Effects of a 500-Mile Backpacking Hike on the Performance of a Competitive Powerlifter

The purpose of this study was to evaluate the effects of a long-distance backpacking trip and a high protein diet on body composition, strength, power, and aerobic performance. A single participant (male, aged 29 years) hiked 34 days on the Colorado Trail. Dependent variables were assessed pre-hike and post-hike and included body mass, body fat percentage, bone mineral density, maximum oxygen consumption (VO2max), resting metabolic rate (RMR), total cholesterol, triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL). Cardiovascular dependent variables included resting heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP). Other performance outcomes included strength in squat, bench press, and deadlift, and vertical leap. Resting heart rate and a journal documenting a breakdown of calories expended and calories consumed were recorded daily while on the hike. The average daily duration of a hike was 8:43 ± 1:45 hours. The participant’s mass decreased by 2.5 kg (4% of body weight), body fat decreased by 1.2%, RMR decreased by 5 kcal/day, and VO2max increased by 8.7 mL/kg/min (17%). Among metabolic variables, total cholesterol increased by 18 mg/dL (10%); triglyceride concentration decreased by 23 mg/dL (29%); HDL decreased by 1 mg/dL (2%), and; LDL increased by 24 mg/dL (23%). With regard to cardiovascular variables, resting heart rate decreased from 85 bpm to 67 bpm (21%), SBP decreased by 39 mmHg (27%), and DBP decreased by 2 mmHg (3%). Among performance variables, maximal squat performance decreased by 29.5 kg (19%), maximal bench press performance decreased by 18.2 kg (16%), maximal deadlift decreased 31.7 kg (17%), and vertical jump distance decreased 13 cm (14%). The average daily dietary variables were as follows: average calories consumed = 4000 ± 463 kcal/day; average calories expended from hiking and metabolic rate combined = 5188 ±1197 kcal/day; average daily caloric deficit = -1165 ± 1070 kcal/day; average carbohydrate intake = 501 ± 78 g/day; average protein intake = 143 ± 19 g/day; average fat intake = 154 ± 25g/day. The magnitude and duration of an extended backpacking trip can lead to a reduction in strength and power. A diet high in protein did not prevent the loss of lean body mass

Influence of Menopausal Status on Lipids and Lipoproteins and Fat Mass Distribution: The Pioneer Project

Following menopause, fat redistribution and increased risk for dyslipidemia are common. The influence of menopause; however, on the associations between total and regional fat mass with lipids and lipoproteins remains unclear. PURPOSE: The purpose of this investigation was to determine the influence of menopausal status on associations between total and regional fat mass and lipids and lipoproteins. METHODS: Sedentary, non-smoking women (n=209) were grouped based on current menstrual status: premenopausal (n=143, mean±SD; age=42.7±7.7 yr, BMI=24.5±4.0 kg•m -2, WC=77.4±9.9 cm) or postmenopausal (n=66, mean±SD; age=52.9±5.3 yr, BMI= 24.9±4.2 kg•m -2, WC=78.8±9.9 cm). Fasting (12 hr) serum samples were analyzed for total cholesterol (TC), triglyceride (Tg), LDL-C, HDL-C, HDL2-C, and HDL3-C concentrations. Total (TF), abdominal (AF), hip (HF) and mid-thigh (MTF) fat mass were quantified by DXA. A MANCOVA was used to determine differences between groups for total and regional fat mass and lipids and lipoproteins controlling for HRT status. Stepwise multiple regression analysis was used to determine if menopausal status influenced the association of total and regional fat mass with lipids and lipoproteins. The criterion reference for statistical significance was set at a P \u3c 0.05. RESULTS: Postmenopausal women had significantly greater TC, HDL-C, LDL-C and HDL3-C concentrations than premenopausal women. No significant differences were observed between groups for total and regional fat mass. In premenopausal women, AF predicted TC, but no associations were observed in postmenopausal women. In premenopausal women, AF+HF and AF+TF were significant predictors of Tg and LDL-C, respectively. In contrast, only AF predicted Tg and LDL-C in postmenopausal women. AF+MTF best predicted HDL-C in premenopausal women; however, TF+MTF best predicted HDL-C in postmenopausal women. In premenopausal women, no associations were observed with HDL2-C or HDL3-C. TF and TF+MTF were best predictors of HDL2-C and HDL3-C, respectively in postmenopausal women. CONCLUSION: Menopausal status has an effect on lipid and lipoprotein-cholesterol concentrations, but not on total and regional fat mass. In addition, menopausal status had an influence on the associations of total and regional fat mass with lipids and lipoproteins

Nursing with Eating, Activity, and Supportive Environment (EASE) : Effects of an Eight-week Mentoring Program

Each year, approximately 2.8 million adults die from complications related to obesity (World Health Organization, 2011). One in three adults aged 20 years or older is obese, and 6% are morbidly obese. This problem is increasing at an alarming rate in young adults, and 20.5% of college students are classified as being overweight based upon their body mass index (BMI) (Adderley-Kelly, 2007). The purpose of this study was to increase knowledge about evidence-based, effective interventions that will enable college-aged, pre-nursing students to attain physical and mental well-being. The participants (N=24) were freshman and sophomore pre-nursing majors who were randomized into two groups (control and intervention). The intervention group met once a week for an eight-week nutrition and physical activity mentoring program at Texas Woman’s University. The participants were educated about proper diet and exercise recommendations and kept physical activity, nutrition, and stress management logs. Measured outcomes, mean changes and standard deviations over the eight week period included body weight (-0.3 kg + 1.7), BMI (-0.12 kg/m2 + 0.68), waist circumference (-2.5 cm + 1.9), and perceived stress scale (0.0 + 3.6). One-way ANOVAs with a p value of 0.05 were used for statistical analysis. There were no significant differences in weight, BMI, waist circumference or stress between the groups. Body composition and mental stress are difficult to change in an eight-week mentoring program, although improved knowledge may set the stage for future behavior change. A longer term program may need to be used to observe changes in weight, BMI, waist circumference, and stress

The Influence of Dietary Sugars and Acute Exercise on Postprandial Triglyceride and Glucose Concentration

Purpose: Examine the effects of prior aerobic exercise on postprandial triglyceride (PPTG) and glucose concentration following a mixed liquid meal (LM) made with either glucose or fructose sugars. Methods: Sedentary pre-menopausal women (n=16; age=28.2±6.1yrs; Wt. = 61.2±10.5kg; BMI= 23.2±2.9 kg/m2; VO2 max =30.8±4.2 ml/kg/min) completed four trials in random order: 1) Control-Fructose, 2) Control-Glucose, 3) Exercise-Fructose, 4) Exercise-Glucose. Exercise consisted of treadmill walking at 65% VO2 max expending 500 calories. Control consisted of resting in the laboratory for approximately 1 hour. Trials were completed 15 hours prior to the LM. The morning after each trial, a fasting (12hr) blood sample was collected followed by the consumption of the LM providing approximately 20 kcal/kg fat-free mass with a macronutrient composition of 55% carbohydrate, 15% protein, and 30% fat. The LM was blended with whole milk and ice cream plus a glucose or fructose powder. The glucose and fructose powder accounted for half of the total carbohydrate content within the LM. Blood was collected again at 0.5, 1, 1.5, 2, 3, 4, 5, and 6 hours post-LM and analyzed for TG and glucose concentration. The areas under the curve (AUC) were calculated for both TG and glucose concentration using the trapezoidal method. A repeated measures ANOVA was used to determine statistical significance (p-1•6hr-1) when compared to the three other trials (Rest-Fructose: 856.5±309.9 mg•dl-1•6hr-1, Exercise-Fructose: 838.0±324.5 mg•dl-1•6hr-1, and Rest-Glucose: 862.1±339.4 mg•dl-1•6hr-1), respectively. No differences in the TG AUC were reported between the other three trials. Glucose AUC was unchanged between the trials (p = .19; Control-Fructose = 660.4 ± 67.2 mg•dl-1•6hr-1; Exercise-Fructose = 636.3 ± 74.8 mg•dl-1•6hr-1; Control-Glucose = 633.3 ± 91.4 mg•dl-1•6hr-1; Exercise-Glucose = 633.3 ± 72.6 mg•dl-1•6hr-1). Discussion: The PPTG AUC was smaller following the Exercise-Glucose trial only. Investigations have reported that glucose supplemented into a meal lowers PPTG AUC when compared to fructose. Acute exercise has been reported to lower PPTG AUC following the ingestion of an extremely high-fat or high-carbohydrate meal. Most postprandial investigations using mixed meals have reported no change in glucose AUC following acute exercise. This study was funded by Texas Woman’s University and the Texas Chapter of the American College of Sports Medicine

Influence of Race on the Female Athlete Triad

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Daytime and nighttime casein supplements similarly increase muscle size and strength in response to resistance training earlier in the day: a preliminary investigation

BACKGROUND: Casein protein consumed before sleep has been suggested to offer an overnight supply of exogenous amino acids for anabolic processes. The purpose of this study was to compare supplemental casein consumed earlier in the day (DayTime, DT) versus shortly before bed (NightTime, NT) on body composition, strength, and muscle hypertrophy in response to supervised resistance training. METHODS: Thirteen males participated in a 10-week exercise and dietary intervention while receiving 35 g casein daily. Isocaloric diets provided 1.8 g protein/kg body weight. RESULTS: Both groups increased (p < 0.05) in lean soft tissue (DT Pre: 58.3 ± 10.3 kg; DT Post: 61.1 ± 11.1 kg; NT Pre: 58.3 ± 8.6 kg; NT Post: 60.3 ± 8.2 kg), cross-sectional area (CSA, DT Pre: 3.4 ± 1.5 cm2; DT Post: 4.1 ± 1.7 cm2; NT Pre: 3.3 ± 1.6 cm2; NT Post: 3.7 ± 1.6 cm2) and strength in the leg press (DT Pre: 341 ± 87.3 kg; DT Post: 421.1 ± 94.0 kg; NT Pre: 450.0 ± 180.3 kg; NT Post: 533.9 ± 155.4 kg) and bench press (DT Pre: 89.0 ± 27.0 kg; DT Post: 101.0 ± 24.0 kg; NT Pre 100.8 ± 32.4 kg; NT Post: 109.1 ± 30.4 kg) with no difference between groups in any variable (p > 0.05). CONCLUSIONS: Both NT and DT protein consumption as part of a 24-h nutrition approach are effective for increasing strength and hypertrophy. The results support the strategy of achieving specific daily protein levels versus specific timing of protein ingestion for increasing muscle mass and performance. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03352583