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Supplementation with anthocyanin-rich blackcurrant increases blood flow, cardiac output, and stroke volume at rest. It is not known whether cardiovascular responses can be replicated over longer timeframes in fed trained cyclists. In a randomized, double-blind, crossover design, 13 male trained cyclists (age 39 ± 10 years, V ˙ O 2 max 55.3 ± 6.7 ml·kg−1·min−1) consumed two doses of New Zealand blackcurrant (NZBC) extract (300 and 600 mg/day for 1 week). Cardiovascular parameters were measured during rest and submaximal cycling (65% V ˙ O 2 max) on day 1 (D1), D4, and D7. Data were analyzed with an RM ANOVA using dose (placebo vs. 300 vs. 600 mg/day) by time point (D1, D4, and D7). Outcomes from placebo were averaged to determine the coefficient of variation within our experimental model, and 95% confidence interval (CI) was examined for differences between placebo and NZBC. There were no differences in cardiovascular responses at rest between conditions and between days. During submaximal exercise, no positive changes were observed on D1 and D4 after consuming NZBC extract. On D7, intake of 600 mg increased stroke volume (3.08 ml, 95% CI [−2.08, 8.26]; d = 0.16, p =.21), cardiac output (0.39 L/min, 95% CI [−1.39,.60]; d = 0.14, p =.40) (both +2.5%), and lowered total peripheral resistance by 6.5% (−0.46 mmHg·min/ml, 95% CI [−1.80,.89]; d = 0.18, p =.46). However, these changes were trivial and fell within the coefficient of variation of our study design. Therefore, we can conclude that NZBC extract was not effective in enhancing cardiovascular function during rest and submaximal exercise in endurance-trained fed cyclists. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We examined effects of intake duration of New Zealand blackcurrant (NZBC) extract on cardiovascular responses during supine rest and moderate-intensity walking. Recreationally active men ( n  = 15, age: 24 ± 6 yr, BMI: 24.7 ± 4.3 kg·m -2 ) volunteered in a randomized, cross-over design. One metabolic equivalent (1-MET) was measured (3.97 ± 0.66 mL·kg -1 ·min -1 ) and an incremental walking test was performed to individualize speed at 4 ( n  = 3) or 5 ( n  = 12) METs for the 30-min walk (5.7 ± 0.7 km·hr -1 ). NZBC extract (210 mg of anthocyanins) was taken with breakfast for 7 and 14 days, with a 14-days washout. The final dose was ingested 2-hr before recording of the cardiovascular responses (Portapres Model-2). At rest, %changes at 7- and 14-days intake were observed for stroke volume (+6.8% (trend), p  = 0.065; +8.5%, p  = 0.012), cardiac output (+10.1%, p  = 0.007; +8.5%, p  = 0.013), total peripheral resistance (-12.0%, p  = 0.004; -13.1%, p  = 0.011), diastolic (-5.7%, p  = 0.045; -9.7%, p  = 0.015) and mean arterial pressure (-4.4%, p  = 0.040; -7.2%, p  = 0.029), but without intake duration effect. During walking, %changes at 7- and 14-days intake were observed for stroke volume (+7.7% (trend), p =  0.063; +9.9%, p =  0.006), cardiac output (+8.7%, p =  0.037; +10.1%, p  = 0.007), diastolic blood pressure (-6.2%, p =  0.042; -10.6%, p  = 0.001), and total peripheral resistance (-9.6%, p =  0.042; -13.5%, p  = 0.005) but without intake duration effect. During walking, %changes at 14-days were observed only for mean arterial pressure (-6.4%, p  = 0.018) and arterio-venous oxygen difference (-7.9%, p  = 0.019). NZBC extract affects cardiovascular responses at rest and during moderate-intensity exercise with 7- and 14-day intake. Only during moderate-intensity exercise, a longer intake of NZBC extract was required for an effect on some cardiovascular responses.