The vaginal microenvironment plays a critical role in genital health, with L-lactic acid and pH acting as key regulators of antimicrobial defense and microbiota stability (1). Alterations in these parameters are well documented in vulvovaginal infections such as vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV) (2).
Pelvic floor muscle training (PFMT) is widely used in pelvic health. However, its potential influence on the vaginal biochemical environment remains poorly understood. Muscle contraction may induce local physiological changes, including alterations in blood flow, oxygenation, and metabolic activity, which could influence vaginal biochemical parameters. Emerging evidence also suggests a relationship between pelvic floor function and vaginal microbiota composition (3).
We hypothesized that PFMT modifies vaginal L-lactic acid concentration, pH, and temperature and that these effects differ between women with and without vulvovaginitis. Therefore, this study aimed to evaluate changes in these parameters before and after PFMT in these populations.

This clinical trial included 80 women recruited from a public hospital-based outpatient clinic specializing in genital infections. Participants were allocated into two groups: 40 without vulvovaginal infection (control group) and 40 with vulvovaginitis, including vulvovaginal candidiasis (VVC, n=22) and bacterial vaginosis (BV, n=18).
Vaginal L-lactic acid concentrations were measured before and immediately after PFMT using enzyme-linked immunosorbent assay (ELISA). Vaginal pH was assessed using pH strips and vaginal temperature was measured with a digital thermometer.
Statistical analysis included repeated measures ANOVA, Tukey’s post hoc test, paired t-test, Fisher’s exact test and chi-square test, with significance set at p<0.05.

PFMT was associated with a significant increase in vaginal L-lactic acid concentration and pH in the overall sample (L-lactic acid p=0.0001; pH p=0.0006).
Subgroup analyses showed similar increases in women without vulvovaginal infection (p<0.0001 for both variables) and in those with VVC (L-lactic acid p<0.0001; pH p=0.0062), whereas no statistically significant changes were identified in women with BV.
Vaginal temperature remained stable across all groups (p>0.05).

PFMT induced acute changes in vaginal biochemical parameters, particularly increased L-lactic acid concentration. These findings suggest that pelvic floor muscle activity may influence local biochemical regulation, potentially through changes in tissue perfusion and metabolic activity.
The differential response observed across groups indicates that the underlying vaginal condition modulates this effect. The absence of changes in women with BV suggests that microbiota-related alterations may influence responsiveness to PFMT.
These results support a previously underexplored interaction between pelvic floor muscle function and the vaginal biochemical environment.

Pelvic floor muscle training was associated with acute increasess in vaginal L-lactic acid concentration and pH in women without infection and in those with vulvovaginal candidiasis, but not in bacterial vaginosis. These findings suggest that pelvic floor muscle activity may influence the vaginal microenvironment, with responses varying according to the vaginal underlying condition. This study provides novel evidence linking pelvic floor function to biochemical regulators of vaginal health and may have implications beyond musculoskeletal outcomes.

Witkin SS, Mendes-Soares H, Linhares IM, et al. Influence of vaginal bacteria and D- and L-lactic acid isomers on vaginal extracellular matrix metalloproteinase inducer: implications for protection against upper genital tract infections. mBio. 2013;4(4):e00460-13.
Smith SB, Ravel J. The vaginal microbiota, host defence and reproductive physiology. J Physiol. 2017;595(2):451–463.
Zhang Y, Yang H, Lin L, Yang W, Xiong G, Gao G. The relationship between pelvic floor functions and vaginal microbiota in 6-8 weeks postpartum women. Front Microbiol. 2022 Nov 3;13:975406.