Clinical trial NCT06596395: Effect of Acute Caffeine and Beetroot Juice Intake on Strength, Power, and Muscular Endurance
Official title: Effect of Acute Caffeine and Beetroot Juice Intake on Strength, Power, and Muscular Endurance Based on Circadian Rhythms.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dietary Supplements
Caffeine
Nitrates
Sports Performance
Resistance Exercise
Lead sponsor: University of Alcala
Sponsor class: OTHER
First posted: 2024-09-19
Enrollment: 14
Sex: MALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Triple-blind, cross-over, randomized controlled-trial
Primary purpose: OTHER

Brief summary: Introduction: Several studies have evaluated and confirmed the ergogenic effect of acute caffeine and beetroot juice intake on sports performance. However, there are few studies focused on the production of strength, power, and muscle endurance, particularly when both supplements are ingested together.

Objectives: Evaluate the acute effect of combined and isolated intake of caffeine and beetroot juice on the production of strength, power, and muscle endurance in young adults, analyzing the effect of circadian rhythms (morning vs. afternoon) on the exercise performed (bench press vs. squat).

Methods: A total of 12 healthy and physically active participants will be recruited for the study. Through a double-blind, crossover, randomized, and controlled design, participants will ingest: a) Caffeine (3 mg/kg body mass); b) Beetroot juice (70 ml, 6.5 mmol of nitrates); c) Caffeine + Beetroot juice; d) Placebo (maltodextrin, 3 mg/kg). The supplements will be ingested 120 minutes (beetroot juice or placebo) and 60 minutes before (caffeine or placebo), the latter dissolved in 200 ml of water. After the ingestion period, strength, power, and muscle endurance will be analyzed with 1RM tests, strength and power tests at 25%, 50%, 75%, and 90% 1RM, and muscle endurance tests at 65% 1RM, in all cases for squat and bench press exercises. Additionally, dynamometry (manual and the isometric mid-thigh pull test) and vertical jump (squat jump and countermovement jump) will be analyzed. The four experimental conditions will be conducted in the morning (8:00 am to 10:00 am) and in the afternoon (4:30 pm to 6:30 pm).


Eligibility criteria: Inclusion Criteria:

* Age between ≥ 18 and ≤ 35 years.
* Body Mass Index (BMI) \&amp;lt; 25 kg/m².
* Resistance-trained individuals (\&amp;gt; 2 years of structured trained).
* Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from exercising.
* Participants must be able to perform the tests described in the following section.

Exclusion Criteria:

* History of neuromuscular diseases, heart diseases, or diseases that may affect liver or muscle metabolism.
* Use of drugs, other stimulants or sport supplements that interfere with the intake of the study\&amp;#39;s dietary supplements.
* Sedentary habits (\&amp;lt; 150 min/week of moderate exercise).
* Having undergone prolonged periods of forced physical inactivity during the 6 months prior to the study.
* Performing strenuous exercise during the 48 hours prior to the tests.
* Failure to replicate the same food intake on the two days of the experiments.
* Consuming caffeine or any other stimulant after 6 pm the day before the training or tests, to avoid headaches, discomfort, or lethargy among regular caffeine consumers.
* Consuming foods rich in NO3- (e.g., beetroot, spinach, or celery) during the 48 hours prior to each experimental condition.

Primary outcomes:
measure: Mean and peak velocity and time to reach peak velocity at different %1RM
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
measure: Mean and peak power output and time to reach peak power output at different %1RM
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
measure: Number of repetitions performed at 65%1RM until task failure
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
Secondary outcomes:
measure: Mood state (tension, depression, anger, vigor, fatigue and confusion)
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
measure: Adverse effects
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
measure: handgrip and isometric mid-thigh pull tests
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
measure: Vertical Jump (cm and power)
timeFrame: On each trial, after dietary supplement intake, during 2 weeks
Other outcomes:
Locations:
city: Alcalá de Henares
country: Spain
facility: Facultad de Medicina y Ciencias de la Salud. Universidad de Alcalá
state: Madrid
Study officials:
References: