Dose-Response Effects of Short-Term *Rhodiola Rosea* on Anaerobic Performance and Cognitive Function in Resistance-Trained Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 27
- 试验地点
- 2
- 主要终点
- Load volume (kg) during 3rd set to failure at 60% 1RM
研究概览
简要总结
This study will evaluate whether 7 days of Rhodiola rosea (golden root) supplementation can improve resistance-exercise performance and cognitive function in resistance-trained men and women. Participants will complete four 7-day periods in a randomized, double-blind, crossover order: (1) no-capsule control, (2) placebo, (3) low-dose Rhodiola rosea, and (4) high-dose Rhodiola rosea. On day 7 of each period, they will report to the laboratory for performance testing that includes bench press and leg press 1-repetition maximum (1RM), a third set to failure at 60% 1RM, Tendo-derived mean and peak power, a 30-second Wingate test, and the paper-and-pencil Stroop Color-Word Test for executive function. Secondary outcomes include ratings of perceived exertion, readiness to perform (visual analog scale), and heart rate and blood pressure measured at rest and 1 minute after exercise. The central hypothesis is that short-term Rhodiola rosea, compared with control and placebo, will produce small but measurable improvements in strength, set-to-failure volume, and Stroop performance, with minimal changes in hemodynamics.
详细描述
Rationale: Rhodiola rosea is an adaptogenic plant extract that has shown modest, context-dependent effects on perception of effort, cognition, and exercise performance. Prior studies suggest that benefits may be more evident with acute or short-term administration; however, the results are heterogeneous. This study employs a within-subject approach in resistance-trained adults to minimize between-person variability and investigate potential dose-response effects over a short time frame.
Design overview: After screening and a familiarization visit, each participant completes four 7-day periods: (1) no-capsule control, (2) placebo, (3) low-dose RR, and (4) high-dose RR. Capsule periods are randomized and double-blind; the no-capsule control precedes capsule periods to avoid carryover of expectancy. Study staff, participants, and outcome assessors are blinded during capsule periods. On day 7 of each period, participants attend a single testing visit conducted under standardized conditions (time of day, pre-test instructions). Short-latency effects are targeted by scheduling capsule ingestion approximately 60 minutes before testing during capsule periods.
Intervention: Low- and high-dose RR are provided in identical-appearing capsules. Placebo capsules contain inert filler. Product identity, dose, and lot information are recorded in the Intervention section of the record. Capsule count and participant logs monitor adherence.
Standardization and compliance: Participants are asked to maintain their habitual training and diet and to refrain from using additional ergogenic aids for a period of 7 days. They record total energy and macronutrients for the three days before each testing day. Testing sessions follow a consistent order of tasks established during the familiarization phase. Resting vital signs are obtained after a seated rest; post-exercise measures are obtained 1 minute after completion of designated tasks.
Population: Resistance-trained adults (men and women) who meet eligibility criteria and provide informed consent. Additional eligibility details are specified in the Eligibility section of the record. The female hormonal status/menstrual phases are documented when available to aid in interpretation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Weeks 至 40 Weeks（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adults 18-40 years old
- •≥2 years of consistent resistance training, including bench press and leg press/squat
- •Able to complete all four 7-day conditions and Day-7 testing in a crossover design
- •Willing to abstain from other performance supplements during the study
- •Provided written informed consent
排除标准
- •Diagnosed metabolic, cardiovascular, or thyroid disorders
- •Cardiac arrhythmias
- •Current prescription drugs with possible cardiovascular or neurocognitive effects
- •Known or suspected sensitivity to Rhodiola rosea
- •Regular alcohol intake >12 drinks/week
- •Recent musculoskeletal injury that could limit resistance-exercise testing
结局指标
主要结局
Load volume (kg) during 3rd set to failure at 60% 1RM
时间窗: Day 7 of each 7-day period
Participants performed bench presses and leg presses at 60% of their familiarization 1RM. On the 3rd set, they lifted to volitional failure; load volume was calculated as load (kg) × repetitions. Values after administration of low- and high-dose Rhodiola rosea were compared with those of the placebo and control groups.
Wingate anaerobic test peak power
时间窗: Day 7 of each 7-day period
Participants completed a 30-s Wingate test on a cycle ergometer; peak power (W) was recorded. Values after low- and high-dose Rhodiola rosea were compared with those of the placebo and control to assess the effects on anaerobic performance.
Executive function (Stroop Color-Word Test)
时间窗: Day 7 of each 7-day period
The paper-and-pencil Stroop Color-Word Test is administered (Word, Color, and Color-Word, 45 s each). The total number of correct responses across the three sections is recorded. Higher scores indicate better executive control.
次要结局
- Readiness to Perform (Visual Analog Scale, 0-100 mm)(Day 7 of each 7-day period)
- Rating of Perceived Exertion (RPE) after resistance exercise(Day 7 of each 7-day period)
- Resting Heart Rate(Day 7 of each 7-day period)
- 1-Minute Post-Exercise Heart Rate(Day 7 of each 7 days (1-min post-bench press; 1-min post-leg press; 1-min post-Wingate).)
- Resting Systolic Blood Pressure(Day 7 of each 7 days (pre-test).)
- Adverse Events / Side-Effects-Frequency (0-5 Likert)(Day 7 of each 7 days (post-condition).)
- Resting Diastolic Blood Pressure(Day 7 of each 7 days (pre-test).)
- 1-Minute Post-Exercise Systolic Blood Pressure(Day 7 of each 7 days (1-min post-bench press; 1-min post-leg press; 1-min post-Wingate).)
- 1-Minute Post-Exercise Diastolic Blood Pressure(Day 7 of each 7 days (1-min post-bench press; 1-min post-leg press; 1-min post-Wingate).)
- Adverse Events / Side-Effects-Severity (0-5 Likert)(Day 7 of each 7 days (post-condition).)
研究者
Majid Koozehchian, PhD
Associate Professor of Kinesiology; Program Coordinator, Human Performance & Nutrition; Principal Investigator
Jacksonville State University