Energy Balance and Dietary Intake in Young Rugby Players during a Pre-Season Micro-Cycle: A Cluster Analysis

Area of Science:

• Sports Nutrition
• Adolescent Physiology
• Exercise Metabolism

Background:

• Adolescent rugby players require high energy and nutrient intake for conditioning and growth.
• Meeting these demands is crucial during intense training periods like pre-season.
• Understanding energy intake and balance is vital for optimizing performance and health.

Purpose of the Study:

• To examine individual differences in energy intake (EI) and energy balance (EB) in young rugby players.
• To identify distinct player clusters based on body composition and EB.
• To understand how EI and EB relate to body composition goals in adolescent athletes.

Main Methods:

• Studied 46 young rugby players during a pre-season micro-cycle.
• Analyzed within-individual variations in energy intake and energy balance.
• Clustered players based on body fat percentage and energy balance status.

Main Results:

• Two distinct clusters emerged: one with low body fat and positive EB (muscle gain goal), another with higher body fat and negative EB (fat loss goal).
• Players adjusted their energy intake to align with body composition objectives.
• Results suggest better EI adaptation than previously reported, but risks remain.

Conclusions:

• Young rugby players can adjust energy intake to meet body composition goals.
• Rigorous nutritional support is essential, particularly for those aiming for fat loss.
• Adequate nutrient intake is critical to prevent deficiencies (e.g., iron, calcium, vitamin D) and severe caloric restriction.