scholarly journals A quasi-experimental examination of weight-reducing dehydration practices in collegiate male rowers

Author(s):  
Dayton J. Kelly ◽  
Sarah L. West ◽  
Nathan O’Keeffe ◽  
Liana E. Brown

Abstract Background Lightweight rowers commonly utilize weight loss techniques over 24-h before competition to achieve the qualifying weight for racing. The objective was to investigate, using a quasi-experimental design, whether changes in weight resulting from dehydration practices are related to changes in proxies of bodily systems involved in rowing and whether these relationships depend on the dehydration technique used. Methods Twelve elite male rowers performed a power test, an incremental VO2max test, and a visuomotor battery following: weight loss via thermal exposure, weight loss via fluid abstinence and then thermal exposure, and no weight loss. The total percent body mass change (%BMC), %BMC attributable to thermal exposure, and %BMC attributable to fluid abstinence were used to predict performance variables. Results Fluid abstinence but not thermal exposure was related to a lower total wattage produced on a incremental VO2max test (b = 4261.51 W/1%BMC, 95%CI = 1502.68–7020.34), lower wattages required to elicit 2 mmol/L (b = 27.84 W/1%BMC, 95%CI = 14.69–40.99) and 4 mmol/L blood lactate (b = 20.45 W/1%BMC, 95%CI = 8.91–31.99), and slower movement time on a visuomotor task (b = -38.06 ms/1%BMC, 95%CI = -62.09–-14.03). Conclusions Dehydration related weight changes are associated with reductions in some proxies of bodily systems involved in rowing but depend on the dehydration technique used.

1980 ◽  
Vol 8 (1) ◽  
pp. 10-12
Author(s):  
F. C. Brenner

Abstract Tread wear rates during first wear measured by groove depth and weight changes do not always agree. Sometimes, the groove depth method shows a high rate and the weight loss method a low rate. Reported here are experiments designed to determine if grooves show depth changes without wear. Four tires were measured before mounting on a wheel, after mounting and inflation, and after inflation and storage. The mounted and inflated tires showed shallower shoulder grooves and deeper center grooves than the unmounted tires. In a second experiment, tires were measured immediately after a tread wear test and then stored mounted for two weeks before remeasuring. Each groove became deeper, and there was no change in the crown radius of any tire.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1359
Author(s):  
Noga C Minsky ◽  
Dafna Pachter ◽  
Galia Zacay ◽  
Naama Chishlevitz ◽  
Miriam Ben-Hamo ◽  
...  

Since the outbreak of COVID-19, billions of people have gone into lockdown, facing pandemic related challenges that engender weight gain, especially in the obese. We report the results of an online survey, conducted during Israel’s first quarantine, of 279 adults treated in hospital-based obesity clinics with counseling, medications, surgery, endoscopic procedures, or any combination of these for weight loss. In this study, we assessed the association between changes in dietary and lifestyle habits and body weight, and the benefits of receiving weight management care remotely through telemedicine during lockdown. Compared to patients not receiving obesity care via telemedicine, patients receiving this care were more likely to lose weight (OR, 2.79; p = 0.042) and also to increase participation in exercise (OR, 2.4; p = 0.022). While 40% of respondents reported consuming more sweet or salty processed snacks and 33% reported less vegetables and fruits, 65% reported more homemade foods. At the same time, 40% of respondents reported a reduction in exercise and 52% reported a decline in mood. Alterations in these eating patterns, as well as in exercise habits and mood, were significantly associated with weight changes. This study highlights that lockdown affects health behaviors associated with weight change, and advocates for the use of telemedicine to provide ongoing obesity care during future quarantines in order to promote weight loss and prevent weight gain.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Shih Lung Woo ◽  
Dina Ben-Nissan ◽  
Zahra Ezzat-Zadeh ◽  
Jieping Yang ◽  
Lijun Zhang ◽  
...  

Abstract Objectives This study was designed to assess the effects of mixed nut consumption on body weight and composition, and gut microbiome in obese individuals. Primary outcome was change in body weight and composition. Secondary outcomes include gut microbiome composition, inflammatory markers, and plasma lipids. Methods The reported results are from an interim analysis (n = 50) of a randomized, placebo controlled, parallel study. Total enrollment target is 154 overweight/obese subjects (BMI 27–35 kg/m2). Participants were randomly assigned to consume either 1.5oz mixed tree nuts or pretzels with equal calorie content daily for 24 weeks. The study included a 12-week weight loss phase (500 kcal per day less than total daily energy expenditure), followed by a 12-week weight maintenance phase. Body composition, fasting blood, and stool samples were collected at baseline, week 12 and 24. Body composition, and vitals were analyzed, whereas plasma lipid profile, fecal microbiome, and microbiome metabolites analysis is still pending. Results At week 12, subjects from both the pretzel (n = 15, 10 dropouts; P = 0.009) and nut group (n = 22, 3 dropouts; P = 0.038) lost significant amount of weight. The trend of weight changes did not differ between groups (P = 0.530). Subjects from both groups were able to sustain weight loss through 24 weeks (pretzel: 81.43 ± 3.85 kg at baseline vs. 79.43 ± 4.08 kg at week 24, P = 0.028; nut: 84.26 ± 3.78 kg at baseline vs. 82.38 ± 3.72 kg at week 24, P = 0.026). At week 12, fat mass in both groups was significantly decreased (pretzel: P = 0.002; nut: P = 0.012). The trend of fat changes did not differ between groups (P = 0.547). Subjects from both groups were able to sustain fat loss through 24 weeks (pretzel: 30.84 ± 1.75 kg at baseline vs. 29.25 ± 2.12 kg at week 24, P = 0.024; nut: 31.51 ± 1.56 kg vs 30.21 ± 1.81 kg at week 24, P = 0.04). Muscle mass, and blood pressure were not significantly different between both groups. Conclusions Our data suggested that tree nuts could be consumed as part of a healthy weight loss meal plan without concern of causing weight gain. Further analysis of the remaining samples is needed to confirm results. Due to higher dropouts in the pretzel group, future intention-to-treat analysis is also needed to eliminate bias. Funding Sources This study is supported by the International Tree Nut Council.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Golnar Rahimzadeh ◽  
Majid Saeedi ◽  
Mahmood Moosazadeh ◽  
Seyyed Mohammad Hassan Hashemi ◽  
Amirhossein Babaei ◽  
...  

AbstractThe therapeutic effectiveness of a chitosan encapsulated bacteriophage cocktail as a smart biocontrol agent was evaluated in this study to be used as a preventative and treatment option for gastrointestinal infections. To evaluate the effect of the bacteriophage formulation on the treatment of gastrointestinal infection, rats were infected with Salmonella enterica, Shigella flexneri, and Escherichia coli. The rats were weighed and their stools cultured. The results showed that the group which had the chitosan encapsulated bacteriophage cocktail did not lose weight after 3 days and had significantly lower group weight changes. Weight loss was significant in the rats that had cefixime administered instead. Positive cultured stools were reduced after 4 days compared to 2 days in the treated group with the chitosan encapsulated bacteriophage cocktail. The chitosan encapsulated bacteriophage cocktail can therefore be effective in the treatment of gastrointestinal infections.


2001 ◽  
Vol 119 (2) ◽  
pp. 62-66 ◽  
Author(s):  
Anelise Bezerra de Vasconcelos ◽  
Gulnar Azevedo e Silva Mendonça ◽  
Rosely Sichieri

CONTEXT: The relationship between body size and breast cancer still remains controversial in considering menopausal status. OBJECTIVE: To evaluate the association of height, weight and weight changes with breast cancer in the city of Rio de Janeiro, Brazil. DESIGN: Case-control study. SETTING: National Cancer Institute (INCA), Rio de Janeiro, Brazil, and State University of Rio de Janeiro (UERJ). SAMPLE: 177 incident cases of invasive breast cancer admitted to the main hospital of INCA between May 1995 and February 1996, and 377 controls recruited from among female visitors to the same hospital. MAIN MEASUREMENTS: Height and weight were measured and information on maximum weight, weight at ages 18 and 30 years, and potential risk factors were ascertained by interview at the hospital. RESULTS: Height was not related to risk of breast cancer among both pre and postmenopausal women. Nevertheless, women in this study were shorter than in studies that have found a positive association. Premenopausal women in the upper quartile of recent body mass index (BMI) and maximum BMI showed a reduced risk of breast cancer (P for trend <= 0.03). Weight loss between ages 18 and 30 years and from 18 years to present was also associated with breast cancer among premenopausal women. CONCLUSIONS: These findings may merely indicate the known association between leanness and breast cancer. Further studies should explore the role of weight loss on breast cancer risk.


1991 ◽  
Vol 69 (3) ◽  
pp. 744-747 ◽  
Author(s):  
Lyle A. Renecker ◽  
W. M. Samuel

Growth rate and potential, 25 hand-reared mule deer (Odocoileus hemionus hemionus) were examined. When possible, body weights of all animals were recorded weekly. Female deer matured faster than males, but males attained a larger body size. Regressions of winter weight loss of both sexes on peak autumn weight were highly correlated. Similarly, spring and summer compensatory gain in females could be predicted from the minimum spring weight. Annual cycles of intake and weight gain may have adaptations that improve reproductive success and winter survival.


Revista CERES ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 360-367
Author(s):  
Fernanda Ferreira de Araújo ◽  
Lucas Cavalcante da Costa ◽  
Tania Pires da Silva ◽  
Mário Puiatti ◽  
Fernando Luiz Finger

ABSTRACT The purpose of this study was to evaluate the sensitivity and the physiological responses of summer squash ‘Menina Brasileira’ to ethylene. Immature fruits were harvested and placed in 20 L sealed buckets, in which ethylene was applied at concentrations of 0.1, 1.0, 10, 100, and 1000 μL L-1 for 24 h. Fruits were placed in buckets with no ethylene as a control treatment. Thereafter, the fruits were taken out of the buckets and maintained on bench, wherein on days 0, 2, 4, 6, and 8, they were evaluated regarding the accumulated fresh weight loss, soluble sugars, reducing and non-reducing sugars, starch, total chlorophyll, content of malondialdehyde, and electrolyte leakage. Fruits of summer squash ‘Menina Brasileira’ showed sensitivity to exogenous ethylene with no weight loss stimulation. Additionally, the fruits exhibited small changes in nutritional quality attributes and changes in the external fruit appearance, including decreased chlorophyll content as well as damage to cell membrane characterized by increase in malondialdehyde content and electrolyte leakage. These changes were stimulated by increasing exogenous ethylene concentration.


Author(s):  
Imēne Ben Salem ◽  
Mourad Rekik ◽  
Mohammed Ben Hamouda ◽  
Narjess Lassoued

The current study assessed the effect of the pattern of live weight change on the ovarian function of maiden Barbarine ewes at approximately 1 year of age. For this purpose, a total of 171 weaned ewe lambs (mean live weight  ± s.d. 34.7±3.07 kg and mean age ± SD 196±10 days at weaning) were selected for the experiment. Adjustment of live weight variation  was used. Based on the slope of the curve, animals were grouped into three classes LWCI (n=46),  LWCII (n=91) and LWCIII (n=34) with live weight loss being highest in LWCI and lowest in LWCIII.  Following laparoscopy at 13 months of age, the proportion of ewe lambs found cycling in LWCIII  (85.3%) was higher in comparison to animals in LWCI (43.4%; P<0.001) and tended to be superior to those in LWCII (61.5%; P<0.05). Following synchronisation with progestagen of the females found cycling, levels of plasma IGF-I concentrations between 6 and 42 hrs after removal of sponges were not significantly different between the three classes of live weight, and respectively averaged 94.2, 90.8 and 89.8 µg/l for LWCI, LWCII and LWCIII females. Levels of estradiol were also not significantly different between the three groups (0.73, 0.70 and 0.67 pg/ml for LWCI, LWCII and LWCIII ewe lambs, respectively). It was concluded that, in low input systems of semi-arid and arid Tunisia, mating ewe lambs at the approximate age of 1 year is likely to lead to depressed reproductive performance particularly when the summer live weight-loss is elevated. 


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Lorraine S Evangelista ◽  
David Heber ◽  
Zhaoping Li ◽  
Michele Hamilton ◽  
Gregg C Fonarow

OBJECTIVE: Clinical management of chronic heart failure (HF) related to adequate nutritional intake currently lacks a strong scientific basis. This study was conducted to evaluate the impact of 3 diet interventions on body weight and its potential to reduce cardiovascular risks and improve functional status. METHOD: Fourteen obese HF patients (BMI > 27 kg/m2) were randomized to1 of 3 diets: high protein (HP); low fat (LF) or average diet/control group (CG). Body anthropometrics (weight, BMI, waist circumference), indices of cardiovascular risks including (% body fat, blood pressure, cholesterol, triglycerides), and measures of functional status (6-minute walk, max VO2) were obtained at baseline and after a 12-week nutritional support program. Statistics included two-way RMANOVA. RESULTS: There were no significant differences in age (59±10 years), gender (78% male), NYHA (43% class II; 57% class III), HF etiology (57% non-ischemic), or ejection fraction (0.26±0.07) between the groups. The HP diet resulted in moderate reductions in body weight (Figure ) and improvements in several health parameters (Table ). CONCLUSION: The data show that in a small group of obese HF patients, a 12-week HP diet resulted in moderate weight loss that was associated with reduced cardiovascular risks and better functional status. However, the long-term effects of a HP diet remain uncertain. Figure Comparison of Weight Changes in the HP, LF and CG from Baseline to 12 Weeks Mean changes in outcomes from baseline to 12 weeks, by diet group and time


2017 ◽  
Vol 34 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Diane DiTomasso ◽  
Andrea L. Paiva

Background: Weight changes in the early weeks of life are important indicators of newborn wellness. Yet, little is known about weight loss patterns for breastfeeding newborns. Research aim: This study aimed to compare weight changes and exclusive breastfeeding rates in newborns who lost ≤ 7% and > 7% of their body weight after birth. Methods: A prospective, observational cohort study was completed. Newborns who lost ≤ 7% made up Group 1 and newborns who lost > 7% of birth weight made up Group 2. Mothers used a digital scale to weigh their newborns daily until 14 days of life. Newborn intake and outputs were also recorded. Results: Mean (with standard deviation in parentheses) weight loss for all newborns ( N = 151) was 7.68% (2.35%). Newborns in Group 1 ( n = 67) lost 5.7% (0.99%) and newborns in Group 2 lost 9.3% (1.87%). More than half of healthy, full-term newborns (56%) lost > 7%. On Day 14, the exclusive breastfeeding rate for newborns in Group 2 was significantly less than for those in Group 1 (60% vs. 82%; p = .033). Newborns gained a mean of 1.1% body weight daily; those in Group 1 gained 1.2% daily, and those in Group 2 gained 1.0% daily. Conclusion: Weight loss > 7% may be a normal phenomenon among breastfeeding newborns. Newborns who lost > 7% had a lower exclusive breastfeeding rate at 2 weeks of age. After the weight nadir was reached, most newborns gained weight at a similar pace, despite differences in early weight loss.


Sign in / Sign up

Export Citation Format

Share Document