Search Results

You are looking at 1 - 10 of 136 items for :

  • Psychology and Behavior in Sport/Exercise x
Clear All
Restricted access

Timothy D. Heden, Ying Liu, Young-Min Park, Nathan C. Winn and Jill A. Kanaley

Background:

This study assessed if walking at a self-selected pace could improve postprandial glucose and insulin concentrations in obese adolescents consuming high-fructose (HF) or high-glucose (HG) diets.

Methods:

Seven obese male and female adolescents (18 ± 1 yr) performed 4, 15-day trials in a random order, including 1) HF-diet (50 g fructose/d added to normal diet) while being sedentary, 2) HG-diet (50 g glucose/d) while sedentary, 3) HF-diet with additional walking, and 4) HG-diet with additional walking. On the 15th day of each trial, the participants performed mixed meal testing in the laboratory in which they consumed three liquid shakes (either HF or HG) and during the HF and HG sedentary trials, the participants took < 4000 steps while in the laboratory but during the walking trials took ≥ 13,000 steps during testing.

Results:

Walking did not alter postprandial glucose concentrations. Although walking reduced insulin secretion by 34% and 25% during the HF- and HG-diet, respectively (P < .05), total insulin concentrations were only significantly reduced (P > .05) with walking during the HF trial, possibly because walking enhanced insulin clearance to a greater extent during the HF-diet.

Conclusions:

Walking reduces postprandial insulin secretion in obese adolescents consuming a high-fructose or high-glucose diet.

Restricted access

Whitney A. Welch, Scott J. Strath, Michael Brondino, Renee Walker and Ann M. Swartz

health effects of sedentary behavior has been performed, research in adults has shown that breaks from sedentary behavior are beneficial for glucose regulation. 9 , 10 These proposed breaks are generally accomplished by introducing some type of LPA such as standing or slow walking; range in duration

Restricted access

Mynor Rodriguez-Hernandez, Jeffrey S. Martin, David D. Pascoe, Michael D. Roberts and Danielle W. Wadsworth

behavior, 7 , 14 , 18 positively affect markers of cardiometabolic diseases, 6 – 8 , 19 , 20 reduce glucose and insulin responses, 7 , 17 reduce lipid concentrations, 1 and improve positive indicators of health such as glucose stability. 14 The growing evidence shows beneficial effects on health

Restricted access

Susan Sullivan Glenney, Derrick Paul Brockemer, Andy C. Ng, Michael A. Smolewski, Vladimir M. Smolgovskiy and Adam S. Lepley

effects of exercise training on cardiovascular health. Traditional serum biomarkers, such as total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), glucose, C-reactive protein (CRP), insulin, and triglyceride levels, have been used to study the effects of exercise interventions

Restricted access

Loretta DiPietro, Catherine W. Yeckel and James Dziura

Background:

Few studies have compared long-term moderate-intensity aerobic versus light-resistance training on serial improvements in glucose tolerance in older people.

Methods:

Healthy, inactive older (74 ± 5 [SD] years) women (N = 20) were randomized into either a high-volume, moderate-intensity aerobic (ATM, n = 12) or a lower-intensity resistance training (RTL, n = 8) group. Both groups exercised under supervision 4 times per week for 45- to 60-minute sessions over 9 months. Measurements of plasma glucose, insulin, and free fatty acid (FFA) responses to an oral glucose tolerance test (OGTT) were performed at baseline and at 3, 6, and 9 months 48 hours after the last exercise session.

Results:

We observed significant improvements in 2-hour glucose concentrations at 3, 6, and 9 months among women in the RTL (152 ± 42 vs 134 ± 33 vs 134 ± 24 vs 130 ± 27 mg · dL−1; P < .05), but not the ATM (151 ± 25 vs 156 ± 37 vs 152 ± 40 vs 155 ± 39 mg · dL−1) group. These improvements were accompanied by an 18% (P < .07) decrease in basal FFA concentrations in the RTL group, whereas basal and 30-minute FFA concentrations increased (P < .05) after training in the ATM group.

Conclusions:

These findings suggest that the net physiological benefits of exercise might have been blunted in the ATM group, owing to higher circulating levels of FFA, which might have temporarily interfered with insulin action.

Restricted access

Elin Ekblom-Bak, Örjan Ekblom, Kate A. Bolam, Björn Ekblom, Göran Bergström and Mats Börjesson

Background:

Although moderate-to-vigorous physical activity (MVPA) is mainly recommended for glucose control, light physical activity (LIPA) may also have the potential to induce favorable changes. We investigated sedentary time (SED) substitution with equal time in LIPA and MVPA, and the association with markers of glucose regulation and insulin sensitivity after stratification by waist circumference, fitness and fasting glucose levels.

Methods:

A total of 654 men and women, 50 to 64 years, from the SCAPIS pilot study were included. Daily SED, LIPA and MVPA were assessed using hip-worn accelerometers. Fasting plasma glucose, insulin and HOMA-IR were determined.

Results:

Substituting 30 min of SED with LIPA was significantly associated with 3.0% lower fasting insulin values and 3.1% lower HOMA-IR values, with even lower levels when substituting SED with MVPA. Participants with lower fitness and participants with high fasting glucose levels benefited significantly more from substituting 30 min of SED with LIPA compared with participants with normal to high fitness levels and participants with normal glucose levels, respectively.

Conclusions:

LIPA, and not only MVPA, may have beneficial associations with glucose regulation. This is of great clinical and public health importance, not least because it may confer a higher compliance rate to regular PA.

Restricted access

Ann M. Swartz, Scott J. Strath, Sarah J. Parker and Nora E. Miller

The purpose of this study was to investigate the combined impact of obesity and physical activity (PA) on the health of older adults. Pedometer-determined steps/d, body-mass index (BMI), resting blood pressure, and fasting glucose (FG) were assessed in 137 older adults (69.0 ± 8.9 yr). The active group (>4,227 steps/d) had lower systolic blood pressure (SBP; p = .001), diastolic blood pressure (DBP; p = .028), and FG (p < .001) than the inactive group (≤4,227 steps/d). The normal-BMI group (18.5-24.9 kg/m2) had lower SBP (p < .001) and DBP (p = .01) than the obese group (≤30 kg/m2). There were no differences in SBP (p = .963) or DBP (p = 1.0) between active obese and inactive normal-BMI groups. The active obese group, however, had a more favorable FG than the inactive normal-BMI group (χ2 = 18.9, df = 3, p = .001). Efforts to increase PA of older adults should receive the same priority as reducing obesity to improve BP and FG levels.

Restricted access

Laura A. Brocklebank, Rob C. Andrews, Angie Page, Catherine L. Falconer, Sam Leary and Ashley Cooper

Background:

The aim of this randomized, 3-period, 3-treatment crossover trial was to examine the acute effects of regularly breaking up seated office work with short bouts of standing or light-intensity walking on postprandial interstitial glucose concentration.

Methods:

Seventeen middle-aged office workers performed 3 5-hour trial conditions at their workplace in a random order: 1) uninterrupted sitting, 2) sitting interrupted by 2 minutes of standing every 20 minutes, and 3) sitting interrupted by 2 minutes of light-intensity walking every 20 minutes. Participants consumed 2 standardized test drinks at the start of each trial condition and an iPro2 continuous glucose monitoring system (CGMS) recorded average interstitial glucose concentration every 5 minutes for the duration of the study.

Results:

The 5-hour interstitial glucose incremental area under the curve (iAUC) was 55.5% lower after sitting interrupted by light-intensity walking compared with after uninterrupted sitting (95% CI, –104.2% to –6.8%). There was also a suggestion of a beneficial effect of regular standing breaks, particularly in overweight men, although they were not as effective as the walking breaks (mean difference [95% CI], –29.6% [–73.9% to 14.7%]).

Conclusions:

Regularly breaking up prolonged sitting lowers postprandial glycemia in middle-aged adults without metabolic impairment.

Restricted access

Margareta I. Hellgren, Charlotte A. Larsson, Bledar Daka, Max Petzold, Per-Anders Jansson and Ulf Lindblad

Background:

We aimed to explore the association between self-reported leisure time physical activity (LTPA) and C-reactive protein (CRP) concentrations in men and women with and without impaired glucose tolerance (IGT).

Methods:

In a cross-sectional study, a random sample (n = 2,816) was examined with an oral glucose tolerance test, CRP and information about LTPA. Those with IGT or normal glucose tolerance (NGT) and CRP value ≤10 mg/L were selected (n = 2,367) for the study.

Results:

An inverse association between LTPA and CRP concentrations was observed in the population (P < .001), though, only in men with IGT (P = .023) and in women with NGT. Men with IGT, reporting slight physical activity up to 4 hours a week presented significantly higher CRP concentrations than normoglycemic men (∆0.6 mg/L, P = .004). However, this difference could not be found in men with IGT reporting more intense physical activity (∆0.01 mg/L, P = .944).

Conclusions:

Physical inactivity seems to have greater inflammatory consequences for men (vs. women) with IGT. More importantly, although 4 hours of physical activity per week is more than the usual minimum recommendation, an even greater intensity of LTPA appears to be required to limit subclinical inflammation in men with IGT.

Restricted access

Daniel P. Bailey, Louise A. Savory, Sarah J. Denton and Catherine J. Kerr

Background:

It is unclear whether cardiorespiratory fitness (CRF) is independently linked to cardiometabolic risk in children. This study investigated a) the association between CRF level and presence of cardiometabolic risk disorders using health-related cut points, and b) whether these associations were mediated by abdominal adiposity in children.

Methods:

This was a cross-sectional design study. Anthropometry, biochemical parameters and CRF were assessed in 147 schoolchildren (75 girls) aged 10 to 14 years. CRF was determined using a maximal cycle ergometer test. Children were classified as ‘fit’ or ‘unfit’ according to published thresholds. Logistic regression was used to investigate the odds of having individual and clustered cardiometabolic risk factors according to CRF level and whether abdominal adiposity mediated these associations.

Results:

Children classified as unfit had increased odds of presenting individual and clustered cardiometabolic risk factors (P < .05), but these associations no longer remained after adjusting for abdominal adiposity (P > .05).

Conclusions:

This study suggests that the association between CRF and cardiometabolic risk is mediated by abdominal adiposity in 10- to 14-year-old children and that abdominal adiposity may be a more important determinant of adverse cardiometabolic health in this age group.