Mental Fatigue, Attentional Focus, and Countermovement Jump Performance
The Effects of Acute Mental Fatigue and Attentional Focus Instructions on Countermovement Jump Performance
調査の概要
状態
詳細な説明
This study uses a sex-stratified, randomized, counterbalanced crossover design with repeated measures to examine the effects of acute mental fatigue and attentional-focus instructions on countermovement jump (CMJ) performance. Thirty-two physically active undergraduate students (16 women, 16 men), aged 18-30 years, will be enrolled from the Faculty of Sport Sciences at İnönü University, Malatya, Türkiye.
Each participant will complete two experimental protocols, separated by at least 72 hours: a control protocol (approximately 30 minutes of passive viewing of a narration-free nature video) and a mental-fatigue protocol (a 30-minute computerized color-word Stroop interference task). Protocol order will be randomized and stratified by sex. In both protocols, participants will perform CMJs under three attentional-focus conditions, presented in a randomized order that is held constant within each participant across sessions: no prescribed focus, internal focus (attention directed to the participant's own body movements), and external focus (attention directed to the effect of movement on the environment). CMJ height will be recorded in centimeters using a validated video-based jump-analysis application (My Jump Lab) on a tablet camera recording at 240 frames per second, with the higher of two valid trials retained as the primary outcome for each protocol-by-focus condition.
Subjective mental fatigue will be assessed immediately before and after each protocol using a 0-10 visual analogue scale to confirm the effectiveness of the fatigue manipulation. Stroop task performance (total trials, accuracy) and adherence to the assigned attentional-focus instructions will be recorded as secondary measures.
The primary analysis will use a 2 (protocol: control, mental fatigue) x 3 (focus: no prescribed, internal, external) x 2 (sex: women, men) mixed-model ANOVA on CMJ height, with protocol and focus as within-participant factors and sex as a between-participant factor. Reporting will follow CONSORT 2025 and the CONSORT extension for randomized crossover trials.
研究の種類
入学 (推定)
段階
- 適用できない
連絡先と場所
研究場所
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Malatya、トルコ（Türkiye）、44280
- İnönü University, Faculty of Sport Sciences
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コンタクト：
- Oguzhan BOZKURT, PhD
- 電話番号：+90 532 620 23 24
- メール：oguzhan.bozkurt@inonu.edu.tr
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主任研究者：
- Oguzhan BOZKURT, PhD
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参加基準
適格基準
就学可能な年齢
- 大人
健康ボランティアの受け入れ
説明
Inclusion Criteria:
- Age 18-30 years
- Third- or fourth-year undergraduate student in the Faculty of Sport Sciences, İnönü University
- Engaged in structured physical activity on at least 2 days per week
- Normal or corrected-to-normal vision and normal color vision
- Able to safely perform maximal vertical jumps
Exclusion Criteria:
- Major lower-extremity surgery or injury
- Musculoskeletal injury during the preceding 6 months that could affect jumping
- Diagnosed neurological, psychiatric, or cardiovascular disorder
- Regular use of medication that could influence alertness, fatigue, cardiovascular responses, or neuromuscular performance
- Any health condition compromising safety or measurement validity
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：基礎科学
- 割り当て：ランダム化
- 介入モデル：クロスオーバー割り当て
- マスキング：なし（オープンラベル）
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
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実験的：Control-First Sequence
Participants complete the control protocol (30-min passive nature-video viewing) in the first session and the mental-fatigue protocol (30-min Stroop task) in the second session, separated by at least 72 hours.
In both sessions, participants perform countermovement jumps under three attentional-focus conditions (no prescribed focus, internal focus, external focus) in a randomized, participant-fixed order.
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Approximately 30 minutes of passive viewing of a narration-free nature video under standardized lighting, seating, and sound conditions, serving as the non-fatiguing control condition matched in duration to the mental-fatigue protocol.
A verbal cue delivered before each jump attempt with no directional attentional instruction: "When you are ready, jump as high as possible."
A verbal cue delivered before each jump attempt directing attention to the participant's own body movements: "When you are ready, focus on extending your knees and hips as quickly and explosively as possible while jumping as high as possible."
A verbal cue delivered before each jump attempt directing attention to the effect of movement on the environment: "When you are ready, focus on pushing the ground away from you as quickly and explosively as possible while jumping as high as possible."
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実験的：Mental-Fatigue-First Sequence
Participants complete the mental-fatigue protocol (30-min Stroop task) in the first session and the control protocol (30-min passive nature-video viewing) in the second session, separated by at least 72 hours.
In both sessions, participants perform countermovement jumps under three attentional-focus conditions (no prescribed focus, internal focus, external focus) in a randomized, participant-fixed order.
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A verbal cue delivered before each jump attempt with no directional attentional instruction: "When you are ready, jump as high as possible."
A verbal cue delivered before each jump attempt directing attention to the participant's own body movements: "When you are ready, focus on extending your knees and hips as quickly and explosively as possible while jumping as high as possible."
A verbal cue delivered before each jump attempt directing attention to the effect of movement on the environment: "When you are ready, focus on pushing the ground away from you as quickly and explosively as possible while jumping as high as possible."
A 30-minute computerized color-word Stroop interference task delivered as one uninterrupted block on a custom program, in which participants identify the font color of color-word stimuli while ignoring word meaning, inducing acute mental fatigue prior to countermovement jump testing.
他の名前：
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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Countermovement Jump Height
時間枠：Assessed once per attentional-focus condition (higher of two valid trials) approximately 30 seconds after completion of each 30-minute protocol (control or mental fatigue), across two sessions separated by at least 72 hours.
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Vertical jump height, measured in centimeters, recorded using a validated video-based jump-analysis application (My Jump Lab) at 240 frames per second.
The higher of two valid trials in each protocol-by-attentional-focus condition (control vs. mental fatigue x no prescribed focus, internal focus, external focus) will be retained as the outcome value for that condition.
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Assessed once per attentional-focus condition (higher of two valid trials) approximately 30 seconds after completion of each 30-minute protocol (control or mental fatigue), across two sessions separated by at least 72 hours.
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二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
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Subjective Mental Fatigue Rating
時間枠：Immediately before and immediately after each 30-minute protocol (control and mental fatigue), across two experimental sessions separated by at least 72 hours.
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Self-reported mental fatigue rated on a 0-10 visual analogue scale, in response to "How mentally fatigued do you feel right now?" (0 = not mentally fatigued at all, 10 = the highest possible level of mental fatigue).
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Immediately before and immediately after each 30-minute protocol (control and mental fatigue), across two experimental sessions separated by at least 72 hours.
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Stroop Task Performance
時間枠：Continuously recorded throughout the 30-minute mental-fatigue protocol, administered in one of the two experimental sessions per participant (protocol order randomized).
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Total trials completed, number of correct and incorrect responses, and accuracy (%), recorded automatically by the Stroop task software during the mental-fatigue protocol.
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Continuously recorded throughout the 30-minute mental-fatigue protocol, administered in one of the two experimental sessions per participant (protocol order randomized).
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Focus-Instruction Adherence
時間枠：Assessed once per attentional-focus condition, immediately after completion of each 30-minute protocol (control or mental fatigue), across two experimental sessions separated by at least 72 hours.
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Self-reported adherence to the assigned attentional-focus instructions, rated on a 0-10 visual analogue scale.
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Assessed once per attentional-focus condition, immediately after completion of each 30-minute protocol (control or mental fatigue), across two experimental sessions separated by at least 72 hours.
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協力者と研究者
スポンサー
研究記録日
主要日程の研究
研究開始 (推定)
一次修了 (推定)
研究の完了 (推定)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (実際)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
本研究に関する用語
その他の研究ID番号
- INU-2026-10953
- 2026/10953 (その他の識別子：Inonu University Scientific Research Ethics Committee for Health Sciences)
個々の参加者データ (IPD) の計画
個々の参加者データ (IPD) を共有する予定はありますか?
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