Fat-Free Mass and the Balance Error Scoring System Predict an Appropriate Maximal Load in the Unilateral Farmer's...

Area of Science:

• Biomechanics
• Exercise Physiology
• Human Movement Science

Background:

• The unilateral farmer's walk (UFW) is a functional exercise, but its performance differences between sexes and predictive factors for safe loading are not well-established.
• Understanding these factors is crucial for designing effective training programs and preventing injuries.

Purpose of the Study:

• To quantify and compare UFW performance between recreationally active males and females.
• To determine if anthropometric, muscular endurance, and balance variables can predict a maximal safe UFW load.

Main Methods:

• Participants (males N=25, females N=26) performed UFW trials with incrementally increasing loads until technical failure.
• Anthropometric measurements, side bridge endurance, and Balance Error Scoring System (BESS) tests were conducted.
• Stepwise linear regression analysis was used to identify predictors of UFW performance.

Main Results:

• Males were significantly taller, heavier, and leaner with higher fat-free mass (FFM) than females.
• Males carried a significantly higher average UFW load (64% body weight) compared to females (53% body weight).
• FFM was a strong predictor of UFW load (r² = 0.774), with the addition of BESS scores improving prediction accuracy (r² = 0.800).

Conclusions:

• Significant sex-based differences exist in UFW performance, with males demonstrating superior load-carrying capacity.
• FFM and balance performance are key predictors of maximal safe UFW load.
• While predictive equations are valuable, they should be used alongside technique assessment and participant feedback to ensure safe and effective training loads.