Gymnastik- och idrottshögskolan, GIH

Purpose: The purpose of this pilot study was to investigate the effects of broccoli sprout supplementation on perceived recovery and neuromuscular performance during a 14-day in-season training block in elite female football players.

Methods: Ten elite female football players were randomly assigned to either a supplementation group or a placebo group in a randomized, double-blind, placebo-controlled design. Players completed a 14-day training period while consuming a daily dose of isothiocyanate supplementation (NOMIO) on training days. External training load was monitored using GPS-derived total distance. Perceived recovery was assessed daily, and neuromuscular performance was evaluated pre- and post-intervention using countermovement jump (CMJ), reactive strength index (RSI), and 10 m and 30 m sprint tests. Linear mixed-effects models were used to assess changes over time and between groups. Effect sizes and smallest worthwhile changes (SWC) were calculated to assess practical significance.

Results: Perceived recovery increased across the intervention period (β = 0.048 day⁻¹, p = 0.016), with no significant group × time interaction (p = 0.22). Neuromuscular performance improved in both groups, with increases in CMJ height (~2.5 cm) and RSI (~0.16), and reductions in 10 m and 30 m sprint times (~0.06 s). All performance changes exceeded the smallest worthwhile change. No significant differences were observed between groups for any outcome measure.

Conclusion: Recovery and neuromuscular performance improved during the intervention period, likely reflecting reductions in accumulated fatigue associated with the structured training camp environment rather than true physiological adaptations. No significant differences were observed between supplementation and placebo conditions.