Acute Effects of Beetroot Juice and Caffeine Co-ingestion on Lower-limb Strength and Muscular Endurance in Females

Summary

The aim of this study is to evaluate the acute effects of beetroot juice and caffeine, consumed individually or in combination, on lower-limb strength and muscular endurance in physically active women. The main questions it aims to answer are:

* Does the co-ingestion of beetroot juice and caffeine enhance lower-limb strength and muscular endurance more than either substance alone or a placebo?
* How do the acute effects of beetroot juice interact with caffeine on physical performance?

The study was conducted using a randomized, crossover design to evaluate the following four conditions:

Beetroot juice with placebo Caffeine with placebo Beetroot juice with caffeine Placebo only

Each participant completed all conditions, with a sufficient washout period between sessions to eliminate potential carryover effects. This design allowed for a direct comparison of the acute effects of each supplementation strategy on lower-limb strength and muscular endurance.

Participant Protocol

Participants consumed their assigned supplement on a single testing day for each condition. After supplementation, they performed standardized tests to measure lower-limb strength and muscular endurance. Progress was monitored, and data from all conditions were collected to assess the acute effects of each intervention.

Conditions

• Beetroot Juice
• Caffeine
• Placebo
• Beetroot Juice with Caffeine Co-ingestion

Interventions

DIETARY_SUPPLEMENT

Beetroot juice combined with caffeine (COM)

* 70 mL of beetroot juice (400 mg NO3-, BEET It Sport; James White Drinks Ltd) 120 minutes before experimental session * 200 mg caffeine capsule from the IO.GENIX Nutrition brand (Toledo, Spain) 60 minutes before experimental session

DIETARY_SUPPLEMENT

Beetroot juice placebo with caffeine (CAF)

\- 70 mL of a blackcurrant beverage, which depletes NO3- (Capri-Sun) 120 minutes before experimental session - 200 mg caffeine capsule from the IO.GENIX Nutrition brand (Toledo, Spain) 60 minutes before experimental session

DIETARY_SUPPLEMENT

Beetroot juice with caffeine placebo (BRJ)

\- 70 mL of beetroot juice (400 mg NO3-, BEET It Sport; James White Drinks Ltd) 120 minutes before experimental session - Multivitamin capsule from NaturrTierra (Leganés, Spain) 60 minutes before experimental session

OTHER

Beetroot placebo with caffeine placebo (PLA)

\- 70 mL of a blackcurrant beverage, which depletes NO3- (Capri-Sun) 120 minutes before experimental session - Multivitamin capsule from NaturrTierra (Leganés, Spain) 60 minutes before experimental session

Sponsors & Collaborators

• Jose Manuel Jurado Castro

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

DOUBLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-08-01

Primary Completion

2024-12-26

Completion

2024-12-26

Countries

• Spain

Study Locations