While many of us compete in sports that are straight-up repeated sprints, the varied, or stochastic, nature of a triathlon, bike race, or even a 5K where you must cover moves makes these studies more relevant to racing.
STUDIES SUMMARY
Research shows that New Zealand blackcurrant (NZBC) extract can improve performance in high-intensity interval and endurance training for athletes. Two studies found that cyclists and runners could exercise longer or faster when taking an anthocyanin-rich NZBC extract.
The first study tested the effects of NZBC extract on a high-intensity running protocol with repeated sprint intervals. Thirteen male runners took either a placebo or 300 mg of CurraNZ NZBC extract (containing 105 mg anthocyanin) for one week. The runners then performed a treadmill run to exhaustion which included six 19-second sprints with 15 seconds of jogging in between. The stages were repeated at higher speeds until exhaustion.
The runners supplemented with NZBC extract ran a total of 10.6% farther, including 10.8% farther during the sprints. While heart rate, oxygen uptake, and perceived effort were similar between groups for the first four stages, blood lactate levels tended to be higher at exhaustion for those taking NZBC extract. Lactate levels also decreased more 15 minutes after the run for the NZBC group, suggesting faster recovery. The results indicate NZBC extract may improve high-intensity interval running performance and recovery.
The second study analyzed the effects of 300 mg of CurraNZ NZBC extract on repeat cycling time trials. Ten male cyclists took either the extract or a placebo for one week. They then performed two 4-km cycling time trials with 10 minutes of rest in between. While time trial completion times and heart rate/lactate levels were similar between groups, the total time for the two trials combined was 0.82% faster for the NZBC extract group. Seven out of ten cyclists had faster total times when taking the extract.
In summary, New Zealand blackcurrant extract may enhance performance in high-intensity intermittent exercise and short-distance endurance cycling. The studies showed improved running distances, cycling times, and recovery with NZBC supplementation versus placebo. The effects appear modest but could provide a performance benefit for competitive athletes, especially in sports with repeated bouts of intense exercise. However, more research is needed to confirm and further analyze these performance enhancements before recommendations can be definitively made. Endurance athletes can consider trying NZBC extract in their training regimen, but should also focus on other established methods like high-intensity interval training, strength training, getting enough rest, and proper nutrition. An anthocyanin-rich NZBC extract like CurraNZ may provide additional benefits, but ultimately hard work and dedication are required to improve endurance performance.
ABSTRACT OF STUDY 1
New Zealand Blackcurrant Extract Improves High-Intensity Intermittent Running.
Published in International Journal of Sport Nutrition and Exercise Metabolism 2015
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, VO2max: 56 ± 4 ml·kg-1·min-1, vVO2max: 17.6 ± 0.8 km·h-1) performed a treadmill running protocol to exhaustion, which consisted of stages with 6 × 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.
Authors
I. Perkins, S. Vine, S. Blacker, M. Willems
ABSTRACT OF STUDY 2
Effect of New Zealand Blackcurrant Extract on Repeated Cycling Time Trial Performance
Published in Sports 5 (2017)
New Zealand blackcurrant (NZBC) extract increased 16.1 km cycling time trial performance. The aim of the present study was to examine the effect of NZBC extract on 2 × 4 km time trial performance. Ten male cyclists (age: 30 ± 12 years, body mass: 74 ± 9 kg, height: 179 ± 7 cm, body fat: 11 ± 3%, V˙O2max: 55 ± 7 mL·kg−1·min−1, mean ± SD) volunteered. Participants were familiarized with the time trials. Participants consumed capsulated NZBC extract (300 mg·day−1 CurraNZ™; containing 105 mg anthocyanin) or placebo for seven days (double blind, randomised, cross-over design, wash-out at least seven days) before 2 × 4 km time trials (10 min active self-paced recovery between trials) (SRM ergometer, SRM International, Germany). Heart rate was recorded and blood lactate sampled immediately after each trial and 8 min into recovery between the trials. Times over comparable one km distances in each 4 km time trial were similar. No effect was observed for the time to complete the first (placebo: 380 ± 28 s, NZBC: 377 ± 27 s) and second 4 km of cycling (placebo: 391 ± 32 s, NZBC: 387 ± 30 s), within both groups the second 4 km times slower by 11 ± 8 s and 11 ± 9 s for placebo and NZBC, respectively. However, the total time of the two 4 km cycling trials was 0.82% faster with NZBC extract (placebo: 771 ± 60 s, NZBC 764 ± 56 s, p = 0.034) with seven participants having faster total times. There was no effect of NZBC on heart rate and lactate values at identical time points. New Zealand blackcurrant extract seems to be beneficial in repeated short-distance cycling time trials for overall performance.
Authors
Connor A Murphy, M. Cook, M. Willems
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Jordan Fowler has experience as a head swimming coach of the Frisco Swim Team, a TAAF-awarded coach, a track and field distance running consultant for select Texas High School runners, and has competed as a triathlete, road runner, and cyclist. Though he is remarkably slower than he was in his 20s and 30s, he still enjoys endurance sports and sports science studies.