Effect of Acute Caffeine and Beetroot Juice Intake on Strength, Power, and Muscular Endurance

NCT06596395 | Completed

• 1 other identifier: CEIP/2023/4/093
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

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).

Conditions

Dietary Supplements; Caffeine; Nitrates; Sports Performance; Resistance Exercise

Outcome Measures

Primary Outcomes (3)

• Mean and peak velocity and time to reach peak velocity at different %1RM

  Measuring bar velocity desplacement during bench press and back squat exercises.

  On each trial, after dietary supplement intake, during 2 weeks

• Mean and peak power output and time to reach peak power output at different %1RM

  Measuring power output generated during bench press and back squat exercises.

  On each trial, after dietary supplement intake, during 2 weeks

• Number of repetitions performed at 65%1RM until task failure

  Additionally to mean and peak velocity, mean and peak power output, time to reach peak velocity and peak power

  On each trial, after dietary supplement intake, during 2 weeks

Secondary Outcomes (4)

• Mood state (tension, depression, anger, vigor, fatigue and confusion)

  On each trial, after dietary supplement intake, during 2 weeks

• Adverse effects

  On each trial, after dietary supplement intake, during 2 weeks

• handgrip and isometric mid-thigh pull tests

  On each trial, after dietary supplement intake, during 2 weeks

• Vertical Jump (cm and power)

  On each trial, after dietary supplement intake, during 2 weeks

Study Arms (4)

Caffeine + Beetroot Juice

EXPERIMENTAL

70 mL of concentrated NO3--rich (BJ, 6.5 mmol NO3-) + 3 mg/kg of caffeine

Dietary Supplement: Acute caffeine and beetroot juice

Beetroot Juice

EXPERIMENTAL

70 mL of concentrated NO3--rich (BJ, 6.5 mmol NO3-) + 3 mg/kg of placebo (maltodextrin)

Dietary Supplement: Acute beetroot juice

Caffeine

EXPERIMENTAL

70 mL of NO3--depleted (BJ, 0.04 mmol NO3-) + 3 mg/kg of caffeine

Dietary Supplement: Acute caffeine

Placebo

PLACEBO COMPARATOR

70 mL of NO3--depleted (BJ, 0.04 mmol NO3-) + 3 mg/kg of placebo (maltodextrin)

Dietary Supplement: Placebo

Interventions

Acute caffeine and beetroot juice DIETARY_SUPPLEMENT

Combined effect of beetroot juice and caffeine intake on muscular strength, power and endurance performance

Caffeine + Beetroot Juice

Acute caffeine DIETARY_SUPPLEMENT

single effect of caffeine intake on muscular strength, power and endurance performance

Caffeine

Acute beetroot juice DIETARY_SUPPLEMENT

single effect of beetroot juice intake on muscular strength, power and endurance performance

Beetroot Juice

Placebo DIETARY_SUPPLEMENT

single effect of placebo on muscular strength, power and endurance performance

Placebo

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between ≥ 18 and ≤ 35 years.
• Body Mass Index (BMI) \< 25 kg/m².
• Resistance-trained individuals (\> 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.

You may not qualify if:

• 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\'s dietary supplements.
• Sedentary habits (\< 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.

Sponsors & Collaborators

• University of Alcala: lead

Study Sites (1)

Facultad de Medicina y Ciencias de la Salud. Universidad de Alcalá

Alcalá de Henares, Madrid, 28805, Spain

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Triple-blind, cross-over, randomized controlled-trial

Study Record Dates

• First Submitted: September 6, 2024
• First Posted: September 19, 2024
• Study Start: September 1, 2023
• Primary Completion: January 30, 2024
• Study Completion: May 1, 2024
• Last Updated: September 19, 2024

Record last verified: 2024-09

Data Sharing

• IPD Sharing: Will share

Locations

ES (1)