Muscle Strength and Size Relationships with Unilateral Progressive Resistance Training.

Purpose: This study defines correlative and causal relationships between muscle strength and size before and after unilateral resistance training (RT) in a large cohort of healthy adults, focusing on sex differences within these relationships.

Methods: Results from 1233 participants (504 males and 729 females) in a retrospective analysis were included. Maximal voluntary isometric contraction strength (MVC), one-repetition maximum strength (1RM), biceps cross-sectional area (CSA) and elbow flexor volume (VOL) measures of the non-dominant and dominant arm were evaluated from baseline and after 12-wk RT twice per week.

Oxygen uptake efficiency slope in 8- to 12-year-old boys and girls.

Background: Oxygen uptake efficiency slope (OUES) is an objective physiological measure that can be obtained from a standard graded exercise test. However, there is conflicting evidence regarding sex differences in OUES values in children. Therefore, this study investigated potential sex differences in absolute, ratio-scaled, and allometrically scaled OUES in 8.