The Effects of Caffeine Supplementation on Motivation, Affect and Performance in Physical Exercise Tests: An Intervention Study
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 40
- 试验地点
- 1
- 主要终点
- Relative outcome expectancy
研究概览
简要总结
The main objective of the study is to evaluate the influence of caffeine intake on participants' energetic arousal, affect, motivation to achieve a training goal, satisfaction with training, and the sense of agency during training. Consequently, participants will engage in three sessions: caffeine, placebo, and no substance (in counterbalanced order). During each session, their affective and motivational states will be assessed, along with the performance of a standardized physical exercise test. The investigators hypothesize that participants who consume caffeine (caffeine condition) will exhibit higher levels of energy and motivation compared to the other two groups. Additionally, they are expected to experience greater optimism and expectancy regarding their training goals and achieve better results in the physical exercise test.
A secondary aim of the study is to examine the impact of genetic variability on motivational and affective states of participants, as well as their performance in the physical exercise test after caffeine. The investigators will assess the CYP1A2 (-163C > A, rs762551; characterized such as "fast" (AA genotype) and "slow" caffeine metabolizers (C-carriers)) and ADORA2A (1976T > C; rs5751876; characterized by "high" (TT genotype) or "low" sensitivity to caffeine (C-carriers)).
详细描述
Before participating in the study, participants will answer questions regarding their consumption of caffeinated beverages and the frequency of their workouts. They will also complete the Extreme Personality Scale measuring the tendency to pursue goals single-mindedly. Subsequently, they will be qualified for the study based on the questionnaire results and a brief interview.
The study will involve the manipulation of energization through the administration of caffeine. Participants will take part in a randomized, crossover, double-blind study, where they will perform three identical training sessions after consuming: a) caffeine at a dose of 3 mg/kg of body weight; b) a placebo; and c) under control conditions (i.e., without substance administration). Capsule consumption will occur 60 minutes before the start of the training. Caffeine and placebo capsules will not differ in size, shape, color, and taste.
As the effectiveness of caffeine use depends on the CYP1A2 (rs762551) and ADORA2 (rs5751876) gene polymorphisms, the study will also genotype these genes. The first gene is responsible for the rate of caffeine metabolism, determining whether people metabolize caffeine "fast" or "slow." The ADORA2A gene, encoding the adenosine A2A receptor, influences how "sensitive" people are to caffeine. DNA isolates obtained from oral epithelial cells collected from participants by qualified medical personnel will constitute the research material. Oral epithelial swabs will be collected directly from the participants into sterile tubes.
Before and after substance intake (and additionally after the exercise test) participants will assess their arousal using the University of Wales Institute of Science and Technology Mood Adjective Checklist. Additionally, after substance intake and before exercise, participants will answer questions about motivation, affect and expectancy regarding training. Subsequently, participants will undergo training, taking the form of a supervised standardized exercise test. After exercise, participants will assess their satisfaction and feelings after completing the training.
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
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 30 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 18-30 years
- •Caffeine consumption
- •Engagement in physical activity.
排除标准
- •Diagnosed cardiovascular, metabolic, gastrointestinal, or neurological diseases
- •Taking medications or supplements that may affect test results
- •Tobacco smoking
- •Pregnancy
- •Potential allergy to caffeine.
- •Participation in the study will be preceded by completing a health questionnaire and providing written consent. Additionally, exclusion from the study will occur upon the explicit request of the participant.
研究组 & 干预措施
Placebo
Participants will take a placebo pill 60 minutes before the physical exercise test.
干预措施: Placebo (Dietary Supplement)
No substance
Participants receive no pills in this condition before the physical exercise test.
干预措施: No substance (Other)
结局指标
主要结局
Relative outcome expectancy
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Expectancy of the training results measured with a question: In relation to participants' typical result, what result do they expect in: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond to each item on a 1-7 scale anchored 1 = definitely worse than usual and 7 = definitely better than usual. Higher scores indicate more positive outcome expectations.
Agency
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Sense of agency measured with two questions: 1) Do participants feel in control over the outcome in..., 2) Do participants feel in control over their performance in... Participants respond to each question in relation to each test outcome: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Responses are given on 1-6 scale anchored 1 = no control and 7 = complete control. Higher scores indicate greater sense of agency.
Performance in the 1RM test
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition)
Participants' performance in the one-repetition maximum test in bench press \[number of kg\]
Performance in the bar velocity in the bench press test
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition)
Participants' performance in the bar velocity during 3 sets of 3 repetitions in the bench press exercise \[m/s\]
Retrospective agency
时间窗: Immediately after the physical exercise test
Sense of agency measured with two questions: 1) Did participants feel in control over the outcome in..., 2) Did participants feel in control over their performance in... Participants respond to each question in relation to each test outcome: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Responses are given on 1-6 scale anchored 1 = no control and 7 = complete control. Higher scores indicate greater sense of agency.
Energetic arousal pre-test
时间窗: Right before the intervention
Self-reported energetic arousal contrasting vigour with fatigue, measured with the energetic arousal sub-scale of the University of Wales Institute of Science and Technology Mood Adjective Checklist. The values range from 1-4; higher scores indicate greater energetic arousal.
Success probability
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Subjective probability of attaining the best result measured with a question: How likely do participants think it is that they will achieve the best result in: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond to each item on a 1-7 scale anchored 1 = completely unlikely and 7 = certain. Higher scores indicate greater probability of success.
Prospective effort
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Participants' willingness to invest effort in the training measured with a question: How much effort are participants planning to invest in: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond on a 0-100% scale. Higher scores indicate greater willingness to invest effort.
Performance in the strength-endurance test
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition)
Participants' performance in the strength-endurance test in bench press test (number of repetitions)
Satisfaction with the results
时间窗: Immediately after the physical exercise test
Participants' satisfaction with their training results measured with a question: How satisfied are participants with their results in: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond to each item on a 1-7 scale anchored 1 = definitely unsatisfied to 7 = definitely satisfied. Higher scores indicate greater satisfaction with the results.
Retrospective effort
时间窗: Immediately after the physical exercise test
Participants' assessment of effort invested in the training measured with a question: How much effort did participants invest in:1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond on a 0-100% scale. Higher scores indicate greater effort.
Energetic arousal post-test
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Self-reported energetic arousal measured with the energetic arousal sub-scale of the University of Wales Institute of Science and Technology Mood Adjective Checklist. The values range from 1-4; higher scores indicate greater energetic arousal. The change relative to the pre-test will be analyzed.
Optimism
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Situational optimism (expectancy of positive outcomes) measured with 4 items were participants rate the extent to which they: 1) are positively oriented. 2) are full of optimism. 3) can achieve what I set out to do. 4) are capable of a lot. Responses are given on a 1-7 Likert scale. Higher scores indicate greater optimism. The mean of these items will be computed and the change relative to the pre-test will be analyzed.
Motivation
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Motivation to accomplish one's training goals measured with a question where participants rate the extent to which they are motivated to achieve the best result in: 1) one-repetition maximum bench press test, 2) bar velocity in the bench press test, 3) strength-endurance test, 4) countermovement jump. Participants respond to each item on a 1-7 Likert scale. Higher scores indicate greater motivation.
Determination
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition); before training
Determination to accomplish one's training goals measured with 4 items: 1) During training, everything else will become irrelevant for \[the participant\[. 2) \[The participant\] will put a lot of energy into the training. 3) \[The participant\] will do everything in their power to achieve the training goal. 4) \[The participant\] will reach the training goal even if it requires a great effort. 5) \[The participant\] will train despite fatigue. Participants respond to each item on a 1-7 Likert scale. Higher scores indicate greater determination.
Performance in the countermovement jump test
时间窗: 60 minutes after taking the capsule (waiting in the no-intervention condition)
Participants' performance in the countermovement jump test (number of cm)
次要结局
- Goal importance(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Prospective difficulty(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Expected performance in the countermovement jump test(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Energetic arousal post-training(Immediately after the physical exercise test)
- Expected performance in the strength-endurance test(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Expected performance in the 1RM test(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Expected performance in the bar velocity in the bench press test(60 minutes after taking the capsule (waiting in the no-intervention condition); before training)
- Tense arousal(Right before the intervention, then 60 minutes after taking the capsule (waiting in the no-intervention condition); and immediately after the physical exercise test)
- Retrospective difficulty(Immediately after the physical exercise test)
- Perceived effect on agency(Immediately after the physical exercise test)
- Hedonic tone(Right before the intervention, then 60 minutes after taking the capsule (waiting in the no-intervention condition); and immediately after the physical exercise test)
研究者
Ewa Szumowska
Assistant
Jagiellonian University