Amount Of Vigorous Physical Activity Research Articles

The Relationship between Body Composition and Physical Activity Level in Students of Medical Faculties.

Maintaining an active lifestyle is crucial for good health. Markers of health risk include tissue components. This study aimed to indicate which body composition elements create the strongest correlations with physical activity performed in young students of medical faculties. The study group consisted of 75 students (33 men and 42 women) from Wroclaw Medical University. Each student underwent accelerometer and anthropometric measurements and body composition analysis. Both men and women had similar physical activity levels. The study found that the amount of vigorous physical activity correlated significantly with the basal metabolic rate (BMR), fat, water and muscle content, fat-free mass (FFM), bone mass, extracellular to intracellular water ratio (ECW/ICW), and phase angle (PA), with r~ ± (0.2-0.4). The amount of moderate physical activity correlated with body mass, body mass index (BMI), BMR, FFM, and bone mass, with r~0.3-0.5. There are dimorphic differences in the strength of correlations between physical activity and elements of body composition. A greater amount of moderate and vigorous physical activity is associated with greater FFM and bone mass in men, which causes BMI to increase as well (in this case, higher BMI is not a sign of being overweight). For women, the beneficial effect of higher amounts of vigorous physical activity on reducing fat content and increasing muscle mass is more pronounced. In both men and women, an improvement in hydration is evident with increased vigorous physical activity volume.

Motivation, stress, recovery, and physical activity of teachers: discoveries with the Reiss Motivation Profile® and the Firstbeat® measurement

AimTeaching is known as a high-stress occupation. Managing fatigue and promoting work engagement, teachers’ expectations and perceptions can impact work-related stress–recovery–balance and physical activity levels. The main objective of the current study was to investigate the relationship between intrinsic motivational factors and the autonomic nervous system, such as heart rate and heart rate variability regulation, sleep, and physical activity levels.MethodsThe research included 66 primary and high school teachers in Tampere, Finland, in 2020–2021. The Reiss Motivation Profile® (RMP) was selected as an instrument to provide a practical approach to understanding people’s intrinsic motivators and the effects of those on the Firstbeat®-measured heart rate and heart rate variability, and accelerometry. Stepwise multiple linear regression models were used to assess whether the RMP motives reflected Firstbeat®-measured outcomes.ResultsMotives such as Acceptance, Eating, Family, Physical Activity, Power, Tranquillity, and Vengeance were found to have a relationship with Firstbeat®-measured outcomes. An increase in the Physical Activity motive was related to lower stress and less light physical activity. Furthermore, an increase in the Physical Activity motive showed a relationship with better recovery and a higher amount of vigorous physical activity. However, the statistical analysis of heart rate and heart rate variability showed only low explanatory power (R2 = 0.111–0.140) for stress, recovery, and sleep. On the contrary, the explanatory power of measurements related to physical activity and sedentary behavior was higher (R2 = 0.171–0.298). In addition, the need for Acceptance as an important intrinsic motive that may prevent people from vigorous physical activity deserves further research.ConclusionThe results indicated that there are several factors affecting the autonomous nervous system but also behavior. The basic desires explained sedentary and physical activity behavior better than the functioning of the autonomic nervous system. The 16 life motives can serve as a valuable theory for understanding better how to encourage people to have healthier habits.

Vigorous physical activity, incident heart disease, and cancer: how little is enough?

Vigorous physical activity (VPA) is a time-efficient way to achieve recommended physical activity levels. There is a very limited understanding of the minimal and optimal amounts of vigorous physical activity in relation to mortality and disease incidence. A prospective study in 71 893 adults [median age (IQR): 62.5 years (55.3, 67.7); 55.9% female] from the UK Biobank cohort with wrist-worn accelerometry. VPA volume (min/week) and frequency of short VPA bouts (≤2 min) were measured. The dose-response associations of VPA volume and frequency with mortality [all-cause, cardiovascular disease (CVD) and cancer], and CVD and cancer incidence were examined after excluding events occurring in the first year. During a mean post-landmark point follow-up of 5.9 years (SD ± 0.8), the adjusted 5-year absolute mortality risk was 4.17% (95% confidence interval: 3.19%, 5.13%) for no VPA, 2.12% (1.81%, 2.44%) for >0 to <10 min, 1.78% (1.53%, 2.03%) for 10 to <30 min, 1.47% (1.21%, 1.73%) for 30 to <60 min, and 1.10% (0.84%, 1.36%) for ≥60 min. The 'optimal dose' (nadir of the curve) was 53.6 (50.5, 56.7) min/week [hazard ratio (HR): 0.64 (0.54, 0.77)] relative to the 5th percentile reference (2.2 min/week). There was an inverse linear dose-response association of VPA with CVD mortality. The 'minimal' volume dose (50% of the optimal dose) was ∼15 (14.3, 16.3) min/week for all-cause [HR: 0.82 (0.75, 0.89)] and cancer [HR: 0.84 (0.74, 0.95)] mortality, and 19.2 (16.5, 21.9) min/week [HR: 0.60 (0.50, 0.72)] for CVD mortality. These associations were consistent for CVD and cancer incidence. There was an inverse linear association between VPA frequency and CVD mortality. 27 (24, 30) bouts/week was associated with the lowest all-cause mortality [HR: 0.73 (0.62, 0.87)]. VPA of 15-20 min/week were associated with a 16-40% lower mortality HR, with further decreases up to 50-57 min/week. These findings suggest reduced health risks may be attainable through relatively modest amounts of VPA accrued in short bouts across the week.

Models based instruction: the Sport Education curriculum model and accruing physical activity

Evidence suggests that physical activity patterns become habitual during childhood, and it is possible that activity patterns continue into adulthood. Unfortunately, traditional physical education practices have been called into question in regard to the amount of vigorous physical activity the class actually provides. Undergraduate physical education teacher education programs provide an opportune setting in which preservice teachers can be introduced to the demand of meeting these unique and challenging goals with less pressure than under the responsibility of teaching full-time without university support. One curriculum model believed to address the concern of facing physical education is Sport Education. The purpose of this study was to determine what impact preservice teachers had on students accruing the recommended levels of moderate to vigorous physical activity (MVPA) during their early field experience of an undergraduate secondary methods course while teaching within the Sport Education curriculum model. Participants were four preservice teachers assigned to teach sport education to middle school students during a secondary methods course field experience. Leeson were filmed and analyzed using a modified version of the System for Observing Fitness Instruction Time and the System for Observing Play and Leisure Activity in Youth. Calculation of overall student activity shows that students were sedentary for 45.19% of the lesson duration, walking for 38.00% of the lesson, and vigorously active for 16.81% of their respective lesson. The discussion section outlines possible reasons for these results, as well as suggestions for physical educators to increase MVPA during Sport Education.

Ectopic fat and aerobic fitness are key determinants of glucose homeostasis in nonobese Asians.

The importance of ectopic fat deposition and physical fitness in the pathogenesis of insulin resistance and beta cell dysfunction in subjects from the nonobese Asians is not known. We conducted a cross-sectional study and measured insulin sensitivity (M value; 4-hour hyperinsulinaemic-euglycaemic clamp), insulin secretion rate (3-hour mixed meal tolerance test with oral minimal modelling), percent body fat, visceral adipose tissue, intramyocellular and intrahepatic lipid contents (magnetic resonance imaging and spectroscopy), cardiorespiratory fitness (VO2 max; graded exercise test) and habitual physical activity (short International Physical Activity Questionnaire) in 60 healthy nonobese Asian subjects (BMI=21.9±1.7kg/m2 , age=41.8±13.4years). M was inversely associated with percent body fat (r=-0.460, P<0.001), visceral fat (r=-0.623, P<0.001) and liver fat (r=-0.601, P<0.001), whereas insulin secretion correlated positively with these adiposity indices (percent body fat: r=0.303, P=0.018; visceral fat: r=0.409, P=0.010; hepatic fat: r=0.393, P=0.002). VO2 max correlated negatively with insulin secretion rate (r=-0.420, P<0.001) and positively with M (r=0.658, P<0.001). The amount of vigorous physical activity was positively associated with VO2 max (r=0.682, P<0.001). Multiple stepwise linear regression analyses indicated that VO2 max, age, and IHTG or VAT were independent determinants of insulin sensitivity and secretion (adjusted R2 =69% and 33%, respectively, P<0.001). Increased ectopic fat deposition is associated with reduced insulin sensitivity and increased insulin secretion in healthy nonobese Asians. Poor cardiorespiratory fitness, likely due to inadequate participation in vigorous exercise, is strongly related to suboptimal metabolic function. Interventions to encourage engagement in physical activity may thus be important for improving metabolic health in nonobese Asians.

Movement behaviors and cardiometabolic risk in schoolchildren.

Growing evidence has accumulated in recent years showing that movement behaviors have important implications for health in children, especially for cardiovascular health, whose risk factors could track from childhood to adulthood. However, these findings are mixed and inconsistent in children. The aim of this study was to examine the relationship between different movement behaviors (sedentary behavior, physical activity and sleep duration) and cardiometabolic risk in schoolchildren. The study shows cross-sectional results of baseline measurement from 146 Spanish schoolchildren, aged 8-to-11 years old, participating in the MOVI-2 study. Movement behaviors were determined using accelerometry combined with self-reported sleep time. Cardiometabolic risk was assessed using a validated metabolic syndrome index. Logistic regression analysis showed that higher levels of vigorous physical activity (OR = 0.110, p = 0.004) and sleeping more than 9 hours (OR = 0.269, p = 0.015) could be protective factors against metabolic syndrome risk in children. ANCOVA analysis showed associations between vigorous physical activity and waist circumference (p < 0.001), and sleep time with insulin resistance (p = 0.017) and lipid profile (p = 0.035). No association was observed between light and moderate physical activity, sedentary behavior and metabolic syndrome (index and components). No statistically significant differences were found for blood pressure and any of the movement behaviors. Our data suggest that both the amount of vigorous physical activity accumulated and sleep duration are independently associated with higher cardiometabolic risk in children.

The Impact of Physical Activity Level on the Oral Microbiome

Previous research indicates that the composition and diversity of the gut and lung microbiome is associated with many autoimmune and inflammatory diseases. However, aerobic exercise has recently been shown to preferentially shift the composition of the gut microbiome. The physiological significance of these changes is not well understood, and currently there are no published data exploring whether physical activity may impact the composition and diversity of the oral microbiome. PURPOSE: We conducted this exploratory analysis to determine whether the composition of the oral microbiome was impacted by habitual physical activity (PA) level. METHODS: Sixteen young adults between the ages of 18- 35 years (n=8 physically inactive (PI) subjects accumulating <30 minutes of planned exercise per week; n=8 trained athletes (TA) >150 minutes of moderate-to-vigorous PA per week) visited the laboratory after an overnight fast and without using any toothpaste or antibacterial mouthwash for 24 hours. Upon arrival to the laboratory, body composition assessment and PA questionnaires were administered, followed by saliva and sputum sample collection. Processing and DNA extraction was performed on samples within 48 hours of collection, and the bacterial 16S rNA gene was amplified followed by sequencing. Subjects were given an accelerometer to wear around their waist for one week to verify chronic PA level. Principle components analysis followed by linear regression was used to compare oral microbial taxonomy across PA levels. RESULTS: PI and TA had significantly different chronic PA levels (PI: 240±26 METS/wk, TA: 3810±1656 METS/wk) (p<0.01). The amount of vigorous PA that subjects accumulated in METS/week explained 19.69% of the composition in the oral microbiome. Of particular interest, Veillonella spp., Streptococcus spp., Gemella spp. and Enterococcus spp. were significantly higher in PI versus TA (p<0.05, respectively), which have been associated with various types of lung diseases, including chronic obstructive pulmonary disease and asthma. CONCLUSION: These data indicate that: (1) habitual PA level differentially impacts the oral microbiome and (2) that the amount of vigorous activity accumulated per week explains a significant portion of the variance in the oral microbiota composition.

Effects of socioeconomic status, health behavior, and physical activity on the prevalence of metabolic syndrome.

Routine medical checkups have been provided by both the government-led and private hospitals for the purposes of prevention and early detection of diseases. Various studies were conducted with clinical results obtained from both government and private hospital based results. However, results from two types of health checkups have not been conducted. The results should be compared for the prevalence of metabolic disease in the aspects of socioeconomic status and health care behaviors to observe the pros and cons of two types of health checkups. Routine health checkup results of the National Health and Nutrition Survey (1,593 men, 2,180 women) and a private hospital (12,823 men, 7,070 women) of the year 2012 were used for the study. Education level and monthly household income were used to assess the socioeconomic status. Alcohol consumption, smoking, and International Physical Activity Questionnaire were used to assess health behaviors. Logistic regression analysis was applied (P<0.05). Participants of the private hospital had significantly greater household income, education level, amount of physical activity and intensity, and number of nonsmokers. Women showed no differences in the amount of vigorous physical activity. The prevalence rates of metabolic syndrome showed similar results. Education level, physical activity, and alcohol consumption were significantly associated in men of the government group. Smoking showed significant influence in men of both groups. Education level, alcohol consumption, and smoking showed significant influence in women of the government group. Participants who conducted government-led health examinations showed stronger influence of socioeconomic level and health behaviors on metabolic syndrome especially in men.

Enhanced insulin sensitivity in successful, long-term weight loss maintainers compared with matched controls with no weight loss history

Background:Weight gain is associated with deterioration in metabolic health, whereas weight loss improves insulin sensitivity. This study assesses the impact of long-term, successfully maintained weight loss and weight-loss relapse on measures of insulin sensitivity and identifies factors that explain variability in insulin sensitivity.Methods:Women (20–45 years) were recruited into four groups: reduced-overweight/obese (RED, n=15); body mass index (BMI)-matched controls (stable low-weight, n=19), BMI⩽27 kg m−2; relapsed-overweight/obese subjects (REL, n=11); and BMI-matched controls (obese stable weight, n=11), BMI⩾27 kg m−2. A 75 g oral glucose tolerance test determined fasting and 2 h plasma glucose and insulin. Homeostatic Model Assessment (HOMA-IR) and insulin sensitivity index (ISI(0,120)) assessed insulin sensitivity. Anthropometric measurements, fasting resting metabolic rate (RMR) and respiratory quotient (RQ) were measured. Questionnaires and dietary intake were recorded, and physical activity was measured using accelerometers.Results:RED were more insulin sensitive, characterised by lower fasting (P=0.001) and 2 h insulin (P=0.003) levels compared with all other groups. There were no significant differences in dietary intake, sedentary, light and moderate activity, RMR or RQ in the RED compared with the other three groups. % Body weight (BW) lost (P<0.001), % BW regained (P<0.05), body fat %, light activity (P<0.05, only log HOMA), vigorous activity (P<0.05) and RQ (P<0.01) predicted 61.4% and 59.7% of variability in log HOMA and log ISI(0,120), respectively, in multiple linear regression models.Conclusion:This study showed sustained enhanced insulin sensitivity in successful weight loss maintainers compared with BMI-matched controls with no weight loss history. Weight-loss-relapsed individuals were indistinguishable from controls. Weight loss itself was the strongest predictor of improved insulin sensitivity, whereas weight regain significantly predicted reduced insulin sensitivity. Weight-loss maintenance programs are essential to retaining metabolic benefits acquired through weight loss. Being physically active, reducing sedentary behaviour and, in particular, including small amounts of vigorous physical activity significantly predicted improved insulin sensitivity.

Experts Ponder Whether Too Much Exercise Can Compromise Cardiovascular Health and Longevity.

Physical activity was once a requirement for survival, but now many people must set aside time or make a conscious effort to incorporate it into their day, which can often be filled with hours spent in sedentary jobs and long commutes. In many cases, people need to boost physical activity levels to improve their health, but studies also are indicating that highly active patients may face health risks for taking exercise to extremes. “We need to examine the possibility that exercise is medicine and you can possibly overdose,” said Paul D. Thompson, MD, Chief of Cardiology at Hartford Hospital Physical activity guidelines recommend that adults engage in at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity exercise weekly. Individuals performing more than the lowest recommended dose of moderate-intensity physical activity experience added benefits, but doses >100 minutes a day do not seem to be associated with further reductions in mortality rates. A similar trend applies to more intense physical activity. “The benefits of vigorous activity are met at low doses and one does not get a lot of additional benefit when the amount of vigorous physical activity is increased much above 8 …

Associations between Physical Fitness, Physical Activity Levels and Fatness in Adults with Intellectual Disabilities

INTRODUCTION: The prevalence of obesity among adults with intellectual disability (AID) is significantly higher than in the general population. At present limited research has been done on the relationship between physical fitness (PF), objectively measured physical activity levels (PAL) and different markers of fatness in AID. PURPOSE: To examine associations between PF, PAL and fatness in AID. METHODS: An AID group (54 m/44 f; 44±12 y) were recruited from an Occupational Day Center. BMI, body fat percentage (BF%), fat free mass percentage (FFM%), waist (WC) and hip circumferences (HC) were obtained. VO2 peak was obtained during a metabolic treadmill test. GT3X Actigraph accelerometers were used to obtain total PA (TPA), steps per day (DS), time spent in sedentary (ST), light PA (LPA); moderate PA (MPA), vigorous PA (VPA), moderate to vigorous PA (MVPA). The timed up and go test (TUGT) to assess dynamic balance and gait speed was used. Handgrip (HG) and leg strength (LS) were also obtained. RESULTS: VO2 peak correlated with TPA (r=.421), DS (r=.318), VPA (r=.240), MVPA (r=.517), BF% (r=-.496), FFM% (r=.480), WC (r=-.445), HC (r=-.412), TUGT(r=-.363), HG (r=.435) and LS (r=.432). TPA and DS were correlated with HG (r=.348; r=.280) and LS (r=.294; r=.221). VPA was correlated with BF% (r=-.229) and FFM% (r=.218). MVPA was correlated HG (r=.347; r=.268), LS (r=.326) and TUGT (r=-.229). CONCLUSIONS: The present results show that high levels of PA are positively associated with PF. VPA, in particular, is associated with BF% and FFM% in AID. Future PA recommendations for AID should consider a particular emphasis on the amount of VPA when promoting PA. Partially supported by: MEC (Ref: DEP2012-35335) & AGAUR (Ref: 2013FI_B2 00091)Table 1: Physical fitness, physical activity levels and fatness data for AIDNote: values are mean (Standard Deviation)Abbreviations: BMI (body mass index); PA (physical activity); LPA (light physical activity); MPA (moderate physical activity); VPA (vigorous physical activity); MVPA (moderate to vigorous physical activity); HG (hand grip); TUGT(timed up and go test). * Significant correlation with relative VO2 peak (p < .05). ? Significant correlation with Total PA and Steps (p < .05). ‡ Significant correlation with VPA (p < .05). § Significant correlation with MVPA (p < .05).

Physical Activity and Sedentary Behavior’s Association With Body Weight in Korean Adolescents

The purpose of this study was to examine whether physical activity (PA) and sedentary behavior were related to weight status in Korean adolescents. A total of 72,399 students in Grades 7-12 participated in the 5th Korea Youth Risk Behavior Web-Based Survey (KYRBWS-V) project in 2009. Body mass index, PA, and sedentary behavior were assessed by the KYRBWS-V. The study results show that boys had higher PA and less sedentary behavior than did girls (p < .01). The amounts of vigorous PA (p < .001), moderate PA (p < .001), moderate PA for at least 60 min (p < .001), exercise for muscle strength (p < .001), walking on a weekday (p < .001), and walking on a weekend (p = .012) were less in boys who were more obese than the other boys. The time spent sitting on a weekday (p < .001) and weekend (p < .001) was higher in more obese individuals in boys. Exercise for muscle strength (p = .011) was less in girls who were more obese. Time spent sitting on a weekday (p = .005) and weekend (p < .001) was higher in more obese individuals in girls. However, vigorous PA (p < .001), moderate PA (p < .001), moderate PA for at least 60 min (p = .003), and walking on a weekday (p < .001) were higher for the more obese girls. PA and sedentary behavior could be independent factors that reduce or prevent obesity in Korean adolescents.

Relations of Diet and Physical Activity to Bone Mass and Height in Black and White Adolescents

Because the development of healthy bodies during the years of growth has life-long health consequences, it is important to understand the early influences of diet and physical activity (PA). One way to generate hypotheses concerning such influences is to conduct cross-sectional studies of how diet and PA are related to different components of body composition. The subjects were 660 black and white adolescents. Total body bone mineral content (BMC) was measured with dual-energy X-ray absorptiometry; free-living diet and PA were assessed with 4–7 separate 24-h recalls. The main dietary variables investigated were: total energy intake, macronutrient distribution (%), dairy servings, vitamin D, and calcium. The main PA variables were hours of moderate PA (3–6 METs) and vigorous PA (>6 METs). BMC was higher in blacks than in whites (P<0.01) and it increased more in boys than in girls (age by sex interaction) as age increased (P<0.01). After adjustment for age, race and sex, higher levels of BMC were associated with higher levels of energy intake, dairy servings, calcium, vitamin D, and vigorous PA (all P 's<0.05). In the multivariable model, significant and independent proportions of the variance in BMC were explained by race, the age by sex interaction, calcium, and vigorous PA (all P 's<0.01). When height was used as the outcome variable, similar diet results were obtained; however, there was a sex by vigorous PA interaction, such that vigorous PA was associated with height only in the girls. These data are consistent with the hypothesis that the bone mass and height of growing youths are positively influenced by higher dietary intake of energy and dairy foods, along with sufficient amounts of vigorous PA. This hypothesis needs to be tested in randomized controlled trials.

Exercise dependence score in patients with longstanding eating disorders and controls: The importance of affect regulation and physical activity intensity

To examine associations among exercise dependence score, amount of physical activity and eating disorder (ED) symptoms in patients with longstanding ED and non-clinical controls. Adult female inpatients (n = 59) and 53 age-matched controls participated in this cross sectional study. Assessments included the eating disorders examination, eating disorders inventory, exercise dependence scale, reasons for exercise inventory, and MTI Actigraph accelerometer. Positive associations were found among vigorous, not moderate, physical activity, exercise dependence score and ED symptoms in patients. In the controls, ED symptoms were negatively associated with vigorous physical activity and not correlated with exercise dependence score. Exercise for negative affect regulation, not weight/appearance, and amount of vigorous physical activity were explanatory variables for exercise dependence score in both groups. The positive associations among exercise dependence score, vigorous physical activity and ED symptoms need proper attention in the treatment of longstanding ED.

Established risk factors account for most of the racial differences in cardiovascular disease mortality.

BackgroundCardiovascular disease (CVD) mortality varies across racial and ethnic groups in the U.S., and the extent that known risk factors can explain the differences has not been extensively explored.MethodsWe examined the risk of dying from acute myocardial infarction (AMI) and other heart disease (OHD) among 139,406 African-American (AA), Native Hawaiian (NH), Japanese-American (JA), Latino and White men and women initially free from cardiovascular disease followed prospectively between 1993–1996 and 2003 in the Multiethnic Cohort Study (MEC). During this period, 946 deaths from AMI and 2,323 deaths from OHD were observed. Relative risks of AMI and OHD mortality were calculated accounting for established CVD risk factors: body mass index (BMI), hypertension, diabetes, smoking, alcohol consumption, amount of vigorous physical activity, educational level, diet and, for women, type and age at menopause and hormone replacement therapy (HRT) use.ResultsEstablished CVD risk factors explained much of the observed racial and ethnic differences in risk of AMI and OHD mortality. After adjustment, NH men and women had greater risks of OHD than Whites (69% excess, P<0.001 and 62% excess, P = 0.003, respectively), and AA women had greater risks of AMI (48% excess, P = 0.01) and OHD (35% excess, P = 0.007). JA men had lower risks of AMI (51% deficit, P<0.001) and OHD (27% deficit, P = 0.001), as did JA women (AMI, 37% deficit, P = 0.03; OHD, 40% deficit, P = 0.001). Latinos had underlying lower risk of AMI death (26% deficit in men and 35% in women, P = 0.03).ConclusionKnown risk factors explain the majority of racial and ethnic differences in mortality due to AMI and OHD. The unexplained excess in NH and AA and the deficits in JA suggest the presence of unmeasured determinants for cardiovascular mortality that are distributed unequally across these populations.

Peripheral Bone Mineral Density and Different Intensities of Physical Activity in Children 6–8 Years Old: The Copenhagen School Child Intervention Study

This study aimed to evaluate the association between objectively measured habitual physical activity and calcaneal and forearm bone mineral density (BMD, g/cm(2)), one mechanically more loaded and one less loaded skeletal region, in children aged 6-8 years. BMD was measured in 297 boys and 265 girls by peripheral dual-energy X-ray absorptiometry in the forearm and calcaneus. An accelerometer registered the level of physical activity during 4 days (2 weekdays and the weekend). Weight, height, and skinfold thickness were measured. In order to establish thresholds (count . min(-1)) for bone-stimulating physical activity, we evaluated different definitions of vigorous physical activity. The boys had 3.2% higher distal forearm bone mineral content (BMC, P < 0.001) and 4.5% higher distal forearm BMD (P < 0.001) than the girls. They also carried out 9.7% more daily physical activity and spent 14.6-19.0% more time in vigorous physical activity (all P < 0.05) compared to the girls. In contrast, the girls had 3.8% higher calcaneal BMC (P < 0.01) and 2.5% higher calcaneal BMD (P < 0.05) than the boys. Both calcaneal and forearm BMD were significantly related to total time of daily physical activity as well as with intense physical activity above all the chosen cut-off points (all P < 0.05). The beta value for mean count . min(-1) physical activity was significantly lower than that for all the chosen cut-off points of vigorous activity both for calcaneal and distal forearm BMD. This study suggests that both habitual daily physical activity and amount of vigorous physical activity in children aged 6-8 years are associated with appendicular BMD.

Validity of Self-Assessed Physical Fitness in Relation to Sex and Physical Activity Level

In large-scale epidemiological studies, directly measured components of physical fitness is time-consuming and expensive. In a recent study, an instrument to selfassess aerobic fitness and muscle strength was shown to be valid and reliable among female health-care workers. However, the instrument has not been validated in other populations and it is unknown whether the physical activity level influences the ability to self-assess physical fitness. PURPOSE: To examine the validity of an instrument to self-assess physical fitness in male and female office workers (characterized by low physical work demands) and to evaluate if the self-assessment is influenced by sex and physical activity level. METHODS: The study population comprised 346 females and 190 males, age 23–67 years. Physical fitness components (muscle strength including back flexion and extension, shoulder elevation and abduction as well as aerobic fitness) were measured directly by performance-based tests and self-assessed by an illustrated scale ranging from 1 to 10. Physical activity level was assessed by questionnaire comparable to IPAQ (long version). Construct validity was evaluated by partial correlations between corresponding performance based and self-assessed components of physical fitness adjusted for sex and age by multiple linear regression analyses. Three groups were defined based on the level of physical activity (inactive/minimally active/sufficiently active) according to the IPAQ questionnaire and was tested in the model. So was the total amount of physical activity per week as well as the amount of vigorous physical activity per week RESULTS: Self-assessed aerobic fitness showed a satisfactory construct validity (r=0.47, p<0.0001) in both sexes, whereas self-assessed strength only showed a satisfactory construct validity for measured shoulder elevation strength in men (r=0.38, p<0.0001) and not in women (r=0.24, p<0.0001). The amount of vigorous physical activity, the total amount of physical activity and the activity group membership did not contribute to further explanation of the measured parameters. Further, the ability to self-assess was not dependent on the physical activity level in any of the three physical activity parameters. CONCLUSION: Self-assessment of aerobic fitness can also be used in office workers with low physical job demands and is not affected by sex. In contrast, self-assessed muscle strength showed a lower validity especially for women. The ability to selfassess physical fitness did not depend on the physical activity level.

Exercise Interventions for Prevention of Obesity and Related Disorders in Youths

Already in childhood, (a) high general and visceral fatness and poor cardiovascular (CV) fitness are linked with dyslipidemia, elevated blood pressure, and insulin resistance; (b) higher fatness is associated with low amounts of vigorous physical activity (PA) and relatively low energy intake; (c) higher CV fitness is more clearly associated with vigorous PA than with moderate PA; (d) higher levels of PA are associated with higher bone density only in youths with relatively high calcium intakes. Physical training in youths has favorable effects on total body and visceral adiposity, bone density, CV fitness, and some risk factors for CV disease and type 2 diabetes. Thus, vigorous PA during childhood may help to prevent some major “adult” health problems.