Vol 14, Issue 1, No 7, July 2026

The Effects of Plyometric and Hill Training on Gastrocnemius Muscle Circumference Among Athletes Across Different Phases of the Menstrual Cycle

Prabhu a/l Ragawan, Nelfianty Mohd Rasyid & Ruaibah Yazani Tengah

Fakulti Sains Sukan & Kejurulatihan, Universiti Pendidikan Sultan Idris, Tanjong Malim, Perak, Malaysia

DOI: http://doi.org/10.47836.14.1.07

ABSTRACT

This study aimed to examine the effects of plyometric and hill training on gastrocnemius muscle circumference across different phases of the menstrual cycle in female athletes. Thirty athletes (mean age = 16.2 ± 0.78 years) from the Cameron Highlands district were randomly assigned to three groups: hill training (n = 10), plyometric training (n = 10) and control (n = 10) following a three-month screening period that monitored menstrual cycle consistency and physical performance. Gastrocnemius muscle circumference was  measured at pre- and post-intervention during three phases of the menstrual cycle: before menstrual (eight days before the estimated menstrual starts), during menstrual (three days after menstrual starts) and after menstrual (eight days after the end of menstrual). The Plyometric and hill training were administered twice weekly for 12 weeks during the late follicular (days 6–12) and early luteal (days 16–23) phases of the menstrual cycle whereas the control group performed a 1400-meter run twice weekly irrespective of menstrual cycle phase. This design ensured comparability across groups with all interventions individualised according to each athlete’s menstrual cycle chart to  facilitate accurate phase alignment and  evaluate the effectiveness of each training modality. A three-way ANOVA revealed significant differences in gastrocnemius muscle circumference among the training groups (p < 0.05). Tukey’s post hoc analysis indicated that the hill training group demonstrated significantly greater improvements compared to the plyometric group (mean difference = 2.267, p < 0.05). In c neither menstrual cycle phase nor the interaction effects had a significant influence on gastrocnemius muscle circumference. These findings indicate that training modality emerged as the primary determinant of changes in gastrocnemius muscle circumference with hill training producing significantly greater adaptations than plyometric training. The results do not support the influence of menstrual cycle phase on gastrocnemius hypertrophic adaptations, suggesting that the observed changes are primarily  attributable to the type of training rather than menstrual phase-related variations in female athletes aged 14-17 years.

Keywords: plyometric training, hill training, gastrocnemius muscle circumference, follicular phase, luteal phase