Statistical analysis
CFS
SECONDARY
Outcome analyses were conducted using intention-to-treat principles, with all participants retained in his or her originally assigned groups. Generalized linear mixed models (GLMMs) assessed for differences between intervention groups on primary and secondary outcomes over time, with intervention effects assessed via entry of intervention group (placebo and ashwagandha) × time interaction. The time points examined for each outcome included: (1) PSS and CFS total score (weeks 0, 4, 8, and 12); (2) PROMIS-29, comprising physical, mental, and sexual health scores (baseline, and the means of weeks 1–4, 5–8, and 9–12); and (3) TT, FT, estradiol, LH, DHEA-S, fasting glucose, HbA1c, MDA, BMI, WC, WHR, grip strength, and HRV (RMSSD) (weeks 0 and 12). Due to significant sex differences in sex hormone concentrations and body compositions, separate analyses were conducted by sex. Random intercepts were utilized in each GLMM, and the covariates of age and BMI were included as fixed effects. Where applicable, gamma (with log link function) and normal (with identity link function) target distributions were used. Appropriate covariance structures with the best model fit were used to model correlation associated with repeated time measurements in gamma and linear models. Robust estimations were used to handle any violations of model assumptions, and least significance tests were used for within-group time contrasts. Intervention group differences at time points were assessed using simple contrasts. All data were analyzed using SPSS (version 26; IBM, Armonk, NY, USA).