The Effects of Combined Energy and Carbohydrate Restriction on Exercise Capacity and Health in Overweight Women
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 40
- 试验地点
- 2
- 主要终点
- Time to exhaustion
研究概览
简要总结
The effect of calorie restriction combined with low or moderate carbohydrate availability on exercise capacity, metabolism and metabolic health indicators will be measured in a randomized parallel group design. Forty overweight (BMI 25-30) and relatively inactive women (20-35 of age) will be included. These will be randomized into one of two experimental groups both receiving a calorie-restricted diet (-1000 kcal) combined with either low carbohydrate availability or moderate carbohydrate availability across a 10 day period. Laboratory-based physical capacity tests and blood and muscle sampling will be performed before and after the intervention. In addition, an additional follow-up test day will be performed after continuing the diet for another 48 h and then standardizing the pre-testing carbohydrate availability before repeating the tests of physical capacity.
详细描述
Overweight (BMI 25-30), but healthy premenopausal women aged 20-35 years (n=40) will be included in the trial, which is structured as a randomized, parallel group design where participants are randomized to either consume a hypocaloric diet (-1000 kcal) with concurrent carbohydrate restriction (low carbohydrate, L-CHO, n=20) or a similar hypocaloric diet with moderate carbohydrate availability (moderate carbohydrate, M-CHO, n=20). The trial will be single-blinded since it might be transparent to the participants which diet they are consuming, whereas the test personnel collecting and processing test results will be blinded to diet allocation. Diet handling will be managed by specific individuals in the research group who do not partake in executing the physical capacity tests. Additionally, the direction of the trial's primary hypothesis will not be disclosed to the participants to avoid creating preconceived expectations about the effects.
After an initial screening interview and two familiarization visits, participants will complete the intervention period consisting of 10 days with the allocated diet manipulation with preceding and subsequent test days with a series of tests. The tests before and after each test period include measurements of the participants' physical capacity level and energy metabolism in the laboratory as well as blood and muscle sampling. In addition, resting metabolism and body composition will be measured. During each test period, participants' habitual activity level will be monitored with an accelerometer attached to the wrist (Axivity). There will also be monitoring of the activity level with an accelerometer in a 7-day cycle before the start of the trial as a baseline measurement.
Similarly, a glucose monitor will be placed on the upper arm for continuous glucose readings via a Freestyle Libre2 sensor during the trial period.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Triple (Care Provider, Investigator, Outcomes Assessor)
盲法说明
The study is labelled as a single-blinded study because the investigators are blinded to the group allocation (the group allocation and diet handling is managed by a researcher not involved in other aspects of the data collection or processing). The participants are not informed about their allocated condition, however, it is conceivably possible for them to recognize this based on the food provided. However, the direction of the hypothesis will not be evident to the participants. Moreover, we include questionnaires before the post-tests related to their perceived diet allocation and their perception of the effect of the diet on the test assessments.
入排标准
- 年龄范围
- 20 Years 至 35 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Age: 20-35
- •BMI: 25-30
排除标准
- •Irregular menstruation within the last 6 months (shorter end 24 days or longer end 35 days cycle)
- •Injuries / pain in the lower body, which prevents participation in intense cycling
- •Medication consumption that may affect primary outcome measures.
- •Pregnancy
- •Systematic physical activity more than 2 hours per week
结局指标
主要结局
Time to exhaustion
时间窗: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Time to exhaustion at 85% VO2max
Sprint performance
时间窗: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Peak and mean 15-s sprint performance
Muscle glycogen levels
时间窗: Pre and post (day 11 of the intervention)
Muscle glycogen levels obtained from biopsy sample
Exercise tolerance
时间窗: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Ratings of perceived exertion (Borg scale) during standardized-intensity exercise from 6 (lowest exertion) to 20 (highest exertion)
次要结局
- Maximal fat oxidation capacity(Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement))
- Muscle metabolic enzyme activity(Pre and post (day 11 of the intervention))
- Continuous glucose levels(14 days from the day before the intervention, throughout the intervention (days 1 to 11) and 2 days after the intervention (follow-up))
- Fasting blood glucose and insulin(Pre and post (day 11 of the intervention))
- Long-term glycemic control (HbAc1)(Pre and post (day 11 of the intervention))
- Physical activity level(During the intervention (days 1 to 11 of the intervention))
- Blood lipid profile(Pre and post (day 11 of the intervention))