Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test

New Zealand blackcurrant (NZBC) extract has been shown to enhance high-intensity intermittent treadmill running. We examined the effects of NZBC extract during the Loughborough Intermittent Shuttle Test (LIST) which involves 5 x 15 min blocks with intermittent 15-m maximal sprints, interspersed by moderate and high-intensity running to simulate team sport activity, and a subsequent run to exhaustion. Thirteen males (age: 22 +/- 1 year,. (V) over dotO(2max): 50 +/- 5 mL.kg(-1).min(-1)) participated in three indoor sessions (T: 24 +/- 3 degrees C, humidity: 52% +/- 9%). In the first session, a multistage fitness test was completed to determine peak running speed and estimate. (V) over dotO(2max). Participants consumed NZBC extract in capsules (300 mg.day(-1) CurraNZ (TM)) or placebo (PL) (300 mg.day(-1) microcrystalline cellulose M102) for seven days in a double-blind, randomized, cross-over design (wash-out at least seven days). NZBC extract did not affect average 15-m sprint times in each block. NZBC reduced slowing of the fastest sprint between block 1 and 5 (PL: 0.12 +/- 0.07 s; NZBC: 0.06 +/- 0.12 s; p < 0.05). NZBC extract had no effect on heart rate, vertical jump power, lactate and time to exhaustion (PL: 13.44 +/- 8.09 min, NZBC: 15.78 +/- 9.40 min, p > 0.05). However, eight participants had higher running times to exhaustion when consuming NZBC extract. New Zealand blackcurrant extract may enhance performance in team sports with repeated maximal sprints.