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

Abstract

This study quantified and compared unilateral farmer’s walk (UFW) performance in recreationally active males and females, and determined if additional variables allowed for the prediction of a maximal safe load. Anthropometric (height, body weight (BW), body mass index, body fat percentage, fat-free mass (FFM), and fat mass), muscular endurance (maximal duration side bridge), and balance (Balance Error Scoring System (BESS)) tests were completed. Participants performed a series of 20 s UFW trials (non-dominant side) at a cadence of 66 beats/min. The initial load was 10% of BW and increased by 10% per trial until deviations in spinal alignment or compromised gait patterns were noted, and the series was terminated. The highest load carried before technical failure was recorded. Descriptive and comparative statistics and a stepwise linear regression analysis were utilized to determine relationships between UFW performance and anthropometric, muscular endurance, and balance tests. Males (N = 25) were significantly taller (177.3 ± 6.7 vs. 164.7 ± 7.2 cm, p < 0.05), heavier (81.7 ± 7.0 vs. 62.0 ± 9.4 kg, p < 0.05), and leaner (14.4 ± 4.4 vs. 22.4 ± 4.8%, p < 0.05) than females (N = 26). Further, males had a higher amount of FFM (p < 0.05) than females. The males (52.2 ± 9.0, 64% BW) carried a higher average UFW load than the females (32.5 ± 7.1 kg, 53% BW, p < 0.05). FFM was strongly predictive of UFW load (load = −9.88876 + 0.88679 × (FFM); r2 = 0.774, p < 0.0001). The addition of the BESS test further increased the accuracy of the prediction equation (r2 = 0.800, p < 0.0001). There are differences in UFW performance ability between males and females. As our method does not account for all potential confounding variables, the use of these equations should be combined with technique analysis and participant feedback to ensure an appropriate workload.

The Biomechanics and Applications of Strongman Exercises: a Systematic Review

“…3). The comparative analysis within each of the studies could be categorized into three main areas: comparisons based on the performance outcome of the exercise [8, 31–34], within exercise comparisons (between phase) [7, 32, 34, 36, 38], and between exercise comparisons [7, 35, 37–39]. The results from the eleven studies are presented in the format outlined in Fig.…”

“…All data are reported as means ± standard deviation, unless specified otherwise. Effect sizes reported for between exercise [7] and performance standard [31]. A positive effect size indicates that the left-hand column (farmer’s walk or higher performer) had a greater value than the respective right-hand column (unloaded walk or lower performer).…”

“…Measures of flexed arm girth, muscle mass and total system force (calculated as the sum of the athlete’s body mass and one-repetition maximum (1RM) squat) were reported to be the greatest anthropometric determinants of performance in the farmer’s walk exercise (flexed arm girth, r = 0.46; muscle mass, r = 0.49; total system force, r = 0.64) [8]. Participants with a greater percentage of fat-free mass were also found to be able to carry greater loads during the suitcase carry before their technique and posture were compromised [31].…”

“…Performance in the suitcase carry has been characterized by an athlete’s ability to maintain a vertical spinal posture (with respect to the frontal and sagittal anatomical plane) and a constant step cadence [31]. This may be deduced by the tendency for an increase in lateral bend and inability to maintain a set cadence as load is progressively increased [31].…”

“…Performance in the suitcase carry has been characterized by an athlete’s ability to maintain a vertical spinal posture (with respect to the frontal and sagittal anatomical plane) and a constant step cadence [31]. This may be deduced by the tendency for an increase in lateral bend and inability to maintain a set cadence as load is progressively increased [31]. As the load used in previous suitcase (McGill et al [35]: ~ 31% bodyweight, Holmstrup et al [31]: ~ 63% bodyweight) and unilateral dumbbell carriage studies may be less than what is expected to be used in strongman training, trunk bend, lumbar spinal loading, ground reaction force asymmetry, and changes in gait characteristics may be further magnified in a true strongman setting where greater loads are carried.…”