No Effects of New Zealand Blackcurrant Extract on Physiological and Performance Responses in Trained Male Cyclists Undertaking Repeated Testing across a Week Period

Abstract

Anthocyanin supplements are receiving attention due to purported benefits to physiological, metabolic, and exercise responses in trained individuals. However, the efficacy of anthocyanin intake over multiple testing days is not known. We compared a placebo and two doses of anthocyanin-rich New Zealand blackcurrant (NZBC) extract (300 and 600 mg·day−1) on plasma lactate, substrate oxidation, and 16.1 km time trial (TT) performance on three occasions over 7-days in a fed state (day 1 (D1), D4, and D7). Thirteen male cyclists participated in a randomized, crossover, placebo-controlled double-blind design. There was no difference in plasma lactate and substrate oxidation between conditions and between days. A time difference was observed between D1 (1701 ± 163 s) and D4 (1682 ± 162 s) for 600 mg (p = 0.05), with an increment in average speed (D1 = 34.3 ± 3.4 vs. D4 = 34.8 ± 3.4 km·h−1, p = 0.04). However, there was no difference between the other days and between conditions. Overall, one week of intake of NZBC extract did not affect physiological and metabolic responses. Intake of 600 mg of NZBC extract showed inconsistent benefits in improving 16.1 km time trial performance over a week period in trained fed cyclists.

No Effects of Different Doses of New Zealand Blackcurrant Extract on Cardiovascular Responses During Rest and Submaximal Exercise Across a Week in Trained Male Cyclists

“…The study was designed to allow a detection of 2-3 % difference in 16.1 km time-trial performance (1 − β =0.80: 0.05 =α level) (Cook et al, 2015). Data on blood lactate, substrate oxidation and TT performance are reported elsewhere (Montanari et al, 2020). Cardiovascular data at rest and during submaximal exercise were checked for homogeneity with the Mauchly test of sphericity and adjusted with the Greenhouse-Geisser test if violations were present.…”

“…The latter study showed that a sample of 9 would be needed to detect a difference of 20% in CO. For the present study, however, cardiovascular responses were not selected as primary outcomes. Data collected were part of a wider study project which included additional physiological (lactate levels, substrate oxidation) and performance parameters (16.1 km TT) as primary outcomes (Montanari et al, 2020).…”

“…Participants then completed an incremental cycling test , rested 15 minutes, and then cycled for 10 min at sub-maximal intensity (65% ̇O 2max) while cardiovascular responses were continuously recorded. Finally, participants completed a 16.1 km best effort TT (Montanari et al, 2020).…”

Fruit-Derived Anthocyanins: Effects on Cycling-Induced Responses and Cycling Performance

“…The effects of anthocyanins on nitric oxide biomarkers, vascular function, muscle oxygenation, and performance were examined in 11 studies [ 15 , 18 , 23 , 28 , 29 , 30 , 38 , 39 , 40 , 41 , 42 , 43 ]. Two studies evaluated nitric oxide biomarkers and vascular function.…”

“…In another study, the protocol consisted of an incremental intensity cycling test followed by 10 min cycling at 65% VO 2max ending with the 16.1 km time trial. Between each test, participants rested for 15 min [ 43 ]. Another study was performed with 2 × 4 km time trials separated by 10 min of active recovery at the selected auto cycling intensity [ 30 ] and one with two incremental cycling protocols with the recording of physiological and cardiovascular responses [ 42 ].…”