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1.
Womens Health Rep (New Rochelle) ; 5(1): 393-403, 2024.
Article in English | MEDLINE | ID: mdl-39035143

ABSTRACT

Introduction: Musculoskeletal injuries (MSKi) are the most common injury type experienced by first-responders and health care providers (HCPs), making them a significant threat to physical and mental well-being. Female reproductive health and injury history has been related to physical fitness in female members of the Canadian Armed Forces. This relationship has not been explored in Canadian protective services personnel (first-responders) or HCPs. Methods: Fifty-seven females employed as firefighters, paramedics, law enforcements, or HCPs completed a physical fitness protocol to assess the following: (1) muscular power (standing long jump and medicine ball throw), (2) muscular strength (4 repetition maximum (4RM) back squats and bench press), (3) muscular endurance (Biering-Sorenson test, single-leg wall sit, and push-ups), (4) flexibility (sit-and-reach), and (5) aerobic capacity (graded treadmill VO2max test). Spearman rho correlation analyses were applied to descriptive analysis, independent-samples t-test, one-way ANCOVA (adjusted by age), and chi-square test. Spearman rho correlation analyses were used to compare physical fitness results for female reproductive health history (e.g., parity status), previous MSKi, and physical activity behaviors (e.g., sports participation). A p value of <0.05 is considered significant. Results: History of childbirth, body composition, and exercise behaviors were related to physical fitness (i.e., standing long jump, Biering-Sorenson test, bench press, and back squat) in law enforcement, firefighting, paramedicine, and health care personnel. Conclusions: Physical training programs aimed at supporting parous first-responders or HCPs should emphasize lower body power, lower body strength, and upper body strength.

2.
BMJ Mil Health ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862249

ABSTRACT

OBJECTIVES: A history of childbirth is associated with musculoskeletal injury (MSKi) in female members of the Canadian Armed Forces (CAF). While previous injury and pregnancy impact knee kinematics, it is unclear if a history of childbirth is associated with medial knee displacement (MKD) in an overhead squat movement screen. The aim of this study is to examine the relationship between MKD and (1) MSKi and (2) parity status in female CAF members. METHODS: 24 nulliparous and 21 parous female participants employed by the CAF completed a comprehensive physical fitness assessment of muscular flexibility, power, strength, endurance, aerobic capacity and a bodyweight overhead squat movement screen (recorded using two-dimensional video, and hip-knee-ankle angle measured using Kinovea software). Interactions between MKD, parity status and MSKi history were assessed by one-way analysis of variance and two-way analysis of covariance (ANCOVA) (adjusted for age). RESULTS: An interaction between parity status and acute injury of the lower extremity was observed (F=4.379, p=0.043, η2 =0.099) in MKD of the right knee. The two-way ANCOVA examining acute injury of the lumbopelvic hip complex (lower back, pelvis, hip) yielded an interaction between acute injury to the lumbopelvic hip complex and parity status (F=4.601, p=0.038, η2=0.103) in MKD asymmetry. DISCUSSION: Parous participants with acute injury to the lower extremity had larger MKD than parous without this injury type. Parous participants without acute injury to the lumbopelvic hip complex had greater MKD asymmetry than nulliparous without this injury type. Our findings suggest that researchers and clinicians should consider parity status in conjunction with MSKi history when assessing knee kinematics in female military members.

4.
Tissue Cell ; 73: 101663, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34653888

ABSTRACT

Metabolomics, the application of analytical chemistry methodologies to survey the chemical composition of a biological system, is used to globally profile and compare metabolites in one or more groups of samples. Given that metabolites are the terminal end-products of cellular metabolic processes, or 'phenotype' of a cell, tissue, or organism, metabolomics is valuable to the study of the maternal-fetal interface as it has the potential to reveal nuanced complexities of a biological system as well as differences over time or between individuals. The placenta acts as the primary site of maternal-fetal exchange, the success of which is paramount to growth and development of offspring during pregnancy and beyond. Although the study of metabolomics has proven moderately useful for the screening, diagnosis, and understanding of the pathophysiology of pregnancy complications, the placental metabolome in the context of a healthy pregnancy remains poorly characterized and understood. Herein, we discuss the technical aspects of metabolomics and review the current literature describing the placental metabolome in human and animal models, in the context of health and disease. Finally, we highlight areas for future opportunities in the emerging field of placental metabolomics.


Subject(s)
Metabolomics , Placenta/metabolism , Animals , Biomedical Research , Disease Models, Animal , Female , Humans , Models, Biological , Pregnancy
5.
Perspect Public Health ; 141(2): 81-88, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33579178

ABSTRACT

AIMS: An increasingly popular exercise modality for women is high-intensity interval training (HIIT). Limited research has assessed HIIT during pregnancy, and as a result, pregnant women may inquire about HIIT on their own through online searches. The purpose of this study was to systematically search and critically evaluate online resources that women may access when inquiring about performing HIIT during pregnancy. METHODS: Following previously published methodology, we systematically examined the online search engine Google with the terms 'HIIT' and 'pregnancy'. Using the 2019 Canadian Guideline for Physical Activity throughout Pregnancy as a reference, we identified evidence-based safety recommendations that apply to all prenatal exercise regimes. All selected links were assessed for whether or not they included evidence-based exercise and pregnancy safety recommendations. Descriptive analyses were performed to report the frequency of each construct. RESULTS: Seventy-six links were retrieved, and 33 relevant links were selected for inclusion. The majority of the retrieved links recommended that women should consult a healthcare provider before beginning any exercise programme (67%), and modify the intensity and types of exercises in the active HIIT bout based on general pregnancy-related changes (73%) and individual comfort level (55%). Just under half of the links recommended modifying intensity based on prepregnancy activity level (46%), offered trimester-specific recommendations (42%), and only 12% mentioned contraindications to exercise. CONCLUSION: Publicly accessible information online on HIIT during pregnancy does not routinely adhere to evidence-based safety recommendations for prenatal exercise. Further research on HIIT during pregnancy and public dissemination of findings is required.


Subject(s)
High-Intensity Interval Training , Information Seeking Behavior , Pregnant Women , Canada , Consumer Health Information , Female , Humans , Internet , Pregnancy , Pregnant Women/psychology
6.
Pediatr Cardiol ; 41(1): 46-53, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31701166

ABSTRACT

The purpose of this study was to investigate parent reports of quality of life for their very young children with congenital heart defects (CHD) and to compare their scores to previously published data. Parents of children 1-3 years old with CHD or innocent heart murmurs completed the Pediatric Quality of Life Inventory (PedsQL) core, cardiac, and family impact modules. Multivariable regression analyses assessed the impact of age, sex, family income, and CHD treatment history (study group) on PedsQL scores. Correlations between family impact and core/cardiac modules were examined. PedsQL scores were compared to healthy norms. 140 parents of young children participated within four study groups: CHD no treatment (n = 44), CHD treatment without bypass (n = 26), CHD treatment with bypass (n = 42) ,and innocent heart murmurs (n = 28). Male sex was associated with higher core (F = 4.16, p = 0.04, σ2 = .03) and cardiac quality of life (F = 4.41, p = .04, σ2 = 0.04). Higher family income was associated with higher family quality of life (F = 8.89, p < .01, σ2 = 0.13). Parents of children with innocent heart murmurs and children with CHD not requiring treatment had higher core quality of life compared to young healthy children. Cardiac-related quality of life scores were associated with family impact (r = 0.68) and core module (r = 0.63) quality of life scores. Parents of very young children with CHD report good quality of life for their children and families. Quality of life exceeds in children with innocent murmurs or CHD not requiring repair. Parents report a lower quality of life among girls, and lower family quality of life is associated with lower family income.


Subject(s)
Heart Defects, Congenital/psychology , Parents/psychology , Quality of Life , Child, Preschool , Female , Humans , Infant , Male , Severity of Illness Index , Sex Factors , Surveys and Questionnaires
7.
Obes Rev ; 17(10): 919-44, 2016 10.
Article in English | MEDLINE | ID: mdl-27465602

ABSTRACT

OBJECTIVE: This study aims to systematically review available evidence from prospective cohort studies to identify intrapersonal, social environmental and physical environmental determinants of moderate-to-vigorous intensity physical activity (MVPA) among working-age women. METHODS: Six databases were searched to identify all prospective cohort studies that reported on intrapersonal (e.g. self-efficacy and socioeconomic status [SES]), social (e.g. crime, area SES and social support) and/or physical (e.g. weather, work and recreation) environmental determinants of MVPA in working-age (mean 18-65 years) women. A qualitative synthesis including harvest plots was completed. PROSPERO: CRD42014009750 RESULTS: Searching identified 17,387 potential articles; 97 were used in the analysis. The majority (n = 87 studies) reported on ≥1 intrapersonal determinant. Very few (n = 34) examined factors in the social or physical environments, and none looked at social policy. Positive and consistent influencers included higher self-efficacy (n = 18/23), self-rated health (n = 8/13) and intentions (n = 10/11) and perceived behavioural control (n = 5/7) to be physically active. Having children in the household was negatively related to MVPA (n = 9/15). CONCLUSIONS: Physical activity intervention studies should consider a woman's level of self-efficacy and perceived behavioural control to be physically active. Additional studies are needed on the impact of children in the household, having a spouse/partner and using group goal setting. More evidence is needed to evaluate the impact of environmental factors.


Subject(s)
Exercise/psychology , Health Behavior , Interpersonal Relations , Leisure Activities/psychology , Self Efficacy , Social Environment , Female , Health Surveys , Humans , Prospective Studies , Social Class
8.
Placenta ; 36(2): 204-12, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25510392

ABSTRACT

INTRODUCTION: Adequate nutrient delivery to the fetus is essential for optimal growth. Differences in prenatal physical activity level and diet quality influence maternal energy balance and these factors may alter placental nutrient transport. We investigated the associations between meeting physical activity guidelines and the quality of maternal diet on the expression of genes involved in fatty acid, amino acid and glucose transport, and mammalian target of rapamycin (mTOR) and insulin signaling in the placenta from 16 term pregnancies. METHODS: Physical activity was directly measured with accelerometry, diet composition was assessed with 24 h dietary recalls, and gene expression was measured with custom polymerase chain reaction (PCR) arrays. RESULTS: Women who met physical activity guidelines had lower gene expression of fatty acid transport protein 4 (FATP4), insulin-like growth factor 1 (IGF1), and the beta non-catalytic subunit of AMP-activated protein kinase (AMPK), and a higher expression of SNAT2. There was a strong positive correlation observed between total sugar intake and glucose transporter 1 (GLUT1) (r = 0.897, p = 0.000, n = 12), and inverse correlations between total sugar and mTOR and IGF1 expression. Percentage of total calories from protein was inversely related to insulin-like growth factor 1 receptor (IGF1R) (r = -0.605, p = 0.028, n = 13). DISCUSSION: Variations in maternal physical activity and diet composition altered the expression of genes involved in fatty acid, amino acid and glucose transport and mTOR signaling. Future research on placental nutrient transport should include direct measures of maternal PA and dietary habits to help eliminate confounding factors.


Subject(s)
Diet , Membrane Transport Proteins/genetics , Motor Activity/physiology , Placenta/metabolism , Prenatal Exposure Delayed Effects/genetics , Prenatal Exposure Delayed Effects/metabolism , TOR Serine-Threonine Kinases/genetics , Adult , Biological Transport/genetics , Energy Metabolism/genetics , Female , Food , Humans , Infant, Newborn , Male , Maternal Nutritional Physiological Phenomena , Membrane Transport Proteins/metabolism , Pregnancy , Prenatal Care , Signal Transduction/genetics , TOR Serine-Threonine Kinases/metabolism
9.
Physiol Behav ; 135: 130-4, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24952265

ABSTRACT

AIM: To examine energy intake adaptations to a 10-week aerobic exercise program in obese adolescents. METHODS: Twenty-six 12-17year old obese adolescents were asked to cycle twice a week for an hour in a research laboratory. Body composition, aerobic fitness (submaximal fitness test) and energy intake (3-day food record) were assessed before and immediately after the 10-week intervention. RESULTS: The average time spent pedaling per session was 55.3±12.1min for a mean energy expenditure of 2196±561kJpersession. The intervention produced significant improvements in percentage of body fat (44.5±10.6% vs. 43.4±9.8%; p<0.05) but no significant weight and fat-free mass change. Peak workload (79.5±20.8W vs. 87.3±17.6W; p<0.05) and peak heart rate (174.6±18.7bpm vs. 166.2±21.0bpm; p<0.01) were improved. The mean total daily energy intake (in kJ/day) showed a tendency to decrease through the intervention (7440±1744 to 6740±2124kJ; p=0.07) but a high inter-individual variability observed in the energy intake response to the intervention may explain the non-significant association between the energy intake response and weight loss. CONCLUSION: A 10-week aerobic exercise program may result in a small decrease in energy intake and an associated decrease in percentage of body fat but no weight loss in obese adolescents. This lack of weight loss could be explained by a decrease in spontaneous energy expenditure outside the intervention sessions.


Subject(s)
Energy Intake/physiology , Exercise Therapy , Obesity/therapy , Adolescent , Body Mass Index , Energy Metabolism/physiology , Exercise/physiology , Female , Humans , Male , Obesity/physiopathology , Treatment Outcome
10.
Int J Obes (Lond) ; 38(5): 626-35, 2014 May.
Article in English | MEDLINE | ID: mdl-24048142

ABSTRACT

For women of reproductive age, excessive gestational weight gain and/or postpartum weight retention can increase the risk of obesity. This systematic review evaluates the effectiveness of lifestyle modification control trials that utilize exercise interventions, with or without dietary intervention, on weight loss among postpartum women. A search of randomized clinical trials (RCT) was performed using the follow databases and the bibliography of candidate studies: MEDLINE, Web of Science, EMBASE, CENTRAL/Cochrane and Physiotherapy Evidence Database. English language RCT papers published up to 31 October 2012, which present changes on maternal body weight from baseline to the end of exercise intervention were included. The primary meta-analysis examined the effects of exercise interventions, with or without complementary dietary intervention, on weight loss during the postpartum period compared with usual standard of care. Five subgroup analyses were performed to examine differences in study interventions and exercise modalities: duration of intervention, quality of study methodology, supervision of exercise intervention, exercise intervention goals used and the type of dietary intervention. In total 11 studies met eligibility criteria with 769 participants, 409 under intervention and 360 in the control group. The primary meta-analysis included all 11 studies and found a mean difference (MD) on weight loss of -2.57 kg (95% CI -3.66 to -1.47). The subgroup analysis demonstrated that the most effective interventions in reducing weight in postpartum women were exercise programs with objectively defined goals, such as the use of heart rate monitors or pedometer (MD of -4.09 kg-95% CI -4.94 to -3.25, I(2)=0%) and exercise combined with intensive dietary intervention (MD of -4.34 kg-95% CI -5.15 to -3.52, I(2)=0%). Thus, there is benefit from overall lifestyle interventions on weight loss in postpartum women and exercise plus intensive diet and objective targets are the most effective intervention strategies.


Subject(s)
Diet , Exercise , Overweight/prevention & control , Pregnancy Complications/prevention & control , Weight Gain , Weight Loss , Adult , Female , Health Behavior , Humans , Infant, Newborn , Overweight/epidemiology , Postpartum Period , Pregnancy , Pregnancy Complications/epidemiology , Quality Assurance, Health Care , Risk Reduction Behavior
11.
ISRN Obes ; 2013: 134835, 2013.
Article in English | MEDLINE | ID: mdl-24533216

ABSTRACT

Background. The physical activity transition is contributing to an increase in childhood obesity and a decrease in fitness worldwide. This study compared body composition and fitness measures in children from three countries and examined intercountry differences in the relationship between these variables. Methods. Participants consisted of 736 Canadian, 193 Mexican, and 179 Kenyan children aged 9-13 years. Body mass index (BMI), waist circumference, triceps skinfolds, aerobic fitness, and muscular fitness were measured. Linear regression was used to examine associations between variables. Results. The prevalence of obesity was the highest in Mexican children (9.2% boys, 8.4% girls) and the lowest in Kenyan children (0.9% boys, 2.8% girls). Aerobic fitness (VO2max in mL/kg/min) was the highest in Kenyan children (50.2 boys, 46.7 girls) and the lowest in Canadian children (41.3 boys, 38.3 girls). Aerobic fitness was negatively associated with body composition measures irrespective of country and sex. Mexican children with low aerobic fitness had higher body composition measures than Canadian and Kenyan children. Muscular fitness was not associated with the body composition measures in Kenyan children but was a weak positive correlate of BMI and waist circumference in Canadian and Mexican children. Conclusion. The current study provides some evidence to support the physical activity transition hypothesis.

12.
Hum Reprod ; 27(8): 2467-75, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22674202

ABSTRACT

STUDY QUESTION: Does maternal obesity affect insulin-like growth factor (IGF) axis protein expression patterns in maternal and cord blood? SUMMARY ANSWER: Maternal obesity attenuates cord blood expression of IGF-binding protein (IGFBP)-4. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: The IGF axis plays a critical role in fetal growth and development. Maternal obesity compromises IGF axis protein expression in fetal circulation, which is consistent with the findings of epidemiological studies suggesting that maternal obesity has an independent effect on fetal growth signals during in utero development. STUDY DESIGN: This cross-sectional case-control study involved 12 lean [body mass index (BMI) 18.5-24.9 kg/m2] and 12 obese (BMI≥30 kg/m2) women and their neonates at term. At the completion of the study, IGF axis protein expression and hormone concentrations in both maternal and cord blood were examined. PARTICIPANTS AND SETTING: We obtained fasting serum samples from cases and controls matched for age, gestation, mode of delivery, parity and glucose tolerance prior to and immediately following elective caesarean section. The corresponding umbilical cord blood was also collected at birth. MAIN RESULTS AND THE ROLE OF CHANCE: Between-group comparisons revealed elevated maternal insulin (P=0.03) and leptin (P<0.01) concentrations in obese gravidas. After adjustment, the maternal homeostasis model of assessment-insulin resistance (HOMA-IR) score was positively correlated with both maternal BMI and leptin levels (P<0.01). Umbilical cord blood levels of IGFBP-3 showed an inverse trend to maternal HOMA-IR (P=0.03) but were directly related to the fetal-placental weight ratio (P<0.01). In cord serum from obese mothers, IGFBP-4 expression was attenuated compared with the controls (P<0.05). LIMITATIONS: The limitations of our study include the cross-sectional design and relatively small sample size. WIDER IMPLICATIONS: Our results provide preliminary evidence for the applicability of our findings to other ethnic groups when pregnancy is complicated by obesity. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the University of Ottawa, Faculty of Health Sciences/Children's Hospital of Eastern Ontario Research Partnership Grant awarded to K.B.A. and Z.M.F. The authors have no conflicts of interest to declare.


Subject(s)
Fetal Blood/metabolism , Gene Expression Profiling , Insulin-Like Growth Factor Binding Protein 4/metabolism , Obesity/metabolism , Somatomedins/metabolism , Adult , Body Mass Index , Case-Control Studies , Cross-Sectional Studies , Female , Glucose/metabolism , Humans , Infant, Newborn , Insulin/metabolism , Insulin Resistance , Insulin-Like Growth Factor Binding Protein 1/metabolism , Insulin-Like Growth Factor Binding Protein 3/metabolism , Leptin/metabolism , Pregnancy , Pregnancy Complications
13.
J Matern Fetal Neonatal Med ; 25(5): 538-42, 2012 May.
Article in English | MEDLINE | ID: mdl-22081936

ABSTRACT

OBJECTIVE: To determine the effects of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on large-for-gestational-age (LGA) birth weight (≥90th % ile). METHODS: We examined 4321 mother-infant pairs from the Ottawa and Kingston (OaK) birth cohort. Multivariate logistic regression (controlling for gestational and maternal age, pre-pregnancy weight, parity, smoking) were performed and odds ratios (ORs) calculated. RESULTS: Prior to pregnancy, a total of 23.7% of women were overweight and 16.2% obese. Only 29.3% of women met GWG targets recommended by the Institute of Medicine (IOM), whereas 57.7% exceeded the guidelines. Adjusting for smoking, parity, age, maternal height, and achieving the IOM's recommended GWG, overweight (OR 1.99; 95%CI 1.17-3.37) or obese (OR 2.64; 95% CI 1.59-4.39) pre-pregnancy was associated with a higher rate of LGA compared to women with normal BMI. In the same model, exceeding GWG guidelines was associated with higher rates of LGA (OR 2.86; 95% CI 2.09-3.92), as was parity (OR 1.49; 95% CI 1.22-1.82). Smoking (OR 0.53; 95%CI 0.35-0.79) was associated with decreased rates of LGA. The adjusted association with LGA was also estimated for women who exceeded the GWG guidelines and were overweight (OR 3.59; 95% CI 2.60-4.95) or obese (OR 6.71; 95% CI 4.83-9.31). CONCLUSION: Pregravid overweight or obesity and gaining in excess of the IOM 2009 GWG guidelines strongly increase a woman's chance of having a larger baby. Lifestyle interventions that aim to optimize GWG by incorporating healthy eating and exercise strategies during pregnancy should be investigated to determine their effects on LGA neonates and down-stream child obesity.


Subject(s)
Body Mass Index , Fetal Macrosomia/etiology , Obesity , Pregnancy Complications , Weight Gain , Adolescent , Adult , Cohort Studies , Female , Guidelines as Topic , Humans , Infant, Newborn , Logistic Models , Middle Aged , Multivariate Analysis , Odds Ratio , Overweight/complications , Patient Compliance , Pregnancy , Young Adult
14.
Acta Paediatr ; 100(12): e260-6, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21649719

ABSTRACT

AIM: To perform a methods comparison of a left or right half-body scan versus whole-body scan for measuring body composition in a sample of obese children. METHODS: A group of obese children (n = 58; ≥ 95th BMI percentile; 8-18 years) were required to undergo a dual-energy X-ray absorptiometry (DXA) body composition measurement as part of an ongoing cohort study; 34 fit within the imaging field of the DXA scanner and were eligible for inclusion in the present analysis. Percent fat, total mass, fat mass, lean mass and bone mineral content (BMC) were estimated from half-body scans and compared with the whole-body results. Assessment was completed using GE enCORE 11.40 software. RESULTS: In comparing left- and right-side scans to whole-body scans, there was significant correlation for all body composition variables (p ≤ 0.005, R(2) = 0.996-1.0). Bland Altman analyses also showed high levels of agreement between half-body estimates and whole-body measurements. CONCLUSION: This study supports using a half-body scan methodology for percent fat, total mass, fat mass, lean mass, and BMC as a valid alternative to full-body analysis in obese children and youth.


Subject(s)
Absorptiometry, Photon/methods , Body Composition , Obesity/diagnostic imaging , Whole Body Imaging/methods , Adipose Tissue/diagnostic imaging , Adolescent , Body Mass Index , Bone Density , Child , Female , Humans , Male , Ontario
15.
J Physiol ; 580(Pt. 2): 617-28, 2007 Apr 15.
Article in English | MEDLINE | ID: mdl-17272352

ABSTRACT

Although data relating to muscle glycogen are interpreted as showing it is homogenous when quantified biochemically, it is actually in granules in specific subcellular locations. We hypothesized that postexercise restoration of muscle glycogen would occur initially by an increase in granule number followed by an increase in size, and also that restoration would differ in various subcellular locations. Five men performed prolonged exercise and had muscle biopsies taken at 0, 4, 24 and 48 h of recovery. We quantified granule number and size as well as the total volume of glycogen in the subsarcolemmal and the intra- and intermyofibrillar regions, using transmission electron microscopy. Muscle glycogen was reduced to 36 +/- 8.3 mmol glucosyl units (kg dry weight)(-1) at exhaustion, and was preferentially depleted and subsequently repleted in the intramyofibrillar space. The repletion rate was greatest in the first 4 h; this was associated with a 186% increase in number (P < or = 0.05) and no change in particle size (P > or = 0.05). From 4 h to 48 h, there was an increase in particle size (P < or = 0.05) but not number (P > or = 0.05). Net rate of G volume synthesis per unit area was 50% greater (P < or = 0.05) in the subsarcolemmal than the myofibrillar compartment. Conversely, the net rate of single-particle volume synthesis was greater (P < or = 0.05) in the myofibrillar than the subsarcolemmal compartment. Glycogen granules varied in size and number depending on location, and in all compartments resynthesis of glycogen was characterized initially by an increase in granule number and later by an increase in size.


Subject(s)
Exercise/physiology , Glycogen/metabolism , Muscle, Skeletal/metabolism , Adult , Glycogen/ultrastructure , Humans , Male , Muscle, Skeletal/ultrastructure , Particle Size , Time Factors
16.
Diabetologia ; 48(8): 1503-9, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15986237

ABSTRACT

AIMS/HYPOTHESIS: Exercise training improves glycaemic control in some but not all individuals and little research has been done regarding genetic impact on the exercise training response in type 2 diabetes. The purpose of this study was to investigate the influence of the Pro(12)Ala variant of the peroxisome proliferator-activated receptor (PPAR) gamma2 gene on changes in fasting plasma glucose in response to exercise training. METHODS: The study population comprised 139 sedentary type 2 diabetic patients (age: 54.4+/-7.2; HbA(1)c: 7.7+/-0.9%) who completed 3 months of supervised exercise training. The primary outcome variable in our analysis was the post-intervention change in blood glucose. Other assessments included measures of body composition, insulin sensitivity indices and maximal oxygen uptake (VO(2max)). RESULTS: The frequency of the Ala allele was 8.3% and the genotypes were in Hardy-Weinberg equilibrium. At baseline, neither body composition variables (weight, BMI, waist circumference), glucose homeostasis variables (glucose, insulin, HbA(1)c, homeostasis model assessment method) nor VO(2max) were different between genotypes (wild-type: Pro(12)Pro n=117, Ala carriers: X(12)Ala n=22). The exercise-training intervention led to similar improvements in body composition and glucose homeostasis variables in both genotype groups (p<0.05). The change in fasting plasma glucose was significantly different between PPARgamma2 genotypes (-1.66 mmol/l vs -0.54 mmol/l, Ala carriers and wild-type, respectively) (p=0.034 unadjusted and p=0.089 including baseline glucose) and the significant association between genotype and glucose response remained after adjusting for statistically significant predictors (age, changes in insulin and BMI [p=0.015]) and including baseline glucose, insulin and BMI (p=0.031). CONCLUSIONS/INTERPRETATION: These data suggest that the Pro(12)Ala polymorphism may influence the glycaemic response to exercise in type 2 diabetes.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Exercise/physiology , PPAR gamma/genetics , Physical Fitness/physiology , Polymorphism, Genetic/genetics , Adult , Aged , Anaerobic Threshold , Body Composition/physiology , Female , Genotype , Homeostasis/physiology , Humans , Male , Middle Aged , Prospective Studies
18.
J Appl Physiol (1985) ; 90(3): 873-9, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11181595

ABSTRACT

We examined the net catabolism of two pools of glycogen, proglycogen (PG) and macroglycogen (MG), in human skeletal muscle during exercise. Male subjects (n = 21) were assigned to one of three groups. Group 1 exercised 45 min at 70% maximal O(2) uptake (VO(2 max)) and had muscle biopsies at rest, 15 min, and 45 min. Group 2 exercised at 85% VO(2 max) to exhaustion (45.4 +/- 3.4 min) and had biopsies at rest, 10 min, and exhaustion. Group 3 performed three 3-min bouts of exercise at 100% VO(2 max) separated by 6 min of rest. Biopsies were taken at rest and after each bout. Group 1 had small MG and PG net glycogenolysis rates (ranging from 3.8 +/- 1.0 to 2.4 +/- 0.6 mmol glucosyl units. kg(-1). min(-1)) that did not change over time. In group 2, the MG glycogenolysis rate remained low and unchanged over time, whereas the PG rate was initially elevated (11.3 +/- 2.3 mmol glucosyl units. kg(-1). min(-1)) and declined (P < or = 0.05) with time. During the first 10 min, PG concentration ([PG]) declined (P < or = 0.05), whereas MG concentration ([MG]) did not. Similarly, in group 3, in both the first and the second bouts of exercise [PG] declined (P < or = 0.05) and [MG] did not, although by the end of the second exercise period the [MG] was lower (P < or = 0.05) than the rest level. The net catabolic rates for PG in the first two exercises were 22.6 +/- 6.8 and 21.8 +/- 8.2 mmol glucosyl units. kg(-1). min(-1), whereas the corresponding values for MG were 17.6 +/- 6.0 and 10.8 +/- 5.6. The MG pool appeared to be more resistant to mobilization, and, when activated, its catabolism was inhibited more rapidly than that of PG. This suggests that the metabolic regulation of the two pools must be different.


Subject(s)
Exercise/physiology , Glycogen/metabolism , Muscle, Skeletal/physiology , Oxygen Consumption/physiology , Physical Exertion/physiology , Adult , Analysis of Variance , Biopsy , Humans , Kinetics , Male , Time Factors
19.
J Cardiopulm Rehabil ; 20(4): 225-30, 2000.
Article in English | MEDLINE | ID: mdl-10955262

ABSTRACT

The Finnish tradition of sauna bathing is meant to be an experience in relaxation, and the length of time spent in the sauna and the preferred temperature vary considerably among individuals. The pleasures of sauna bathing can be considered safe and without undue risk of cardiac complications even for CVD patients, providing bathing is conducted sensibly for an appropriate period of time, and extremes in temperature are voided.


Subject(s)
Cardiovascular Diseases , Steam Bath , Adult , Aged , Blood Circulation , Blood Pressure , Body Temperature , Cardiovascular Diseases/physiopathology , Contraindications , Female , Finland , Heart Failure/physiopathology , Heart Transplantation , Hemodynamics , Hormones/blood , Hot Temperature , Humans , Hypertension/physiopathology , Male , Myocardial Ischemia/physiopathology , Physical Exertion , Risk Factors , Safety , Skin/blood supply , Steam Bath/adverse effects , Temperature , Time Factors
20.
Can J Appl Physiol ; 24(5): 393-415, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10566104

ABSTRACT

This review of carbohydrate (CHO) ingestion and exercise addresses three major issues: (a) how CHO ingestion influences CHO and fat stores, (b) how exercise, by changing CHO stores, alters the responses to CHO or fat ingestion, and (c) the roles of CHO in exercise performance and metabolism. Dietary manipulation is not a simple issue; increasing the dietary content of any specific nutrient alters the entire diet composition. High CHO diets are often low fat diets, hence changing the metabolism and storage of both fat and CHO. Acute CHO ingestion increases CHO oxidation and the "spared" fats are deposited as fat. Chronic high CHO ingestion (without an active lifestyle) leads to muscle becoming insulin-insensitive, adipose tissue processing CHO to fatty acids, and the liver increasing production of VLDL triglycerides. CHO ingestion prior to and during prolonged exercise can increase endurance. It has been suggested that moderate or low glycemic index forms be used prior to and during the exercise, but there is no consensus as to whether it should be a recommendation. The physiological nature of the regulation of CHO stores is poorly understood, but the recent identification of a key enzyme, glycogenin, and two forms of glycogen (pro- and macroglycogen) show promise of a deeper understanding.


Subject(s)
Dietary Carbohydrates/metabolism , Dietary Fats/metabolism , Exercise/physiology , Body Composition , Energy Metabolism , Humans
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