Sensitivity and specificity of measuring children's free-living cycling with a thigh-worn Fibion® accelerometer.

Objective: Cycling is an important part of children's active travel, but its measurement using accelerometry is a challenge. The aim of the present study was to evaluate physical activity duration and intensity, and sensitivity and specificity of free-living cycling measured with a thigh-worn accelerometer. Methods: Participants were 160 children (44 boys) aged 11.5 ± 0.9 years who wore a triaxial Fibion® accelerometer on right thigh for 8 days, 24 h per day, and reported start time and duration of all cycling, walking and car trips to a travel log. Linear mixed effects models were used to predict and compare Fibion-measured activity and moderate-to-vigorous activity duration, cycling duration and metabolic equivalents (METs) between the travel types. Sensitivity and specificity of cycling bouts during cycling trips as compared to walking and car trips was also evaluated. Results: Children reported a total of 1,049 cycling trips (mean 7.08 ± 4.58 trips per child), 379 walking trips (3.08 ± 2.81) and 716 car trips (4.79 ± 3.96). There was no difference in activity and moderate-to-vigorous activity duration (p > .105), a lower cycling duration (-1.83 min, p < .001), and a higher MET-level (0.95, p < .001) during walking trips as compared to cycling trips. Both activity (-4.54 min, p < .001), moderate-to-vigorous activity (-3.60 min, p < .001), cycling duration (-1.74 min, p < .001) and MET-level (-0.99, p < .001) were lower during car trips as compared to cycling trips. Fibion showed the sensitivity of 72.2% and specificity of 81.9% for measuring cycling activity type during the reported cycling trips as compared to walking and car trips when the minimum required duration for cycling was less than 29 s. Conclusions: The thigh-worn Fibion® accelerometer measured a greater duration of cycling, a lower MET-level, and a similar duration of total activity and moderate-to-vigorous activity during free-living cycling trips as compared to walking trips, suggesting it can be used to measure free-living cycling activity and moderate-to-vigorous activity duration in 10-12-year-old children.

A Greater Intrinsic, but Not External, Motivation Toward Physical Activity Is Associated With a Lower Sitting Time.

Background: Both reducing sitting and increasing physical exercise promote health but exercising more does not necessarily reduce sitting time. One reason for this non-dependency may be that different aspects of exercise motivation are differently related to sitting time. Identifying the type of exercise motivation that would also be associated with sitting time can help to reduce sitting indirectly through increased exercise, thus bringing greater benefits. Methods: The present study explored the association between quality of motivations toward physical activity with physical activity and sitting time in a total of 373 adults (age range = 23-81; women n = 256). The short version of international physical activity questionnaire (IPAQ) was used for measuring physical activity and sitting time. Reasons for exercising regularly were measured with the Self-Regulated Questionnaire-Exercise (SRQ-E), including four regulation subscales to assess regulation styles (i.e., intrinsic motivation, identified regulation, introjected regulation and external regulation). Confirmatory factor analysis (CFA) was used to test the four subscales of SRQ-E (latent variables) with the data obtained using AMOS v.23 (Analysis of Moment Structures). Then, structural equation model (SEM) with maximum likelihood estimates was used to test the hypothesized model. Results: The results indicated that only intrinsic motivation, but not identified, introjected or external motivation, toward physical activity predicted both physical activity and sitting time. Higher intrinsic motivation toward physical activity was associated with both higher physical activity and lower sitting time. In addition, physical activity was a mediator for lower sitting time when the source was intrinsic motivation. Conclusion: Previous studies have shown low between and within participant correlation between sitting time and physical activity, and interventions have generally failed to both increase physical activity while decreasing sitting time. The present cross-sectional results suggest that targeting increased physical activity by increased intrinsic motivation has the potential to both increase physical activity and decrease sitting time.

Strength-Cognitive Training: A Systemic Review in Adults and Older Adults, and Guidelines to Promote "Strength Exergaming" Innovations.

Background: Despite functional and cognitive benefits, few adults and older adults do strength training twice per week with sufficient intensity. Exercise-based active video games (exergaming) may amplify the cognitive benefits of exercise and increase adherence and motivation toward training. However, the benefits of a well-defined and monitored dose of strength training, executed simultaneously or sequentially with a cognitive element, has received little attention. In this study we have two aims: First, to systematically gather the available evidence; second, to suggest possible ways to promote strength exergaming innovations. Methods: We systematically reviewed randomized controlled trials using simultaneous or sequent combined strength and cognitive training or strength exergaming to improve cognitive or functional outcomes in adults and older adults. Results: After screening 1,785 studies (Google Scholar, ACM Digital Library, IEEE Xplore Library, PsycARTICLES, Scopus, Cochrane Library and PubMed) we found three eligible studies. Of the two studies using sequent strength and cognitive training, one showed improved functionality, but the other showed negative effects on cognition. The third study using simultaneous intervention, reported a positive influence on both cognition and function, when compared with either strength training alone or a control group. Moderate level of evidence was showed on GRADE analysis. Conclusion: The existing little evidence suggests that strength and cognitive training improves cognition and function in adults and older adults. The following suggestions may help to promote further innovation: (1) ensure minimal dosage of strength training (30-60 min, 2 × /week), (2) use machine-based strength training devices to control volume and intensity (to prevent cognitive components from interfering with strength training), (3) include power training by using cognitive tasks requiring rapid reactions, and (4) add cognitive memory tasks (to extend the cognitive benefits of strength training per se), and (5) include motivational exergame elements to increase adherence.

Allometrically scaled explosive strength, but not static strength or maximal oxygen uptake is associated with better central processing time in young males.

BACKGROUND: We aimed to examine the associations of cardiorespiratory fitness (CRF), static strength and explosive strength with cognitive functions in young males. METHODS: Eighty-six young males (age 16-24 years) participated in the study and took part in a number of tests including: static strength (grip strength test), explosive strength (Sargent jump test), and CRF (via direct measure of maximal oxygen uptake [VO2max]). Static strength and explosive strength were scaled by allometrically modeled skeletal muscle mass (SMM) and height while VO2max was scaled by SMM and body mass (BM). Cognition was assessed by inhibitory control, simple and choice reaction time tasks using computerized Cambridge Neuropsychological Test Battery (CANTAB). Central processing time was measured by surface electromyography changes in isometric contraction response to an audio stimulus. RESULTS: VO2max scaled by BM (but not SMM), was associated with better central processing time and stop-signal reaction time (SSRT). Explosive strength was also associated with better central processing time independent of VO2max. However, static strength was not associated with cognition. CONCLUSIONS: The results suggest that explosive strength is a better predictor of central processing than static strength or VO2max in young males. Longitudinal studies are needed to examine whether explosive strength training in youth would improve central processing time.

Is obesity associated with impaired reaction time in youth?

BACKGROUND AND PURPOSE: Recent research demonstrates a significant relationship between weight status and impaired reaction time in young, adult, and elderly individuals. However, most such studies were performed on small samples, used only body mass index as the body obesity index, used simple reaction time, and oftentimes did not consider some potential confounders such as age, socioeconomic status, or physical activity in their studies. The present study explored the relationship between various reaction time tasks and various obesity indices in a sample of youth. METHODS: Two hundred and thirty-four young males (19-24 years) underwent standard anthropometry, various information processing tasks (e.g., clinical reaction time, simple audio and visual reaction time, and choice reaction time), as well as an inhibitory control task (congruent and incongruent Simon reaction time). RESULTS: Results revealed no significant relationship between any of the information processing tests and body mass index, nor for fat percentage, waist circumference, and waist-to-height ratio after adjustment for potential confounders. A weak positive association was observed only between congruent Simon reaction time (but not incongruent Simon reaction time) and waist circumference in participants (t value = 0.199; Std error = 0.0014; p = 0.047; Cohen's f2 = 0.09). CONCLUSION: Inhibitory control, but not information processing speed, was associated only with waist circumference in apparently healthy young men. LEVEL OF EVIDENCE: Level I, experimental study.

Impact of obesity on central processing time rather than overall reaction time in young adult men.

BACKGROUND AND PURPOSE: The association between weight status with simple cognitive tasks such as reaction time (RT) may not be observed in young people as cognitive functioning development has reached its peak. In the present study, we aimed to examine the association between overall and central adiposity with overall and central processing of RT in a sample of young adult men with different weight status from Ardabil, Iran. METHODS: Eighty-six young males between June-July 2018 completed RT tests as well as premotor time (PMT) using surface electromyography changes in isometric contraction response to an audio stimulus. RESULTS: No significant associations were observed between RT and PMT and different body mass index categories (underweight, normal weight, overweight and obese), as well as fat mass and fat to skeletal muscle mass ratio quartiles (Q). However, participants with greater waist to height ratio (WHtR) had longer PMT (but not RT) than their peers with lower WHtR (Q3 than Q2 and Q1 groups; p < 0.05, d = 1.23). Participants in the skeletal muscle mass quartile Q2 tended to have longer RT than participants in Q3 in an adjusted comparison model (p = 0.05, d = 0.72). CONCLUSIONS: Although the association between weight status and RT might be elusive in young adults, our results show that higher central adiposity is negatively associated with PMT in young adults. Longitudinal studies are needed to explore the changes in obesity indexes and process speed in longer terms. LEVEL OF EVIDENCE: Level I, experimental study.

Association Between Weight Status and Executive Function in Young Adults.

Background and objectives: To explore the association between weight status and executive function in young adults. Materials and Methods: Ninety-seven young males (age 17-26 years) underwent adiposity and body composition measurements using body composition analyzer. Inhibitory control and working memory were measured using the Cambridge Neuropsychological Test Battery (CANTAB). Results: Multiple linear regression using both unadjusted and adjusted analyses revealed no association between adiposity and body composition variables with executive tasks, apart from a significant association between skeletal muscle mass (SMM) and mean reaction time on go trial (standardized B = -0.28; p = 0.02). Multivariate analysis of covariance (MANCOVA) revealed that underweight participants presented inferior working memory compared to their normal weight (p = 0.001) or overweight peers (p = 0.008). However, according to the percentage fat quartiles (Q) participants with the highest quartile (Q4) were inferior in inhibitory control than their peers with Q2 (p = 0.04), and participants with the lowest quartile (Q1) were inferior in working memory compared with their peers with Q2 (p = 0.01) or Q3 (p = 0.02). A worse inhibitory control was observed for participants with the highest fat/SMM (Q4) compared to participants in Q3 (p = 0.03), and in contrast worse working memory was observed for participants with the lowest fat/SMM (Q1) compared to participants in Q2 (p = 0.04) or Q3 (p = 0.009). Conclusions: Low adiposity is associated with worse working memory, whereas high adiposity is associated with worse inhibitory control. Therefore, our findings show that normal adiposity, but greater SMM may have a positive impact on executive function in young adults.

Association between Physical and Motor Fitness with Cognition in Children.

Background and objective: There is an increased interest in exploring the association between fitness components with cognitive development in children in recent years. One of the scopes is to find the best exercise prescription to enhance health and cognition. Most of the studies so far have focused on cardiorespiratory fitness with little evidence on other fitness components. The present study aimed to explore the association between physical fitness (PF) and motor fitness (MF) with cognitive performance in children. Methods: Two hundred and six schoolboys (11.0 ± 0.8 y) underwent a battery of tests to measure information processing speed (i.e., simple and choice reaction time) and inhibitory control (i.e., Simon task). PF components (i.e., flexibility, muscular strength, and endurance) and MF components (speed and agility) were measured. Results: Multiple linear regression analysis adjusted for potential confounders (i.e., age, socioeconomic status, %fat and physical activity) revealed no relationship between flexibility, speed, muscular strength, and endurance with either information processing tasks or inhibitory control tasks. However, a positive association was observed between agility with both congruent reaction time and incongruent reaction time. Conclusions: No relationship was observed between the underlying fitness components with either information processing or inhibitory control. However, an association was observed between agility with inhibitory control.

Central or overall obesity: which one is a better predictor of depressive symptoms in children, adolescents, and youths?

BACKGROUND AND PURPOSE: Despite the strong effect of central obesity on individuals' physical health outcomes, there is little evidence underlying the relationship between central obesity and mental disorders such as depression, especially in children, adolescents, and youths of the developing countries. This study explores the relationship between depressive symptoms (DS) with central and overall obesity in a sample of Iranian children, adolescents, and youths. METHODS: One thousand and fifty-two male participants ranging from 7 to 24 years old underwent standard anthropometry, and filled the DS questionnaire. RESULTS: Having controlled the potential confounders (e.g., age, socioeconomic status, pubertal maturation status, and physical activity), we found waist circumference (WC) significantly related to DS in the children (standardized ß = 0.14; P < 0.05) and adolescents (standardized ß = 0.13; P < 0.05). No significant relationship was observed between WC and DS in the youths (standardized ß = 0.09; P = 0.22). In addition, no significant relationship was observed between DS and the percentage of fat in the sampled children (standardized ß = 0.085; P = 0.13), adolescents (standardized ß = 0.10; P = 0.10), and youths (standardized ß = -0.02; P = 0.75). CONCLUSION: Central obesity (but not overall obesity) was a significant predictor of DS in the children and adolescents (7-18 years). However, DS in the youths (19-24 years) were not significantly associated with both the central and overall body obesity indices.

Association between physical fitness and cognitive performance in 19-24 year old males.

The present study aimed to explore the association between physical fitness (PF) and cognitive performance in a sample of 19-24 year old males. Two hundred and eleven young males (20.2±1.5 years) participated in the study. Cognitive functioning tasks including information processing speed and inhibitory control were measured in addition to PF and motor fitness components such as aerobic fitness, static strength, explosive strength, agility and speed. Regression analysis showed that after adjustment for potential confounders (e.g. age, socioeconomic status, adiposity and physical activity), aerobic fitness (represented by shorter time in the one-mile run) was positively associated with composite inhibitory control scores (standardized ß=0.17; p=0.04) and negatively associated with ∆ Simon (standardized ß= -0.21; p=0.04). Explosive strength was negatively associated with composite information processing scores (standardized ß= -0.24; P=0.01), and composite inhibitory control scores (standardized ß= -0.22; p=0.02). Speed of movement, agility and static strength were not associated with any of the cognitive tests. In conclusion, aerobic fitness and explosive strength but not speed, agility or static strength might be indicators of underlying cognitive functioning tasks in 19-24 year old males.

Simple reaction time and obesity in children: whether there is a relationship?

OBJECTIVE: Reaction time (RT) testing is one of the oldest diagnostic methods used in modern psychology, and is known as simple and sensitive cognitive test. It has been recently reported that RT is related to obesity in young, adult and elderly individuals. However, most of the studies included small sample of participants, used just body mass index (BMI) as body obesity index, and did not consider some potential confounders such as age, socioeconomic status and physical activity in their studies. Furthermore, there is little and contradictory results for children. Therefore, the present study aimed to examine the relationship between RT and weight status in a sample of children. METHODS: Three hundred and fifty four 9-12 year old schoolboys underwent standard anthropometry, and various simple RT tests. RESULTS: After controlling for potential confounders no significant relationship was observed between audio-RT (RTA) and clinical RT (RTclin) with BMI, %fat, waist circumference (WC) and waist to height ratio (WHtR) (P > 0.05). But, significant relationship (ß = 0.18; P = 0.02) was observed between visual-RT (RTV) and %fat (but not BMI, WC and WHtR). CONCLUSIONS: Among the various simple RT tasks and central and total body obesity indices, just significant relationship was observed between %fat and RTV in the schoolboys. According to the results, it is concluded that RT impairment due to obesity may less be observed, or may not be observed for some types of RT tasks and obesity indices during childhood.

Association between academic achievement and physical status including physical activity, aerobic and muscular fitness tests in adolescent boys.

OBJECTIVE: The study aimed to explore the association between academic achievement and physical status including physical activity, aerobic and muscular fitness tests in a sample of adolescents. METHODS: Five hundred and eighty 15-17 years old adolescent boys underwent standard anthropometry and various physical fitness tests (e.g., one-mile run/walk, grip strength, run speed, agility, push-ups and sit and reach tests). PA was obtained by questionnaire. Academic achievement of the boys was extracted from the cumulative grade point averages (CGPA) from school records. Possible covariates/confounders such as adiposity, pubertal maturation status and socioeconomic status were obtained. RESULTS: After controlling for potential confounders PA was not significantly correlated to CGPA (P > 0.05). Among the physical fitness tests, just time in one-mile run/walk test added significant effect on prediction of CGPA (P < 0.01). None of the other fitness tests were significantly correlated to CGPA (P > 0.05). CONCLUSIONS: Aerobic fitness (but not PA and muscular fitness) was significantly correlated to better academic achievement in the adolescent boys.

The association between depressive symptoms and physical status including physical activity, aerobic and muscular fitness tests in children.

OBJECTIVES: The aims of the study were to explore the association between depressive symptoms (DS), physical activity (PA), aerobic and muscular fitness in a sample of children. METHODS: Four hundred and fifty-six schoolboys aged 7-11-year-old underwent standard anthropometry and various physical fitness tests (e.g., aerobic fitness, strength, speed, power, agility and flexibility). DS and PA were obtained by questionnaires. RESULTS: After adjustment for potential confounders (e.g., age, socioeconomic status and adiposity), PA was significantly and negatively related to DS (P < 0.05). Among the physical fitness tests, just time in one-mile run/walk was significantly related to DS (P < 0.05). CONCLUSION: Physical activity and aerobic fitness were significantly correlated with DS; however, no significant relationship was observed between DS and the muscular fitness tests in the children.

Reaction time: does it relate to weight status in children?

It has been recently reported that reaction time (RT) is related to weight status [measured by body mass index (BMI)] in young, adult and older people. However, there is little evidence for children, and the similar studies included small sample of participants. The aim of this study was to evaluate the relationship between a new RT test and weight status among a sample of 7-11 year old schoolboys. Therefore, 533 apparently healthy schoolboys underwent clinical reaction time (RT clin) measurements and standard anthropometry. Participants according to different obesity indices [waist circumference (WC), waist to height ratio (WHtR), BMI and fat%] were assigned to different weight status categories. Results indicated that time of RT clin decreased as age of the boys increased (F=63; P<0.01). No significant difference was observed for RT clin among the BMI, WC, WHtR and fat% categories after controlling for age (P>0.05). In conclusion, it seems that there is no relationship between simple RT (measured by RT clin) and weight status in the boys. Additional studies for finding relationship between RT and weight status are needed by including larger samples of participants, various age groups and various RT tests.

Physical fitness, physical activity and sedentary activities of 7 to 11 year old boys with different body mass indexes.

PURPOSE: The purpose of this study was to examine the differences in physical fitness, physical activity, and sedentary activities among 7 to 11 year old boys with varying body mass index in Ardabil, Iran. METHODS: The sample consisted of 766 boys who participated in eight weight bearing (1 mile walk/run, sit ups, standing long jump, vertical jump, shuttle run 4 × 10 m, 30-meter sprint, pull ups, pushups) and four non-weight-bearing physical fitness tests (flamingo balance, handgrip; sit and reach and finger reaction time). Physical activity and sedentary activities were assessed by questionnaires. Body mass index (BMI) was computed to classify participants into normal weight, underweight, overweight and obese groups. RESULTS: The prevalence of underweight, overweight and obesity was 10.7%, 14.1% and 4.2% respectively. Cardiorespiratory fitness (VO(2max)) decreased progressively as the BMI increased and differences among the all body mass index categories were significant (P<0.01). Obese subjects performed worse in all weight bearing fitness tests than normal weight subjects (P<0.01). Moreover, overweight subjects performed worse in one mile, pushups and pull ups than normal weight subjects (P<0.01). Underweight subjects had significantly lower Pushups than normal weight subjects (P<0.01). Obese subjects had significantly higher sedentary activities and lower physical activity than other counterparts (P<0.01). CONCLUSIONS: This study showed that weight bearing physical fitness, cardiorespiratory fitness and physical activity progressively decreased as the BMI increased and conversely, sedentary activities increased as the BMI increased.