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Title: The Relationship between Moderate, Within Day Protein Intake and Energy Balance on Body Composition of Collegiate Sand Volleyball Players Background: Achieving an ideal body composition with relatively low fat mass and relatively high fat-free mass (FFM) is desirable for virtually all competitive athletes. Some studies suggest that protein intake, depending on quality, amount, and timing, may improve relative musculature by stimulating muscle protein synthesis, but some issues related to timing and amount of protein intake remain unclear. Current evidence suggests that frequent consumption of moderate amounts of protein is useful for muscle building. Purpose: The purpose of this study was to simultaneously assess energy balance and protein intake to determine if these factors are associated with body composition in a population of collegiate sand volleyball players. Methods: In a cross sectional, observational study, players completed a food intake and activity form for a 24-hour period to serve as the basis of energy balance and protein intake assessment. The assessment day was representative of a typical day during the regular training season. These data were entered into a software program providing total and hourly energy balance and nutrient content of the consumed foods. Athletes were measured for body composition via a multi-current bioelectrical impedance scale to predict weight, BMI, fat mass and fat free mass. Height was measured using a standard wall-mounted stadiometer. Data analyses included descriptive and frequency statistics, Spearman correlations and regression analyses. Results: Twelve women from the GSU sand volleyball team participated in the study using an IRB-approved protocol. The mean BMI was 22 kg/m2 (±3 kg/m2) and the mean body fat percentage was 18% (±7%). The mean protein intake for all participants was 132 grams (±52 g). Protein intake distribution was skewed, on average, toward the latter half of the day with approximately 19% of protein consumed in the morning and 34% consumed in the evening. The mean net energy balance at the end of the 24-hour assessment period was -404 (±385) kcal. Athletes, on average, spent 17 hours in a catabolic energy balance state (< 0 kcal). No significant correlation was found between energy balance per gram of protein consumption and body composition. However, regression analyses indicated that energy balance and protein variables explain a significant proportion (p=.037) of the variance in body fat percentage. Conclusions: Sand volleyball players in this study spent a high proportion of time in a negative energy balance, which may have compromised the potential benefit that frequent protein consumption may have had on FFM. Since both energy balance and protein explain a significant proportion of the variance in body composition, these athletes might benefit from improving within-day energy balance as a strategy for optimizing body composition.

Early research with beta-alanine (beta-ALA) supplementation has shown increases in muscle carnosine as well as improvements in body composition, exercise performance and blood lactate levels. Creatine monohydrate supplementation has been extensively researched for its effects on anaerobic exercise performance. Recently, a new line of studies have examined the combined effects beta-ALA and creatine supplementation on anaerobic exercise performance and lactate threshold. The purpose of the present study is to examine the acute and chronic effects of beta-ALA supplementation with and without creatine monohydrate on body composition, aerobic and anaerobic exercise performance, and muscle carnosine and phosphagen levels in college-aged recreationally active females. Thirty-two females were randomized in a double-blind placebo controlled manner into one of four supplementation groups including beta-ALA only, creatine only, beta-ALA and creatine combined and placebo. Participants supplemented for four weeks and reported for testing at baseline, day 7 and day 28. Testing sessions consisted of a resting muscle biopsy of the vastus lateralis, body composition measurements, a graded exercise test on the cycle ergometer for VO2max and lactate threshold, and multiple Wingate tests for anaerobic exercise performance. Results showed all supplementation strategies increasing muscle carnosine levels over placebo after four weeks, but not between groups. Muscle creatine increased for all groups after four weeks, but not between groups. There were improvements for all groups with body composition after four weeks, despite the present study not including a specific training protocol. There were no group differences observed for aerobic exercise, blood lactate levels, lactate threshold, ventilatory threshold, peak power, mean power, total work or rate of fatigue. There were some trends for anaerobic exercise indicating groups supplementing with creatine may have greater improvements, however, these findings were not statistically significant. The present study failed to show any additive effects of beta-ALA and creatine supplementation for body composition, aerobic exercise, lactate threshold or anaerobic exercise measures. This could be due to the small sample size resulting in low power and effect sizes. Previous research has demonstrated that four weeks of beta-ALA and creatine supplementation was enough time to increase muscle carnosine and phosphagen levels. However, perhaps more time is needed for performance adaptations to occur, especially without the addition of an exercise training component.

The objective of this research was to study relationship(s) of ethnicity, physical activity and diet with adiposity development in Aboriginal youth. To meet this objective, three separate, yet inter-related studies were undertaken: 1) to comprehensively assess adiposity in Aboriginal youth and their age, sex and maturity matched Caucasian peers; 2) to assess the role of ethnicity and sex on physical activity (PA) levels and identify the proportion of Aboriginal youth meeting international recommendations; and 3) to explore relationships of ethnicity, physical activity and diet with adiposity. In study one, it was hypothesized that Aboriginal youth would have greater adiposity than their Caucasian peers. While much of the research to date has focused on body mass index, this investigation used DXA and waist circumference to show that Aboriginal youth had greater total and central adiposity in comparison to their Caucasian counterparts.<p> Study two examined physical activity behaviors of Canadian Aboriginal youth in relation to ethnicity and sex. It was hypothesized that the physical activity levels of Aboriginal youth would be lower than their Caucasian peers; that the majority of Aboriginal youth would not meet PA and T.V. viewing recommendations; and that Aboriginal boys would have higher adjusted physical activity energy expenditures than girls. Findings indicated that physical activity levels of the two ethnic groups were generally comparable, that Aboriginal boys had greater activity energy expenditures than girls, and that a greater percentage of boys were meeting the international recommendations for physical activity and T.V. viewing. Study three built upon the first two investigations, to explore relationships of physical activity and diet with adiposity in Aboriginal youth. It was hypothesized that when age, size and maturity, and their interactions were accounted for, diet and physical activity variables would be related to adiposity (waist circumference, total body and trunk fatness). Results indicated physical activity was inversely related to adiposity level, independent of biological factors. Although energy intake was the sole dietary variable related to the adiposity measures, descriptives showed the eating behaviors (i.e., consumption of fruits and vegetables, sugar sweetened beverages and other foods) of the Aboriginal youth were sub-optimal when compared to current recommendations. This research project is unique because it comprehensively assessed adiposity, diet and physical activity, and the relationships between these variables, in a relatively large sample of Aboriginal boys and girls. Furthermore, these relationships were established using a variety of measures (i.e., DXA, waist circumference, height and weight) while controlling for biological confounders. Overall, the results highlight the urgent need to promote physical activity and healthy eating in Aboriginal youth and set the stage for future research.

BACKGROUND: Breast cancer patients typically present with unhealthy body composition (high fat mass and low muscularity) near diagnosis. These body composition characteristics often worsen during treatment and ultimately contribute to the development of secondary diseases like diabetes and cardiovascular disease in survivorship. Inflammation in overweight or obese individuals is associated with impaired glucose metabolism; the presence of the tumour may lead to greater impairments in glucose metabolism in breast cancer patients. OBJECTIVES AND HYPOTHESES: The objectives of this study were to: 1) evaluate breast cancer patients near the onset of treatment for metabolic measures including an oral glucose tolerance test (OGTT), cytokine profiles, as well as body composition, nutritional status and fitness and, 2) make comparisons between breast cancer patients, age- and BMI-matched females (HM females), and a group of young, non-malignant females with healthy BMIs (HY females) on these measures. We hypothesized that breast cancer patients would demonstrate impaired glucose metabolism relative to HM females, and that this would be attributed to systemic inflammation. We also hypothesized that both breast cancer patients and HM females would present with unhealthy body composition, impaired glucose and lipid metabolism, systemic inflammation, poor fitness and greater caloric intake compared to HY females. METHODS: We evaluated body composition using % body fat (skinfold callipers) and waist circumference. Following collection of fasting blood samples, an OGTT was conducted to assess glucose, insulin, c-peptide and glucagon dynamics. Fasting blood samples were analysed for lipids and pro- and anti-inflammatory cytokines. Incremental exercise tests were conducted to assess VO2peak, and estimated 1-RM tests assessed strength of the biceps, triceps and quadriceps muscles. Baecke and CHAMPS questionnaires provided an indication of habitual physical activity. A 3-day food record was used to analyze daily caloric intake and macronutrient distribution. Breast cancer patients and HM females were compared using paired t-tests. Patients and HM females were compared to HY females using t-tests. Statistical significance was accepted at p < 0.05. RESULTS: Overall, breast cancer patients were overweight (BMI: 28.8 ± 6.0 kg/m2) and presented with abdominal obesity (waist circumference: 94.6 ± 14.0 cm) and dyslipidemia (TAG: 1.84 ± 1.17 mM and HDL-c: 1.08 ± 0.23 mM), indicating risk for metabolic syndrome. Although fasting glucose concentrations did not differ between the 3 groups, breast cancer patients demonstrated higher glucose concentrations at 30 min during an OGTT. Similar to glucose, fasting insulin concentrations did not differ between the 3 groups, but patients demonstrated higher insulin at 150 min during an OGTT. Breast cancer patients had elevated fasting serum c-peptide (2.6 ± 1.2 ng/mL vs. 1.9 ± 0.8 ng/mL, p = 0.005). C-peptide remained elevated in patients compared to non-malignant females during the last hour of the OGTT, indicating that insulin secretion was sustained in breast cancer patients. We observed no difference in serum cytokines between patients and HM females or between patients and HY females. VO2peak, although lower compared to HY females, was similar in patients and HM females. There were no differences in habitual physical activity or nutrition measures between any groups. DISCUSSION AND CONCLUSIONS: Breast cancer patients presented with poorer glucose features during an OGTT compared to HM and HY females. However, systemic inflammation, body composition, energy expenditure and energy intake were similar in breast cancer patients and HM females. Thus, these impairments may be tumour-related. Future studies need to specifically elucidate the effects of the tumour in host glucose metabolism.

Background: Persons who sustain a spinal cord injury (SCI) experience a dramatic loss of muscle and bone, and a dramatic increase in adipose tissue. It has been suggested that the muscle atrophy, obesity, and sublesional osteoporosis (SLOP) that occurs after SCI is due in part to the loss of voluntary control of the skeletal muscles in the lower extremities, impaired energy metabolism below the level of the lesion, and cessation of sufficient mechanical strain on bone. The prevalence of obesity and SLOP after SCI leads to increased cardiovascular disease and fracture risk, respectively. Current body composition screening procedures for the general population fail to identify individuals with SCI who are obese or have SLOP. Muscle contractions provide physiological loads on bone; thereby a muscle-bone relationship is proposed with proportional declines in muscle and bone after SCI. In addition, both positive and negative relationships have been proposed between adipose tissue and bone; increased skeletal load bearing from excess adipose tissue mass may account for the positive associations reported to date. Due to a lack of load bearing activity after SCI, there should be a negative association between adipose tissue and bone. Objectives: The primary objective is to characterize body composition among adults with chronic SCI using valid, reliable, and interpretable measures, and to suggest screening procedures for the detection of obesity and SLOP in this population. The secondary objectives are to explore the associations between: 1) muscle and bone, and 2) adipose tissue and bone. Design and Setting: Cross sectional observational. Population: A sample of 16 individuals (13 men, 3 women) with chronic SCI participated in this study. The neurological level of lesion ranged from C3-T12, with 9 motor complete and 7 incomplete SCI. Average±standard deviation for age was 51.12±12.37 years, and duration of injury 16.5±7.87 years. An additional 29 individuals with chronic SCI were included when exploring the relationship between muscle and bone. Forty-one individuals (31 men, 9 women) were included in this analysis; the neurological level of lesion ranged from C2-T12, with 13 motor complete and 28 incomplete SCI. Average±standard deviation for age was 48.7±13.36 years, and duration of injury 114.22±10.4 years. Methods: Lean tissue, adipose tissue, and bone tissue were measured via surrogates of body adiposity, as well as two different scanning technologies. Lean tissue was assessed via muscle cross sectional area (CSA) (mm2) and muscle density (mg/cm3), and measured using peripheral quantitative computed tomography (pQCT). Adipose tissue was assessed via body mass index (BMI) (kg/m2), waist circumference (WC) (cm), and % body fat, and measured using a floor scale, tape measure, and dual energy x-ray absorptiometry (DXA), respectively. Bone tissue was assessed via hip, distal femur, and proximal tibia areal bone mineral density (aBMD) (g/cm2) using DXA, as well as cortical thickness (mm) and total volumetric bone mineral density (vBMD) (mg/cm3) at the 1/3 proximal tibia, and trabecular vBMD (mg/cm3) and total vBMD (mg/cm3) at the distal tibia using pQCT. The relationships between muscle and bone, and adipose tissue and bone, were determined by correlating muscle CSA with indices of bone strength, and indices of obesity with indices of SLOP, respectively. Results: The majority of participants had lean tissue values below able-bodied norms (67-100%). When using the able-bodied definition of BMI >30 kg/m2, 19% of individuals were obese, whereas 63% and 81% were obese when using SCI-specific definitions of BMI >25 kg/m2 or >22 kg/m2, respectively. One hundred percent of individuals had SLOP using distal femur Z-score, and over 50% were at risk of fracture using distal femur fracture threshold of <0.78 g/cm2. Weak (r=0.42) to moderate (r=0.57) correlations were found between muscle CSA and indices of bone strength, supporting the theory of a muscle-bone unit. No correlations were found between adipose tissue and bone. Conclusions: Based on the cohort data, we propose that individuals with ≥2 risk factors (female, ≥60 years of age, duration of injury (DOI) ≥10, tetraplegia, motor complete) should be screened for obesity using % body fat from DXA as well as a combination of carefully interpreted SCI-specific BMI and WC. In addition, these same individuals should be screened for SLOP using a distal femur Z-score and fracture threshold from DXA. It is clear that due to the prevalence of obesity and SLOP in this population, intervention for prevention or treatment is essential. The presence of a muscle-bone unit indicates that muscle atrophy contributes to a reduction in bone strength; this is clinically important, as muscle strength is potentially amenable to rehabilitation intervention. No correlation was found between adipose tissue and bone. Future work should continue to explore these relationships using appropriate technology.

Background: Persons who sustain a spinal cord injury (SCI) experience a dramatic loss of muscle and bone, and a dramatic increase in adipose tissue. It has been suggested that the muscle atrophy, obesity, and sublesional osteoporosis (SLOP) that occurs after SCI is due in part to the loss of voluntary control of the skeletal muscles in the lower extremities, impaired energy metabolism below the level of the lesion, and cessation of sufficient mechanical strain on bone. The prevalence of obesity and SLOP after SCI leads to increased cardiovascular disease and fracture risk, respectively. Current body composition screening procedures for the general population fail to identify individuals with SCI who are obese or have SLOP. Muscle contractions provide physiological loads on bone; thereby a muscle-bone relationship is proposed with proportional declines in muscle and bone after SCI. In addition, both positive and negative relationships have been proposed between adipose tissue and bone; increased skeletal load bearing from excess adipose tissue mass may account for the positive associations reported to date. Due to a lack of load bearing activity after SCI, there should be a negative association between adipose tissue and bone. Objectives: The primary objective is to characterize body composition among adults with chronic SCI using valid, reliable, and interpretable measures, and to suggest screening procedures for the detection of obesity and SLOP in this population. The secondary objectives are to explore the associations between: 1) muscle and bone, and 2) adipose tissue and bone. Design and Setting: Cross sectional observational. Population: A sample of 16 individuals (13 men, 3 women) with chronic SCI participated in this study. The neurological level of lesion ranged from C3-T12, with 9 motor complete and 7 incomplete SCI. Average±standard deviation for age was 51.12±12.37 years, and duration of injury 16.5±7.87 years. An additional 29 individuals with chronic SCI were included when exploring the relationship between muscle and bone. Forty-one individuals (31 men, 9 women) were included in this analysis; the neurological level of lesion ranged from C2-T12, with 13 motor complete and 28 incomplete SCI. Average±standard deviation for age was 48.7±13.36 years, and duration of injury 114.22±10.4 years. Methods: Lean tissue, adipose tissue, and bone tissue were measured via surrogates of body adiposity, as well as two different scanning technologies. Lean tissue was assessed via muscle cross sectional area (CSA) (mm2) and muscle density (mg/cm3), and measured using peripheral quantitative computed tomography (pQCT). Adipose tissue was assessed via body mass index (BMI) (kg/m2), waist circumference (WC) (cm), and % body fat, and measured using a floor scale, tape measure, and dual energy x-ray absorptiometry (DXA), respectively. Bone tissue was assessed via hip, distal femur, and proximal tibia areal bone mineral density (aBMD) (g/cm2) using DXA, as well as cortical thickness (mm) and total volumetric bone mineral density (vBMD) (mg/cm3) at the 1/3 proximal tibia, and trabecular vBMD (mg/cm3) and total vBMD (mg/cm3) at the distal tibia using pQCT. The relationships between muscle and bone, and adipose tissue and bone, were determined by correlating muscle CSA with indices of bone strength, and indices of obesity with indices of SLOP, respectively. Results: The majority of participants had lean tissue values below able-bodied norms (67-100%). When using the able-bodied definition of BMI >30 kg/m2, 19% of individuals were obese, whereas 63% and 81% were obese when using SCI-specific definitions of BMI >25 kg/m2 or >22 kg/m2, respectively. One hundred percent of individuals had SLOP using distal femur Z-score, and over 50% were at risk of fracture using distal femur fracture threshold of <0.78 g/cm2. Weak (r=0.42) to moderate (r=0.57) correlations were found between muscle CSA and indices of bone strength, supporting the theory of a muscle-bone unit. No correlations were found between adipose tissue and bone. Conclusions: Based on the cohort data, we propose that individuals with ≥2 risk factors (female, ≥60 years of age, duration of injury (DOI) ≥10, tetraplegia, motor complete) should be screened for obesity using % body fat from DXA as well as a combination of carefully interpreted SCI-specific BMI and WC. In addition, these same individuals should be screened for SLOP using a distal femur Z-score and fracture threshold from DXA. It is clear that due to the prevalence of obesity and SLOP in this population, intervention for prevention or treatment is essential. The presence of a muscle-bone unit indicates that muscle atrophy contributes to a reduction in bone strength; this is clinically important, as muscle strength is potentially amenable to rehabilitation intervention. No correlation was found between adipose tissue and bone. Future work should continue to explore these relationships using appropriate technology.

The objective of this research was to study relationship(s) of ethnicity, physical activity and diet with adiposity development in Aboriginal youth. To meet this objective, three separate, yet inter-related studies were undertaken: 1) to comprehensively assess adiposity in Aboriginal youth and their age, sex and maturity matched Caucasian peers; 2) to assess the role of ethnicity and sex on physical activity (PA) levels and identify the proportion of Aboriginal youth meeting international recommendations; and 3) to explore relationships of ethnicity, physical activity and diet with adiposity. In study one, it was hypothesized that Aboriginal youth would have greater adiposity than their Caucasian peers. While much of the research to date has focused on body mass index, this investigation used DXA and waist circumference to show that Aboriginal youth had greater total and central adiposity in comparison to their Caucasian counterparts.<p> Study two examined physical activity behaviors of Canadian Aboriginal youth in relation to ethnicity and sex. It was hypothesized that the physical activity levels of Aboriginal youth would be lower than their Caucasian peers; that the majority of Aboriginal youth would not meet PA and T.V. viewing recommendations; and that Aboriginal boys would have higher adjusted physical activity energy expenditures than girls. Findings indicated that physical activity levels of the two ethnic groups were generally comparable, that Aboriginal boys had greater activity energy expenditures than girls, and that a greater percentage of boys were meeting the international recommendations for physical activity and T.V. viewing. Study three built upon the first two investigations, to explore relationships of physical activity and diet with adiposity in Aboriginal youth. It was hypothesized that when age, size and maturity, and their interactions were accounted for, diet and physical activity variables would be related to adiposity (waist circumference, total body and trunk fatness). Results indicated physical activity was inversely related to adiposity level, independent of biological factors. Although energy intake was the sole dietary variable related to the adiposity measures, descriptives showed the eating behaviors (i.e., consumption of fruits and vegetables, sugar sweetened beverages and other foods) of the Aboriginal youth were sub-optimal when compared to current recommendations. This research project is unique because it comprehensively assessed adiposity, diet and physical activity, and the relationships between these variables, in a relatively large sample of Aboriginal boys and girls. Furthermore, these relationships were established using a variety of measures (i.e., DXA, waist circumference, height and weight) while controlling for biological confounders. Overall, the results highlight the urgent need to promote physical activity and healthy eating in Aboriginal youth and set the stage for future research.

Background: Sexual satisfaction is a multidimensional construct encompassing the positive and negative aspects of a sexual relationship and is influenced by many factors. Objectives: To investigate the relationship between body composition (weight (kg), total fat (kg, %) and trunk fat (kg, %)) and sexual satisfaction in young adults while controlling for age, body image, relationship satisfaction, sexual function and sexual frequency. Methods: A cross-sectional sample of 157 young adults completed a series of questionnaires and underwent body composition testing (DXA). Stepwise logistic regression models were tested. Results: For both women and men, trunk fat (kg) but no other body composition variable predicted sexual satisfaction. For women, sexual function had the greatest impact followed by relationship satisfaction, trunk fat (kg) and sexual frequency. For men, relationship satisfaction had the greatest impact followed by sexual frequency, age and trunk fat (kg). Conclusions: Other variables better predict sexual satisfaction than body composition. / Social Sciences and Humanities Research Council of Canada

BACKGROUND: Breast cancer patients typically present with unhealthy body composition (high fat mass and low muscularity) near diagnosis. These body composition characteristics often worsen during treatment and ultimately contribute to the development of secondary diseases like diabetes and cardiovascular disease in survivorship. Inflammation in overweight or obese individuals is associated with impaired glucose metabolism; the presence of the tumour may lead to greater impairments in glucose metabolism in breast cancer patients. OBJECTIVES AND HYPOTHESES: The objectives of this study were to: 1) evaluate breast cancer patients near the onset of treatment for metabolic measures including an oral glucose tolerance test (OGTT), cytokine profiles, as well as body composition, nutritional status and fitness and, 2) make comparisons between breast cancer patients, age- and BMI-matched females (HM females), and a group of young, non-malignant females with healthy BMIs (HY females) on these measures. We hypothesized that breast cancer patients would demonstrate impaired glucose metabolism relative to HM females, and that this would be attributed to systemic inflammation. We also hypothesized that both breast cancer patients and HM females would present with unhealthy body composition, impaired glucose and lipid metabolism, systemic inflammation, poor fitness and greater caloric intake compared to HY females. METHODS: We evaluated body composition using % body fat (skinfold callipers) and waist circumference. Following collection of fasting blood samples, an OGTT was conducted to assess glucose, insulin, c-peptide and glucagon dynamics. Fasting blood samples were analysed for lipids and pro- and anti-inflammatory cytokines. Incremental exercise tests were conducted to assess VO2peak, and estimated 1-RM tests assessed strength of the biceps, triceps and quadriceps muscles. Baecke and CHAMPS questionnaires provided an indication of habitual physical activity. A 3-day food record was used to analyze daily caloric intake and macronutrient distribution. Breast cancer patients and HM females were compared using paired t-tests. Patients and HM females were compared to HY females using t-tests. Statistical significance was accepted at p < 0.05. RESULTS: Overall, breast cancer patients were overweight (BMI: 28.8 ± 6.0 kg/m2) and presented with abdominal obesity (waist circumference: 94.6 ± 14.0 cm) and dyslipidemia (TAG: 1.84 ± 1.17 mM and HDL-c: 1.08 ± 0.23 mM), indicating risk for metabolic syndrome. Although fasting glucose concentrations did not differ between the 3 groups, breast cancer patients demonstrated higher glucose concentrations at 30 min during an OGTT. Similar to glucose, fasting insulin concentrations did not differ between the 3 groups, but patients demonstrated higher insulin at 150 min during an OGTT. Breast cancer patients had elevated fasting serum c-peptide (2.6 ± 1.2 ng/mL vs. 1.9 ± 0.8 ng/mL, p = 0.005). C-peptide remained elevated in patients compared to non-malignant females during the last hour of the OGTT, indicating that insulin secretion was sustained in breast cancer patients. We observed no difference in serum cytokines between patients and HM females or between patients and HY females. VO2peak, although lower compared to HY females, was similar in patients and HM females. There were no differences in habitual physical activity or nutrition measures between any groups. DISCUSSION AND CONCLUSIONS: Breast cancer patients presented with poorer glucose features during an OGTT compared to HM and HY females. However, systemic inflammation, body composition, energy expenditure and energy intake were similar in breast cancer patients and HM females. Thus, these impairments may be tumour-related. Future studies need to specifically elucidate the effects of the tumour in host glucose metabolism.