New Zealand Blackcurrant Extract Improves High-Intensity Intermittent Running

We examined the effect of New Zealand blackcurrant (NZBC) extract on high-intensity intermittent running and postrunning lactate responses. Thirteen active males (age: 25 +/- 4 yrs, height: 1.82 +/- 0.07 m, body mass: 81 +/- 14 kg, (V)(over dot)O-2max: 56 +/- 4 ml.kg(-1).min(-1), v(V)(over dot)O-2max: 17.6 +/- 0.8 km.h(-1)) performed a treadmill running protocol to exhaustion, which consisted of stages with 6 x 19 s of sprints with 15 s of low-intensity running between sprints. Interstage rest time was 1 min and stages were repeated with increasing sprint speeds. Subjects consumed capsuled NZBC extract (300 mg.day(-1) CurraNZ; containing 105 mg anthocyanin) or placebo for 7 days (double-blind, randomized, crossover design, wash-out at least 14 days). Blood lactate was collected for 30 min postexhaustion. NZBC increased total running distance by 10.6% (NZBC: 4282 +/- 833 m, placebo: 3871 +/- 622 m, p = .02), with the distance during sprints increased by 10.8% (p = .02). Heart rate, oxygen uptake, lactate and rating of perceived exertion were not different between conditions for the first 4 stages completed by all subjects. At exhaustion, blood lactate tended to be higher for NZBC (NZBC: 6.01 +/- 1.07 mmol.L-1, placebo: 5.22 +/- 1.52 mmol.L-1, p = .07). There was a trend for larger changes in lactate following 15 min (NZBC: -2.89 +/- 0.51 mmol.L-1, placebo: -2.46 +/- 0.39 mmol-L-1, p = .07) of passive recovery. New Zealand blackcurrant extract (CurraNZ) may enhance performance in sports characterized by high-intensity intermittent exercise as greater distances were covered with repeated sprints, there was higher lactate at exhaustion, and larger changes in lactate during early recovery after repeated sprints to exhaustion.