Legume-Enriched Mediterranean Diet and Cellular Hydration in Competitive Swimmers

NCT07315529 | Completed

• 2 other identifiers: LEGUMES-SWIMLazio Area 5, N.57/SR/23
• Study Type: interventional
• Target: 39
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigates whether increasing legume consumption within a Mediterranean diet framework improves cellular hydration, autonomic regulation, and functional performance in competitive swimmers. Thirty-nine adolescent and young adult swimmers were monitored over a five-month competitive season under standardized training conditions. Participants were allocated to three groups according to habitual legume intake: a control group (\<1 serving/week, no dietary change), a moderate-intake group (≈2 servings/week increased to 3/week), and a high-intake group (≈3-4 servings/week increased to 6/week). Dietary counseling focused exclusively on adjusting legume intake, while overall training load and other dietary components were maintained. Primary outcomes include bioelectrical impedance-derived phase angle and body water distribution indices (extracellular water, intracellular water, ECW/ICW ratio) as markers of cellular health and hydration. Secondary outcomes include heart rate variability, cardiac coherence as indices of autonomic balance, and critical swim speed as a performance-related measure. The study aims to clarify whether a simple, sustainable increase in legume intake can support athletes' cellular integrity, autonomic function, and functional status without altering standard training programs.

Conditions

Diet Habits; Athlete

Keywords

Mediterranean diet; Legume consumption; Competitive swimmers; Athletes; Bioelectrical impedance analysis; Phase angle; Extracellular water; Intracellular water; Heart rate variability; Critical swim speed

Outcome Measures

Primary Outcomes (1)

• Change in phase angle (degrees)

  Phase angle derived from whole-body bioelectrical impedance analysis, reflecting cellular integrity and body cell mass. Measured at baseline and after 5 months in each arm.

  Baseline and 5 months

Secondary Outcomes (2)

• Change in extracellular water percentage (ECW)

  Baseline and 5 months

• Change in ECW/ICW ratio

  Baseline and 5 months

Study Arms (3)

3-Legumes

EXPERIMENTAL

Competitive swimmers increasing legume intake to 3 servings per week while maintaining usual diet and training load.

Other: Legume-enriched Mediterranean diet

6-Legumes

EXPERIMENTAL

Competitive swimmers increasing legume intake to 6 servings per week while maintaining usual diet and training load.

Other: Legume-enriched Mediterranean diet

Control

NO INTERVENTION

Competitive swimmers with habitual legume intake \<1 serving/week, receiving no prescribed change in legume consumption.

Interventions

Legume-enriched Mediterranean diet OTHER

Adjustment of habitual legume intake within a Mediterranean diet pattern to 3 or 6 servings per week, without altering other dietary components or training regimen.

3-Legumes; 6-Legumes

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Competitive swimmers training at least six sessions per week.
• Age ≥18 years.
• Ability to complete an online questionnaire in Italian prior to the first clinical evaluation.
• Willingness to comply with the prescribed legume intake pattern for the assigned group.
• Provision of written informed consent.

You may not qualify if:

• Current use of performance-enhancing drugs or any chronic medication.
• Musculoskeletal injury or medical conditions that could interfere with training or study assessments.
• Consumption of alcohol or caffeinated beverages within 15 hours before testing sessions.
• Inability or unwillingness to complete the scheduled assessments or to provide informed consent.

Sponsors & Collaborators

• San Raffaele Telematic University: lead

Study Sites (1)

San Raffaele Open University

Roma, RM, 00141, Italy

Location

MeSH Terms

Conditions

Feeding Behavior

Condition Hierarchy (Ancestors)

Behavior, Animal; Behavior

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor

Model Details: Parallel-group interventional study with three diet-based arms: control group with no change in legume intake, moderate-intake group increasing to 3 servings/week, and high-intake group increasing to 6 servings/week, under standardized training conditions.

Study Record Dates

• First Submitted: December 18, 2025
• First Posted: January 2, 2026
• Study Start: February 1, 2025
• Primary Completion: July 31, 2025
• Study Completion: July 31, 2025
• Last Updated: January 2, 2026

Record last verified: 2025-12

Locations

IT (1)