Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz
Philip von Rosen and Maria Hagströmer
Background: This study investigates the association between self-rated health and the time spent in sedentary behavior (SB), low light-intensity physical activity (LLPA), high light-intensity physical activity (HLPA), and moderate to vigorous physical activity (MVPA), by controlling for demographics, socioeconomic status, and chronic diseases. Methods: A total of 1665 participants (55% women) completed a questionnaire about demographics, chronic diseases, and anthropometric characteristics and provided objective physical activity data on time in SB, LLPA, HLPA, and MVPA, using an ActiGraph 7164 accelerometer. Association between self-rated health and activity data was explored in a compositional data analysis. Results: The multinomial logistic regression analysis showed a significantly lower time spent in MVPA in proportion to time in other movement behaviors (SB, LLPA, and HLPA) for participants who rated their health as alright or poor compared with excellent (P < .001). Participants with poor, compared with excellent health, spent about a third of the time in MVPA (17 vs 50 min), marginally higher time in HLPA (134 vs 125 min), more time in LLPA (324 vs 300 min), and similar time in SB (383 vs 383 min), accounting for confounders and time in other movement behaviors. Conclusions: Promoting MVPA, as opposed to time in other movement behaviors, is suggested to be beneficial for excellent self-rated health.
Xiaoxia Zhang, Xiangli Gu, Tao Zhang, Priscila Caçola and Jing Wang
Purpose: Using 2012 National Health and Nutrition Examination Survey (NHANES) National Youth Fitness Survey data, the authors conducted a cross-sectional secondary analysis to examine the associations of movement behaviors (ie, physical activity [PA] and screen-based sedentary behaviors) and fundamental motor skills (FMS) with fitness (ie, muscular fitness) and fatness (ie, body mass index and waist circumference) in 3- to 5-year-old children. The effect of ethnicity (Hispanic vs non-Hispanic) on these associations was also examined. Methods: A total of 352 children (173 girls; mean age = 4.02 y) from the 2012 NHANES data set were included. Parents reported their child’s PA and screen-based sedentary behaviors. FMS (ie, locomotor and object control) were assessed with the Test of Gross Motor Development, 2nd edition. Other variables used were body mass index, waist circumference, and plank. Results: Hispanic children demonstrated lower levels of PA than non-Hispanic children (P < .05). Children’s FMS emerged as significant predictors of muscular fitness and waist circumference, but not for body mass index in the Hispanic group. In the non-Hispanic group, FMS (ie, object control skills) and PA accounted for significant variances of muscular fitness and waist circumference, respectively. Conclusion: The associations of movement behaviors and FMS with fitness and fatness are different between Hispanic and non-Hispanic young children. Changes in policy or early childhood curriculum may be tailed to promote FMS for an impact on fitness and fatness in both Hispanic and non-Hispanic children.
Salomé Aubert, Joel D. Barnes, Megan L. Forse, Evan Turner, Silvia A. González, Jakub Kalinowski, Peter T. Katzmarzyk, Eun-Young Lee, Reginald Ocansey, John J. Reilly, Natasha Schranz, Leigh M. Vanderloo and Mark S. Tremblay
Background: In response to growing concerns over high levels of physical inactivity among young people, the Active Healthy Kids Global Alliance developed a series of national Report Cards on physical activity for children and youth to advocate for the promotion of physical activity. This article provides updated evidence of the impact of the Report Cards on powering the movement to get children and youth moving globally. Methods: This assessment was performed using quantitative and qualitative sources of information, including surveys, peer-reviewed publications, e-mails, gray literature, and other sources. Results: Although it is still too early to observe a positive change in physical activity levels among children and youth, an impact on raising awareness and capacity building in the national and international scientific community, disseminating information to the general population and stakeholders, and on powering the movement to get kids moving has been observed. Conclusions: It is hoped that the Report Card activities will initiate a measurable shift in the physical activity levels of children and contribute to achieving the 4 strategic objectives of the World Health Organization Global Action Plan as follows: creating an active society, creating active environments, creating active lives, and creating active systems.
Jungyun Hwang, I-Min Lee, Austin M. Fernandez, Charles H. Hillman and Amy Shirong Lu
Purpose: This study examined differences in energy expenditure and bodily movement among children of different weight status during exergames that varied in mode and intensity. Methods: Fifty-seven 8- to 12-year-old children including overweight/obesity (n = 28) and normal weight (n = 29) played three 10-minute interval Xbox One exergames (Fruit Ninja, Kung-Fu, and Shape Up) categorized based on predominantly upper-, whole-, or lower-limb movement, respectively. The authors measured bodily movement through accelerometry and obtained energy expenditure and metabolic equivalent (MET) via indirect calorimetry. Results: Energy expended during gameplay was the highest in Shape Up (P < .01) and higher in Kung-Fu than Fruit Ninja (P < .01). Absolute energy expenditure was significantly higher in overweight/obese children (P < .01), but not when controlling for body mass across 3 exergames (P > .05). Based on the MET cut-points, overweight/obese children spent more time at light intensity (<3 METs) for Fruit Ninja (P < .05) and Shape Up (P < .01), but less time at vigorous intensity (≥6 METs) for Kung-Fu (P < .01) and Shape Up (P < .01). Lower-limb movements during Shape Up were less in overweight/obese children (P = .03). Conclusion: Although children in both groups expended similar energy relative to their body mass during gameplay, overweight/obese children spent more time at light intensity but less time at vigorous intensity with fewer movements especially while playing a lower limb–controlled exergame.
Yvonne G. Ellis, Dylan P. Cliff, Steven J. Howard and Anthony D. Okely
Purpose: To examine the acute effects of a reduced sitting day on executive function (EF) and musculoskeletal health in preschoolers. Methods: A sample of 29 children (54% boys; 4–5 y) participated in a randomized cross-over trial. Each child completed 2 protocols, which simulate a day at childcare in random order for 2.5 hours; a typical preschool day (50% sitting) and a reduced preschool day (25% sitting) where most sitting activities were replaced with standing activities. Sitting, standing, and stepping time were objectively assessed using an activPAL accelerometer. EF was evaluated using tablet-based EF assessments (inhibition, working memory, and task shifting). Musculoskeletal health was assessed using a handheld dynamometer and goniometer. Results: Compared with the typical preschool day, the reduced sitting day showed no significant differences for EF scores. Effect sizes for inhibition (d = 0.04), working memory (d = 0.02), and shifting (d = 0.11) were all small. For musculoskeletal health, no significant differences were reported after the reduced preschool day. The effect sizes for the hip extension force, hamstring flexibility, gastrocnemius length, and balancing on 1 leg were all small (d = 0.21, d = 0.25, d = 0.28, and d = 0.28). Conclusions: This study suggests that reducing sitting time is unlikely to result in acute changes in EF and musculoskeletal health among preschoolers.
Sanaz Nosrat, James W. Whitworth, Nicholas J. SantaBarbara, Shira I. Dunsiger and Joseph T. Ciccolo
Depressive symptoms and fatigue are prevalent among people living with human immunodeficiency virus. Resistance exercise is known to stimulate a positive affective response. Objective: To examine the acute psychological effects of resistance-exercise intensity among Black/African-American people living with human immunodeficiency virus and experiencing depressive symptoms. Methods: A total of 42 participants were randomized into a moderate- (n = 21) or high-intensity (n = 21) group. Assessments were collected before exercise (PRE), at the midpoint (MID), immediately following (POST) exercise, and 15 (DELAY 15) and 30 (DELAY 30) min after. Results: In the moderate-intensity group, affect improved PRE to POST, PRE to DELAY 15 and DELAY 30, and perceived distress decreased from PRE to all time points. In the high-intensity group, affect declined PRE to MID, and perceived distress decreased PRE to DELAY 15 and DELAY 30. Perceived activation increased PRE to MID, and POST in both groups (ps < .01). Conclusions: The moderate-intensity group compared with the high-intensity group is more effective at improving affect and energy and at reducing distress.
Mohammad Siahpush, Trish D. Levan, Minh N. Nguyen, Brandon L. Grimm, Athena K. Ramos, Tzeyu L. Michaud and Patrik L. Johansson
Background: The mortality benefits of meeting the US federal guidelines for physical activity, which includes recommendations for both aerobic and muscle-strengthening activities, have never been examined among smokers. Our aim was to investigate the association between reporting to meet the guidelines and all-cause, cancer, cardiovascular disease, and respiratory disease mortality among smokers. Methods: We pooled data from the 1998–2009 National Health Interview Survey, which were linked to records in the National Death Index (n = 68,706). Hazard ratios (HR) were computed to estimate the effect of meeting the physical activity guidelines on mortality. Results: Smokers who reported meeting the guidelines for physical activity had 29% lower risk of all-cause mortality (HR: 0.71; 95% confidence interval [CI], 0.62–0.81), 46% lower risk of mortality from cardiovascular disease (HR: 0.54; 95% CI, 0.39–0.76), and 26% lower risk of mortality from cancer (HR: 0.74; 95% CI, 0.59–0.93), compared with those who reported meeting neither the aerobic nor the muscle-strengthening recommendations of the guidelines. Meeting the aerobic recommendation of the guidelines was associated with a 42% decline in that risk (HR: 0.58; 95% CI, 0.44–0.77). Conclusion: Smokers who adhere to physical activity guidelines show a significant reduction in mortality.
Astrid C.J. Balemans, Han Houdijk, Gilbert R. Koelewijn, Marjolein Piek, Frank Tubbing, Anne Visser-Meily and Olaf Verschuren
Background: It is questionable whether postures that are regarded as sedentary behavior in able-bodied persons evoke comparable physiological responses in adults with stroke or cerebral palsy (CP). This study aimed to compare metabolic demand and muscle activity in healthy controls, adults with stroke, and adults with CP during sedentary behavior and light physical activities. Methods: Seventy-one adults (45.6 [18.9] y, range 18–86) participated in this study, of which there were 18 controls, 31 with stroke, and 22 with CP. The metabolic equivalent of task (MET) and level of muscle activation were assessed for different sedentary positions (sitting supported and unsupported) and light physical activities (standing and walking). Results: During sitting supported and unsupported, people with mild to moderate stroke and CP show comparable MET and electromyographic values as controls. While sitting unsupported, people with severe stroke show higher METs and electromyographic values (P < .001), and people with severe CP only show higher METs compared with controls (P < .05) but all below 1.5 METs. Standing increased electromyographic values in people with severe stroke or CP (P < .001) and reached values above 1.5 METs. Conclusions: Physiologic responses during sedentary behavior are comparable for controls and adults with mild to moderate stroke and CP, whereas higher metabolic demands and muscle activity (stroke only) were observed in severely affected individuals.
Cui Zhang, Qipeng Song, Wei Sun and Yu Liu
Daily stair activities have become increasingly challenging for older adults with deterioration in physical and cognitive capabilities. However, the dynamic stability of older adults during stair descent under a concurrent dual-task condition remains undetermined. The gait and dynamic stability variables of 40 healthy older adults were measured under single- and dual-task conditions during stair descent. The step length, step width, and single support time did not significantly increase (p > .05) under the dual-task condition during stair descent. The medial–lateral center of mass velocity significantly increased (p < .003), whereas the medial–lateral margin of dynamic stability value significantly decreased (p < .006) at the landing and initial single support under the dual-task condition during stair descent. The self-regulatory ability of healthy older adults under the dual-task condition during stair descent was underestimated. Dual tasking displayed a positive impact on the anterior–posterior dynamic stability of healthy older adults.