Re-esterified DHA improves ventilatory threshold 2 in competitive amateur cyclists

Abstract

Background: Fish oils were studied as ergogenic aids in a number of mixed physical trial designs showingpromising results. However, the heterogeneous purity of the studied supplements, combined with the variety ofphysical tests employed call for more studies to confirm these findings, ideally with standardised supplements. Ouraim was to test a supplement highly concentrated in DHA (DHA:EPA ratio equal to approximately 8:1) on a maximalcycling test to elucidate performance improvements mainly due to DHA. Methods: A double-blind, placebo controlled, randomised balanced, parallel design, in competitive amateur cyclistswas employed. They were all male, older than 18 years old, with training routine of 2 to 4 sessions per week lasting atleast one hour each. A ramp cycling test to exhaustion with a subsequent 5 min recovery phase was employed beforeand after treatment to analyse aerobic metabolism and lactate clearance after the bout. After 30 days ofsupplementation with 975 mg of re-esterified DHA, the thirty-eight cyclist who completed the study were finallyincluded for statistical analysis. Results: Mean power output at ventilatory threshold 2 (VT2) improved after DHA supplementation both as absolute( DHA versus PLA: 6.33–26.54 Watts; CI 95%) and relative (p = 0.006) values, paralleled with higher oxygenconsumption at VT2 both for absolute (DHA 2729.4 ±304.5, 3045.9 ±335.0; PLA 2792.3 ±339.5, 2845.5 ±357.1;ml · min−1 baseline versus post p = 0.025) and relative values (DHA 36.6 ±5.0, 41.2 ±5.4; PLA 37.2 ±5.7, 38.1 ±5.2;ml · kg−1 · min−1 baseline versus post p = 0.024). Heart rate recovery rate improved during the recovery phase in the DHA group compared to PLA (p = 0.005). Conclusion: DHA is capable of improving mean power output at the ventilatory threshold 2 (anaerobic ventilatorythreshold) in amateur competitive cyclists. It is unclear if these findings are the result of the specific DHA supplementblend or another factor.