Does krill oil improve exercise recovery? Original paper

In this randomized controlled trial in resistance-trained men, supplementation with krill oil improved exercise recovery.

The effect of supplementation with krill oil on exercise recovery. The outcomes assessed were (i) performance metrics such as knee flexion and extension isokinetic strength, 20-meter sprint time, and time to complete the hexagon test (an agility test); (ii) biomarkers of muscle damage such as creatine kinase and lactate dehydrogenase; biomarkers of oxidant/antioxidant activity such as superoxide dismutase (SOD), total antioxidant capacity (TAC), reactive oxygen species, and malondialdehyde (MDA); and (iv) biomarkers of inflammation such as interleukin 6, interleukin 2, and TNF-alpha.

30 resistance-trained men (average age of 20).

The participants were randomly assigned to supplement with 3 grams of krill oil per day or a placebo 3 days before and 3 days after a muscle-damaging exercise protocol. The exercise protocol consisted of 10 sets of 8 repetitions of squats (3-second lowering phase) using 70% of 1-repetition maximum load, followed by 5 sets of 20 repetitions of split jump squats.

Performance outcomes and blood biomarkers were assessed before the intervention, immediately after exercise, and at 6, 24, 48, and 72 hours after exercise.

Compared to placebo, levels of creatine kinase were lower (improved) in the krill oil group at 24 and 48 hours after exercise. Additionally, compared to placebo, the krill oil group had higher (improved) SOD levels immediately after and at 6 and 24 hours after exercise, higher (improved) TAC immediately after and at 6 and 72 hours after exercise, and lower (improved) MDA levels at 6 hours after exercise.

For performance outcomes, time to complete the hexagon test was lower (better) in the krill oil group at 6 and 24 hours after exercise. Additionally, compared to the placebo group, the krill oil group had higher knee extension strength at 24, 48, and 72 hours after exercise and higher knee flexion strength at 24 and 72 hours after exercise.

Interestingly, for the knee extension and flexion outcomes, recovery was not only improved in the krill oil group, but there were also signs of “over-recovery” (the term used by the researchers) at 72 hours after exercise; in other words, strength was slightly higher than baseline levels.