functioning scales. Girls reported significantly lower emotional (t = -2.43, P = 0.02) functioning than boys. Child self reports show lower social (t = -2.57, P = 0.01) and school (t = -3.44, P = 0.0006) functioning, and higher emotional (t = 5.82, P0.0001) and physical (t = 4.79, P0.0001) functioning than their parent-proxy assessments.Interventions aiming at supporting the emotional and school functioning of the school children are recommended. Parents may overestimate the social and school functioning and underestimate the physical and emotional functioning compared to their children's own perceptions.

Exercise training seems to restore impaired vascular function in both peripheral and myocardial vessels in patients with coronary artery and peripheral vascular disease or in patients with risk factors for these diseases. However, the results on the effects of exercise training on vascular function in apparently healthy subjects are controversial. We studied the effects of long-term volitionally increased physical activity on peripheral and myocardial vascular function in nine young healthy male monozygotic twin pairs discordant for physical activity and fitness. The brothers were divided into more (MAG) and less active groups according to physical activity and fitness. The difference between groups in VO(2max) was 18+/-10% (P

Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 +/- 10% higher (P0.001) compared to the less active brothers with lower physical activity. Low-intensity knee-extension exercise increased skeletal muscle FFA and oxygen uptake six to 10 times compared to resting values but no differences were observed between the groups at rest or during exercise. At rest the more active group had lower hepatic FFA uptake compared to the less active group (5.5 +/- 4.3 versus 9.0 +/- 6.1 micromol (100 ml)(-1) min(-1), P = 0.04). Hepatic FFA uptake associated significantly with body fat percentage (P = 0.05). Myocardial FFA uptake was similar between the groups. In conclusion, in the absence of the confounding effects of genetic factors, moderately increased physical activity and aerobic fitness decrease body adiposity even in normal-weighted healthy young adult men. Further, increased physical activity together with decreased intra-abdominal adiposity seems to decrease hepatic FFA uptake but has no effects on skeletal muscle or myocardial FFA uptake.

The leisure-time physical activity of 13-year-old Finnish adolescents was assessed in the prospective STRIP study. A self-administered questionnaire (N=565) was used. The leisure-time physical activity index (PAI; MET h/week) was calculated on the basis of reported exercise intensity, duration and frequency (N=558; 53% boys). The participants were divided into Sedentary, Moderately Active and Active groups by PAI tertiles. A subpopulation (N=197) also used a heart rate monitor (3 days, >/=8 h/day) to assess the time spent on different activity intensities. The median male PAI was 31.3 (inter-quartile range (IQR) 44.2) MET h/week and female 19.5 (IQR 26.3) MET h/week (P=0.0002). The cutoff points of the PAI tertiles were similar for the Active girls (31.3 MET h/week) and boys (32.6 MET h/week), but for the Sedentary boys it was 19.5 MET h/week and only 5.0 MET h/week for the Sedentary girls. High self-reported leisure-time physical activity associated poorly with time spent on moderate or vigorous exercise measured by heart rate monitoring. Active mothers had more often Active daughters or sons. In conclusion, the amount of leisure-time physical activity of one-third of 13-year-old girls is extremely low. Sedentary adolescents, especially girls, should therefore be put into focus for active efforts to increase their leisure-time physical activity. Parental models may be important.

Sonographic parameters of the heel were recorded in order to investigate the effects of changes in physical activities among 140 healthy growing peripubertal Caucasian girls. Calcaneal quantitative ultrasound measurements (Hologic Sahara) were recorded at baseline and 2- and 6-year follow-up. Broadband ultrasound attenuation, speed of sound (SOS), and T scores were documented. Altogether, 30 girls reduced their physical activity by >50% and 29 girls by 25–50%, whereas 81 girls continued at the present level or increased it. Age and physical activity together accounted for 16.7% of the variation in calcaneal T scores at baseline and for 16.4% at 2-year follow-up, whereas physical activity alone accounted for 11.3% of the variation at 6-year follow-up. The reduction in mean T scores was significant (from 2.0 to 0.8, P < 0.001) among those having discontinued their physical activity by the 6-year measurement. The changes between three groups were statistically significantly different from each other (P = 0.003). The mean SOS values decreased 16.78 meters per second (95% CI −26.9 to −6.7) among those having discontinued their physical activity between the 2- and 6-year follow-up measurements. The SOS value sensitively reacts to changes in physical activity, and consequently, it will help assess changes in bone quality. Because of such an immediate reaction, SOS is a good-quality measure for the physical condition of bone in young people and a suitable tool for detecting changes in calcaneal bone.

The effect of metformin or rosiglitazone monotherapy versus placebo on insulin signaling and gene expression in skeletal muscle of patients with newly diagnosed type 2 diabetes was determined. A euglycemic-hyperinsulinemic clamp, combined with skeletal muscle biopsies and glucose uptake measurements over rested and exercised muscle, was performed before and after 26 weeks of metformin (n = 9), rosiglitazone (n = 10), or placebo (n = 11) treatment. Insulin-mediated whole-body and leg muscle glucose uptake was enhanced 36 and 32%, respectively, after rosiglitazone (P0.01) but not after metformin or placebo treatment. Insulin increased insulin receptor substrate 1 (IRS-1) tyrosine phosphorylation, IRS-1-associated phosphatidylinositol (PI) 3-kinase activity, and phosphorylation of Akt Ser473 and AS160, a newly described Akt substrate that plays a role in GLUT4 exocytosis, approximately 2.3 fold before treatment. These insulin signaling parameters were unaltered after metformin, rosiglitazone, or placebo treatment. Expression of selected genes involved in glucose and fatty acid metabolism in skeletal muscle was unchanged between the treatment groups. Low-intensity acute exercise increased insulin-mediated glucose uptake but was without effect on insulin signaling. In conclusion, the insulin-sensitizing effects of rosiglitazone are independent of enhanced signaling of IRS-1/PI 3-kinase/Akt/AS160 in patients with newly diagnosed type 2 diabetes.

Cross-sectional studies in athletes and untrained subjects suggest that exercise training induces adaptations in cardiac structure and function. However, the role of genetic variation on the results has largely been ignored in these studies. The purpose of this study was to investigate the effects of long-term volitionally increased physical activity on electrocardiographic and echocardiographic parameters in male monozygotic twin pairs discordant for physical activity and fitness. On the basis of the mailed questionnaires, a telephone interview, and the inclusion criteria, 12 pairs of young adult male monozygotic twins were recruited from a Finnish twin cohort. All subjects completed a maximal oxygen uptake (V̇o2 max) test and electrocardiography and echocardiography studies. Nine pairs had at least 9% difference in V̇o2 max and were selected for further analysis and for a second echocardiography study. Twins were divided into the more (MAG) and less active group (LAG), according to their V̇o2 max. On average, MAG had 18% higher V̇o2 max compared with LAG. In electrocardiography, MAG had 29% ( P = 0.02) higher Cornell voltage and 37% ( P = 0.01) higher right-side hypertrophy index. In echocardiography, no significant differences were observed between the groups, and left ventricular mass index was only 7% ( P = 0.16) higher in MAG. These results show that the volitionally increased physical activity that has led to an 18% increase in cardiorespiratory fitness induces greater changes in electro- than echocardiographic parameters. Electrocardiographic changes were suggestive of left ventricular hypertrophy, and echocardiography showed a similar but statistically nonsignificant trend.

Serum soluble transferrin receptor (sTfR) has been established in recent years as a powerful tool for detecting iron deficiency (ID) in adults, especially in distinguishing between iron deficiency anemia (IDA) and anemia of chronic disease (1)(2)(3)(4)(5)(6)(7)(8). Investigations regarding sTfR as a measure of iron status in infants and children have provided promising results, including evidence that, in infants, sTfR concentrations may be superior to ferritin measurements in diagnosing ID (9). However, to date, concrete reference values and other decision-supporting limits for the commercially available methods have been virtually absent, and the age-relatedness of sTfR concentrations, although introduced as a concept, has not been unequivocally modeled statistically (10)(11)(12)(13)(14)(15). In this study we measured the sTfR concentrations from a selection of 301 healthy children, 6 months to 18 years of age, using a commercially available automated immunoturbidimetric assay. We then used a regression-based method to construct age-dependent 2.5% and 97.5% reference limits for sTfR as well as 95% confidence intervals for these limits in our population (16). The purpose was to demonstrate consistent age-dependent changes in sTfR concentrations and to establish appropriate reference limits to enable the use of sTfR measurements in routine pediatric clinical practice. A total of 301 children (130 boys and 171 girls; age range, 6 months to 18 years) were included in the healthy population of this study. The selection was made on the basis of detailed anamnesis and laboratory tests. Febrile episodes during the preceding 6 weeks, diet restrictions, chronic inflammatory or renal diseases, hematological diseases, recent iron supplementation, ongoing inflammation (C-reactive protein >10 mg/L; erythrocyte sedimentation rate >6 mm/h), anemia or abnormal red cell indices (17), and low ferritin concentrations (

Objective/purpose To investigate clinical variation in a genetically homogenous group of subjects with gyrate atrophy of choroid and retina with hyperornithinemia (GA). The group was made up of homozygotes and compound heterozygotes for mutation L402P in the ornithine aminotransferase (OAT) gene. Design Cross-sectional study. Participants Thirty-five Finnish subjects (18 men) with GA with a mean age of 33 years (range, 5–74 years) carrying the Finnish founder mutation L402P. Methods All subjects were examined between 1993 and 1995. The analysis was composed of, in addition to careful clinical evaluation, studies of visual fields with Goldmann perimeter, photographing of the eye fundi, and corneal electroretinography (ERG) recordings. Main outcome measures The changes in eye fundi, visual acuity, cataract changes in the lens, visual field constriction, and ERG responses were determined. Results Myopia, early cataracts, and highly abnormal ERG were typical for the GA subjects. The changes progressed rather uniformly with age. However, visual acuity, funduscopic findings, and visual fields showed great phenotypic variation. Despite the great interindividual variation, both eyes of each subject were always similarly affected. Conclusions This study of 35 subjects with GA carrying a single mutation shows that the ophthalmologic symptoms and findings vary widely. The data also reveal that GA subjects are already affected by severe visual impairment in young adulthood. However, the diagnosis is often made very late.

Hyperornithinaemia and gyrate atrophy of choroid and retina (GA; McKusick 258870) is a rare inborn error of amino acid metabolism caused by impaired activity of ornithine aminotransferase (OAT; EC 2.6.1.13). Plasma ornithine concentration is 10 20 times higher than normal. Vision becomes progressively impaired so that blindness usually develops in the fifth decade. Type II muscle fibre atrophy and variable mild central nervous system abnormalities also occur (Heinanen et al 1999; Nanto-Salonen et al 1999; Sipila et al 1979; Takki and Simell 1974). The pathophysiology of GA remains unknown, and a variety of experimental therapies have been attempted. Lowering plasma ornithine via dietary protein restriction may slow progression of the ophthalmological findings (Kaiser-Kupfer et al 1980, 1991). However, strict low-protein diet is cumbersome to follow and expensive, thus decreasing compliance of the patient. Ornithine and the ornithine precursor arginine share a common renal transport system with lysine and cyst(e)ine. High blood lysine concentration may block the reabsorption of ornithine and arginine in the kidney and induce increased renal loss of ornithine, thereby decreasing plasma ornithine (Giordana et al 1978; Simell and Perheentupa 1974). Excess lysine might thus provide a new approach for decreasing plasma ornithine concentration. In this pilot study we studied whether short-term oral lysine feeding is effective in lowering plasma ornithine concentration in patients with GA.

The aim of this cross-sectional study was to investigate whether two types of physical exercise affect the growing skeleton differently. We used calcaneal quantitative ultrasound measurements (QUS) and dual-energy X-ray absorptiometry (DXA) for measurement of bone mineral density (BMD), and to test how QUS values reflect the axial DXA values in these various study groups. A total of 184 peripubertal Caucasian girls aged 11-17 years (65 gymnasts, 63 runners, and 56 nonathletic controls) were studied. Weight, height, stage of puberty, years of training, and the amount of leisure-time physical activity were recorded. Broadband ultrasound attenuation (BUA) and sound of speed (SOS) through the calcaneus were measured. The BMD of the femoral neck and the lumbar spine were measured by DXA. The differences in mean values of bone measurements among each exercise group were more evident in pubertal than prepubertal girls. The mean BUA and SOS values of the pubertal gymnasts were 13.7% (77.8 dB/MHz versus 68.4 dB/MHz, P < 0.05) and 2.2% (1607.7 m/s versus 1572.4 m/s, P < 0.001) higher than of the controls, respectively. The mean BMD of the femoral neck in the pubertal gymnasts and runners was 20% (0.989 g/cm2 versus 0.824 g/cm2, P < 0.001) and 9.0% (0.901 g/cm2 versus 0.824 g/cm2, P < 0.05) higher than in the controls, respectively. The amount of physical activity correlated weakly but statistically significantly with all measured BMD and ultrasonographic values in the pubertal group (r = 0.19-0.35). The correlation between ultrasonographic parameters and BMD were weak, but significant among pubertal runners (r = 0.47-0.55) and controls (r = 0.39-0.42), whereas the DXA values of the femoral neck and the ultrasonographic parameters of the calcaneus did not correlate among highly physically active gymnasts. By stepwise regression analysis, physical activity accounted for much more of the variation in the DXA values than the ultrasonographic values. We conclude that the beneficial influence of exercise on bone status as measured by ultrasound and DXA was evident in these peripubertal girls. In highly active gymnasts the increase of the calcaneal ultrasonographic values did not reflect statistically significantly the BMD values of the femoral neck.

The responses of serum myocellular proteins and hormones to exercise were studied in ten well-trained middle-distance runners [maximal oxygen consumption (VO(2max)) = 69.4 (5.1) ml x kg(-1) x min(-1)] during 3 recovery days and compared to various measures of physical performance. The purpose was to establish the duration of recovery from typical intermittent middle-distance running exercises. The subjects performed, in random, order two 28-min treadmill running exercises at a velocity associated with VO(2max): 14 bouts of 60-s runs with 60 s of rest between each run (IR(60)) and 7 bouts of 120-s runs with 120 s of rest between each run (IR(120)). Before the exercises (pre- exercise), 2 h after, and 1, 2 and 3 days after the exercises, the same series of measurements were performed, including those for serum levels of the myocellular proteins creatine kinase, myoglobin and carbonic anhydrase III (S-CK, S-Mb and S-CA III, respectively), serum hormones testosterone, Luteinizing hormone, follicle-stimulating hormone and cortisol (S-testosterone, S-LH, S-FSH and S-cortisol, respectively) and various performance parameters: maximal vertical jump height (CMJ) and stride length, heart rate and ratings of perceived exertion during an 8-min run at 15 km x h(-1) (SL(15 km x h(-1)), HR(15 km x h(-1)) and RPE(15 km x h(-1)), respectively). Two hours after the end of both exercise bouts the concentration of each measured serum protein had increased significantly (P < 0.001) compared to the pre-exercise level, but there were no changes in SL(15 km x h(-1)) or CMJ. During the recovery days only S-CK was significantly raised (P < 0.01), concomitant with a decrease in CMJ (P < 0.01) and an increase in RPE(15 km x h(-1)) (P < 0.01). Hormone levels remained unchanged compared to the pre-exercise levels during the recovery days and there were no significant differences between the two exercise bouts in any of the observed post-exercise day-to-day responses. With the exception of S-CK, after IR(120) the post-exercise responses returned to their pre-exercise levels within the 3 days of recovery. The present findings suggest that a single 28-min intermittent middle-distance running exercise does not induce changes in serum hormones of well-trained runners during recovery over 3 days, while changes in S-CK, CMJ and RPE(15 km x h(-1)) indicate that 2-3 days of light training may be needed before the recovery at muscle level is complete.

Deficiency of omithine-delta-aminotransferase (OAT) causes gyrate atrophy of the choroid and retina with hyperornithinemia (GA; McKusick 258870), a progressive autosomal recessive chorioretinal degeneration leading to early blindness. As residual enzyme activity may vary in different mutations of the OAT gene and explain individual variations in disease progression, a sensitive HPLC modification of the OAT assay in lymphocytes was developed, based on measurement of the dihydroquinozolinium reaction product. The OAT activities (ranges) of 43 Finnish GA patients with mutations L402P/L402P, R180T/L402P, N89K/ L402P, and L402P/x (x = previously unknown allele), were

In the present study we introduce a new device for exercise magnetic resonance spectroscopy (MRS). It operates in a standard whole-body scanner. Mechanical exertion unit allows maximal 10 degrees to 15 degrees short-arc knee extensions. The device operates hydraulically and is based on isokinetic movement. The force and work conducted are automatically controlled by the electronic control and computer unit. A small surface coil placed on the vastus medialis muscle allows the collection of spectra without interfering spectra from nearby resting muscles. The force used for the extensions can be followed simultaneously as a curve on the screen in the operator's room and the data is transferred to a personal computer for later analysis. Total work and fatigue percentage are also calculated by the device. It also allows the use of different isokinetic exercise protocols. The measurements of force proved reliable in repeat measurements using an isokinetic test device as a control. This device has been used clinically for over a year, is easy to operate, and offers reliable measurements. It is well suited to trials where muscle energy states versus time are followed since it allows noninvasive simultaneous quantification of muscle performance and collecting MRS spectra at rest, during exercise, and in the recovery phase.

Serum lipid peroxidation was measured by three different methods (diene conjugation, DC; thiobarbituric acid reactive material, TBARM; and fluorescent chromolipids, FC) during physical exercise of different duration. The aim of the study was to investigate which of the three methods is the most representative in measuring oxidative stress after physiological stimulus (physical exercise) in man. In general, diene conjugation is a measure of early events of lipid peroxidation reactions, TBARM measures end products of lipid peroxidation and FC are products formed by reaction of end products of lipid peroxidation with the amino groups. In trial I, 8 subjects ran 1 km with maximal speed; in trial II, 7 subjects ran 10 km with maximal speed; in trial III, 9 subjects ran 27 km with maximal speed, and in trial IV, 5 subjects cycled 8 days in competition, altogether 1061 km biking. In each trial venous blood samples were taken before and immediately after the exercise. In trials II, III, and IV serum DC concentration increased by 14% (P < 0.05), 11% (P < 0.01), and 25% (P < 0.05), respectively, during the exercise. FC or TBARM did not change in the trials. We conclude that DC as a measure of the early phase of lipid peroxidation may be less affected by protective antioxidant functions than FC and TBARM methods, which both measure end products of lipid peroxidation. Therefore, DC may be the most sensitive of the three methods to estimate serum lipid peroxidation induced by exercise in man.(ABSTRACT TRUNCATED AT 250 WORDS)

Carnitine plays a central role in lipid metabolism by transporting long-chain fatty acids into the mitochondria for beta-oxidation. Reduction of carnitine concentration does not automatically imply that functional carnitine deficiency exists with direct consequences on energy metabolism. In our experimental model, we reduced tissue concentrations of carnitine to levels that are comparable to those in patients with various metabolic disorders with secondary carnitine deficiency and did a study on the in vivo effects of moderate carnitine depletion on palmitate oxidation, exercise capacity, and nitrogen balance. Thirty rats were divided into a carnitine-depleted group (group I) and pair-fed controls (group II). Carnitine depletion resulting in a 48% reduction of tissue carnitine concentrations was induced by feeding ad libitum a carnitine-free oral diet consisting of parenteral nutrition solutions. Palmitate oxidation was measured by collecting expired 14CO2 after an intraperitoneal injection of [1-14C]palmitate, and exercise capacity was determined by having the rats swim to exhaustion. Despite the 48% depletion of carnitine in serum, muscle, and liver, there were no differences in cumulative palmitate oxidation in 3 h (group I, 40 +/- 7%; group II, 37 +/- 9% of injected activity), swimming time to exhaustion (group I, 8.1 +/- 2.8 h; group II, 7.7 +/- 3.6 h), or nitrogen balance (group I, 1.1 +/- 0.5 g of nitrogen/kg/d; group II, 1.2 +/- 0.5 g of nitrogen/kg/d). We conclude that carnitine depletion of 48% has no effect on palmitate oxidation, exercise capacity, or nitrogen balance in the rats studied.

Physical training increases skeletal muscle insulin sensitivity. Since training also causes functional and structural changes in the myocardium, we compared glucose uptake rates in the heart and skeletal muscles of trained and untrained individuals. Seven male endurance athletes (VO2max 72 +/- 2 ml/kg/min) and seven sedentary subjects matched for characteristics other than VO2max (43 +/- 2 ml/kg/min) were studied. Whole body glucose uptake was determined with a 2-h euglycemic hyperinsulinemic clamp, and regional glucose uptake in femoral and arm muscles, and myocardium using 18F-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose uptake in the athletes was increased by 68% in whole body (P < 0.0001), by 99% in the femoral muscles (P < 0.01), and by 62% in arm muscles (P = 0.06), but it was decreased by 33% in the heart muscle (P < 0.05) as compared with the sedentary subjects. The total glucose uptake rate in the heart was similar in the athletes and control subjects. Left ventricular mass in the athletes was 79% greater (P < 0.001) and the meridional wall stress smaller (P < 0.001) as estimated by echocardiography. VO2max correlated directly with left ventricular mass (r = 0.87, P < 0.001) and inversely with left ventricular wall stress (r = -0.86, P < 0.001). Myocardial glucose uptake correlated directly with the rate-pressure product (r = 0.75, P < 0.02) and inversely with left ventricular mass (r = -0.60, P < 0.05) or with the whole body glucose disposal (r = -0.68, P < 0.01). Thus, in athletes, (a) insulin-stimulated glucose uptake is enhanced in the whole body and skeletal muscles, (b) whereas myocardial glucose uptake per muscle mass is reduced possibly due to decreased wall stress and energy requirements or the use of alternative fuels, or both.

Carnitine has a potential effect on exercise capacity due to its role in the transport of long-chain fatty acids into the mitochondria forβ-oxidation, the export of acyl-coenzyme A compounds from mitochondria and the activation of branched-chain amino acid oxidation in the muscle. We studied the effect of carnitine supplementation on palmitate oxidation, maximal exercise capacity and nitrogen balance in rats. Daily carnitine supplementation (500 mg - kg−1 body mass for 6 weeks) was given to 30 rats, 15 of which were on an otherwise carnitine-free diet (group 1) and 15 pair-fed with a conventional pellet diet (group II). A control group (group III,n = 6) was fed ad libitum the pellet diet. Palmitate oxidation was measured by collecting14CO2 after an intraperitoneal injection of [1-14C]palmitate and exercise capacity by swimming to exhaustion. After carnitine supplementation carnitine concentrations in serum were supranormal [group I, total 150.8 (SD 48.5), free 78.9 (SD 18.4); group II, total 170.9 (SD 27.9), free 115.8 (SD 24.6) gmol·1−1] and liver carnitine concentrations were normal in both groups [group I, total 1.6 (SD 0.3), free 1.2 (SD 0.2); group II, total 1.3 (SD 0.3), free 0.9 (SD 0.2) μmol·g−1 dry mass]. In muscle carnitine concentrations were normal in group I [total 3.8 (SD 1.2), free 3.2 (SD 1.0) μmol · g−1 dry mass] and increased in group II [total 6.6 (SD 0.5), free 4.9 (SD 0.9) μmol·g−1 dry mass]. Despite the difference in muscle carnitine concentrations there were no differences among the groups in cumulative palmitate oxidation after 3 h [group I, 39.7 (SD 11.6)%, group II, 29.6 (SD 14.0)%; group III, 36.5 (SD 10.8)% of injected activity] or swimming time to exhaustion [group I, 9.7 (SD 2.9); group II, 8.4 (SD 3.6); group III, 7.1 (SD 2.8) h]. A borderline increase in nitrogen balance was observed in group II. We concluded that increasing carnitine tissue concentrations by carnitine supplementation had no effect on palmitate oxidation and maximal exercise capacity in the rats studied.