The impact of nutritional counselling on iron status and physical performance in young biathletes

Single-group pre–post intervention study. Participants (young biathletes aged 12–18 years) will receive a 12-week personalised nutrition counselling program designed to improve dietary habits, iron status, and aerobic performance. The intervention includes three group-based education sessions (90 minutes each, one per week) covering principles of healthy nutrition, energy availability, iron intake, and supplementation. Each participant will also attend one individual dietary consultation lasting approximately 60 minutes, during which dietary habits, training load, and body composition will be reviewed, and a personalised dietary plan will be developed. The personalised dietary plan will include recommendations for daily energy intake, macronutrient distribution, iron-rich food sources, meal timing in relation to training, and hydration strategies adapted to adolescent athletes. Participants will remain under continuous dietitian supervision for 12 weeks, including regular follow-up consultations approximately every two weeks (about 30 minutes each) to monitor progress and adjust dietary recommendations if needed. Adherence to the intervention will be monitored using dietary records (3-day food diaries) reviewed by the dietitian during follow-up visits. The intervention will be delivered face-to-face by a qualified dietitian at the Academy of Physical Education (AWF Katowice). Biochemical and physiological assessments (blood tests, body composition analysis, and aerobic capacity testing) will be conducted before and after the 12-week intervention.