Effects of a nutritional supplement containing fish protein, vitamin D, and ω3 fatty acids, taken during high-intensity functional training, on physical performance in recreationally trained individuals: a randomized controlled trial.

What Was Tested

The paper reports a study of Vitamin D, K2, Magnesium and Zinc and Copper (Supplement), published as a randomized controlled trial.

Research on supplementation during high-intensity functional training (HIFT) is limited.

The researchers examined the effects of a multi-ingredient supplement containing fish protein, vitamin D, and ω3 fatty acids, taken during HIFT, on physical performance in trained individuals.

Who Took Part

The age groups tagged for this paper are young adults and adults, both men and women.

Twenty-five recreationally trained participants (14 females, 11 males) underwent 6 weeks of HIFT (3 times/week) while taking each of three supplements, separated by 2-week washout periods in a researcher-blinded, randomized, triple-crossover, and counterbalanced fashion.

Data were analyzed using 2-way repeated-measure ANOVA (supplement × training).

How the Study Was Run

The design is described as randomized and crossover.

The participants were allocated by chance, so the Vitamin D, K2, Magnesium and Zinc group and the comparison group should start out alike.

Each person switched between Vitamin D, K2, Magnesium and Zinc and the comparison at some point, usually with a gap in between.

Training variables were assessed during the 1st and 6th weeks of each intervention period.

Endurance and strength variables were measured before and after each intervention period.

What Was Measured

PubMed files the paper under topics including Dietary Supplements, Fatty Acids, Omega-3, Vitamin D, Physical Functional Performance, Eicosapentaenoic Acid, Docosahexaenoic Acids and Fish Proteins.

Author keywords: High-intensity functional training, Multi-ingredient supplement and ω3 fatty acids.

What This Means in Plain Language

The paper is a randomized and crossover study of Vitamin D, K2, Magnesium and Zinc and Copper (Supplement).

Its findings take up roughly 5 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2026 (European journal of nutrition), a journal based in Germany.

More context: the Vitamin D, K2, Magnesium and Zinc compound page and the Copper (Supplement) compound page, all human trials.