Effects of Caffeine Ingestion on Morning Cognitive and Muscle Repeated Sprint Performance in Males

Официальное название

Effects of Caffeine Ingestion on Morning Cognitive and Muscle Repeated Sprint Performance in Males. Where a Standardized Approach Has Been Employed

Обзор

Athletes often compete in the morning when they are biologically weaker; normally in competition heats or quarterfinals to qualify for the finals scheduled in the evening. Some athletes may even choose to perform at submaximal levels in these qualifying rounds, especially when they are expected to perform multiple times in the same day (such as weightlifting at the Olympic Games). Gross muscular performance such as power output or force production is greater in the evening than the morning (\~3-14% variation). Similarly, time-trial performance and repeated sprint performance (RSP; a good measure of performance in team sport) is \~3 and 5 % greater in the evening than the morning. The reason for this daily variation in performance is attributed to central factors (such as the body clock), as well as motivational and peripheral factors, including higher core and muscle temperatures in the evening compared to the morning. The body clock located within the anterior hypothalamus consists of a group of neurons known as suprachiasmatic nuclei, which are responsible for controlling the rhythm of core temperature. This 'master clock' has an endogenous period (\~24.2 h) slightly longer than the 24-h solar day; therefore, must be entrained by time cues (zeitgebers) to remain in sync with the environment, of these the light-dark cycle is the most powerful in humans. The most efficient nutritional ergogenic is caffeine. Recently caffeine has been investigated to reduce the negative influence of diurnal variations on repeated-sprint ability test (10 × 6 s cycle sprints, with 30 s of rest) at 60 min after ingestion of either 5 mg·kg-1 or placebo. A recent study reported that caffeine supplementation did not prevent the reduction in performance in the morning. However, placebo effect can be 3-5% and hence the use of a No-pill condition would ensure that any placebo effect is accounted for and that the true potential effect of caffeine can be established. To the best of our knowledge, no study has yet investigated a) caffeine (300 mg), NoPill or Placebo (300 mg dextrose) effects on cognitive and physiological morning performance.

Вмешательства

• Препарат Caffeine
  300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight
• Другое Placabo
  3 capsules of PLACEBO similar to caffeine condition in size and weight
• Другое No Pill
  No capsules were given

Первичные конечные точки

• Morning repeated sprint performance test [Срок оценки: From enrolment to last experimental session (~4 weeks)]
• Morning repeated sprint performance test heart rate [Срок оценки: From familiarisation to the final experimental session (~4 weeks).]
• Rating of perceived exertion every sprint [Срок оценки: From familiarisation to the final experimental session (~4 weeks)]
• Blood lactate and glucose at the end of the 10 sprints [Срок оценки: From enrolment to last experimental session (4 weeks)]
• Core body temperature [Срок оценки: From enrolment to last experimental session (4 weeks)]
• Morning Rey Auditory Verbal Learning Test [Срок оценки: From familiarisation to the final experimental session (~4 weeks)]
• Morning Stroop word-colour interference test [Срок оценки: From familiarisation to the final experimental session (~4 weeks)]

Вторичные конечные точки (12)

• Morning grip strength [Срок оценки: Time Frame: From enrolment to last experimental session (4 weeks)]
• Vertical jump (Counter movement Jump and hands on hips - best of 3) [Срок оценки: From enrolment to last experimental session (4 weeks)]]
• Witty Cognitive agility test 2x 90 s [Срок оценки: From enrolment to last experimental session (4 weeks)]]
• Morning Trail Making Test time to completion in seconds (TMT; parts A and B) [Срок оценки: From enrolment to last experimental session (4 weeks)]
• Morning profile of mood states questionnaire [Срок оценки: From familiarisation to the final experimental session (~4 weeks)]
• Sleep questions from the Liverpool Jet lag Questionnaire [Срок оценки: From familiarisation to the final experimental session (~4 weeks)]
• 7-day food diary [Срок оценки: Baseline]
• Habitual caffeine consumption [Срок оценки: Baseline]
• Self-reported 2-week training diary [Срок оценки: 2 weeks before the main experiment]
• Chronotype [Срок оценки: Baseline]
• Poor sleep quality [Срок оценки: Baseline]
• Depressed mood [Срок оценки: Baseline]

Критерии участия

Критерии включения

• Healthy adults
• 18-35 years old
• Injury-free
• ≥ 2 years of weight/strength training experience
• Not receiving any pharmacological treatment (including non-steroidal anti-inflammatory drugs, NSAIDs) throughout the study period
• Low habitual caffeine consumers (≤ 150mg per day)
• No preference to training regarding time-of-day

Критерии исключения

• Depressed mood (from the Beck depression inventory)

• Poor sleep quality (a Pittsburgh sleep quality index global score >5
• Recent shift work or travel across multiple time-zones
• 'Extreme' chronotype (assessed via the Composite Morningness Questionnaire
• Risk factors and/or symptoms of cardiovascular disease.
• Page 9 of 11 - • Minimal knowledge of the effects of time-of-day or time-since-sleep on human performance

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Перекрёстный дизайн

Маскирование

Двойное слепое

Основная цель

Лечение

Центры проведения

Великобритания · 1 центр

• Tom Reilly Building (LJMU) — Liverpool

Публикации

• Walsh NP, Halson SL, Sargent C, Roach GD, Nedelec M, Gupta L, Leeder J, Fullagar HH, Coutts AJ, Edwards BJ, Pullinger SA, Robertson CM, Burniston JG, Lastella M, Le Meur Y, Hausswirth C, Bender AM, Grandner MA, Samuels CH. Sleep and the athlete: narrative review and 2021 expert consensus recommendations. Br J Sports Med. 2020 Nov 3:bjsports-2020-102025. doi: 10.1136/bjsports-2020-102025. Online ah PMID 33144349
• Drust B, Waterhouse J, Atkinson G, Edwards B, Reilly T. Circadian rhythms in sports performance--an update. Chronobiol Int. 2005;22(1):21-44. doi: 10.1081/cbi-200041039. PMID 15865319
• Munnilari M, Bommasamudram T, Easow J, Tod D, Varamenti E, Edwards BJ, Ravindrakumar A, Gallagher C, Pullinger SA. Diurnal variation in variables related to cognitive performance: a systematic review. Sleep Breath. 2024 Mar;28(1):495-510. doi: 10.1007/s11325-023-02895-0. Epub 2023 Aug 17. PMID 37589927
• Mitchell PJ, Redman JR. Effects of caffeine, time of day and user history on study-related performance. Psychopharmacology (Berl). 1992;109(1-2):121-6. doi: 10.1007/BF02245489. PMID 1365645

Идентификаторы

NCT: NCT07466732 · 251127LJMUSPSREC93

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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