Carbohydrate supplementation improves time-trial cycle performance during energy deficit at 4,300-m altitude

2005 ◽  
Vol 99 (3) ◽  
pp. 867-876 ◽  
Author(s):  
C. S. Fulco ◽  
K. W. Kambis ◽  
A. L. Friedlander ◽  
P. B. Rock ◽  
S. R. Muza ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Energy Balance ◽  
Time Trial ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Cycle Performance ◽  
Double Blind ◽  
Carbohydrate Supplementation ◽  
Carbohydrate Solution

Carbohydrate supplementation (CHOS) typically improves prolonged time-trial (TT) performance at sea level (SL). This study determined whether CHOS also improves TT performance at high altitude (ALT; 4,300 M) despite increased hypoxemia and while in negative energy balance (∼1,250 kcal/day). Two groups of fasting, fitness-matched men performed a 720-kJ cycle TT at SL and while living at ALT on days 3 (ALT3) and 10 (ALT10). Eight men drank a 10% carbohydrate solution (0.175 g/kg body wt) and eight drank a placebo (PLA; double blind) at the start of and every 15 min of the TT. Blood glucose during each TT was higher ( P < 0.05) for CHOS than for PLA. At SL, TT duration (∼59 min) and watts (∼218 or ∼61% of peak watts; %SL Wpeak) were similar for both groups. At ALT, the TT was longer for both groups ( P < 0.01) but was shorter for CHOS than for PLA on ALT3 (means ± SE: 80 ± 7 vs. 105 ± 9 min; P < 0.01) and ALT10 (77 ± 7 vs. 90 ± 5 min; P < 0.01). At ALT, %SL Wpeak was reduced ( P < 0.01) with the reduction on ALT3 being larger for PLA (to 33 ± 3%) than for CHOS (to 43 ± 2%; P < 0.05). On ALT3, O2 saturation fell similarly from 84 ± 2% at rest to 73 ± 1% during the TT for both groups ( P < 0.05), and on ALT10 O2 saturation fell more ( P < 0.02) for CHOS (91 ± 1 to 76 ± 2%) than for PLA (90 ± 1 to 81 ± 1%). %SL Wpeak and O2 saturation were inversely related during the TT for both groups at ALT ( r ≥ −0.76; P ≤ 0.03). It was concluded that, despite hypoxemia exacerbated by exercise, CHOS greatly improved TT performance at ALT in which there was a negative energy balance.

scholarly journals Lipoprotein Subclass Profile after Progressive Energy Deficits Induced by Calorie Restriction or Exercise

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1814 ◽  
Author(s):  
Yu Chooi ◽  
Cherlyn Ding ◽  
Zhiling Chan ◽  
Jezebel Lo ◽  
John Choo ◽  
...  
Keyword(s):  
Energy Balance ◽  
Aerobic Exercise ◽  
Calorie Restriction ◽  
Plasma Concentrations ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Dependent Manner ◽  
Blood Lipid Profile ◽  
Diet And Exercise

Weight loss, induced by chronic energy deficit, improves the blood lipid profile. However, the effects of an acute negative energy balance and the comparative efficacy of diet and exercise are not well-established. We determined the effects of progressive, acute energy deficits (20% or 40% of daily energy requirements) induced by a single day of calorie restriction (n = 19) or aerobic exercise (n = 13) in healthy subjects (age: 26 ± 9 years; body mass index (BMI): 21.8 ± 2.9 kg/m2). Fasting plasma concentrations of very low-, intermediate-, low-, and high-density lipoprotein (VLDL, LDL, IDL, and HDL, respectively) particles and their subclasses were determined using nuclear magnetic resonance. Total plasma triglyceride and VLDL-triglyceride concentrations decreased after calorie restriction and exercise (all p ≤ 0.025); the pattern of change was linear with an increasing energy deficit (all p < 0.03), with no evidence of plateauing. The number of circulating large and medium VLDL particles decreased after diet and exercise (all p < 0.015), with no change in small VLDL particles. The concentrations of IDL, LDL, and HDL particles, their relative distributions, and the particle sizes were not altered. Our data indicate that an acute negative energy balance induced by calorie restriction and aerobic exercise reduces triglyceride concentrations in a dose-dependent manner, by decreasing circulating large and medium VLDL particles.

scholarly journals Metabolic adaptations during negative energy balance and their potential impact on appetite and food intake

2019 ◽  
Vol 78 (3) ◽  
pp. 279-289 ◽  
Author(s):  
Nuno Casanova ◽  
Kristine Beaulieu ◽  
Graham Finlayson ◽  
Mark Hopkins
Keyword(s):  
Weight Loss ◽  
Energy Balance ◽  
Food Intake ◽  
Negative Energy ◽  
Fat Free Mass ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Behavioural Responses ◽  
Compensatory Responses ◽  
Metabolic Adaptations

This review examines the metabolic adaptations that occur in response to negative energy balance and their potential putative or functional impact on appetite and food intake. Sustained negative energy balance will result in weight loss, with body composition changes similar for different dietary interventions if total energy and protein intake are equated. During periods of underfeeding, compensatory metabolic and behavioural responses occur that attenuate the prescribed energy deficit. While losses of metabolically active tissue during energy deficit result in reduced energy expenditure, an additional down-regulation in expenditure has been noted that cannot be explained by changes in body tissue (e.g. adaptive thermogenesis). Sustained negative energy balance is also associated with an increase in orexigenic drive and changes in appetite-related peptides during weight loss that may act as cues for increased hunger and food intake. It has also been suggested that losses of fat-free mass (FFM) could also act as an orexigenic signal during weight loss, but more data are needed to support these findings and the signalling pathways linking FFM and energy intake remain unclear. Taken together, these metabolic and behavioural responses to weight loss point to a highly complex and dynamic energy balance system in which perturbations to individual components can cause co-ordinated and inter-related compensatory responses elsewhere. The strength of these compensatory responses is individually subtle, and early identification of this variability may help identify individuals that respond well or poorly to an intervention.

scholarly journals ENERGY BALANCE AND VITAL SIGNS IN PEDIATRIC PATIENTS

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0020
Author(s):  
Julie A. Young ◽  
Jessica Napolitano ◽  
Mitchell J. Rauh ◽  
Jeanne Nichols ◽  
Anastasia N. Fischer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Vital Signs ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Energy Deficiency ◽  
Males And Females

BACKGROUND: Prior studies have shown that vital signs such as heart rate, blood pressure and body temperature are depressed in patients with an eating disorder who have experienced a negative energy balance for a significant amount of time. More recently, a negative energy balance has been the focus of Relative Energy Deficiency in Sport (RED-S), which links energy availability to the health of multiple body systems in adults in as little as 5 days with a negative energy balance. High rates of disordered eating patterns have been reported in high school athletes. As adolescents grow, the consequences of a negative energy balance can be significant and potentially irreversible. Thus, vital signs may help clinicians quickly evaluate a patient’s energy status or highlight them for further evaluation. PURPOSE: The purpose of this study was to examine energy balance and vital signs in a cohort of adolescents who were seen by a sports dietitian to gain weight or optimize sports performance. METHODS: We evaluated 240 subjects, 83% female, average age 15.0±2.3 years. Heart rate and blood pressure were measured with a dynamometer in a seated position. Body temperature was measured orally. Height and weight were recorded. BMI was then calculated and evaluated by percentile. Energy intake was assessed using a 3-day food recall log. Energy expenditure was calculated using Harris Benedict Equation and combined with estimated exercise energy expenditure. Energy balance was estimated as energy intake minus energy expenditure. RESULTS: Average age was 15.03±2.71. 85% were female. 30% were below the 15th percentile for BMI. There were no differences in BMI percentiles between males and females (p=0.99). The average heart rate was 71.62±13.4 bpm and 19% were below the 10th percentile for heart rate. Average systolic blood pressure was 110±11 mm Hg and average diastolic blood pressure was 62±7 mmHg. Average temperature was 98.1±.4 degrees F. 88%were in a negative energy balance with an average energy deficit of 552±511 calories. There were no statistically significant differences in energy balance between males and females (p=0.08). CONCLUSIONS: A disproportional number of children with low BMI and heart rate percentiles was observed, which may indicate a long-standing energy deficiency. We also found a high proportion of adolescents who experienced a standalone negative energy balance itself or vital signs consistent with a negative energy balance. Additional studies are needed to study the relationships between energy deficit magnitude and duration in adolescents and children.

Relationships between energy balance and health traits of dairy cattle in early lactation

1999 ◽  
Vol 24 ◽  
pp. 171-175 ◽  
Author(s):  
B. L. Collard ◽  
P. J. Boettcher ◽  
J. C. M. Dekkers ◽  
L. R. Schaeffer ◽  
D. Petitclerc
Keyword(s):  
Energy Balance ◽  
Food Intake ◽  
Total Energy ◽  
Milk Production ◽  
Additive Genetic Variance ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Research Station ◽  
Daily Energy

AbstractData were records of daily food intake and milk production, periodic measures of milk composition and all health and reproductive information from 140 multiparous Holstein cows involved in various experiments at the Agriculture Canada dairy research station in Lennoxville, Quebec. Energy concentrations of the total mixed rations were also available. Daily energy balance was calculated by multiplying the food intake by the concentration of energy in the diet and then subtracting from this quantity the expected (National Research Council) amount of energy required for maintenance (based on parity and body weight) and for milk production (based on yield and concentrations of fat, protein and lactose). Four energy balance traits were defined: (1) average daily energy balance within the first 10 to 100 days of lactation, (2) minimum daily energy balance, (3) days in negative energy balance and (4) total energy deficit during the period of negative energy balance. Health traits were the numbers of incidences of each of the following: (1) all udder problems, (2) mastitis, (3) all locomotive problems, (4) laminitis, (5) digestive problems and (6) reproductive problems. Reproductive traits were the number of days to first observed oestrous and number of inseminations. Phenotypic relationships between energy balance and health were investigated by regressing the energy balance traits on each health trait. Parity and treatment (according to the research trial that the cow was involved with) were also included in the model. Genetic parameters were estimated with restricted maximum likelihood and a model that included effects of parity, treatment and animal. Phenotypically, several significant (P<0.10) relationships between energy balance and health were observed. Cows with longer periods of negative energy balance had increased digestive problems. Cows with greater total energy deficit had more digestive problems and laminitis. Estimates of heritabilities for energy intake and milk energy were 0.42 and 0.12, respectively but estimates of heritability for all energy balance traits were zero. The low estimates for these traits may have been due to (1) low true additive genetic variance, (2) small amount of data, or (3) relatively few genetic ties among cows.

scholarly journals Insulin restores GH responsiveness during lactation-induced negative energy balance in dairy cattle: effects on expression of IGF-I and GH receptor 1A

2003 ◽  
Vol 176 (2) ◽  
pp. 205-217 ◽  
Author(s):  
ST Butler ◽  
AL Marr ◽  
SH Pelton ◽  
RP Radcliff ◽  
MC Lucy ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Blood Glucose ◽  
Energy Balance ◽  
Dairy Cattle ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Mrna Levels ◽  
Hepatic Expression ◽  
Gh Receptor ◽  
Igf I

Early lactation in dairy cattle is a period of severe negative energy balance (NEB) characterized by reduced blood glucose and insulin concentrations and elevated blood GH concentrations. The liver is refractory to GH during NEB and this uncoupling of the GH-IGF axis results in diminished plasma concentrations of IGF-I. Our objectives were to examine the effects of insulin administration during the immediate postpartum period on plasma IGF-I and GH concentrations and to examine the hepatic expression of total GH receptors (all GH receptor transcripts), GH receptor 1A (GHR 1A) and IGF-I. In addition, we examined adipose tissue for total GH receptor and IGF-I mRNA levels to establish the effects of chronic hyperinsulinemia on an insulin-responsive peripheral tissue. Holstein cows (n=14) were subjected to either a hyperinsulinemic-euglycemic clamp (insulin; INS) or saline infusion (control; CTL) for 96 h starting on day 10 postpartum. Insulin was infused i.v. (1 micro g/kg body weight per h), blood samples were collected hourly, and euglycemia was maintained by infusion of glucose. Insulin concentrations during the infusions were increased 8-fold in INS compared with CTL cows (2.33+/-0.14 vs 0.27+/-0.14 ng/ml (S.E.M.); P<0.001) while blood glucose concentrations were not different between treatments (45.3+/-2.2 vs 42.5+/-2.2 mg/dl; P>0.1). Plasma IGF-I increased continuously during the insulin infusion, and reached the highest concentrations at the end of the clamp, being almost 4-fold higher in INS compared with CTL cows (117+/-4 vs 30+/-4 ng/ml; P<0.001). Hepatic expression of GHR 1A and IGF-I mRNA was low in CTL cows, but was increased 3.6-fold (P<0.05) and 6.3-fold (P<0.001) respectively in INS cows. By contrast, in adipose tissue the changes in gene expression in response to insulin were reversed with decreases in both total GHR and IGF-I mRNA. The expressions of GHR 1A and IGF-I mRNA in liver tissue were correlated in INS (r=0.86; P<0.05), but not CTL cows (r=0.43; P>0.1). Insulin appears to be a key metabolic signal in coupling the GH-IGF axis, thus orchestrating a marked elevation in circulating IGF-I concentrations.

scholarly journals Negative energy balance alters global gene expression and immune responses in the uterus of postpartum dairy cows

2009 ◽  
Vol 39 (1) ◽  
pp. 1-13 ◽  
Author(s):  
D. Claire Wathes ◽  
Zhangrui Cheng ◽  
Waliul Chowdhury ◽  
Mark A. Fenwick ◽  
Richard Fitzpatrick ◽  
...  
Keyword(s):  
Energy Balance ◽  
Inflammatory Response ◽  
Dairy Cows ◽  
Global Gene Expression ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Nonesterified Fatty Acid ◽  
Canonical Pathways ◽  
Time Required

Most dairy cows suffer uterine microbial contamination postpartum. Persistent endometritis often develops, associated with reduced fertility. We used a model of differential feeding and milking regimes to produce cows in differing negative energy balance status in early lactation (mild or severe, MNEB or SNEB). Blood hematology was assessed preslaughter at 2 wk postpartum. RNA expression in endometrial samples was compared using bovine Affymetrix arrays. Data were mapped using Ingenuity Pathway Analysis. Circulating concentrations of IGF-I remained lower in the SNEB group, whereas blood nonesterified fatty acid and β-hydroxybutyrate concentrations were raised. White blood cell count and lymphocyte number were reduced in SNEB cows. Array analysis of endometrial samples identified 274 differentially expressed probes representing 197 recognized genes between the energy balance groups. The main canonical pathways affected related to immunological and inflammatory disease and connective tissue disorders. Inflammatory response genes with major upregulation in SNEB cows included matrix metalloproteinases, chemokines, cytokines, and calgranulins. Expression of several interferon-inducible genes including ISG20, IFIH1, MX1, and MX2 were also significantly increased in the SNEB cows. These results provide evidence that cows in SNEB were still undergoing an active uterine inflammatory response 2 wk postpartum, whereas MNEB cows had more fully recovered from their energy deficit, with their endometrium reaching a more advanced stage of repair. SNEB may therefore prevent cows from mounting an effective immune response to the microbial challenge experienced after calving, prolonging the time required for uterine recovery and compromising subsequent fertility.

scholarly journals Decreased concentration of plasma leptin in periparturient dairy cows is caused by negative energy balance

2001 ◽  
Vol 171 (2) ◽  
pp. 339-348 ◽  
Author(s):  
SS Block ◽  
WR Butler ◽  
RA Ehrhardt ◽  
AW Bell ◽  
ME Van Amburgh ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Energy Balance ◽  
Dairy Cows ◽  
Plasma Concentrations ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Energy Deficit ◽  
Gradual Improvement ◽  
Maternal Metabolism ◽  
Plasma Leptin

Dairy cows suffer from an intense energy deficit at parturition due to the onset of copious milk synthesis and depressed appetite. Despite this deficit, maternal metabolism is almost completely devoted to the support of mammary metabolism. Evidence from rodents suggests that, during periods of nutritional insufficiency, a reduction in plasma leptin serves to co-ordinate energy metabolism. As an initial step to determine if leptin plays this role in periparturient dairy cows, changes in the plasma concentration of leptin were measured during the period from 35 days before to 56 days after parturition. The plasma concentration of leptin was reduced by approximately 50% after parturition and remained depressed during lactation despite a gradual improvement in energy balance; corresponding changes occurred in the abundance of leptin mRNA in white adipose tissue. To determine whether negative energy balance caused this reduction in circulating leptin, cows were either milked or not milked after parturition. Absence of milk removal eliminated the energy deficit of early lactation, and doubled the plasma concentration of leptin. The plasma concentration of leptin was positively correlated with plasma concentrations of insulin and glucose, and negatively correlated with plasma concentrations of growth hormone and non-esterified fatty acids. In conclusion, the energy deficit of periparturient cows causes a sustained reduction in plasma leptin. This reduction could benefit early lactating dairy cows by promoting a faster increase in feed intake and by diverting energy from non-vital functions such as reproduction.

Caffeine and carbohydrate supplementation during exercise when in negative energy balance: effects on performance, metabolism, and salivary cortisol

2008 ◽  
Vol 33 (6) ◽  
pp. 1079-1085 ◽  
Author(s):  
Dustin Slivka ◽  
Walter Hailes ◽  
John Cuddy ◽  
Brent Ruby
Keyword(s):  
Energy Balance ◽  
Salivary Cortisol ◽  
Vastus Lateralis ◽  
Saliva Sample ◽  
Time Trial ◽  
Random Order ◽  
Negative Energy ◽  
The Other ◽  
Negative Energy Balance ◽  
Positive Energy

The ingestion of carbohydrate (+CHO) and caffeine (+CAF) during exercise is a commonly used ergogenic practice. Investigations are typically conducted with subjects who are in a rested state after an overnight fast. However, this state of positive energy balance is not achieved during many work and exercise circumstances. The aim of this study was to evaluate the substrate use and performance effects of caffeine and carbohydrate consumed alone and in combination while participants were in negative energy balance. Male participants (n = 9; 23 ± 3 years; 74.1 ± 10.6 kg) completed 4 trials in random order: –CAF/–CHO, –CAF/+CHO, +CAF/–CHO, and +CAF/+CHO. Diet and exercise were prescribed for 2 days before each trial to ensure negative energy balance. For each trial, before and after 2 h of cycling at 50% of maximal watts, a saliva sample and a muscle biopsy (vastus lateralis) were obtained. A simulated 20 km time trial was then performed. The respiratory exchange ratio was higher (p < 0.05) in +CHO trials and lower (p < 0.05) in the +CAF/+CHO trial than in the –CAF/+CHO trial. Salivary cortisol response was higher (p < 0.05) in the +CAF/–CHO trial than in any of the other trials. Muscle glycogen and heart rates were similar in all trials. Performance in the 20 km time trial was better in the –CAF/+CHO trial than in the –CAF/–CHO trial (p < 0.05), but the +CAF/+CHO trial was no better than the +CAF/–CHO trial (p > 0.05), or any of the other trials. When co-ingested with carbohydrate, caffeine increased fat use and decreased nonmuscle glycogen carbohydrate use over carbohydrate alone when participants are in negative energy balance; however, caffeine had no effect on the 20 km cycling time trial performance.

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