Abstract / Summary
Purpose: : To examine the effects of 12 weeks of strength and resistance training on serum calcium, phosphorus, and parathyroid hormone (PTH) in elite under-23 (U23) male footballers, and to elucidate differential mechanobiological and endocrine mechanisms underlying distinct training modality responses, a question previously unaddressed in this population. Methods: Thirty elite U23 male footballers were assigned to a resistance training group (RTG; n = 10), strength training group (STG; n = 10), and control group (CG; n = 10) in a quasi-experimental, pretest–posttest design. RTG and STG completed supervised training three times per week for 12 weeks while CG continued routine football training. Fasting venous blood samples were collected pre and post intervention to assess serum calcium, phosphorus, and PTH, and analysed with one-way ANOVA and Tukey's HSD. Results: Post intervention ANOVA revealed highly significant between-group differences for calcium (F(2,27) = 131.01, η²p = .91), phosphorus (F(2,27) = 74.91, η²p = .85), and PTH (F(2,27) = 54.35, η²p = .80) (all p < .001). RTG elicited significantly higher serum calcium than STG (mean difference = 1.03 mg/dL, p < .001), while phosphorus and PTH responses were statistically comparable between training groups. Conclusion: Twelve weeks of structured training significantly improved mineral homeostasis and suppressed PTH in elite U23 footballers. Resistance training elicited a superior calcaemic response, likely attributable to greater cumulative mechanical strain volume. Routine football training alone failed to induce comparable biochemical adaptations, highlighting the need for structured supplementary loading in elite football conditioning.