Acute Effects of Intermittent Physical Activity on Perceptions of Exercise-Related Fatigue in Children

2020 ◽  
Vol 17 (6) ◽  
pp. 603-609
Author(s):  
Matthew Nagy ◽  
Molly O’Sullivan ◽  
Shannon Block ◽  
Rebecca E. Hasson
Keyword(s):  
Physical Activity ◽  
Random Order ◽  
Regular Exercise ◽  
Average Heart Rate ◽  
Acute Effects ◽  
Experimental Conditions ◽  
Main Effect ◽  
Sedentary Breaks ◽  
Intermittent Activity ◽  
Condition Interaction

Purpose: To investigate the acute effects of intermittent activity performed at varying intensities on the perceptions of exercise-related fatigue in children. Methods: A total of 30 children completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary breaks. The perceptions of exercise-related fatigue were determined via the Subjective Exercise Experience Scale at the beginning (0 breaks), middle (after 10 breaks), and end (after 20 breaks) of each condition. Results: The average heart rate was significantly higher with increasing exercise intensity (sedentary: 89.6 ± 1.2 beats/min, low: 114.6 ± 1.8 beats/min, moderate: 147.2 ± 1.8 beats/min, and high: 172.3 ± 1.8 beats/min, P < .0001). There was no significant main effect of condition (sedentary: −0.5 ± 0.6, low: −1.0 ± 0.7, moderate: −0.2 ± 0.5, and high: −0.6 ± 1.2; P = .86) and time (10–0 breaks: −0.7 ± 0.5 and 20–0 breaks: −0.5 ± 0.5; P = .45), nor time by condition interaction (P = .99) on change in exercise-related fatigue. Conclusions: Incorporating intermittent activity into physical activity programs may help to reduce barriers to regular exercise by minimizing perceptions of exercise-related fatigue in children.

Acute Effects of Interrupting Prolonged Sitting With Intermittent Physical Activity on Blood Pressure in Preadolescent Children

2019 ◽  
Vol 31 (4) ◽  
pp. 408-415
Author(s):  
Emma Weston ◽  
Matthew Nagy ◽  
Tiwaloluwa A. Ajibewa ◽  
Molly O’Sullivan ◽  
Shannon Block ◽  
...  
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Random Order ◽  
Future Research ◽  
Healthy Children ◽  
Acute Effects ◽  
Experimental Conditions ◽  
Prolonged Sitting ◽  
Preadolescent Children ◽  
Adults And Children

Purpose: To compare the acute effects of intermittent physical activity (PA) across 4 different intensities on blood pressure. Methods: Thirty children (12 males and 18 females; aged 7–11 y; 33% overweight/obese; 53% nonwhite) completed 4 experimental conditions in random order: 8 hours sitting interrupted with 20, 2-minute low-, moderate-, high-intensity PA breaks, or sedentary screen-time breaks. PA intensity corresponded with 25%, 50%, and 75% of heart rate reserve. Blood pressure was measured during each condition in the morning (0800 h), noon (1200 h), and afternoon (1600 h). Results: There were no significant differences across conditions for systolic blood pressure (SBP; all Ps > .05). There was a significant effect of time with SBP decreasing throughout the day for all conditions (average morning SBP: 106 [1] mm Hg, average noon SBP: 101 [2] mm Hg, average afternoon SBP: 103 [1] mm Hg; P = .01). There were no significant effects of condition or time on diastolic blood pressure (all Ps > .05). Conclusion: While sedentary behavior is known to be associated with hypertension in both adults and children, a single bout of prolonged sitting may be insufficient to produce hypertensive effects in otherwise healthy children. Future research should examine the appropriate dose of intermittent PA to accrue hypotensive responses in preadolescent children.

Acute Compensatory Responses to Interrupting Prolonged Sitting With Intermittent Activity in Preadolescent Children

2018 ◽  
Vol 30 (2) ◽  
pp. 259-265 ◽  
Author(s):  
Molly P. O’Sullivan ◽  
Matthew R. Nagy ◽  
Shannon S. Block ◽  
Trevor R. Tooley ◽  
Leah E. Robinson ◽  
...  
Keyword(s):  
Physical Activity ◽  
High Intensity ◽  
Computer Game ◽  
Random Order ◽  
Preliminary Evidence ◽  
Moderate Intensity ◽  
Experimental Conditions ◽  
Prolonged Sitting ◽  
Intensity Condition ◽  
Intermittent Activity

Purpose: The purpose of this study was to compare the effects of intermittent activity performed at varying intensities and of prolonged sitting on physical activity compensation. Methods: A total of 33 children (14 boys and 19 girls; age 7–11 y; 24% overweight/obese; 61% nonwhite) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary computer game breaks. Physical activity energy expenditure (PAEE) was assessed via accelerometry to establish baseline PAEE and throughout each condition day (8-h in-lab PAEE, out-of-lab PAEE, and 3-d postcondition). Results: Compared with baseline PAEE, total daily PAEE was significantly higher during the high-intensity condition day (153 ± 43 kcal, P = .03), unchanged during the low-intensity (−40 ± 23 kcal, P > .05) and moderate-intensity condition days (−11 ± 18 kcal, P > .05), and decreased in response to prolonged sitting (−79 ± 22 kcal, P = .03). There were no significant differences in PAEE 3-day postcondition across conditions (P > .05). Conclusion: Despite the varying levels of PAEE accumulated during the 8-hour laboratory conditions, out-of-lab PAEE during each condition day and 3-day postcondition did not change from the baseline. These findings provide preliminary evidence that spontaneous physical activity in children does not change in response to intermittent activity or prolonged sitting.

Breaking up sitting time after stroke (BUST-stroke)

2018 ◽  
Vol 13 (9) ◽  
pp. 921-931 ◽  
Author(s):  
Coralie English ◽  
Heidi Janssen ◽  
Gary Crowfoot ◽  
Robin Callister ◽  
Ashlee Dunn ◽  
...  
Keyword(s):  
Physical Activity ◽  
Glucose Metabolism ◽  
Light Intensity ◽  
Plasma Glucose ◽  
Recurrent Stroke ◽  
Blood Glucose Control ◽  
Random Order ◽  
Sitting Time ◽  
Experimental Conditions ◽  
Intensity Physical Activity

Objectives People with stroke sit for long periods each day, which may compromise blood glucose control and increase risk of recurrent stroke. Studies in other populations have found regular activity breaks have a significant immediate (within-day) positive effect on glucose metabolism. We examined the effects of breaking up uninterrupted sitting with frequent, short bouts of light-intensity physical activity in people with stroke on post-prandial plasma glucose and insulin. Methods Randomized within-participant crossover trial. We included people between 3 months and 10 years post-stroke, ambulant with minimal assistance and not taking diabetic medication other than metformin. The three experimental conditions (completed in random order) were: sitting for 8 h uninterrupted, sitting with 3 min bouts of light-intensity exercise while standing every 30 min, or sitting with 3 min of walking every 30 min. Meals were standardized and bloods were collected half- to one-hourly via an intravenous cannula. Results A total of 19 participants (9 female, mean [SD] age 68.2 [10.2]) completed the trial. The majority ( n = 12, 63%) had mild stroke symptoms (National Institutes of Stroke Scale score 0–13). There was no significant effect of experimental condition on glucose (mean [SD] positive incremental area [+iAUC] mmol·L·h-1 under the curve during sitting 42.3 [29.5], standing 47.4 [23.1], walking 44.6 [26.5], p = 0.563) or insulin (mean + iAUC pmol·L·h-1 sitting 14,161 [7,560], standing 14,043 [8,312], walking 14,008 [8,269], p = 0.987). Conclusion Frequent, short bouts of light-intensity physical activity did not have a significant effect on post-prandial plasma glucose and insulin in this sample of people with stroke. Further studies are needed to identify strategies that improve inactivity-related glucose metabolism after stroke.

scholarly journals Examining the Acute Effects of Classroom-Based Physical Activity Breaks on Executive Functioning in 11- to 14-Year-Old Children: Single and Additive Moderation Effects of Physical Fitness

2021 ◽  
Vol 9 ◽  
Author(s):  
Jeffrey D. Graham ◽  
Emily Bremer ◽  
Barbara Fenesi ◽  
John Cairney
Keyword(s):  
Physical Activity ◽  
Executive Function ◽  
Executive Functioning ◽  
Physical Fitness ◽  
Self Efficacy ◽  
Future Research ◽  
Acute Effects ◽  
Experimental Conditions ◽  
Psychological States ◽  
Post Test

Objective: Research supports the efficacy of acute, classroom-based, physical activity breaks on executive functioning in children. However, research pertaining to the effect of physical fitness on the acute physical activity—executive functioning relationship remains limited. The primary purpose of this study was to investigate the acute effects of classroom-based, teacher-delivered, physical activity breaks on executive functioning in 11–14-year-old children. We also investigated the potential moderating effects of both aerobic and musculoskeletal fitness on the acute physical activity—executive functioning relationship.Method: Participants (N = 116) completed pre- and post-test assessments of executive functioning (i.e., inhibition, switching, and updating) separated by a classroom-based physical activity break or sedentary classroom work. We manipulated the dose (i.e., length) and type of physical activity breaks. With regards to dose, participants in the experimental conditions engaged in 5-, 10-, or 20-min of physical activity whereas controls completed sedentary classroom math work at their desk. With regards to type, one experimental condition completed traditional physical activity breaks whereas the other experimental condition completed academic physical activity breaks (i.e., performed mental math and physical activity). Participants' mood, motivation, and self-efficacy were also assessed following the experimental manipulations.Results: Overall, executive function scores improved across each assessment following the physical activity breaks when compared to sedentary classroom work regardless of dose and type. Participants also reported more positive mood states, higher motivation to complete the executive function tests, and higher self-efficacy to perform the executive functions tests following the physical activity breaks. Single moderation analyses showed that low-moderate levels of aerobic fitness moderated the acute physical activity—executive functioning relationship. Additive moderation analysis showed, collectively, that both aerobic and musculoskeletal fitness moderated the acute physical activity—executive functioning relationship.Conclusion: Findings from the present study provide evidence for the acute effects of short (i.e., 5–20 min) classroom-based physical activity breaks on executive functioning and psychological states in children. Results also suggest levels of both aerobic and musculoskeletal fitness moderate these effects, however future research is needed to further elucidate this complex relationship.

Concanavalin A-induced Aggregation of Human Blood Platelets

1975 ◽  
Vol 33 (02) ◽  
pp. 354-360 ◽  
Author(s):  
Heinrich Patscheke ◽  
Reinhard Brossmer
Keyword(s):  
Concanavalin A ◽  
Binding Capacity ◽  
Specific Binding ◽  
Blood Platelets ◽  
Residual Effect ◽  
Independent Effect ◽  
Con A ◽  
Experimental Conditions ◽  
Main Effect ◽  
Induced Aggregation

SummaryConcanavalin A (CON A) causes platelets to aggregate. A Ca++-independent effect of CON A could be separated from a main effect which depends on Ca++. The main effect probably is a consequence of the CON A-induced platelet release reaction and therefore is platelet-specific. The weak residual effect observed in the presence of Na2EDTA may be due to a similar mechanism as has been demonstrated for CON A-induced aggregations of several other normal and malignant transformed animal cells.Na2EDTA did not inhibit the carbohydrate-specific binding capacity of CON A. Therefore, Na2EDTA appears not to demineralize the CON A molecules under these experimental conditions.α-methyl-D-glucoside inhibits the Ca++-independent as well as the Ca++-dependent effect of CON A.Pretreatment by neuraminidase stimulated the platelet aggregation induced by CON A. It is possible that removal of terminal sialic acid residues makes additional receptors accessible for the binding of CON A.

scholarly journals Regular exercise is associated with a lower risk of developing dementia in patients with a new diagnosis of atrial fibrillation: a nationwide population-based study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J.H Lim ◽  
S.R Lee ◽  
E.K Choi ◽  
J.P Yun ◽  
H.J Ahn ◽  
...  
Keyword(s):  
Physical Activity ◽  
Atrial Fibrillation ◽  
Vascular Dementia ◽  
Lower Risk ◽  
Alzheimer’S Dementia ◽  
P Value ◽  
Regular Exercise ◽  
Newly Diagnosed ◽  
Exercise Habit ◽  
New Diagnosis

Abstract Introduction Regular exercise is known to decrease the risk of dementia. There is a paucity of information about the impact of the change of exercise habit on cardiovascular outcomes after a new diagnosis of atrial fibrillation (AF). We aimed to investigate whether regular exercise is associated with the risk of developing dementia in patients with AF. Methods Using the Korean National Health Insurance Service database, we enrolled patients with newly diagnosed AF who had undergone health screening between 2010 and 2016. The study population was divided into four groups based on the consistency of regular exercise before and after AF diagnosis: (1) persistent non-exerciser, (2) exercise starter, (3) exercise quitter, and (4) exercise maintainer. We investigated the association between exercise and the risk of dementia. Results A total of 126,555 patients were included (mean age 62.7 years, male 62.0%, and mean CHA2DS2-VASc Score 2.7). During a median follow-up duration of 3.0 years, 5,943 patients were newly diagnosed as dementia (1.57 per 100 person-years). Among patients with incident dementia, 4,410 patients had Alzheimer's dementia and 951 patients had vascular dementia (1.16 and 0.25 per 100 person-years, respectively). Persistent non-exerciser, exercise starter, quitter, and maintainer groups were 65.1%, 12.8%, 12.7%, and 9.4%, respectively. After multivariable adjustment, we found that exercise was associated with a lower risk of developing overall dementia. When compared to persistent non-exerciser, exercise starter and maintainer showed reduced risk of developing dementia (hazard ratio [HR] 0.80, 95% confidence interval [95% CI] 0.73–0.88 and HR 0.63, 95% CI 0.54–0.73, respectively, all p-value &lt;0.0001), but exercise quitter showed no significant risk reduction (HR 0.95, 95% CI 0.88–1.03, Figure). Alzheimer's dementia showed consistent results: a 20% lower risk with exercise starter, and a 37% lower risk with exercise maintainer. Change of exercise habit, however, did not affect the risk of vascular dementia (all, p-value &gt;0.05, Figure). Conclusions Regular exercise showed a lower risk of dementia in patients with new-onset AF. Starting exercise even after the diagnosis of AF was beneficial to patients who had little physical activity previously. These findings may support physicians to recommend that AF patients should start exercise or keep their physical activity to reduce the risk of dementia. Funding Acknowledgement Type of funding source: None

scholarly journals Acute Effects of Handheld Loading on Standing Broad Jump in Youth Athletes

2021 ◽  
Vol 18 (9) ◽  
pp. 5046
Author(s):  
Wei-Hsun Tai ◽  
Ray-Hsien Tang ◽  
Chen-Fu Huang ◽  
Shin-Liang Lo ◽  
Yu-Chi Sung ◽  
...  
Keyword(s):  
High Speed ◽  
Center Of Mass ◽  
Reaction Force ◽  
Sampling Rate ◽  
Random Order ◽  
Horizontal Distance ◽  
Acute Effects ◽  
Vertical Ground Reaction Force ◽  
Strength And Conditioning ◽  
Peak Knee

The study aimed to investigate the acute effects of handheld loading on standing broad jump (SBJ) performance and biomechanics. Fifteen youth male athletes (mean age: 14.7 ± 0.9 years; body mass: 59.3 ± 8.0 kg; height: 1.73 ± 0.07 m) volunteered to participate in the study. Participants were assigned to perform SBJ with and without 4 kg dumbbells in a random order. Kinematic and kinetic data were collected using 10 infrared high-speed motion-capture cameras at a 250 Hz sampling rate and two force platforms at a 1000 Hz sampling rate. A paired t-test was applied to all variables to determine the significance between loading and unloading SBJs. Horizontal distance (p < 0.001), take-off distance (p = 0.001), landing distance (p < 0.001), horizontal velocity of center of mass (CoM; p < 0.001), push time (p < 0.001), vertical impulse (p = 0.003), and peak horizontal and vertical ground reaction force (GRF; p < 0.001, p = 0.017) were significantly greater in loading SBJ than in unloading SBJ. The take-off vertical velocity of CoM (p = 0.001), take-off angle (p < 0.001), peak knee and hip velocity (p < 0.001, p = 0.007), peak ankle and hip moment (p = 0.006, p = 0.011), and peak hip power (p = 0.014) were significantly greater in unloading SBJ than in loading SBJ. Conclusions: Acute enhancement in SBJ performance was observed with handheld loading. The present findings contribute to the understanding of biomechanical differences in SBJ performance with handheld loading and are highly applicable to strength and conditioning training for athletes.

Accelerometer-measured Physical Activity and Sedentary Breaks are associated with Maximal Fat Oxidation in young adults

2021 ◽  
pp. 1-25
Author(s):  
Juan Corral-Pérez ◽  
Daniel Velázquez-Díaz ◽  
Alejandro Perez-Bey ◽  
Adrián Montes-de-Oca-García ◽  
Jorge R. Fernandez-Santos ◽  
...  
Keyword(s):  
Physical Activity ◽  
Young Adults ◽  
Fat Oxidation ◽  
Sedentary Breaks ◽  
Maximal Fat Oxidation

Interactions between insulin and exercise

2021 ◽  
Vol 478 (21) ◽  
pp. 3827-3846
Author(s):  
Erik A. Richter ◽  
Lykke Sylow ◽  
Mark Hargreaves
Keyword(s):  
Physical Activity ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Insulin Action ◽  
Regular Exercise ◽  
Fuel Storage ◽  
Storage Effects ◽  
Glucose Storage ◽  
Glycogen Stores

The interaction between insulin and exercise is an example of balancing and modifying the effects of two opposing metabolic regulatory forces under varying conditions. While insulin is secreted after food intake and is the primary hormone increasing glucose storage as glycogen and fatty acid storage as triglycerides, exercise is a condition where fuel stores need to be mobilized and oxidized. Thus, during physical activity the fuel storage effects of insulin need to be suppressed. This is done primarily by inhibiting insulin secretion during exercise as well as activating local and systemic fuel mobilizing processes. In contrast, following exercise there is a need for refilling the fuel depots mobilized during exercise, particularly the glycogen stores in muscle. This process is facilitated by an increase in insulin sensitivity of the muscles previously engaged in physical activity which directs glucose to glycogen resynthesis. In physically trained individuals, insulin sensitivity is also higher than in untrained individuals due to adaptations in the vasculature, skeletal muscle and adipose tissue. In this paper, we review the interactions between insulin and exercise during and after exercise, as well as the effects of regular exercise training on insulin action.

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