Achmad Widodo, Abdul Aziz Hakim, Afif Rusdiawan, Himawan Wismanadi, Zsolt Németh, Hijrin Fithroni, Mellyana Putri Mentari, Hasan Basri
Background. Soccer players competing in tropical climates experience combined dehydration, thermal strain, and metabolic stress, yet field-based evidence linking these factors to performance decline remains limited. Objectives. This study aimed to examine the predictive relationships between hydration status, thermal stress, metabolic factors, and fatigue-related performance decline in sub-elite soccer players under tropical heat conditions. Materials and Methods. Thirty male sub-elite soccer players (22.4 ± 3.1 years) participated in a simulated 90-minute match conducted in temperatures ranging from 31 to 33°C, with relative humidity levels between 65 and 75%. Hydration (bioimpedance), blood lactate, muscle temperature, heart rate, shooting accuracy, and anaerobic power (RAST) were assessed pre-, mid-, and post-match. Repeated-measures ANOVA and multiple regression were used (p < 0.05). Results. TBW decreased significantly (−4.2%), while lactate (1.3 → 10.4 mmol·L-1) and muscle temperature (33.4 → 37.1°C) increased across match segments (p < 0.001). Shooting accuracy (−14%) and peak anaerobic power (−4.6%) declined post-match. Regression analysis identified ΔTBW (β = −0.41, p = 0.008) and peak lactate (β = 0.48, p = 0.003) as significant predictors of fatigue (R² = 0.61). Conclusions. The findings indicate that loss of hydration, thermal strain, and metabolic accumulation are all important signs of a subject’s deterioration in performance levels under tropical match conditions. Athletes can improve their health and performance by drinking enough fluids and keeping their body temperature under control. © Widodo, A., Hakim, A. A., Rusdiawan, A., Wismanadi, H., Németh, Z., Fithroni, H., Mentari, M. P., & Basri, H., 2026.
Department of Sport Science, Faculty of Sports and Health Sciences, Postgraduate Students of Sport Science, Universitas Negeri Surabaya, Lidah Wetan Street, Lidah Wetan, Lakarsantri, East Java, Surabaya City, 60213, Indonesia; Institute of Sports Science and Physical Education, Faculty of Science, University of Pécs, Vasvári Pál utca 4, Pécs, H-7622, Hungary; Department of Physical Education, Health And Recreation, Faculty of Teacher Training and Education, Universitas Islam 45, Cut Mutia Street No. 15, Marga Jaya, South Bekasi, West Java, Bekasi, 17113, Indonesia
