Author(s): THURNHERR, L., BAYARD, A., BENTLEY, M.R.N., KUBICA, C., LOMAZZI, M., KOEHLER, K., Institution: TECHNICAL UNIVERSITY OF MUNICH , Country: SWITZERLAND, Abstract-ID: 2765

INTRODUCTION:
Swiss fencing lacks a nutritional framework that (i) identifies behavioural barriers/enablers to nutritional adherence and (ii) quantifies intake, biomarkers, and performance. This project develops a data-driven nutrition framework for Swiss fencers, underpinned by behavioural science. Quantitative data capture dietary changes while qualitative data explain why they occur, making the framework comprehensive and reproducible.
METHODS:
A panel of sports nutrition experts rated candidate behaviours and retained 21 target behaviours for the Swiss Fencing Nutrition Service Strategy (SFNSS). Semi-structured focus groups used the Capability, Opportunity, Motivation, and Behaviour (COM-B) model, the Theoretical Domains Framework (TDF) and reflexive thematic analysis (RTA) to identify barriers and enablers to nutritinal adherence. Dietary intake was captured via 4-day food logs and the German Athlete Diet Index (G-ADI). Blood and urine biomarkers were collected. Performance diagnostics consisted of countermovement jump (CMJ) and squat jump (SJ) on a force plate, maximal incremental cycling for VO2max, and a fencing-specific change-of-direction/reaction-time test.
RESULTS:
Eighteen fencers took part in four focus groups. RTA identified six themes: Lack of Knowledge and Need for Guidance (barrier); The Paradox of Coaching Influence on Nutrition (barrier & enabler); Navigating Training and Competition Settings (barrier & enabler); Food Curiosity as a Double-Edged Sword (barrier & enabler); Self Confidence and Performance (enabler); Wellbeing and Emotional State of Mind (enabler). Thirteen fencers completed the G-ADI. Protein rich intake averaged 5.6 +/- 0.4 portions/day, exceeding the SFNSS minimum of 3 portions/day. Fruit intake was 1 +/- 0.7 portions/day, falling short of the recommended 2 portions/day in 3 of 13 fencers; vegetable intake was 2 +/- 1.5 portions/day, below the recommended 3 portions/day in 4 of 13 fencers. Serum 25-OH-D averaged 65.7 +/- 13.4 nmol/L, with 79% of fencers below the athlete specific threshold of 75 nmol/L. Oxidative stress biomarkers exceeded the clinical reference range by 30 +/- 62%; 9 of 15 fencers were outside the reference range. Mean CMJ and SJ heights were 0.402 +/- 0.064 m (males) and 0.264 +/- 0.026 m (females) and 0.352 +/- 0.058 m (males) and 0.231 +/- 0.022 m (females). Maximal oxygen uptake was 41.0 +/- 5.5 ml/kg/min (females) and 50.5 +/- 4.7 ml/kg/min (males). The fencing-specific change-of-direction and reaction-time test produced mean decrement scores of 4.9 +/- 1.8% (sprint time) and 23.5 +/- 7.3% (reaction time).
CONCLUSION:
These measurements provide a preliminary baseline for nutritional interventions and sport-specific performance norms in Swiss fencing. The combined behavioural, nutritional, and physiological baseline creates a platform for targeted, theory-driven nutrition interventions and longitudinal observation of behavior, diet and biomarkers throughout the 2025/26 season.