scholarly journals Why is it so hard to lose fat? Because it has to get out through your nose! An exercise physiology laboratory on oxygen consumption, metabolism, and weight loss

2021 ◽  
Vol 45 (3) ◽  
pp. 599-606
Author(s):  
Edward K. Merritt
Keyword(s):  
Weight Loss ◽  
Oxygen Consumption ◽  
Exercise Physiology ◽  
Effective Means ◽  
Mechanical Work ◽  
Energy Utilization ◽  
Laboratory Activity ◽  
Exercise Induced ◽  
Average Size ◽  
Physiology Laboratory

Exercise is thought to be an effective means to quick weight loss. However, few people have realistic exercise-induced weight loss expectations. Fewer understand how weight is “lost” and where the lost mass goes. Understanding that fat is “burned” with inhaled oxygen and most of the mass lost must be exhaled as carbon dioxide might help individuals create realistic weight loss expectations. The purpose of this laboratory activity is to 1) provide students with a basic understanding of the role of oxygen in fuel metabolism during physical activity and its relationship to energy expenditure and mechanical work, and 2) engage students with collection of their own data to determine a realistic timeframe for exercise-induced weight loss. In the prelaboratory, questions such as, “When you lose weight, where does it go?” are asked. A guided discussion helps students understand the basic biochemistry required for weight loss. For the activity, students complete walking or running exercise, recording the time and distance. The relationship of exercise to physics’ concepts of mechanical work and energy utilization are discussed with the concept of “calorie burn” and its relationship to oxygen consumption. Students estimate oxygen consumed and calories burned during exercise using established metabolic equations. Finally, the amount of energy (i.e., calories) equivalent to 1 pound of fat is discussed. Students calculate how long he/she would have to exercise to burn 10 pounds (4.5 kg) of fat. A person of average size and fitness, needs 60+ h of exercise to burn 10 pounds of fat. Supplementary activities including a dramatic gummy bear oxidation and the use of a metabolic cart reinforces these concepts and validates the laboratory estimates.

Evaluation of the Virtual Physiology of Exercise Laboratory program

2009 ◽  
Vol 33 (4) ◽  
pp. 335-342 ◽  
Author(s):  
John L. Dobson
Keyword(s):  
Ventilatory Threshold ◽  
Exercise Physiology ◽  
Design Data ◽  
Laboratory Activity ◽  
Assessment Scores ◽  
Hands On ◽  
Group 2 ◽  
Additional Support ◽  
Physiology Laboratory ◽  
Group 1

The Virtual Physiology of Exercise Laboratory (VPEL) program was created to simulate the test design, data collection, and analysis phases of selected exercise physiology laboratories. The VPEL program consists of four modules: 1) cardiovascular, 2) maximal O2 consumption (V̇o2max), 3) lactate and ventilatory thresholds, and 4) respiratory exchange ratio. The purpose of this investigation was to compare student learning from the VPEL program with that from traditional “hands-on” exercise physiology laboratory activities. Student participants from the spring 2009 Integrated Fitness Programming course were randomly assigned to either experimental group 1 or group 2. Group 1 completed a hands-on version of a typical V̇o2max laboratory activity, whereas group 2 completed the VPEL V̇o2max module. Both groups then completed the same assessment to evaluate their understanding of V̇o2max laboratory concepts. Group 1 then completed the VPEL lactate and ventilatory threshold module, whereas group 2 completed a hands-on version of that same activity. Both groups then completed the same assessment to evaluate their understanding of lactate and ventilatory threshold laboratory concepts. Mean V̇o2max assessment scores were 86.39 ± 4.13 and 85.64 ± 6.72 and mean lactate and ventilatory threshold assessment scores were 85.50 ± 8.05 and 86.15 ± 6.45 for groups 1 and 2, respectively. These findings lend additional support to the following conclusion of similar investigations ( 2 , 4 , 6 ): that virtual laboratories instruct students as effectively as hands-on laboratories.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Multimodal measurement of body composition change with diet- and exercise-induced weight loss in obese women

2011 ◽  
Vol 35 (2) ◽  
pp. 204-205
Author(s):  
A.R. Josse ◽  
S.A. Atkinson ◽  
M.A. Tarnopolsky ◽  
H. Azizian ◽  
J.K.G. Kramer ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Obese Women ◽  
Composition Change ◽  
Body Composition Change ◽  
Diet And Exercise ◽  
Exercise Induced

The Effects of Walking on Gastrocnemius Cooling During an Ice Bag Treatment

2014 ◽  
Vol 19 (6) ◽  
pp. 34-40 ◽  
Author(s):  
Stephanie J. Guzzo ◽  
Susan W. Yeargin ◽  
Jeffery S. Carr ◽  
Timothy J. Demchak ◽  
Jeffrey E. Edwards
Keyword(s):  
Outcome Measures ◽  
Gastrocnemius Muscle ◽  
Athletic Trainers ◽  
Exercise Physiology ◽  
Lower Extremity Injury ◽  
Physically Active ◽  
Treatment Conditions ◽  
Males And Females ◽  
Physiology Laboratory ◽  
Randomized Crossover Study

Context:Many athletic trainers use “ice to go” to treat their athletes. However, researchers have reported that icing a working muscle may negate intramuscular (IM) cooling.Objective:The purpose of our study was to determine the length of time needed to cool the gastrocnemius while walking followed by rest.Design:A randomized crossover study design was used.Setting:Exercise Physiology Laboratory.Patients or Other Participants:Nine healthy, physically active males and females (males 5, females 4; age 24.0 ± 2.0 years; height 174.0 ± 8.0 cm; weight 86.3 ± 6.5 kg; skinfold taken at center of gastrocnemius greatest girth, R leg 20.3 ± 4.4 mm, L leg 19.6 ± 4.1 mm) without lower extremity injury or cold allergy volunteered to complete the study.Intervention:Participants randomly experienced three treatment conditions on separate days: rest (R), walk for 15 minutes followed by rest (W15R), or walk for 30 minutes followed by rest (W30R). During each treatment, participants wore a 1 kg ice bag secured to their right gastrocnemius muscle. Participants walked at a 4.5km/hr pace on a treadmill during the W15R and W30R trials.Main Outcome Measures:A 1 × 3 within groups ANOVA was used to determine the effect of activity on cooling time needed for the gastrocnemius temperature to decrease 6 °C below baseline.Results:The R condition cooled faster (25.9 ± 5.5 min) than both W15R (33.7 ± 9.3 min;P= .002) and W30R (49.4 ± 8.4 min;P< .001). Average time to decrease 6 °C after W15R was 18.7 ± 9.3 minutes and after W30R was 19.4 ± 8.4 minutes.Conclusions:Clinicians should instruct their patients to stay and ice or to keep the ice on for an additional 20 minutes after they stop walking and begin to rest.

Carbohydrate and Protein Supplements, an Effective Means for Maintaining Exercise-Induced Glucose Metabolism Homeostasis

2021 ◽  
Vol 11 (6) ◽  
pp. 1120-1128
Author(s):  
Dingguo Ruan ◽  
Hong Deng ◽  
Xiaoyang Xu
Keyword(s):  
Blood Glucose ◽  
Glucose Metabolism ◽  
Normal Saline ◽  
Glucose Transporter ◽  
Glycogen Synthesis ◽  
Effective Means ◽  
Recovery Period ◽  
Future Application ◽  
Glut 4 ◽  
Exercise Induced

This study aimed to verify the effects of an independently developed carbohydrate and protein (CHO+P) beverage (7.2% oligosaccharide and 1.6% soy-polypeptide) supplement on exerciseinduced glucose metabolism and associated gene expression. Mice received 1 mL/100 g body weight of normal saline (group C; n = 36) or CHO+P (group E; n = 36) at 30 min before an immediately after exercise. Mice without exercise and supplementation served as normal controls (group NC; n = 9). The expression levels related to glucose metabolism were measured at 0, 4, 12, and 24 h after exercise (n = 9 per group). The blood glucose, insulin, and liver glycogen contents in groups C and E were dramatically lower than group NC immediately after exercise. Those in group E were significantly higher than group C, with few differences between the two. Muscle glycogen was restored more quickly when the CHO+P beverage was consumed compared to normal saline. Furthermore, exercise-induced increase in glucose transporter-4 (GLUT-4) mRNA could be depressed by CHO+P supplementation but enhanced in GLUT-4 protein. Interleukin-6 (IL-6) showed a double peak curve in the recovery period, but IL-6 increased again in group E earlier than group C. These findings confirmed that the beverage has significantly improved time in maintaining blood glucose stability, reducing glycogen consumption, accelerating glycogen resynthesis, and repairing injury in rats. This study suggests the future application of this beverage in humans with experimental support and provides a scientific direction for promoting glycogen synthesis and recovery through nutrition.

scholarly journals Lower extremity muscle size and strength and aerobic capacity decrease with caloric restriction but not with exercise-induced weight loss

2007 ◽  
Vol 102 (2) ◽  
pp. 634-640 ◽  
Author(s):  
Edward P. Weiss ◽  
Susan B. Racette ◽  
Dennis T. Villareal ◽  
Luigi Fontana ◽  
Karen Steger-May ◽  
...  
Keyword(s):  
Weight Loss ◽  
Caloric Restriction ◽  
Aerobic Capacity ◽  
Lean Mass ◽  
Muscle Volume ◽  
Muscle Size ◽  
Thigh Muscle ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Exercise Induced

Caloric restriction (CR) results in fat loss; however, it may also result in loss of muscle and thereby reduce strength and aerobic capacity (V̇o2 max). These effects may not occur with exercise-induced weight loss (EX) because of the anabolic effects of exercise on heart and skeletal muscle. We tested the hypothesis that CR reduces muscle size and strength and V̇o2 max, whereas EX preserves or improves these parameters. Healthy 50- to 60-yr-old men and women (body mass index of 23.5–29.9 kg/m2) were studied before and after 12 mo of weight loss by CR ( n = 18) or EX ( n = 16). Lean mass was assessed by dual-energy X-ray absorptiometry, thigh muscle volume by MRI, isometric and isokinetic knee flexor strength by dynamometry, and treadmill V̇o2 max by indirect calorimetry. Both interventions caused significant decreases in body weight (CR: −10.7 ± 1.4%, EX: −9.5 ± 1.5%) and lean mass (CR: −3.5 ± 0.7%, EX: −2.2 ± 0.8%), with no significant differences between groups. Significant decreases in thigh muscle volume (−6.9 ± 0.8%) and composite knee flexion strength (−7.2 ± 3%) occurred in the CR group only. Absolute V̇o2 max decreased significantly in the CR group (−6.8 ± 2.3%), whereas the EX group had significant increases in both absolute (+15.5 ± 2.4%) and relative (+28.3 ± 3.0%) V̇o2 max. These data provide evidence that muscle mass and absolute physical work capacity decrease in response to 12 mo of CR but not in response to a similar weight loss induced by exercise. These findings suggest that, during EX, the body adapts to maintain or even enhance physical performance capacity.

scholarly journals SUN-543 Real World Evidence of Successful Weight Management for the Obese Population: Complete Reversal of Obesity Related Metabolic Co-Morbidities and Weight Loss in Patients Attending a Multidisciplinary Weight Management Clinic in Australia

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Zoe Rock ◽  
Juliana Chen ◽  
Joanna Jaques ◽  
Bernard L Champion ◽  
Reginald V Lord ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Weight Management ◽  
Exercise Physiology ◽  
Body Weight Loss ◽  
Total Body Weight ◽  
Management Interventions ◽  
Co Morbidity ◽  
Total Body ◽  
Total Body Weight Loss

Abstract Over 2.5 billion people worldwide are overweight or obese. Multidisciplinary weight management interventions have evolved to address the complexity of weight loss for those with one or more chronic diseases, and the trend of weight regain. The aim of these interventions is to encourage sustainable lifestyle changes, resulting in weight loss and weight maintenance and improvements in comorbidities. While some prospective clinical trials have demonstrated efficacy, results are often not reported by real life practices. The aim of this study was to evaluate the effectiveness of a Sydney based multidisciplinary weight management clinic with endocrinology, dietetics, exercise physiology, psychology, and bariatric surgical domains. All patients who attended the clinic for weight loss purposes between March 2017 and April 2019 were included (n=220). A retrospective chart review was conducted. Patient data on weight, BMI, waist circumference, body composition measurements, and selected blood test results and co-morbidities were analysed. All patient therapy included endocrinological input for co-morbidity identification and management, lifestyle intervention (dietetic and exercise physiology input) with optional adjunct pharmacotherapy or psychological counselling. Of the 220 cohort, 20 of the patients had sleeve gastrectomy. Patient retention in the clinic after the first consultation was 85% (n=186), a high rate within the weight management community. 59% of patients achieved a minimum of 5% total body weight loss, including 18% who achieved greater than 10% total body weight loss. Additionally, 31% of patients lost enough weight to decrease their BMI class by up to 2 or more classes. Of the gastric sleeve cohort average excess body weight loss was 32kg (21-56kg) enhanced by multidisciplinary care in the lead up to surgery. Across the cohort some patients completely reversed co-morbidities; including dyslipidaemia (n=1), hypertension (n=3), NAFLD (n=1), pre-diabetes (n=8) and type 2 diabetes (n=3), OSA (n=1). These results demonstrate that obesity is a chronic condition that can be successfully managed. We have demonstrated significant durable weight loss and improvement in metabolic co-morbidities with holistic coordinated care. Future directions include translating this model of care into standard practice in Australia and other countries where obesity to date not received the same coordinated approach as other chronic conditions.

scholarly journals Exercise, weight loss, and changes in body composition in mice: phenotypic relationships and genetic architecture

2011 ◽  
Vol 43 (4) ◽  
pp. 199-212 ◽  
Author(s):  
Scott A. Kelly ◽  
Derrick L. Nehrenberg ◽  
Kunjie Hua ◽  
Theodore Garland ◽  
Daniel Pomp
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Body Weight ◽  
Food Consumption ◽  
Genetic Architecture ◽  
Interval Mapping ◽  
Voluntary Exercise ◽  
Exercise Induced ◽  
Running Wheels ◽  
The Relationship

The regulation of body weight and composition is complex, simultaneously affected by genetic architecture, the environment, and their interactions. We sought to analyze the complex phenotypic relationships between voluntary exercise, food consumption, and changes in body weight and composition and simultaneously localize quantitative trait loci (QTL) controlling these traits. A large ( n = 815) murine advanced intercross line (G4) was created from a reciprocal cross between a high-running line and the inbred strain C57BL/6J. Body weight and composition (% fat, % lean) were measured at 4, 6, and 8 wk of age. After measurements at 8 wk of age, mice were given access to running wheels, during which food consumption was quantified and after which body weight and composition were assessed to evaluate exercise-induced changes. Phenotypic correlations indicated that the relationship between exercise and overall change in weight and adiposity depended on body composition before the initiation of exercise. Interval mapping revealed QTL for body weight, % fat, and % lean at 4, 6, and 8 wk of age. Furthermore, QTL were observed for food consumption and changes in weight, % fat, and % lean in response to short-term exercise. Here we provide some clarity for the relationship between weight loss, reduction in adiposity, food consumption, and exercise. Simultaneously, we reinforce the genetic basis for body weight and composition with some independent loci controlling growth at different ages. Finally, we present unique QTL providing insight regarding variation in weight loss and reduction in adiposity in response to exercise.

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