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

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

Interventions

DIETARY_SUPPLEMENT

Acute caffeine and beetroot juice

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

DIETARY_SUPPLEMENT

Acute caffeine

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

DIETARY_SUPPLEMENT

Acute beetroot juice

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

DIETARY_SUPPLEMENT

Placebo

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

Sponsors & Collaborators

• University of Alcala

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-09-01

Primary Completion

2024-01-30

Completion

2024-05-01

Countries

• Spain

Study Locations