Differences in Lipolysis, Circulating Hormones, and Muscle Quality Between Recreational Female Endurance Athletes of Different Body Sizes
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 15
- 试验地点
- 1
- 主要终点
- Compositional Muscle Quality
研究概览
简要总结
The popularity of marathons and endurance events has increased over the last few decades and, interestingly, the demographics of participants have also changed. From 1980 to 2002 the average race time to complete the marathon lengthened from ~3.5 hours to ~4.5 hours. Likewise, many endurance races include "Clydesdale" and "Athena" divisions for heavier weight male and female runners, respectively. As such, there has been an increase of overweight and obese participants in these races. For example, one study consisting of 250 runners determined, according to BMI, that approximately 15% and 31% of the female and male participants, respectively, were classified as overweight, with 31% and 33% classified as obese. Therefore, many recreational endurance athletes are overweight despite their high level of activity. On one hand, these data are positive as regular exercise reduces cardiovascular disease and all-cause mortality in overweight and obese populations. Yet, it is well documented in sedentary obese individuals that excess adiposity can lead to disturbances in adipocyte lipolysis and altered substrate utilization at rest and during exercise, and can decrease muscle quality. However, it is unknown if overweight individuals that exercise regularly have disrupted fat metabolism, circulating hormones, or muscle quality. No study has directly determined if differences exist in fat metabolism, circulating hormones, and muscle quality between overweight recreational female athletes and their lean counterparts when training status is equivalent. Therefore, the purpose of this investigation is to determine if differences in pre and post-exercise fat metabolism, circulating insulin and growth hormone, and muscle quality exist between active overweight individuals compared to active lean individuals with similar training history and who have regularly trained for and participated in endurance events within the last few years.
详细描述
Fourteen active female endurance athletes (8 lower body fat, 6 higher body fat) will be recruited to participate in this study. The study will consist of two experimental days at the Institute of Sports Science and Medicine (ISSM) and the Sandels building at Florida State University. Participants will arrive at the laboratory in a fasted state for laboratory testing days. All participants will fill out a health history questionnaire, physical activity questionnaire, and sign the informed consent before any testing will be performed.
Testing Day 1:
For Day 1 of testing, participants will arrive in the morning at ISSM for informed consent, anthropometric testing, body composition, resting blood pressure, and fitness testing. All testing will be overseen by a certified strength and conditioning specialist.
Anthropometrics:
Anthropometric and body composition measurements will be assessed on the first day in the lab to ensure inclusion criteria are met. Height and weight will be measured with a wall-mounted stadiometer (SECA, Hamburg, Germany) and a digital scale (Detecto®, Webb City, MO, USA) respectively, and used to calculate body mass index (BMI: kg/m2). Fat-free mass, fat mass, and percent body fat will be assessed by Bod Pod (Cosmed, Chicago, IL) following the manufactures instructions.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Female participants will be recruited for the study
- •(BMI of <29.9 kg/m2).
- •Ages of 18 and 45 years old
- •Weight stable (± 2 kg) for the last three months
- •Regularly endurance training on most days of the week for at least one hour for the last two years
- •No exclusion will be made for race or socioeconomic status
- •Participants will be eumenorrheic and premenopausal
排除标准
- •Resting blood pressure above 160 mmHg systolic or 100 mmHg diastolic
- •Type 1 or type 2 diabetes; 3)
- •Other medical problems in which exercise is contraindicated
- •chronic infections
- •Diagnoses, signs, or symptoms of cardiovascular disease
- •Respiratory disease
- •Musculoskeletal disease
- •Musculoskeletal injuries in the last six months that would prevent them from engaging in endurance training.
- •Pregnant or lactating and must have a
- •Irregular menstrual cycle
- •Diagnosed eating disorders
结局指标
主要结局
Compositional Muscle Quality
时间窗: First experimental visit - 15 minutes
Intramuscular fat accumulation percentage will be measured and estimated using B-mode ultrasound echo intensity via histogram analysis and composition equations
Functional Muscle Quality
时间窗: First experimental visit - 30 minutes
Functional MQ is measured via force production (via Biodex) divided muscle size (via dual energy X-ray absorptiometry).
Change in circulating insulin around an exercise bout
时间窗: Second experimental visit - Pre-exercise, Immediately post-exercise, and 120-minutes post-exercise
Insulin will be collected via blood draws. Blood will be drawn immediately following metabolic testing for resting measurements, immediately after the bout of physical activity, and every hour for 120 minutes' post activity.
Change in circulating growth hormone around an exercise bout
时间窗: Second experimental visit - Pre-exercise, Immediately post-exercise, and 120-minutes post-exercise
Growth hormone Insulin will be collected via blood draws. Blood will be drawn immediately following
Lipolysis
时间窗: Second experimental visit for a total of 6 hours
Tested via microdialysis. Two probe inserted into the subcutaneous abdominal adipose tissue to collect glycerol molecules (byproduct of lipolysis).
次要结局
- Blood Sampling Analysis(Second experimental visit - Pre-exercise, immediately after the resting metabolic measurements)
研究者
Michael J. Ormsbee
Principle Investigator
Florida State University