2.7. Data Analysis
RET
REGRESSION
All statistical analyses were conducted using SAS/STAT software (version 9.4; SAS Institute Inc., Cary, NC, USA). The mean intakes of all nutrients were calculated from the diet logs that were entered into NutriBase software (version 7, Cybersoft Inc., Phoenix, AZ, USA) or direct calculations from the USDA database for choline [The differences between choline groups were analyzed by one-way ANOVA. The assumption of equal variance was checked using Levene’s test, and the Tukey method was used to perform pairwise comparisons. When the equal variance assumption was not met, Welch’s variance-weighted ANOVA test was performed. ANCOVA tests were conducted to examine the effects of dietary choline, controlling for effects of potential confounders (e.g., cholesterol and other nutrients, sex, age, lean mass, etc.) on RET responses. Multiple linear regression analyses were performed to examine the independent effects of choline consumption and any other factors on RET responses. Composite strength was defined as chest press 1RM + leg press 1RM, and percent change was calculated as 100 × (post-training measurement − pre-training measurement)/pre-training measurement. The 