College of Education, Health & Human Development
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The College of Education, Health and Human Development (EHHD) is comprised of two departments: the Department of Education and the Department of Health and Human Development.
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Item Carbohydrates for physical activity: A strategy to avoid undesirable health consequences(2012-03) Miles, MaryIntake of carbohydrates above the dietary guidelines to support performance of physical activity is common but may be unnecessary and counterproductive. Sports nutrition guidelines have not been designed to incorporate characteristics that may make high carbohydrate consumption a source of metabolic stress that may increase oxidative stress, inflammation, and lipogenesis. This metabolic stress is linked to the physiology underlying the development of insulin resistance, type 2 diabetes mellitus, and cardiovascular diseases. This review describes research-based evidence to aid in bridging the gap between dietary guidelines for overall health and those to support physical activity. Characteristics that increase the likelihood of metabolic stress resulting from carbohydrate intake include overweight and obesity, central/visceral adiposity, older age, sedentary lifestyle, and caloric state. Carbohydrate-based foods that provide the most health benefits are whole grains, beans and legumes, fruits, and vegetables. Carbohydrate-based foods that most readily elicit metabolic stress are those with added sugars and refined grains or that have a high glycemic index. A checklist that incorporates both the number of these characteristics and prevailing guidelines for nutrition and physical activity is presented. This may be useful in determining whether additional carbohydrates are needed to support the physical activity level of the individual.Item Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain(Elsevier, 2011-04) Miles, Mary; Rawson, E.S.; Stech, M.J.; Frederickson, Sara J.Objective: We examined the effects of 6 wk of low-dose creatine supplementation on body composition, muscle function, and body creatine retention. Methods: Twenty healthy men and women (21 ± 2 y old) were randomized to receive creatine (0.03 g • kg -1 • d-1; n=10, 4 women) for 6 wk in a double-blind placebo-controlled fashion. Participants were tested on two occasions before supplementation to establish a reliable baseline, and then were retested after supplementation. Testing included body composition, maximal strength (three-repetition maximal concentric knee extension at 180 degrees/s), muscle fatigue (five sets of 30 concentric knee extensions at 180 degrees/s), and plasma creatine concentration. Results: There were no significant differences in body mass, fat-free mass, fat mass, body fat percentage, total body water, or maximal strength in either group from before to after supple-mentation (all P > 0.05). After supplementation, plasma creatine increased significantly in the creatine group (+182%, P = 0.03), with no difference in the placebo group. Compared with baseline values, creatine-supplemented volunteers were more resistant to fatigue during sets 2 (7%), 3 (9%), 4 (9%), and 5 (11%) (all P < 0.05). In placebo-supplemented participants, there was no improvement in fatigue resistance during sets 2 (0%), 3 (1%), 4 (0%), and 5 (1%) (all P > 0.05). Conclusion: Ingesting a low dose (2.3 g/d) of creatine for 6 wk significantly increased plasma creatine concentration and enhanced resistance to fatigue during repeated bouts of high-intensity contractions.Item Basal, diurnal, and acute inflammation in normal versus overweight men.(Lippincott Williams & Wilkins, 2012-12) Miles, Mary; Keller, J.M.; Kordick, L.K.; Kidd, J.R.Increased inflammation is present in obese compared with normal weight individuals, but inflammation characteristics of nonobese, overweight individuals are less clear. Purpose: The objective of this study was to determine whether basal, circadian, and posteccentric exercise inflammation levels differ between normal and overweight men. Methods: Men (18–35 yr old) classified as normal weight (body mass index ≤2 5 kg·m-2, n = 20) and overweight (body mass index = 25–30 kg·m-2 conditions in random order. Maximal voluntary effort and eccentric actions (3 X 15) using the elbow flexor muscles of one arm were performed, and blood was collected preexercise and 4, 8, 12, and 24 h postexercise at 7:00 a.m., 12:00 p.m., 4:00 p.m., 8:00 p.m., and 7:00 a.m. Blood was collected on a time-matched schedule without exercise for CON. Soluble tumor necrosis factor receptor-1, interleukin-6, C-reactive protein (CRP), and cortisol responses (EX value j time-matched CON value) were measured. Results: Basal CRP was higher in the overweight compared with normal weight group (mean ± SD, 0.542 ± 0.578 vs 1.395 ± 1.041 mg·L-1). Soluble tumor necrosis factor receptor-1 increased (P < 0.05) 8 h postexercise in both groups, and the response was greater 12 and 24 h postexercise in the overweight compared with normal weight groups. Interleukin-6 increased (P < 0.05) 8 h postexercise, with a trend (P = 0.09) to be greater in the overweight group. CRP and cortisol responses were not detected. Conclusions: The low-grade inflammation state in overweight compared with normal weight men includes both higher basal CRP concentrations and enhanced acute inflammation, but not in changes to the circadian patterns of cortisol and inflammation variables.Item Enhanced inflammation with high carbohydrate intake during recovery from eccentric exercise(Springer, 2010-08) Miles, Mary; Depner, Chris M.; Kirwan, Rochelle D.; Frederickson, Sara J.Inflammation associated with adipose tissue is modulated by macronutrient availability. For example, glucose increases inflammation in obese but not lean individuals. Little is known about how macronutrient intake influences inflammation associated with muscle. The aim of this study was to determine the impact of macronutrient intake differences during recovery from eccentric exercise on the inflammatory response. The study was a cross-over design in which young men and women (n = 12) completed high and low carbohydrate (CHO) conditions. Both conditions consisted of six sets of ten maximal high-force eccentric contractions of the elbow flexors and extensors followed by a controlled diet for the first 8 h post-exercise. Glucose, insulin, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and C-reactive protein were measured from blood samples pre-exercise, 1.5, 4, 8, and 24 h post-exercise. Perceived muscle soreness, strength loss, and serum CK activity were measured through 120 h post-exercise. Perceived soreness was elevated (P < 0.001) at all time points post-exercise in both conditions and was higher (P < 0.05) in the high compared to the low CHO condition. IL-1β increased (P = 0.05) 24 h post-exercise in the high compared to the low CHO condition. There was a trend (P = 0.06) for IL-6 to be elevated in the high compared to the low CHO condition. We conclude that inflammation induced by high-force eccentric exercise in skeletal muscle is greater when a high CHO compared to a low CHO diet is consumed during recovery.Item Influence of macronutrient intake and anthropometric characteristics on plasma insulin after eccentric exercise(W.B. Saunders Co, 2010-10) Miles, Mary; Frederickson, Sara J.; Depner, Chris M.; Kirwan, Rochelle D.To increase understanding of the interaction between macronutrients and insulin resistance (IR), this study sought to determine the influence of macronutrient intake and anthropometric differences on IR and inflammation responses to eccentric resistance exercise. Men and women (n = 12, 19-36 years old) participated in a crossover study and completed 6 sets of 10 unilateral maximal eccentric contractions of the elbow flexors and extensors followed by controlled diet conditions for the first 8 hours postexercise of carbohydrate/fat/protein proportions of either 75%/15%/10% (CHO) or 6%/70%/24% (FAT/PRO). Fasting glucose, insulin, homeostatic model assessment (HOMA) variables, and interleukin (IL)-1β were measured preexercise and 23 hours postexercise (additional measures of glucose and insulin 1 hour after meals consumed 0.5, 3, and 7 hours postexercise). Insulin increased more (P < .01) in the CHO compared with the FAT/PRO condition at 1.5, 4, and 8 hours postexercise. Insulin, HOMA-IR, and HOMA-β-cell function increased 23 hours postexercise in both conditions, whereas IL-1β increased 23 hours postexercise only in the CHO condition. Magnitude of change (Δ) for these variables associated positively with body mass index (BMI) and waist to hip ratio (WHR) in the CHO and inversely in the FAT/PRO condition; that is, r = 0.53 (P = .10) and r = −0.82 (P < .01) for BMI vs Δ insulin in CHO and FAT/PRO conditions, respectively. The Δ IL-1β associated with BMI (r = 0.62, P < .05) and WHR (r = 0.84, P < .01) in the CHO condition. The CHO enhanced IR and inflammation as BMI and WHR increased, whereas fat and protein enhanced IR as BMI and WHR decreased. Thus, BMI and WHR may need to be taken into account in the development of nutritional strategies to prevent IR.Item Interactive Effects of APOE Haplotype, Sex, and Exercise on Postheparin Plasma Lipase Activities(American Physiological Society, 2011) Miles, Mary; Seip, R.L.; Zoeller, Robert F.; Angelopoulos, T.J.; Salonia, J.; Bilbie, C.; Moyna, Niall M.; Visich, Paul S.; Pescatello, Linda S.; Gordon, P.M.; Tsongalis, Gregory J.; Bausserman, L.; Thompson, P.D.Hepatic lipase (HL) and lipoprotein lipase (LPL) activities (HLA, LPLA) modify lipoproteins and facilitate their binding to hepatic receptors. Apolipoprotein E (APOE) physically interacts with the lipases, and the three common haplotypes of the APOE gene (ε2, ε3, and ε4) yield protein isoforms (E2, E3, and E4, respectively) that are functionally different. Lipase activities themselves differ by sex and exercise training status. The interaction of APOE genotype, exercise training, and sex effects on lipase activities has not been studied. We measured postheparin plasma lipase activities in normolipidemic men and women with the three most common APOE genotypes, which are the haplotype combinations ε2/ε3 (n 53 ), ε3/ε3 (n 62), and ε4/ε3 (n 52), enrolled in 6 mo of aerobic exercise training. These haplotype combinations comprise an estimated 11.6, 62.3, and 21.3% of the population, respectively. Baseline HLA was 35% lower in women than in men (P 0.0001). In men but not women, HLA was higher in ε2/ε3 group compared with ε4/ε3 (P 0.01) and ε3/ε3 (P 0.05). Neither sex nor APOE genotype affected baseline LPLA. Training decreased HLA by 5.2% (P 0.018) with no APOE effect. The apparent increase in LPLA following exercise was significant and APOE dependent only when corrected for baseline insulin (P 0.05). Exercise decreased LPLA by 0.8 mol free fatty acid (FFA)·ml 1·h 1 ( 6%) in ε3/ε3 compared with the combined increases of 6.6% in ε2/ε3 and 12% in ε4/ε3 (P 0.018 vs. ε3/ε3). However, these differences were statistically significant only after correcting for baseline insulin. We conclude that common APOE genotypes interact with 1) sex to modulate HLA regardless of training status, with ε2/ε3 men demonstrating higher HLA than ε3/ε3 or ε4/ε3 men, and 2) aerobic training to modulate LPLA, regardless of sex, with ε3/ε3 subjects showing a significant decrease compared with an increase in ε2/ε3 and ε3/ε4 after controlling for baseline insulin.Item Dietary, Anthropometric, Blood Lipid, and Performance Patterns of College Football Players During 8 Weeks of Training(Human Kinetics, 2012) Miles, Mary; Kirwan, Rochelle D.; Kordick, L.K.; McFarland, S.; Lancaster, D.; Clark, K.The purpose of this study was to determine the dietary, anthropometric, blood-lipid, and performance patterns of university-level American football players attempting to increase body mass during 8 wk of training. Methods: Three-day diet records, body composition (DEXA scan), blood lipids, and performance measures were collected in redshirt football players (N = 15, age 18.5 ± 0.6 yr) early season and after 8 wk of in-season training. Results: There was an increase (p < .05) from early-season to postseason testing for reported energy (+45%), carbohydrate (+82%), and protein (+29%) intakes and no change in the intake of fat. Fat intake was 41% of energy at the early-season test and 32% of energy at the postseason test. Increases (p < .05 for all) in performance measures, lean mass (70.5 ± 7.7–71.8 ± 7.7 kg), fat mass (15.9 ± 6.2–17.3 ± 6.8 kg), plasma total cholesterol (193.5 ± 32.4–222.6 ± 40.0 mg/dl), and low-density lipoproteins (LDL; 92.7 ± 32.7–124.5 ± 34.7 mg/dl) were measured. No changes were measured in triglycerides, very-low-density lipoproteins, or high-density lipoproteins. Conclusion: Increases in strength, power, speed, total body mass, muscle mass, and fat mass were measured. Cholesterol and LDL levels increased during the study to levels associated with higher risk for cardiovascular disease. It is possible that this is a temporary phenomenon, but it is cause for concern and an indication that dietary education to promote weight gain in a manner less likely to adversely affect the lipid profile is warranted.