The Effect of Quercetin on Bone Turnover Markers, Inflammatory Markers, and Bone Mineral Density in Postmenopausal Women: A Double-Blind Placebo-Controlled Investigation

Maintaining optimal bone health prevents major bone disorders (e.g., osteoporosis) and prolongs longevity. Quercetin is a plant-based flavonoid that is suggested to have anti-inflammatory effects and may improve bone health. PURPOSE: To investigate the effects of quercetin supplementation over 90-days on prominent bone turnover markers (BTMs), inflammatory markers, bone mineral density (BMD), body composition, and physical functioning in postmenopausal women. METHODS: Thirty-three healthy, nonosteoporotic, postmenopausal women (59.2±7.0 years) participated in a double-blind, placebo-controlled investigation. Participants were randomized into one of two supplement groups: 1) 500 mg of quercetin (QUE) once daily or 2) 500 mg of methylcellulose (placebo; PLB) once daily. Pre- and post-testing visits included assessments of BTMs (i.e., osteocalcin [OC], procollagen type-I N-terminal propeptide [PINP], and type-I collagen cross-linked C-terminal telopeptide [CTX]), inflammatory markers (i.e., interleukin [IL]-6, tumor necrosis factor-alpha [TNF-a], and C-reactive protein [CRP]), BMD measurements, body composition measurements (i.e., body fat percentage), and physical function. RESULTS: The QUE group increased OC (p=0.016; d=0.89), PINP (p=0.030; d=0.64), and CTX (p=0.023; d=0.91) levels and decreased IL-6 (p=0.045; d=0.73) and TNF-a (p=0.021; d=0.90) levels compared to PLB. CRP (p=0.448; d=0.34), BMD, body composition, and physical function remained unchanged. CONCLUSION: The results indicate that QUE may maintain optimal bone health by mediating bone formation and decreasing pro-inflammatory cytokines

Carbohydrate Rinse Fails to Enhance Cycling Performance or Alter Metabolic and Autonomic Recovery in Recreational Cyclists

The purpose of the study was to examine the effects of carbohydrate (CHO) mouth rinsing on autonomic and metabolic recovery as well as cycling performance. Ten male recreational cyclists (age = 30 ± 6 years, VO2peak = 54.5 ± 8.1 mL·kg-1·min-1) completed a randomized, double-blind, placebo-controlled, crossover designed study. A CHO or a placebo (PLA) rinse was administered every 12.5% of a work to completion trial (75%Wmax). Heart rate variability (lnRMSSD), the respiratory exchange ratio, and plasma epinephrine, norepinephrine, insulin, glucose, free fatty acids (FFA), and lactate were measured pre- and post-exercise. The CHO rinse did not improve time to completion of the test trial (CHO: 4108 ± 307 s, PLA: 4176 ± 374 s, p = 0.545). Further, the CHO rinse did not impact autonomic recovery, as measured by lnRMSSD (p = 0.787) and epinephrine (p = 0.132). Metabolic biomarkers were also unaffected by the CHO rinse, with no differences observed in responses of FFA (p = 0.064), lactate (p = 0.302), glucose (p = 0.113) or insulin (p = 0.408). Therefore, the CHO mouth rinse does not reduce the acute sympathetic response following strenuous exercise and does not result in improvements in cycling time to completion

Physiological Responses to Balance Walking

AIM: The aim of the study was to determine the effects of the use of walking poles and angle-soled shoes (i.e., Balance Walking), cumulatively, and independently, on the physiological responses to walking, and to determine the influence of velocity on those effects. METHODS: Twenty females and 5 males (22.36 ± 3.23 yr) exercised in 4 conditions – flat-soled shoes/no poles; angle-soled shoes/no poles; flat-soled shoes/with poles; angle-soled shoes/with poles) in random order. Each session consisted of walking for 3 min at 5 velocities (53.6, 67.0, 80.4, 93.8, and 107.2 m ∙ min-1 )while heart rate (HR) and oxygen uptake (VO2) were recorded. RESULTS: A significant main-effect for shoe-condition and pole-condition was found for HR and VO2 at all walking velocities. In addition, the influence of angle-soled shoes and walking poles was greater at faster velocities. CONCLUSION: The use of angle-soled shoes or walking poles independently increase the physiological responses to walking, with the combination of both (Balance Walking) being additive

Should Body Size Categories Be More Common in Endurance Running Events?

Thousands of endurance running events are held each year in the United States, and most of them use age and sex categories to account for documented effects of those factors on running performance. However, most running events do not provide categories of body mass, despite abundant evidence that it, too, dramatically influences endurance running performance. The purposes of this article are to (1) discuss how body mass affects endurance running performance, (2) explain several mechanisms through which body mass influences endurance running performance, and (3) suggest possible ways in which body mass might be categorized in endurance running events

Personalizing activity recommendations for individuals with type 2 diabetes

By reading this article, fitness professionals who work with novice exercisers with type 2 diabetes mellitus (T2DM) will be able to: individualize recommendations for activity timing, reducing sedentary time, and modes of exercise to maximize blood sugar control for clients with T2DM; summarize the benefits and limitations of step tracking on blood sugar control for individuals with T2DM

Exercise for the Management of Type 2 Diabetes Mellitus – Factors to Consider with Current Guidelines

It has long been established that exercise is powerful medicine for those with type 2 diabetes mellitus (T2DM), such that it should represent a priority in the treatment and management of that condition. In spite of this, exercise adherence among those with T2DM is low, with lack of time and fear of doing harm commonly cited as reasons for not being more active. Published guidelines for aerobic exercise in those with T2DM recommend only moderate intensity, due to the elevated risk of untoward outcomes with more vigorous exercise in persons with chronic disease. However, considerable research evidence has appeared in the literature since the publication of those guidelines in 2010 addressing the safety and efficacy of more vigorous forms of exercise (i.e., interval training) in those with T2DM. Many such studies have reported improvements in glucose control as great as or greater than those associated with moderate intensity exercise, with significantly reduced time requirements, and mechanisms of improved glucose control via interval training may be unique to this mode of exercise. Resistance training, too, appears to confer significant improvements in glucose control in those with T2DM through unique mechanisms. These recent findings may be of interest to physicians and exercise practitioners, as they may provide for greater adherence to more optimal exercise prescriptions that are better suited to each patient’s time availability and motivational level

Sit-and-Reach Flexibility and Running Economy of Men and Women Collegiate Distance Runners

Flexibility has been controversially suggested as one of the biomechanical factors contributing to the variability observed in running economy among distance runners. The purpose of this investigation was to determine the magnitude of the relationship between sit-and-reach flexibility and running economy in men and women. Eight collegiate distance runners (4 men and 4 women) served as subjects for this correlational study (age = 19.9 ± 1.25 years; ... = 63.2 ± 3.4 ml*kg^sup -1^*min^sup -1^). Each subject\u27s flexibility was measured using the standard sit-and-reach test, and running economy was recorded during an incremental maximal treadmill test at both absolute (men = 241.2 m*min^sup -1^; women = 198.32 m*min^sup -1^) and relative (10-km pace) velocities. Statistical analyses indicated a significant relationship between sit-and-reach scores and running economy at an absolute velocity (r = 0.826, p ≤ 0.05), as well as a significant sex difference in sit-and-reach scores (p ≤ 0.05). The significant relationship demonstrates that the less flexible distance runners tended to be more economical, possibly as a result of the energy-efficient function of the elastic components in the muscles and tendons during the stretch-shortening cycl

PRESCRIPTION OF STEP COUNTS FOR WEIGHT MANAGEMENT IN OVERWEIGHT/OBESE ADULTS

Each year, many adults alter their diets in an effort to lose weight, often with disappointing results. However, a recent study reported a strong inverse relationship between daily step counts and body fat percentage when steps were expressed relative to fat mass (e.g., steps·kg of fat-1 mass·day-1) while people were eating to their own comfort, suggesting that it may be possible to determine the average number of daily steps necessary to achieve a specific weight loss. Therefore, the purpose of this research study is to test the efficacy of application of relationship between daily steps and body composition reported in a previous study for producing predictable weight loss in overweight/obese adults. To accomplish this, up to 20 males and 20 females between 19-40 years of age who are overweight or obese will undergo an assessment of body weight and composition. Thereafter, the step count target will be identified by determining the step count associated with a 7% reduction in body weight. Participants will be given a triaxial pedometer which will be worn all day, every day, except while swimming or bathing, and will be encouraged to consistently accumulate their step count target. After three months, participants will undergo an assessment of body weight and composition identical to that which was conducted at the onset of the study, and step count targets will be adjusted if need be. After completing six months of pedometer wear, participants will undergo a final assessment of body weight and composition. Target weight will be compared with actual weight, and the efficacy of the model for yielding a predictable weight loss will be determined. If application of this model is shown to be effective at yielding predictable changes in body weight, it may present an effective and appealing alternative to dieting for weight management

Feasibility of Minimal Dose High Intensity Body-Weight Circuit Training in Individuals With Type 2 Diabetes: A Pilot Study

Background: The use of body-weight resistance exercise and a minimal time duration requirement can be combined to form a high intensity body-weight circuit training program (HIBC), and may be a feasible and attractive option for those with Type 2 Diabetes Mellitus (T2DM). The purpose of this pilot was to evaluate the effectiveness of an minimal time commitment HIBC intervention on metabolic biomarkers, body composition, and fitness. Methods: Three females (55±4yrs) and two males (64±1yrs) with T2DM underwent assessments of glycosylated hemoglobin (HbA1c) and fasting glucose (FG), and lipids. Body composition via dual-energy x-ray absorptiometry, aerobic fitness (submaximal treadmill test), blood pressure (SBP/DBP), and resting heart rate (RHR) were assessed. Participants completed 16-weeks of HIBC. All assessments were repeated upon completion. Results: No differences were observed in the following variables; Body composition: Pre and Post changes in mean weight 2.2 ± 2.8 (p=0.31), body fat% -0.1 ± 1.1% (p=1.0), lean mass 1.2 ± 1.22 kg (p=0.13). Aerobic fitness: estimated VO2max 2.26 ± 4.5 ml/kg/min (p=0.63), SBP -6.4 ± 12.5mmhg (p=0.38), DBP -1.4 ± 3.5mmhg (p=0.50), RHR -1.8 ± 4.7bpm (p=0.50). Metabolic biomarkers: FG -14.9 ± 33.4 mg/dL (p=0.44), HDL 1.4 ± 4.2 mg/dL (p=0.63), LDL -4.0 ± 12.6 mg/dL (p=0.63), HbA1c -0.3 ± .28% (p=0.25). Conclusions: Though the main findings of this study were not statistically significant, but the physiological responses could be clinically meaningful in that improvements in metabolic profiles were similar in magnitude to both aerobic and resistance training interventions

Steps expressed relative to body fat mass predicts body composition and cardiometabolic risk in adults eating ad libitum

BACKGROUND: Excess body fatness is a consequence of a chronic energy surplus (energy intake is greater than energy expenditure). Given the serious health consequences of excess body fatness, factors that influence energy balance and body composition are increasingly important to understand. METHODS: A total of 34 adults between the ages of 19-40 years made a laboratory visit in which height, weight, body composition, and cardiometabolic risk (CMR) factors were quantified. Participants wore accelerometers for 21-28 days, then returned to the laboratory for a second body composition assessment. Changes in weight and body composition were used to quantify energy balance, and data derived from accelerometers provided markers of physical activity (PA) and sedentariness. RESULTS: Of the markers of PA that we measured, daily step counts expressed relative to fat mass was most strongly and consistently associated with body fatness and CMR status. CONCLUSIONS: Step counts expressed relative to fat mass were strongly associated with body composition and CMR in adults eating ad libitum. Longitudinal interventional studies are necessary to determine the efficacy of step count prescriptions expressed relative to existing and target body fatness and CMR levels for improving weight management and metabolic outcomes. KEY WORDS: Obesity; Sedentary behavior; Cardiometabolic risk factor